ROOM-BY-ROOM GUIDE TO OREGON CAVES OF Natural and Cultural History Visible to Full Tours -- By John Roth, April 1, 2001
 
MAIN ENTRANCE 
Bears: Davidson said the bear he shot was a hybrid between a grizzly and a black bear, a so-called "mealy nose bear". Burch, who first explored over half the known cave, said it was a grizzly called "Clubfoot," so named because it had its paw deformed when caught in a trap. 

Harvestmen (daddy longlegs) Like many cave animals who need humidity because of a high surface area to volume ratio and who need food near entrances, they occur in Watson's Grotto (moist outgoing summer air) and the Exit Tunnel (moist outgoing winter air). They are not spiders as they lack venom, silk glands, a two-part body, and pedipalps, short sperm-transferring appendages near the mouth. They eat plants, detritus, mites, spiders, insects, and harvestmen. They have taste and short-range odor receptors on the second and longest pair of legs. Genitals are just below the mouth. If the species here behaves like a related eastern species, the males congregate on rock (where it is easier to apply the leverage needed to mate) and wait for females to wander by. Recognition only comes from physical contact (no hearing and eyes mostly just sense light). After wrestling, perhaps to determine size, females choose the larger males. When disturbed, harvestmen secrete ketones (smells like radishes) that appear to deter predators. "Pushups" done when disturbed may help spread the odor. A huge pulsating mass of harvestmen itself may intimidate predators.

Marble: The wallrock in the cave is part of the western Hayfork Formation, the upper part of the Applegate Group, itself a part of the Paleozoic and Jurassic Terrane and the Hayfork subterrane. The term "terrane" refers to an association of geologic features, such as stratigraphic formations, intrusive rocks, mineral deposits, and earth movement history, some or all of which lend a distinguishing character to a particular tract of rocks and which differ from those of an adjacent terrane. The western Hayfork consists of massive volcanic sandstone and tuff (welded ash deposits with interbedded siltstone and argillite and with lesser amounts of conglomerate, pillow basalt breccia and lahars (volcanic mud flows). Metabasalt is locally common, as in the Monument. Most of the silts and muds eroded from lava flows and surface volcanoes with most eroded from ongoing volcanism caused by a sinking plate and some eroded from the underlying Rattlesnake terrane, a 171-78 million year old volcanic arc. Most of these rocks and sediment lay deep underwater, from dozens of feet to thousands of feet. A small amount of calcite-rich mud formed on a sea bottom a few feet to perhaps dozens of feet deep. The age of the Hayfork is mostly Late Triassic to Earliest Jurassic (200-175 million years). It was heated from 100-200 degrees C. during initial burial and then from 300-425 degrees 169 million years ago when it was thrust under blueschist rock that had sunk at least 12 miles deep before rising up. Marble likely first formed then. Many plutons (tear-shaped bodies of molten or once-molten rock) reheated the Hayfork from 500-600 degrees 153 million years ago, the mid-point of the dinosaurs.

Carbon Dioxide: Rapid breathing in caves is partly triggered by high carbon dioxide since it is the increase of carbonic acid (carbon dioxide dissolved in the blood) that triggers renewed breathing. High carbon dioxide in cave air explains why some people become claustrophobic in caves or other enclosed places. The higher carbon dioxide causes faster breathing. Without any obvious cause, the faster breathing makes us anxious.

Entrance Size: Little ice-split rock suggest non-stream entrances here were never very large. Such rock comes from many freeze-thaw cycles. It occurs at large cave entrances that exchange much moist air with the outside. 

Entrances: Most caves do not have entrances that are human size. Most entrances are unrelated to the formation of a cave and are largely random events with a frequency determined by the cave's length. Over half of caves don't have entrances. Low airflow indicates few undiscovered passages exist that connect with known Monument caves.

Coralloids are nodular, globular, botryoidal, or coral-like speleothems, with the more angular ones often called cave coral. The more rounded, small to medium-size coralloids are often called cave popcorn. It can form underwater, by slow seepage of water from cave walls, by the action of algae, or by evaporation. In Oregon Caves it formed mostly by loss of carbon dioxide and water during slow seepage of water on cave walls. Flowstone occurs where water flow is greater and loss of carbon dioxide is more important than evaporation. Cave coral, usually forms underwater where slow degassing and subsequent calcite deposition creates larger, angular crystals. It isn't nearly as common as cave popcorn in Oregon Caves.

Much of the cave popcorn in Oregon Caves points towards cave entrances. As cold outside air enters in winter, the relative humidity drops as the air warms. As airflow impacts entrance-facing sides of formations, evaporation and dilution of carbon dioxide causes evaporation and degassing of cave water and subsequent deposition of cave popcorn. The outward growth of the popcorn is self-limiting as the actively growing tip moves away from its water supply. So no popcorn in the Caves is thicker than about two inches.

Entrances: Most caves become beautiful only in middle age, when a sizeable entrance flushes carbon dioxide out of the cave. This makes it more likely that water cave will lose carbon dioxide to the cave atmosphere, thus reducing acid and precipitating calcite. Many entrances indicate that a cave is nearing old age when erosion changes the cave into an open-air grotto.

Discovery: The first record of cave entry was by Elijah Davidson in the fall of 1874 while with a hunting party of 6-7, including a brother, brother-in-law and possibly a Yurok Indian hunting guide. Elijah just killed a deer when his dog smelled a bear and headed into a cave after it. The dog came out of the cave a few minutes after Elijah had crawled back out and only had a few minor scratches. Elijah baited the entrance with the deer. By next morning, after the bear had eaten part of the deer, Elijah shot it while it was sleeping at the entrance.

Food storage (milk, cheese, meat) for the Chalet kitchen was just inside the cave near the stream. There was a "potato pit" nearby.

The initial cracks of what would become the Caves may have formed during the deposition of 2-3 million-year-old gravels at 4,000 feet in the Siskiyous. Erosion may have stagnated there long enough to form caves. 

                              WATSON'S GROTTO
Location: 92' from Entrance, 4' higher, 65' below surface

Chert, being much less soluble than calcite, commonly juts out from the walls in slabs a few inches thick. Chert is a hard, extremely dense or compact rock of microscopic quartz crystals, similar to beach sand only with much smaller crystals. Many nodules grew in place by drawing in dissolved silica from radiolarians (tiny single cell animals) and/or volcanic ash.

Until 14 years ago, all of the visible River Styx ran through culverts. The culverts and the rubble on top of them were removed in 1986.

The twilight zone, the area between the entrance and total darkness, is usually the most biologically active area of a cave because more food is available there than deeper in a cave and it serves as a convenient area for animals who mostly use the surface (even bats can get lost). However, there are fewer cave-adapted species in this area compared to further in the cave.

Flooding in Nov. of 1974 began in the cave 24 hours after a major rainfall. The water rose over a foot over the trail. Flow usually increases within about two days after rain begins in the lower part of the cave.

Discovery: The Carbide Room entrance (restored in 1991) was likely where Elijah first came in as the room he entered was reported to have been blasted. Elijah also does not mention sloshing through water on the way in which he would have had to do if he entered through the main entrance.

Ice Wedging: A temperature of 4 degrees F. in the late 1980s caused air to be sucked into this area, resulting in ice damage. No damage occurred after installing 1990 airlocks.

Water Source: Part of the stream comes from water seeping into the cave. The source of the upper part of the stream (Ghost Room) comes, in order of importance, as seepage through sediment-filled former entrances, faults, joints, and bedding planes. In the lower part of the cave, bedding planes may be a more important water source. There is less dissolved calcium in the water that leaves the cave, compared to the stream in the Ghost Room. This and high dissolved silica indicates that most of the water enters the stream between the Ghost Room and lower cave and it comes from a largely non-marble drainage (Upper Cave Creek). Therefore, unlike the Ghost Room stream, it is dissolving most of the year except during low flow in July and April (water still frozen?)

Stream Piracy: A fault that determined the location of the drainage may shunt water past the cave through highly permeable parts of the fault. The difference between the fairly flat profile of the River Styx and the profile of the rest of the Caves suggests that the integration of the River Styx with the rest of the Caves was recent stream piracy. Also the water in River Styx has less dissolved calcite than water in most of the rest of the cave, suggesting that that there is only a weak water connection between the two areas and if both parts of the cave started forming at the same time, the lower part should have larger rooms than the upper part. In the fall of 1992, flow went down to just a few gallons per minute, the lowest ever recorded. It usually is 1.3 (spring snowmelt) to .2 cubic feet (before first fall rains, usually October) per second or 602 to 90 gallons per minute).

Cracks here show how caves begin. Caves form because there is slow growth when the ability of water to dissolve calcite must persist for long distances through narrow fissures and there is later rapid growth to achieve large size.

PETRIFIED GARDENS
Location: 203' from Entrance, 12' higher, 55' below surface.

Staining: Formations are more stained here than most other areas in the cave, likely because visitors want to find out what the rock feels like and then often don't touch the rock afterwards. Like most organics, skin oil turn black with age but the oil doesn't waterproof the formations and stop them from growing.

Roots: These are the world's deepest known Douglas fir roots. The roots were killed when the tree above was cut down during hazard tree removal in the 1970s. The Forest Service recommended cutting all the trees, which NPS did. Nowadays a survey every two years of about 450 trees that could fall and damage people or buildings are monitored and an average of a tree a year is taken down. The roots were in clay that was washed out during cleaning. Rarely do even rootlets grow far into a large underground opening. 

The white myccorhizae threads that always produce fruiting bodies (mushrooms) in spring on the roots is velvet foot or velvet stem (Flammulina velutipes). It is edible and occurs in most of North American. This is the only or one of the few recorded cases of it growing on conifer wood, as the other accounts always mention hardwoods or bush lupine.

Energy: Forest productivity worldwide ranges from 200-500 grams/square meter/ year. Measurements of dissolved organics in cave water in various parts of this cave indicates the amount of surface organics to underground organics ratio is 100 to 1. There is an equal amount of organics from lint, human hair and skin flakes within one meter of the main trails. This reduces the number of cave-adapted species near the trails as less cave-adapted species can best use that energy and outcompete cave arthropods and slow growing actinomycetes. Compared to most surface environments, most caves have little food or other types of energy. Caves usually lack much wind, light, ice, or organics. Thus, fragile crystals, jaguar bones, and species with low metabolism can persist underground. Foot traffic, lights, lint, and tunnels are high energy/food impacts on caves. Visitors bring in skin flakes, dust, spores, and detergent-rich lint; all this helps grow non-native plants. 

Cave animals often save energy by living longer, having more efficient reproduction (few large eggs and caring of young), reducing eyes, pigments and waterproof body coverings, and having long limbs and antenna for feeling their way around in darkness. Most groundwater animals display similar adaptations except for wormlike bodies, more segmentations, thick body coverings, flattened legs and reduced appendages so they are less likely to get stuck moving through sand or gravel. Most of these adaptations make animals from both habitats more likely to absorb pollutants and accumulate them (being long-lived). Old-growth species also are at risk because many are at the top of long food chains; toxins become progressively more concentrated as they move up food chains. Many cave animals eat detritus that can be from animals high up in the food chain, thus concentrating pollutants even more.

Studies of pool bacteria indicate that those nearest the trail are not adversely affected by human impacts such as lint. This may be because the amount of natural input of organics in Oregon Caves pools is high relative to the amount of human impact, unlike many most other western caves. Contrast this with cave slime bacteria, which look like small dots of white lichens on ceilings above the tree root. They likely depend on small amounts of organics and are very slow growing compared to pool bacteria. They apparently are affected by being near the trail, perhaps being out-competed by other bacteria that can best use the extra organics near the trail.

Drapery edges that are actively forming are smooth while the rest of some draperies have cave popcorn. The two main ways formations form is by loss of carbon dioxide (edges) and by evaporation (in-between areas). Where water is actively running down the edges of the draperies; the loss of carbon dioxide dominates over evaporation. Where there is less water flow, evaporation dominates and results in cave popcorn.

A bell canopy overlies the stream beyond the railing. They likely formed when the cave climate here was drier, as evaporation aids their formation. 

BRIDGE OVER THE RIVER STYX
Location: 291' from Entrance, 28' higher, 60' below surface.

Bevels on the walls are notches about 2 feet high and deep that dissolved out during stagnation of floodwaters. They commonly occur where passages narrow and sediment has a greater likelihood of plugging up a passage. Bevels and caves form at the top of a water surface because the width of cracks and the effect of the hydaulic gradient (the sloping surface that water runs down) tends to decrease with depth and therefore waterflow is not as fast. Bevels also form at the water's surface due to organics and mixed corrosion (when the mixing of two waters of different partial pressures of CO2 causes additional solution even if both waters were initially saturated with calcite). High carbonic acid results from oxidation of organics after it reaches the water surface. Less oxygen and microbes are available for oxidation and decomposition further down. Carbonic acid may also be high further up but the time acid stays there may not be enough to dissolve calcite before water moves down to the water table or stagnant floodwaters. Density driven convection currents rise upward and carry aggressive water (lacking calcite to the walls (forming flat ceilings if everything is underwater) and notching them. The now calcium rich and therefor heavy water sinks alongside the walls dissolving less calcite and thereby producing outward facing slopes before reaching the bottom of the passageway and displacing lighter water that then moves upward and completes the cycle.

Waterflow in River Styx peaks in April or May, declines rapidly until August, then declines slowly or increases slowly depending upon surface precipitation that season. Surface rainfall increases flow after a lag of 24 to 36 hours. Aging limestone or marble generally decreases in the total pores space (mostly microscopic) but increases in waterflow due to wider interconnected cracks. Porosity decreases but permeability increases.

Much of the water in the cave now comes from snowmelt in the largest meadow in the Monument. Dyes take 50 hours for some of it to travel 1,000' from the surface to the stream exiting the cave. Despite summer long droughts, the stream runs all year, a result of water retention in old-growth, bedding planes, and in glacial silts above and in the Caves, a big "sponge" that keeps lower passages wet all year. 

Palettes: White lines of calcite on ceilings formed after graphite-gray marble formed and before recent organic brown limestone formed. Filled-in joint or fault cracks developed subparallel to a larger fault that bisects and guided passage formation. Acid dew dissolved the surrounding marble, producing palettes, a type of petromorph, a cave formation that projects from bedrock and is part of the bedrock. When palettes intersect from at least three directions, they are called boxwork.

Discovery: This could be where Davidson ended up after running out of Chinese sulfur matches. He headed to the noisy stream and followed it back to the entrance. The matches were ignited by scratching a varnish coating and exposing the sulfur and flammable chemicals to the air. They were much more dangerous to use than present day matches and often ignited on their own when the coatings cracked or wore. Davidson's niece said he had five to six matches in his pocket when he started into the cave.

Water Flow: Most of the flowstone covers the right side of the passage right after the bridge. That is the direction in which water moving down the mountain has been intercepted by this passage that lies parallel to the surface slope. The next passage has much less flowstone because it is at right angles to the slope and therefore cannot capture as much dissolved calcite. A fault perpendicular to the passage intercepts water just before the bridge.

Graphite: Black bedding lines on the ceiling are graphite from a rain of organic matter and mostly single cell organisms from the ocean's near-surface. They likely developed in lagoons protected by reefs or mud mounds from muds from eroding volcanoes and lavas. When muds did pour in, they shut down calcite production. The black lines indicate an ocean floor where few animals churned up sediment and obscured layers. It likely results from high salinity as opposed to low oxygen (high organics) because of the lack of sulphide minerals associated with low oxygen and high organics.

Blackouts have almost no light here. Have visitors wave their hands in front of their face with their thumbs pointed towards their nose. They won't see their hand but most will see a line or shadow moving back and forth. If they can't see it, tell them to move their hands more slowly. This illusion may be related to the phantom limb phenomenon, where somebody who has lost an appendage will feel it for up to two years afterwards. You brain says you should be seeing or feeling something and sure enough you do. We are not passive observers of the environment but are active participants; the world we perceive is partly an invention as well as a discovery. The brain needs a certain amount of information coming in and, if it doesn't get it, will produce its own info. That is partly why most people in total darkness first perceive hypnogogic images (spirals, grids, tunnels, etc., forms seen just before falling asleep and under the influence of some hallucinogens) and geometric forms. The forms become more complex and after several days of darkness some people may see cavers with lights walking down a passageway when nobody is really there. Experiments have rarely proceeded beyond this point for fear of causing permanent personality changes.

                        PASSAGEWAY OF THE WHALE
Location: 350' from Entrance, 59' higher, 70 below surface, between Bridge Over the River Styx and Dry Room.

Layers of marble and chert generally tilt to the southeast but the various orientation of the tilting suggest the marble was bent during intrusion of the Grayback Pluton. Near the left side of the stream are potholes, rounded depressions from the grinding of pebbles swirled by the stream.

Global Warming: The deeper rock has a relict temperature several thousand years old while global warming has increased the temperature of the larger rooms because there is not enough rock close enough to cool air entering the cave. The temperature of the lowest part of the cave has also increased since 1916 (41 F.) because it is so close to the surface and therefore lacks insulating rock thickness of deeper parts of the cave. The mean temperature of the outside during the last twenty years is 47.5 F. while average cave temperature (which is the mean of the outside temperatures at some point in time) now is 42.5 F. Warming may increase the metabolism of cave insects so much that they starve.

Projection of global warming for this area suggests that there is and will be less water available in summer. Like the effects of increased evapo-transpiration from fire suppression, this also creates air pockets in rock, allowing for increased acid through absorption of carbon dioxide before water enters the cave. Add increased atmospheric carbon dioxide (30% more in last 100 years) and this could increase solution in the upper part of the cave and deposit more calcite in the lower part.

Two Cycle Speleogenesis: Where the floor and lower walls of a passage are shielded by sediment, bedrock solution is concentrated. As the passage grows, more sediment is deposited, so the flow velocity is kept roughly at the threshold for sediment transport. This may be the case for the upward part of the passage in the Passageway of the Whale, the "key" of the keyhole that formed completely underwater. The lower part of the "key" was probably carved/dissolved out by the present stream with a free air surface above it. Most of the sediment was removed once a lowering of the base level below the stream increased flow and erosion rates.

Effects of cabins: During December of 1985, pipes froze in the ranger cabin. Upon thawing, much water flowed into the cave on the left just after the keyhole passage; lesser amounts came through the joint running lengthwise along the top of the passage. Because of this and the decision of the concession not to renovate the cabins, sewage and water pipes and all of the cabins (except the Ranger Cabin) above the cave were removed in 1989.

                   CONNECTING TUNNEL
Location: 441' from Entrance, 30' higher, 85' below surface

Bedrock: Dark brown rock here is mostly argillite, a low-grade metamorphic formed from clay-rich sediments derived in this case from eroding lava flows and volcanoes. Contact metamorphic heating of the clays and probably silica-rich volcanic ash dissolved ("sweated") enough silica to precipitate white quartz in veins. Because of mica, chlorite, sericite, and other platy minerals, argillites can deform like silly putty under pressure. Platy minerals slide over one another much like a pile of loose paper pushed on one side. In contrast, marble and chert don't flow as easily and are more likely to fracture. Most of the cave chert is highly fractured while most of the marble cracks have been filled in with calcite. Some faulting parallels bedding but other faults are steeper. Faults parallel to the bedding occurred because bedding planes are often weak and will slide over one another under stress. Some rock flowed into higher angle faults. Ptygmatic folds may be related to dragging of the intruded material on the adjacent marble. Large, lenticular mineral grains or aggregates of minerals have an eye-shaped cross section and have been molded by argillite flow.

Metamorphism: Heated by the nearby Grayback Pluton, the dark brown, chlorite-rich argillite was hotter than marble it flowed into. Based on minerals and the color of fossil conodonts, the Hayfork was buried to a depth of about 20 kilometers (about 12 miles) and heated (300-425 C. or 800-1050 degrees F.), a bit higher than that of heating coils in kitchen ovens. The minerals actinolite and cordierite here and garnets and wollastonite elsewhere suggests contact metamorphism from the quartz diorite intrusion raised the temperature up to 800 degrees Centigrade (1800 degrees F) up to several feet from the intrusions and raised the temperature in the rest of the rock to 500-600 degrees. Contact metamorphism recrystallized the marble (causing larger crystals) and obscured the graphite layers or isolated them into small lumps up to two feet adjacent to the contact.

Uplift: A loss of 2"of rock every thousand years, average for Monument conditions, would have taken 280 million years to uncover the marble. This suggests the Monument had short periods of rapid uplift and erosion. Since quartz diorite and serpentine is lightweight, the area kept rising, much like a canoe rising when you step out of it. Some of the more recent uplift may be from the pressure of the subducting plate off the coast.

Origin: Nearby marine density current deposits (turbidites), albite feldspar lava flows, and much chert suggest deposition near a deep ocean basin. Radiolarian ooze usually is masked by other sediments at depths less than 3,750 meters (12,000'). However, fragmental limestone (blasted by erupting lava), lava droplets that appear to have been shaped by flying through air, and the large gas vesicules in lava in the Monument suggests relatively shallow water. Most of the chert may have formed later during burial and deepening of the basin. On the other hand, stylolites may indicate slow cementation, a common occurrence in deep water carbonate. Nearshore limy muds usually cement quickly and often lack stylolites. However, little deformation of some stylolites and their being parallel to folding indicate they formed after metamorphism of the limestone into a marble.

Forming Rock: Pressure from overlying sediments caused pressure solution where smaller crystals touched each other. Solution precipitated calcite onto larger crystals, eventually interlocking sediment into rock. Metamorphism into marble continued this process of "rich (bigger) get richer and poor (smaller) get poorer." Marble almost always has larger crystals on the average than does limestone except for crystals forming in caves or cracks. Although pressure indirectly plays a role, limy muds are not pressed into limestone or marble (like Superman making diamonds out of coal).

Concentration of Flow: A solution pocket occurs above the metabreccia. A joint moved water down but mica flowage in the metabreccia likely sealed the fault up at the level of the breccia. A bend in the meta-breccia may have prevented the water from moving down dip. Concentration of flow then dissolved out the pocket. Within 24 hours of heavy rain on the surface, a steady stream falls here. 

Muddy Water: After heavy rains, the stream is turbid. Part is from erosion of the metabreccia, which the stream follows as a zone of weakness and flow concentration.

Tunnel Built: The Civilian Conservation Corps (CCC) blasted out the tunnel (Sept., 1937-1938). 6" holes were drilled, filled with power and ignited. Some rock was wheelbarrowed out but most of it was put into the Imagination Room & Passageway of the Whale.

Echoes: Smooth walls reflect sound uniformly, producing echoes. High humidity also help transmit sound. More complex cave walls cause different reflections that partly cancel each other out. However, the smooth part of the tunnel is less than fifty feet long, not long enough to allow our ears enough time to distinguish between our own sounds and the returning echoes but long enough to give a reverberating sound to one's voice.

DRY ROOM
Location: 585' from entrance, 48' higher, 65' below surface.

History: An old carbide arrow points the way out on the right. In 1922, District Forester Cecil said visitors were defacing cave walls with carbide lamps and urged electrification to put an end to this.

Bedding and Faults: Compression of the Hayfork during destruction of the ocean basin it formed in folded rock and tilted it. The three main ways passages in the Caves develop occur past the railing. The more tilted rock layer is a fault surface and the less tilted one is a bedding plane with cave developed alongside the fault, bedding plane, and down the plane. 

Most passages in Oregon Caves formed along strike (intersection of rock layers (bedding planes) and a horizontal surface). The next major orientation follows faults steeper than most bedding planes (but often in the same orientation), and the least important directions are down dip (direction you take if you slid down rock layers) and along vertical fissures. The latter is not very significant because vertical fissures are not very continuous except at shallow depths. The Caves is long partly because bedding tilts towards the Grayback Pluton. When the pluton cooled and contracted, rock may have faulted parallel to bedding or in badding and towards empty space around the pluton. 

Combining faults, joints and bedding planes allowed greater water flow and subsequent development of cave passages. That is, the joints and faults often lie in the same direction as the strike of the bedding. Bedding planes are also where water flow is concentrated because of a waterproof layer or where acids are released from sulphides. The main passage orientation zigs and zags down under the surface, largely following the surface contours (which is close to the hydraulic gradient and towards a spring outlet) but changing direction when the main orientation of bedding planes or near-vertical faults and joints change direction. Thus cave development is a compromise between the fastest way water can go downhill and the easiest (along rock cracks). Over time, as cracks and conduits become more interconnected, water heading down the hydraulic gradient becomes more important than geologic structure such as cracks.

Cave Size: If the orientation of bedding, fault and joint cracks largely controlled cave passage direction, water volume largely controlled the cave's size. This in turn was set by annual precipitation (now 55 inches) and the drainage basin size and direction. North-facing slopes tend to be steeper due to erosion by frost shattering. They keep snow longer, allowing it to seep into caves instead of evaporating or running off as surface streams. The steep slopes also increased the speed and solution of waterflow. 

Complexity of passages was largely controlled by a high water pressure, a short block of marble, wide cracks, tilted bedding planes, and a lot of sediment (plugging up initial passages and so creating new ones; three miles of passages occur under ten acres of land. High passage sinuosity (waviness) likely results from intersecting fractures and local irregularities in dip or strike likely caused by the intrusion of the Grayback Pluton. Oregon Caves is partly an anastomotic maze, the cave type that normally forms with concentrated and variable discharge (sinking streams) moving along bedding planes, and partly a curvilinear cave (= branchwork) passages, dendritic like a bush) due to more limited and even discharge through sinkholes. More diffuse discharge forms spongework. Sinking streams through vertical fractures form irregular networks like that of boxwork (often in two or more intersecting directions). 

Long blocks of marble with low water gradients and with long breakthrough times (time it takes to initiate turbulent flow and subsequent faster enlargement of protocaves and then caves) often have one or two large, long passages with few side ones, like Mammoth. Initially wide cracks and high water pressure more likely result in exploiting and enlarging more  cracks and initiating turbulent flow, resulting in cave complexity.

Cave formation began when erosion exposed the Oregon Caves' marble.  Metamorphism seals fractures in most marble fractures and the remaining ones are too tight or few to allow caves to develop in the time available before the marble eroded away. In the case of Oregon Caves, though, faulting during metamorphism (during the shouldering aside of rock during the rise of the Grayback Pluton) and post-metamorphic uplift fractured the marble just enough for caves to form. Too many fractures result in few large caves because the water get too saturated with calcite before moving very far.

If the stream exiting the cave had as much dissolved marble as it does today, it would have taken about 10,000 years to dissolve out a human-size hole. Since solution is much slower at the birth of a cave, more time would have been needed for the cave to reach its present size. 

Whiteness of the ceiling formations appears at least partly due to acid dew and drying. Acid dew occurs when warm, moist air rising in a cave condenses on colder surfaces and, by absorbing carbon dioxide, dissolves calcite. The convection is driven by a combined 1.5 degree F. geothermal gradient between the top and bottom of the Caves. Acid dew solution in Oregon Caves is minor; the most is about a 4" thickness of calcite on some asymmetric flowstone. Condensation water still occurs in the highest and lowest parts of the cave in summer but large entrances now present flush out most carbon dioxide. Global warming also heats the top part of the cave faster than the deepest part; this lowers the geothermal gradient. Both processes reduce acid dew.

Drying formation results in air pockets in cracks and fissures in the partly dissolved formations. Air bubbles and pockets are also why milky quartz, snow, waterfalls and old-people hairs are white. Pure, single, undeformed calcite crystals are clear and colorless; changes in crystal orientation can also make them look white. Ice usually is white except glacial ice where pressure has squeezed out or collapsed the air pockets. Translucent calcite has fewer air pockets than white calcite. The drying may be due to reduced water and airflow since the Pleistocene and is increased due to global warming and fire suppression.

Woodrats: To the left of the pit and a few feet above the trail is the dark brown remains of a dried-urine (amberat) woodrat trail. Bushy-tailed woodrats can go far into caves because they have cheek glands to leave secretions so they can follow their scent in total darkness. Dusky-footed woodrats don't go beyond the twilight zone because they lack those scent glands. They specialize on hard-to-digest conifer needles. They do this with stomach microbes, by reingesting feces, and by hoarding needles until fungi and bacteria render the leaves less toxic. The federally threatened spotted owls in this area eat about 50% flying squirrels and about 50% wood rats. Amberat in front of the Imagination Room platform was washed off in 1988 before it was realized to have been natural.

IMAGINATION ROOM
Location:671' from Entrance, 50' higher, 55' below earth's surface.

Restoration: Rubble from the Connecting Tunnel was piled here up close to the platform's floor. Starting in 1986 and mostly ending in 1993, paid park staff removed 1200 tons of rubble while volunteers removed about 200 tons. The three million pounds of such rubble was carried out of the cave by hand. That would have taken over 100,000 trips with one bucket.

Scallops on the ceiling above the far end of the platform are cusps in wallrock dissolved out by turbulent water during stream erosion. Small scallops indicates faster waterflow (30 centimeters per second here). The cave was mostly filled with gravels around a half to two million years ago. Mountain uplift and/or removal of surface glacial stream sediment (thus lowering the water table) renewed stream erosion that removed the cave gravels. Based on scallop size lower down, the initial stream flow was not as fast as that at the present time but it went faster later on during major flooding when outlets had enlarged. 

Moonmilk is white and feels like grease when wet and looks like powdered chalk or milk when dry. The origin for the name Mondmilch (moonmilk that is >90% calcite) is from the German Mannlimilch, meaning "little earth-man." Peasants in Europe used Mondmilch's mysterious properties for centuries to heal infected cuts in livestock. Some Europeans believed that little men we would call gnomes put Mondmilch in caves for people to use. Much Mondmilch sampled does contain actinomycetes, the main producers of antibiotics that humans use. Mondmilch in Oregon Caves occurs near the high evaporation of cave entrances and along cracks that drip in dissolved organics. The absence of any mondmilch under flowstone suggest most of the Caves's mondmilch has recently formed due to higher evaporation from increased airflow from natural and/or man-caused entrance enlargement. Rapid evaporation would cause rapid crystallization around many centers of crystallization (nuclei), resulting in very small crystals. 

Use of organics by bacteria would reduce acids and so precipitate moonmilk. Organic coatings then prevent the smaller crystals from dissolving and larger crystals from growing larger, recrystallization common in wet
dripstone and flowstone. Some drier Mondmilch in the Caves has recrystallized into hard rock once the bacteria left and the organic films oxidized, as in the limestone with water drop grooves above the scallops. A 1990-96 study indicated that bleaching moomilk to remove algae is not causing the moonmilk to harden.

A helictite occurs on the slope in front of and just below the platform. Another one visible to a full tour is in the next room. from the Greek root "helick," meaning "to spiral," they may twist in any direction. Each one has a central canal through which water moves under capillary pressure. Growth is by carbonate precipitation due to evaporation and degassing of capillary water at the tip. They often form when flowstone blockage of a wall builds up water pressure until water under pressure comes out from a small hole. The relative lack of helictites in this cave suggests that closeness to the surface prevents evelopment of high water pressures that help form helictites. The helictite here formed at the base of a sloping wall that was covered with flowstone. The flowstone stopped most waterflow and built up pressure that encouraged helictite growth in one hole in the flowstone.

Helictite shape is governed by crystal shapes, evaporation or internal blockages caused by impurities, air bubbles, etc. Latex casts indicate that the central canals of some are not large enough to supply enough calcite to keep them growing at the observed rates. Water flow on the outside of the helictites is likely drawn to the tip because of higher evaporation there. That point is usually further away from wall friction and water and so air flow there is drier and faster than air closer to the wall. Precipitation would then occur at the tip of the helictite, contributing to its growth. 

Density Currents: The sloping wall is likely the result of density flow where water rises and dissolves out flat ceilings and then moves down the walls, sinking as more dissolved calcium added to the water makes it denser.

Drips: A 1999 study with tilt bucket and datalogger indicated that it takes 2-3 hours for over an inch of rainfall to arrive in the Imagination room.

Rootcicles: The Inside-out-Gopher Hole could be an antler helictite or a rootcicle. Antler helictites are helictites that not only have a central canal but also have canals radiating out from the central canal, allowing the formation to become much thicker than most helictites. However, no antler helictites are known from this cave. As similar broken formations in the Caves have central roots, this is the most likely explanation. Calcite forming on normally acidic roots to form a rootcicle is a mystery. 

                              BEEHIVE ROOM
Shells: The abundance of snail shells in woodrat nests suggests that the woodrats eat the snails or at least carry the shells in. 

Death: Frank Ellis, his wife and some friends reached the Caves on August 2, 1909. He was 21 and had been married only three months. Having become suspicious of two strangers who had been in the cave when they arrived, Frank hand carried his cocked revolver. While climbing a ladder, he slipped and fell. His gun hit the side of the wall and discharged. The bullet entered Frank's left eye and brain. The group cried "murder" and fled the cave, except for his wife. All lights were taken. He died in a few hours. His wife followed the guide string out of the Caves.

110 EXIT
Location: 784' from Entrance, 50' higher, 30 ' from surface.

History: In 1877, the first or second trip after the discovery included Davidson, John H. Kincaid, Frank M. Nickerson, and John M. Chapman. A second trip that year used pitch pine for light. Small trees were made into ladders and a rope was tied to the entrance so as not to get lost. Balls of string were used on a 1878 trip to find the way out.

Fossils: Below the woodrat nest and the steps leading up to the start of the room is the richest set of fossils or subfossils found so far. Bones include those of salmanders (Pacific giant: Dicamptodon), clouded Aneides cf. ferreus, and Del Norte or Siskiyou Mountains: Plethodon) Pacific water (Sorex bendirii), vagrant (S. vagrans) and Trowbridge (S. trowbridgii) shrews, shrew-mole (Neurotrichus gibbsii), black bear, skunk (Spilogale), mountain beaver, jumping mouse (Zapus), tree voles (Aborimus longicaudus), redback vole (Clethrionomys), elk and deer, bushy-tail woodrat (Neotoma fuscipes), white footed mouse (Peromyscus), flying squirrel (Glaucomys), and chipmunk (Tamias). The possible bones of the mountain cottontail (Sylvilagus nuttallii) indicate that the vegetation and/or the climate 1945 to 1535 years before the present (based on charcoal radiocarbon dating) may have been different as this species does not occur at the Monument but just to the east.

Bats: The old gate here was inadvertently one of the worst possible gates for bats; one bat was found dead on one of the diagonal bars. In 1989 a new gate helped bats fly in and out. Bat wings easily fit through the long horizontal spaces. The angle irons allow additional height for a bat to fly through, since it is so small, but prevents most people from entering. The flat surfaces of the angle irons also allow bats to more easily see or use sonar to spot the location of the bars and to slide off them without damage if they do collide with the bars. Starting in 1995, bats now regularly use this entrance although it took them about six years.

Acid dew: Dissolving occurs shortly beyond the 110 entrance, especially on the right side of the trail. This may have occurred before a large entrance formed here. The airflow was driven by the geothermal gradient, with the warmer air at the bottom of the cave rising to the top of the cave. As the warm, moist air reached the upper ceilings and walls, the colder walls caused the carbon dioxide-rich air to condense and form carbonic acid. Solution from acidic dew occurred along cleavage planes and between calcite crystals. The solution between crystals resulted in a mosaic of small knobs known as lizard skin popcorn. The resulting knobs that remained after solution were sites of popcorn formation, presumably after the entrance became large and evaporation increased. This mixing of dissolving and precipitation of calcite in one place is rare; lizard skin popocorn is known from only a few caves. Flowstone has also been dissolved on the left side (right side of passage just before steps) such that each flowstone mass appears to have only about half of its original mass.

Coralloids that point upward to the right after the entrance at least partly formed from evaporation. Coralloids on the left that point to the entrance and have black tips probably form in part from cyanobacteria forming moist mats that transfer dissolved calcite to the tip where evaporation deposits it. The extent of this type of popcorn suggests the 110 entrance is natural. So does the 2,770 +-90 year old charcoal radiocarbon dated and lying in a small clay pocket in flowstone at the bottom of the steps beyond the 110 Exit. The charcoal from a forest fire likely came in nearby through a large whole and didn't travel very far (otherwise it would have been destroyed).
At least at one time, there were probably one or several natural entrances to Oregon Caves higher than the 110 Exit. The resulting chimney effect moved air through the cave that helped deposit much of the cave popcorn through evaporation and loss of carbon dioxide.
 
                           BANANA GROVE
Speleothems: Stalagmites are more common in this cave than are stalactites, probably the result of drip rates that are so fast that there is not enough time for much calcite to deposit on a stalactite. If the water stays on the stalactite a few hours, most of the calcite will come out of the water. But if the water stays only a few seconds, most of the dissolved calcite will continue to fall to the floor of the cave. As it hits the floor, splashing stirs up the water and out comes the fizz and calcite to form a stalagmite. Much of the water may sink further on a sandy floor. Water running down an inclined ceiling may leave enough calcite to form draperies while water running down a slope leaves flowstone. Draperies may meander like rivers because such a path is the most energy efficient and any deviation from a straight line will be preferentially exagerrated as the curved section will grow faster (more exposure of calcite) than the straight part.

                          NIAGARA FALLS 
Location: 962' from Entrance, 80' higher, 90' below surface.

Cave springtails evolved from ones that inhabit tiny spaces in the ground, as they are small enough not to have to make major adaptations to a cave compared to a small crack or in the soil. However, in general, cave invertebrate faunas contain different species compared to those known in cracks, soils or in groundwater. The greater jumping ability probably evolved in caves so springtails could escape trechine beetles or pseudoscorpions. Such an ability would be less needed in soil habitats. Elongation of appendages helps springtails walk on the surface tension film of cave pools instead of being trapped by it. Development of larger "claws" helps movement on slippery mud. Caves springtails often have longer antennae and legs, a flattened outermost antennal segment (humidity sensor) and a large body size than the ancestors they evolved from. Relatives of Oregon Caves springtails live in the Sierra Nevada, reinforcing geo-evidence for the Sierras being linked to Siskiyous (now broken off and transported 60 miles to the west). Both are part of one of six "hotspots" of cave biodiversity in the US. There are 10 species found in Oregon Caves and nowhere else, more than in any other US cave. This cave may be just the right size for high biodiversity. It is small and isolated enough that mutations and new species can arise without being swamped by interbreeding with large populations. But it is big enough to include a variety of habitats and low extinction rates.

Caves popcorn on the right side of the stalagmites on Niagara Falls indicate air flow from the surface from right to left. It usually forms through a combination of evaporation and loss of carbon dioxide. Cold air, especially during winters, nights and glacial periods, flows into the cave. As it moves into the cave, the air warms up and is therefore able to evaporate more water. This air is also, relative to other cave air, lower in carbon dioxide. Therefore, more carbon dioxide is going to be lost to this air from water in the cave in order to equalize the difference. 

Faults: This area marks the major change in fault and cave passage orientation. Most passages before this (and passages south of the Ghost Room and in the Bone Dome) are oriented along faults that run northeast. Most of the rest of the cave is aligned along northwest trending faults.
 
Signatures: The most easily seen set from 1885 or 1886 is from Thomas Condon (1822-1907) an inspiring Oregon teacher of natural science in general and of geology, paleontology and the theory of evolution in particular. Condon's first trip here was in 1883. He implanted scientific curiosity whether his listeners were gamblers or cavalrymen, farmers or miners. His lectures were packed even at rough frontier towns. He was heartily cheered at the end of the lecture he gave to nearly all Jacksonville residents in 1833.  He taught geology, paleontology, mineralogy, geomorphology, botany, rhetoric, history of civilization, mental philosophy, international law, the Constitution, and ethnology. Apparently a calcite cover had already formed by 1917 over his geology class roster as efforts by the Forest Guard to erase them failed. This is likely a better example of average rate of formation growth in the cave than are formations in the Connecting Tunnel.

Discovery: Where the area is first cut at the first right angle turn after Niagara Falls is where Walter Burch enlarged a windy opening in 1886. He used small shots of powder because he feared too much rock would fall and trap him. He worked in a pool of water two inches deep and worked hard enough to keep his teeth from chattering. By removing his outer garments, he was able to squeeze through (see the next stop for more of the story). Crawling would continue to be a part of the public tour until 1922, when most crawlways along the route were eliminated.

Broken soda straws: This is the best place to see broken soda straws cemented to the floor. Earthquakes or bears could have done this but the most likely explanation is that the upper parts of the cave, that part of the cave that would change the most temperature wise with surface cooling, were ice damaged during the height of the last glacial from 25 to 14 thousand years ago. Broken formations are also seen in the flowstone cut before Neptune's Grotto; they occur during the height of a glacial period.
The lack of translucent sections of soda straws in the floor suggests that the cementation has only occurred in the last ten thousand years or so (translucent soda straws are more likely to have formed within that time period).

                         NEPTUNE'S GROTTO
Floods: Just before the stairs are two layers of flowstone with stream gravels sandwiched in between. This is likely where Burch came out. He then went down the domepit where the stairs are now (see the next stop for more of the story).

Cave Age: Stalactites, shelfstone, and flowstone are more common in the upper part of the cave because that part of the cave is older and thus has had more time for formations to grow in it. It also escaped the late-stage re- flooding of lower parts of the cave. Slow drips from increasing drought may be why there are more stalactites than stalagmites and why many of the stalagmites are hemispherical mounds. 

Shelfstone occurs to the left of the top of the Spiral Stairs. It is a flat calcite deposit attached as a ledge or eave-like projection to the edge of a cave pool. The curved water line at the edge of the water, as is the case with soda straws, allows greater evaporation and fizzing off of carbon dioxide because of the greater surface area. Turbulence from drip-caused small waves colliding with the edge of the pool precipitates the calcite by fizzing off carbon dioxide, much like shaking a can of soda pop. Lke water moving up a piece of blotter paper, water may move to the top of the shelfstone by surface tension and thus drop its load of calcite. The thickness of each layer may be due to seasonal changes in water level. The great thickness of the different layers suggest a high rate of seasonal change when the shelfstone was forming.

Domepits most likely formed from concentrated, aggressive inflowing water enters aster the cave mostly drained. Domepits are formed where there is a local input of water, as under the head of a stream valley, beneath the centers of sinkholes, or along a line where a layer of impermeable non-carbonate rock cover has been eroded off the limestone. The situation here is probably the latter case as the contact between the argillite and the marble lies above the line of dome pits in the cave. 

Given the great thickness of the flowstone and no deepening of the domepit beyond the level of the Grand Column, it is most likely that the domepits here formed at the start of older deglaciations when glacial and permafrost ice melted (125,000 250,000 350,000 425,000 and/or 500,000 years ago) or are even older.There is no pit below the lower cave passages, suggesting that acid water drains away fairly quickly before it can dissolve & deepen the domepit. Drainage may have been through a former stream but now is through interconnected cracks, indicating a mature karst network, unlike the more recent and less mature karst in the upper end of the cave where domepits are still actively deepening.

Rainfall moves within a few hours (near natural entrances) to about two days (Ghost Room) down to the cave. A study in 1999 with tilt buckets and dataloggers indicated that it takes 12 hours for over an inch of rainfall to begin arriving in the King's and Queens Room. Because surface tension and friction slows flow in tight cracks, a "capillary barrier" at the base of the soil zone and wide joints may cause concentrate flow into a few large joints, faults, or bedding planes that became cave passages and then became decorated with calcite from more waterflow after the cave mostly drained.

Lint: Over a pound is deposited in Oregon Caves every year. Differences in lint accumulation result from the rate of lint decomposition, wind patterns, distance from the trail, and body movements. More lint falls on stairs as people descend them. Over 90% of the lint likely falls within the first 4' on either side of the trail. The lint here shows less than 5 percent wool or cotton fibers (normal clothing ratio of organic to synthetic fibers is 1/1), suggesting that natural fibers decay rapidly in the cave.

Oldest Age: The cutaway area just before the small room on the left is where one of the oldest dates of limestone was found in the cave. Since cave limestone is so dense and impervious to water (unlike many limestones formed in the ocean or on the surface) and usually lacks fragments of past rocks, it is ideal for deriving an age from the radioactive metals thorium and uranium. Thorium is insoluble in water while uranium is not. Therefore, when the flowtone was deposited, it only contained uranium (assuming no rock fragments). The uranium immediately breaks down into thorium at a known, steady rate. Measuring the ratio of the thorium and uranium gives the age of the flowstone, the oldest date here being about 330,000 years. Near the bottom of the layers there is not enough uranium in the rock to date it this year. Instead, oxygen and carbon isotope ratios were matched to ratios in ocean cores and gives the start of speleothem deposition in Oregon Caves at 516,000 years. The ratios are largely affected by differences in evaporation rates during glacials and interglacials.

There are other ways to date cave sediments. Unstable isotopes of aluminum (Al-26 with meanlife of 1 million years) and beryllium (Be-10, meanlife of 2.2 myrs.) are produced in quartz pebbles near the ground by cosmogenic neutrons and muons from cosmic rays. When the pebbles enter a cave, the inherited radioactive isotopes decay Because the aluminum isotope decays faster than that of the beryllium, the ratio decreases over time and can be used to date sediment burial over the past 5 million years, much longer than thorium-uranium or radiocarbon methods. However, uncertainties in determining burial dating commonly exceed 100-200 thousand years.

Other radiation damage methods include electron spin resonance that measures the absorption of microwave radiation by unpaired electrons-that is, those having very little stability-in radiation-damaged minerals and glasses when they are exposed to a strong magnetic field. The results provide estimates of the amount of damage to electrons, a type of damage that occurs at a known rate in some settings. In thermoluminescens, radiation damage displaces electrons from a parent atom, and the displaced electrons become trapped in the atoms' crystal lattice. When the mineral is heated the electrons return to their stable configuration, releasing excess energy as light, or luminescence. To estimate the amount of orginal radation damage, the luminescence is measured on a glow curve. This method is mostly used in archeology to date glasses, ceramics, bone, and flints. During radioactive decay, the fission fragments leave a trail of damage called "fission tracks" in a mineral. The longer the decay, the greater the density of tracks, so counting the tracks can give an estimate of the duration of decay since the last heating event. 

Ash: The ash layers near the Spiral Stairs date from the last two glacial periods. This provides an independent check on the uranium/thorium dates as the ash came from Cascade volcanoes when glacial ice sheets to the north reversed the normal wind direction, changing it to from east to west.

                            GRAND COLUMN
Location: 1112' from Entrance, 59' higher, 135' below surface.

Drips: The year round wetness here indicates that some of the water is taking several months to get down this far. 

Loops: This area likely is the lower part of a phreatic loop. Water tables are rarely horizontal or stable over long distances in carbonates so the term can be misleading. In immature limestones and marbles, not all openings are filled with water in the phreatic zone (where all open spaces are filled with water). In mountains, in uplifting areas, or in calcite layers with only a moderate number of wide cracks, as is all true for Oregon Caves, horizontal water table caves don't usually develop. Instead, water is forced downward at times. The steep dip of marble beds at Oregon Caves and much sediment blocked straight waterflow so that phreatic loops were created. Because there likely were many fissures at Oregon Caves, the loops were not very deep (few but large fissures result in deeper loops).

Steep gradient vadose tubes may have partly resulted from uplift and the tilted bedding. The result is an up-and-down cave. As Oregon Caves matured and pores became more interconnected, it approached more of a water table-type and vadose (above the major zone of saturation) cave, as is probably the case for the first few rooms. Similar development is seen in Bigfoot Cave in the Marble Mountains (60 miles south of us) in which the same rocks are involved (equivalent of Western Hayfork or possibly Rattlesnake Creek Terrane) but which are more metamorphosed (our argillite or metabasalts have become almandine garnet amphibolite. Like Oregon Caves, Bigfoot Cave has experienced two periods of cave development, an earlier phase where small, round sinuous passages were developed in the upper reaches of the marble bed, and a later phase of vadose development occurring at the base of the marble where it contacts impermeable rock. One difference, though, is that Bigfoot's main control on passage development are high angle faults while Oregon Caves mainly has developed along bedding planes and faults along low bedding planes at lower angles than the Bigfoot faults.

Grand Column: Burch saw dripstone of "transparent beauty near the main column in 1886. The Grand Column was white in 1888 but was later entirely surrounded by asphalt. A little asphalt dissolves in water that then is kicked up into water droplets that stain formations. A formation in Miller's Chapel was cleaned in the seventies and subsequently darkened again even though it hadn't been touched. This is likely why the 110 Exit is still light colored; it's too dry there for much water to be kicked up and moonmilk is also actively forming there. 

Trail: The new trail is a combination of high tensile cement, inert aluminum oxides grains for traction on top of the cement, and a special type of extruded fiberglass, all designed for durability and all not likely to leak material into the cave. The cement has low calcium hydroxides, the material that forms stalactites under bridges.

Protocaves: The right wall at the base of the Spiral Stairs shows an anastomosing protocave developed in a vertical fault. They appear less common than those developed along bedding planes.

JOAQUIN MILLERS CHAPEL
Location: 1283' from Entrance, 70' higher, 155' below surface.

Discovery: When Burch first entered this room in 1886, he placed a crown of heavy straw (used to protect his head like a helmet) at the entrance so he could find his way back (see the Ghost Room for more of the story).

Speleogens: On the right side of Headhunter's Trophy Room are rillenkarren, downslope solution grooves about one centimeter wide, with sharp intergroove crests. They likely result from turbulent flow, more water than the horizontal grooves but not splashing. The more irregular flutes, which resemble scallops, result from acidic water splashing down the dome pit. Where the solution grooves intersect, a sharp point (spitzkarren) formed. 
To the right of the canopy are horizontal notches (like mini-bevels) caused by acidic water coming down the domepit as sheets of water rather than as dripping water (which forms flutes) or turbulent flow (rillenkarren). How these form is not clear but it likely is related to wave action in which certain areas are more turbulent, causing greater solution. On the left side of the Trophy Room is a canopy formed over sediments now washed away. This area formed parallel to the tilt of the marble and chert beds). 

Soda Straws: One of the longest soda straws (14") visible from the trail lies above the trail in front of the chapel area. The most rapid growth in the world may have been a soda straw in Jewel Caves in Augusta. It grew over an inch/year and then stopped growing. The world's longest known soda straw (21'2") may be in Kartchner's Cave in Arizona. The theoretical limit is 26', after which it falls from its own weight (there is an rumor of a 27' long soda straw in France). 

Since <1% of the soda straws in Oregon Caves show any regrowth, the average is <.0014/century or around .015"(.032mm)/1,000 years. The bigger stalactites here grew a lot faster than that. The flowstone and dripstone sampled by Turgeon (2001) in Oregon Caves showed growth rates between 1.54 to 31.5 millimeters (close to an inch and a half) per thousand years during early to mid-interglacial periods of the last 500,000 years. Increases in both temperature and water film thickness (related to precipitation) increases growth in Oregon Caves (Turgeon 2001); studies in caves with grasslands above indicate growth rate is only proportional to precipitation while increases in the solar constant increases fulvic acid amounts and its fluorescense. Studies in the dome pits of Oregon Caves indicate that surface temperature increases carbon dioxide available for carrying dissolved calcite into the cave; grassland soils may dry out too fast in summer to provide much extra carbon dioxide or enough water film thickness to increase growth rates. The larger amounts of organics and thicker soils in forests may hold the water in long enough to pick up carbon dioxide as the temperature increases in early summer. The solubility graphs indicate that there is little growth during winter.

Growth progressively increased from one interglacial to the next (greater flushing of carbon dioxide from cave) but stopped during the height of glacials, the increase duration and severity of which increased the time that speleothems stopped growing (14,000, 2,000, 63,000 and 96,000 years) in intervals ranging from 14 to 102,000 years. Then, not only was groundwater frozen but the ice or periglacial/tundra material likely also plugged up entrances. The higher carbon 13 isotope values during the height of the glacials suggest reduced biological activity due to a lowering of treeline below that of the caves. Speleothem formation in Oregon Caves stops very early during the transition from interglacial to glacial and begins again at the very end of a glacial period. The cessation of growth get longer over time, indicating increased cold periods and/or continued uplift.

Vermiculations are also called clay worms. They are thin, irregular, discontinuous deposits usually of clay or mud, likely formed from flocculation of drying, liquid films. Directed water flow with ripples may result in the tiger skin vermiculation along vertical walls. The clay or silt might be deposited in the troughs of the ripples where turbulence would be less (the opposite of microgour formation) A relatively high proportion of water and slower drying results in more complex forms. The colloidal mass (particles thousandth to a hundred thousandth of a millimeter) flocculates into shapes determined by particle size and amounts, bedrock irregularities, rate of evaporation, and electric charges. Because of the flat nature of clay minerals, there are a lot of unsatisfied ionic charges in the part of the molecules that stick out of the flat surface. Therefore, clay particles are often highly charged and enough can be attracted to each other to cause visible flocculation whereas before they are invisible because the individual colloidal size particles are so small.

Color: The more recent, deeper formations in the cave may be white because organics and dissolved iron often doesn't get this far and because the iron in formations have not have time to oxidize enough to darken the rock. A 1993 study of the amount of white formations showed that they were much more common away from the trail; historical accounts indicate that many formations near the trail were white in the 1800s before torches were used.

Faults either vertical or near vertical occur here. Their abundance near the Grayback Pluton indicates how they formed. Most of the vertical faults show little displacement and don't seem to form passages whereas the more tilted ones (and presumably more offset) do.

                     ABOVE THE RIMSTONE ROOM 
Pendants to the right just before reaching the first dikes are sharp pointed remnants of wallrock. They form in areas of rapid erosion, such as from very acidic or turbulent water. The stream or domepit cuts down into its floor so fast that even sharp points are left high and dry before they can be eroded away. 

Rimstone dams (also called gours) have a dam and pool (sometimes dry). Degassing of CO2 by turbulence, release of pressure, and/or evaporation as water upwells over the top of the dam deposits calcite and builds the dam up. The basin side is usually slightly overhung (facing upstream), while the spillway side usually slopes downstream. This appears to be a compromise between growing up to the area of the most calcium ions (because water is evaporating and carbon dioxide is being lost at the water's surface) and growing into the direction that causes maximum turbulence and further loss of carbon dioxide. The slant becomes less as water flow decreases and as evaporation increases, as appears to be the case here. Even slower flow and higher evaporation produces very convoluted dams. Height is determined by how deep the stream is. Microgours are miniature rimstone dams on steep flowstone slopes that produce frequent turbulent flow.

Cave ghosts occur to the left after the Rimstone Room. These are remnant sheets of flowstone that remain after acidic water coming down a dome pit has eroded the more soluble marble underneath it.

                       GHOST ROOM PLATFORM
Discovery: When Burch came to this room on top of a large boulder, his candle burned his fingers. He found he had about than an inch left. He hurried out but got lost under the boulder. He then climbed the boulder and found one of his exploring marks (a cross with the long end pointing out) and then found his straw hat. He made it out the 110 Exit just as his candle had completely burned down. In 1885, Homer Harkness and brother-in-law Burch charged one dollar per person for a guided the cave trip, camping, "medicinal" cave waters, and good pasture, as advertised in the Grants Pass Courier newspapaper. Burch and Harkness spend about $1,000 enlarging passages and building surface trails during the next 2 years.
 
Rills on the ceiling are likely from acid dew caused by two large masses of humid air mixing and/or by warm floodwaters. The resulting carbonic acid runs down many ceiling inclines in rills. The series of dome pits formed from acidic water entering the cave as the water comes off the argillite above the cave. 

Resolution: Water dripping on a stalagmite (the Spitting Stone) was acidic enough to dissolve a hole. Once this occurred, water splattered upward, reducing crystallization of calcite because less water stayed around. As the hole deepened, splashing no longer removed dissolved calcium as easily so the water became saturated with respect to calcite and solution stopped. The result is a steady state with neither solution nor deposition.

Passage Size: The cave is a mix of mazes and branching rivers in three dimensions, with large rooms (Ghost & South), closest to argillite near the surface and quartz diorite near the cave's base. Water coming off argillite has little dissolved calcium and so it can dissolve much marble. Water near the main entrance is almost saturated with dissolved calcite and so cannot dissolve much more, resulting in small rooms in the lower cave. However, because various flows join before they reach the exit, the higher flow volume should result in larger passages, as it does in most caves. There is a tendency for convergence of flow toward the relatively low hydraulic head (pressure) of the major conduits. The effect of increase flow does occur along the known length of the lower River Styx (the entrance area is the largest) but does not occur when compared to the Ghost Room and further upstream. This is more evidence that the lower cave linked the rest of the cave via stream piracy late in its history. In and near the Ghost Room, adjacent quartz diorite concentrates waterflow and solution higher up but blocks cave development lower down. 

Because of rapid erosion, uplift and uncovering of the marble, release of pressure likely caused fairly wide cracks (.2 mm.) near the surface where most of the cave formed. It would have taken several tens of thousands of years for such cracks to enlarge to the breakthrough time, when flow becomes turbulent and enlargement greatly increases. Further enlargement occurs at about 1-2' every thousand years. So this room took about 200 thousand years to form. Add to this the flowstone age, and one can say that the minimum cave age is about half a million years. The cave is probably not much older than a few million as that is the age of the Henley surface and (assuming the slopes here were not recently steepened by uplift), older caves would have been eroded away.

                   FIRST PLATFORM TO PARADISE LOST
Location: 1554' from Entrance, 100' higher, 190' below surface.
 
Sediment: A mix of volcanic ash, loess and marine sediments coats walls and ceilings. Some is the upper part of a stream deposit, being finest and so the last material deposited from the stream. A written report in the park's geology files indicates the silts contain Globorotalia truncatulinoides, a tiny foramanifera (single-cell animal) in subtropic oceans. That means downfaulting and an ocean invasion no earlier than 2.8-2.3 million years ago, when G.t. evolved from its ancestor. The Hanley Surface now at this elevation may have been a peneplain near sea level. The foram most likely has been misidentified and more likely is another species of Globorotalia from an Eocene marine invasion about 30 million years ago. Remnants of 100 million-year-old Cretaceous marine rocks (a spreading center under the continent) have been tentatively identified on the Monument's  surface.

Glaciers: Ice heaving and moving rock-imbedded glaciers (like sandpaper) ground up rocks into fine silts. Fresh, unaltered hornblende and feldspar minerals in the cave silts indicates that they had been separated by mechanical grinding of quartz diorite rather than by the warm-weather chemical breakdown of feldspars into muds. The even and tiny size of the grains and the vertical silt walls in the caves also suggest that the stream silts was loess, debris blown off rock piles bordering the glaciers that gouged out Bigelow Lakes a mile to the southeast. Wind-blown silts still come in over the top part of the Monument but likely at a much slower rate. Whenever you have a lot of silt, glaciers are often responsible because less intensive mechanical produces sand and chemical weathering produces clays. The silts have been here for a long time because sepiolite clay in the Rain Room has formed after the silts were laid down.

Domepits: While there are no large entrances that can flush out carbon dioxide, domepit water can absorb carbon dioxide from the cave air and continue enlarging the pit. When surface soils and large entrances formed, most of the domepits started depositing flowstone. Most water likely is more saturated with respect to calcite by the time it goes from the top of domepits to the bottom, likely because some calcite is dissolved on the way down and there is some degassing of carbon dioxide. The amount here during the middle of the summer can be up to five times the amount on the surface. This suggests that the high amount is due to degassing of the domepits (high summer-time organics releases more carbon dioxide) as high summer airflow should be flushing out carbon dioxide, not increasing it.

Floods: Silts and gravels shaped by frost heaving and meltwater raised the level of surface streams and the water table and, perhaps with glacial ice as well, blocked cave outlets to the surface and the deeper cave passages. The resulting floods enlarged side and upper passages (ones not oriented to usual waterflow), drilled domepits into the cave, and etched bevels. Since the last Ice Age, reduced water flow and the cutting of surface streams below much of the cave has largely stopped enlargement of the cave. By about 90,000 years ago, the latest mountain uplift rejuvenated the streams and removed most of the silt and gravel from this area while an earlier uplift may have removed sediment from the upper cave and created steep vadose tubes in the upper part of the cave past the South Room. 

Manganese: The dark stains on the chert to the left of the fiberglass/metal stairs leading to the to of Paradise Lost are likely manganese oxides and perhaps some iron oxides. During dry climates, evaporative wicking and oxidation of manganese by proteobacteria (a phylum of bacteria that includes Leptothrix) deposited the oxides on the chert. The bacteria derive energy from the oxidation. Manganese may also deposit on the marble but there the underlying layers get dissolved away faster than the manganese can build up.

Flat-topped stalagmites result from the long fall of the water droplets. Wind currents cause slight deviations in where the droplet hits so that the same spot is rarely hit twice. The water also splatters before it has a chance to precipitate much calcite. The high pressure impact of the droplet from such a height may also cause carbon dioxide to remain in solution, thus not allowing the calcite to immediately precipitate.    

Discovery: Dick Rowley used a powerful flashlight and something reflect white. He brought in long poles and cleats for steps and built a ladder to the top. He was struck by the beauty and immediately named it Paradise Lost. 

In the late 1880s, a party that includes O.L. McPherson of Kerby visits the cave and gets lost near the Ghost Room.  By following a string left by an earlier party, the group eventually finds its way through several narrow passages and emerges through the 110 exit. In 1891 the Examiner party from San Francisco used twine and charcoal markings to find their way out. In 1909, Nickerson's dog helps find the way out of Paradise Lost.

Cavers today often stop and turn around to lock at passages as they explore a cave new to them as the same passageway looked at in one direction can look very different in the opposite directions.  Cavers of course never admit to being lost, only momentarily confused.

In 1911, about 90% of the people visiting the Cave came from the Williams Creek side and most of them reach it on foot. That year the Forest Service employs a cave guide to give free tours from June 1 to October 1 and to protect the cave. Cave guides and guards Vickers Smith, Richard Sowell, and Dick Rowley improved cave trails through 1913 and gave cave tours. This is before one of the first naturalists in the National Park System begins work at Mount Rainier (1913). Thus, Smith, Sowell  and Rowley may have been the first paid interpreters in the National Park System. Rowley's first cave trip was in 1908 with Elijah Davidson. Rowley thought he was hired because of his experience as a miner. He found his way around by taking a pocketful of huckleberry leaves into the cave. At each intersection he would put a leaf down with a stone on top and the tip of the leaf pointing the way out.

Rowley was quite the prankster. He would often lead a group into an area and then exclaim that he was totally lost. The rest of the group would panic, figuring that if Rowley was lost, they would never get out of the cave. At the end of a good story in the Ghost Room, he would turn off the lights and briefly disappear. In latter years, a retired Rowley would hide in the cave and howl like a wolf when a tour came by.

                        FLOOR OF GHOST ROOM
Dikes: The quartz diorite dikes in Oregon Caves consists of abundant quartz and plagioclase feldspar (probably oligoclase & partly replaced by scapolite) and fairly abundant biotite and epidote and green hornblende are fairly abundant. Rock fragments are tremolite schist (originally mudstones, now more metamophosed than argillite), altered volcanics, marble, quartzite (a metamorphosed sandstone), argillite and a rock of hornblende and epidote (often associated with hot water "black smokers"). The dike is from the Grayback Pluton which cooled for up to several hundred thousand years and mostly crystallized by 153 million years ago. Just as a burst pressure cooker forms steam, a spreading back-arc basin reduced pressure. This, along with water acting as a flux to lower the melting temperature, caused partial melting of the upper mantle and substantial melting of continental and oceanic rock as the molten mass rose up. The intermediate composition of the quartz diorite results from the molten mass moving upward through an ocean basin, as opposed to the more quartz- and microcline feldspar- rich granite that moved up through quartz-rich continental crust in the Sierras at the same time and which now forms Half Dome in Yosemite. The upward movement and high water pressures cracked the surrounding rock. The reduced pressure remelted part of the pluton; the liquid then squirted into the cracks.

Fossils: Jaguar bones from two species were found just off the Ghost Room in 1996. one size indicate an age of from 40-100,000 years but the surrounding calcite had too many rock fragments to date accurately. Bear bones, likely those of a grizzly, are radiocarbon dated at over 50,000 years old, by far the oldest known grizzly in North America. The previous oldest grizzly was from 10-15,000 years old. Dates the following year establish 35,000 year old bones for a grizzly in Alaska. 

Rock Diversity: Oregon Caves may be the only show cave with the three main rock types and each major subdivision: igneous (volcanic and plutonic), sedimentary (fragmental and cements), and metamorphic (regional and contact) rock. All of the basalts are at least slightly metamorphosed and the calcified ash technically is a sedimentary rock because it has been redeposited by water but both rocks are close enough to be "volcanic." 

Earthquakes: The middle of the lowest trail segment is best for pointing out a fault. No earthquakes have been felt in Oregon Caves but three were felt on the Monument's surface (1963, 1991, 1992. An earthquake did occur 25 years ago in northern California and was heard as a rumble or distant train inside a cave. Most earthquake damage occurs in loose sediments that shake like a bowl of jelly. Vibrations in such material bounce back and forth and amplify one another. However, the solid rock of the Caves would probably suffer little damage as it would move in rhythm with the earthquake. Also, much earthquake damage comes from surface waves that would not greatly affect the deeper parts of the Caves. However, a very large magnitude earthquake, like the New Madrid Earthquake near the Mississippi River, would probably cause some damage as it did to a cave near that earthquake.

Fluorescein dye put in the stream at the bottom of the Ghost Room reappeared at the entrance in <4 hours. The stream overlies flowstone, indicating calcite deposition. Calcite deposited in 1992-3; only a small amount dissolved in spring thaw (much more in April) and in summers (much more in one Aug. from a summer rain). The most solution occurred after rare heavy summer rains or the first heavy fall rain. These rains pick up much stored soil carbon dioxide as a result of decomposition during warm weather. The first flush also increases dissolved ions; latter rains dilute this input.

                         ANGEL FALLS
Location: 1843' from Entrance, 130' higher, 170' below surface

Climate Study: How much glow there is from a blacklight depends on the amount of fulvic acid in the calcite. The thinnest lines record changes in calcite deposition during individual days and so are far better than tree rings in reconstructing past climates, being hundreds of times more detailed and up to ten times as old(up to half a million years). The thickness of the line records how much rain fell or (in the case of Oregon Caves) how warm it was, and water film thickness (29% of growth variability) and the UV brightness tells how hot the sun was, the so-called solar constant (it really isn't constant). Speleothem studies indicate that changes in the solar constant in a cycle of 11,500 years produces climate change equal to that caused the orbital variations thought to be responsible for glacials/ interglacials. Estimating the solar constant works best in grasslands as tree shading can affect fulvic acid amounts. Calcite is mostly deposited in a cave when there is a soil, which apparently was lacking or reduced here during the height of the glacials and sometimes during interglacials. Growth increased during the last half million years irrespective of the glacials, suggesting that openings to the cave increased and the overburden decreased. Calcite precipitation in Oregon Caves was thus severely reduced during glacials in part because the groundwater froze. The lowering of the treeline below the caves may have caused a change in carbon isotopes in Oregon Caves at this time. Lower carbon 13 and carbon 18 indicates that evaporation was lower during cooler periods.

Full glacials produce a lot of rock broken by ice expansion and this may have plugged up most entrances, resulting in renewed solution in the cave especially in domepits. The Bone Dome records bedrock solution, flowstone deposition, flowstone solution, flowstone deposition and then further solution, suggesting there has been periodic opening and closing of entrances to the surface.

Phosphorescence is luminescence in which a stimulated substance emits light after the external stimulus ends. Electrons move to higher energy levels and then slowly fall back to their former orbits, emitting characteristic wavelengths of light. In normal light, the browns, yellows, reds, and orange of most older formations are likely due to organics (especially humic acids and other organics with high molecular weight) and, to a lesser extent, iron. Most organics and iron don't usually make it down very deep so deeper passages often have white formations, as is the case here.

The lack of phosphorescence in the older, darker formations may be due to more iron and/or higher molecular weight (like humic acid) organics. Most of the presently forming dripstone in the cave is nearly pure white, suggesting that formations in the deeper parts of the cave darken only as they become more oxidized over a long period of time, are affected by human impact, or have a fast route downward. Dome pits have a faster route into the cave than joints and so have darker formations.

Some algae (especially black cyanobacteria) can usually be seen on the wet wall to the left of Angel Falls. Flourescent lights installed in the mid-seventies created much algae that was first treated with chlorox in 1984. Systematic control began in 1988 and now uses about 40% household bleach to 60% water. Installing an more limited incandescent system in 1997-8 resulted in a reduction of algae coverage to about 25%.

WEDDING CAKE ROOM
Location: 1912' from Entrance, 130' higher, 170' below surface.

Boxwork is a network of cracks filled with a material that dissolves more slowly than adjacent wallrock and so resembles a maze of post office boxes. Boxwork in Oregon Caves is most common near faults. Faults cracked the surrounding rock and the cracks were subsequently filled with calcite. Crystals grew large because there was little competition during growth. Large crystals are usually more resistant to solution than fine-grained ones and so are exposed as boxwork by atmospheric corrosion on the ceiling. In the same way, a block of salt dissolves more slowly than a pile of salt. 

Fault: The White Formation Passage, the last Natural Room and the Hayfork volcanic ash layer are offset by a fault, the same one that bisects the quartz diorite dike in the Ghost Room. 

Slow Water: The water for the abundant flowstone comes out along bedding planes. Water sampled here indicates it usually is full of calcite. The peaks of calcite precipitation (Sept. (1992), Nov., Jan., June (1993) indicates it responds to rainfall after months or years. Travel is so slow that it is wet year round and has had a lot of time to pick up calcite. 

Karren: The mushroom-shaped bedrock (more solution at the base) likely results from an influx of acidic sediment down vadose passages. Much of the sediment has now been washed away, exposing what on the surface is called subsoil karren. It is usually only seen on the surface where most of an area's soil has been eroded. The cave must have drained soon after the sediment came in, allowing acids to migrate down to the base of the sediment where most of the solution of bedrock occurred.

Large crystals of calcite can be seen on the right side of the passage just after the room. The large crystal termination layers grew during increased thickness of water films, probably resulting from higher rainfall on the surface.

                   FIRST SECTION OF EXIT TUNNEL
Dimensions: Tunnel 470' long, climbs at 16% grade (1'foot/6')

Development: Before 1933, tours exited at 110. The Exit Tunnel was begun in 1930 and opened to the public in 1938. Digging the tunnel was begun in 1930. Wooden pegs in the ceiling (remains still visible) served as survey points. The tunnel was excavated by drilling a radial pattern of about 10 or 14 1/2" by 2" deep holes with air-powered jackhammers (water cooled and with a water spray to keep down dust). The holes were packed with ammonium nitrate dynamite and blasted electronically. With up to 20 men working in 2 shifts a day, it took a few weeks to complete 80' of tunnel. The tunnel was mostly constructed from the outside in at least until the 1st clay pocket was reached. The rate was 4-6' per day. They then blasted 2' a day from both ends, with the connection alignment error being less than 1" or 4". 

Avery went bankrupt just before reaching the first clay pocket. He underbid ($6,140), likely thinking he would intersect much cave. His crew didn't hit cave until just a week after he left in the middle of the night. It also took longer as most of the rock was metabasalt, much harder than marble. Avery's bonding company went bankrupt after hitting the 1st clay pocket in 1931. They likely had trouble boarding up the clay banks. The company was penalized for failing to finish the tunnel on time and this may have been the partial cause of the bankruptcy. Apparently the company never paid its workers so the work was not completed and the Forest Service cancelled the bonds. The Forest Service then hires miners from the Queen Bronze Mine to complete the work. On January 16, 1931, the last natural room is reached and by the 17th workers are able to talk to men in the main cave. In February, the cave exit tunnel is essentially finished.  Electric lightning is placed throughout the cave.  CCC cleared rubble from the tunnel from Sept. of 1937 to 1938, and opened to the public that year.

Bear Bones: The black bear bones were found during the final replacement of asphalt trail with cement in 1998. Most of the bones were already disturbed by the trail in the 1930s but some bones, like the one furthest on the left are still undisturbed. The uranium-thorium date of the flowstone enclosing the bones is about 3,000 years. This accords with the orange clays that all of the bones were imbedded in; similar sediment in West Virginia records interglacial intensive weathering in contrast to unweathered loess minerals and more pebbly sediments, both of which more likely formed during glacials when there was less intensive chemical weathering and higher energy streams from glacial meltwaters.

         1ST CLAY POCKET
Location: The largest clay pocket is 2159' from the entrance and 174' from the beginning of the tunnel. It is about 135' below the surface. 

Fault control shapes the pocket. It occurs on the left near the end of the pocket. A sharply inclined layer of marble abuts a layer of meta-basalt that continues until near the end of the Exit Tunnel.

Earth fingers on the sediment form in the same way larger hoodos do, by harder material such as rock preventing looser material underneath from eroding out from splash erosion.

Velvet flowstone occurs agove 7' high to the right near the end of the pocket. Dogtooth spar crystals grown in high humidity due to little airflow, are too small to see individually but give it a velvet-like appearance.

                           2nd CLAY POCKET
A fault 60 degree tilted can be seen along the left side shortly before the tunnel begins again. The adjacent marble layer is pocketed with solution while the metabasalt shows no solution. The elongation of this room along with other rooms upstream from the Ghost Room down the dip of faults and bedding planes suggest that a vadose zone existed here and water seeping down enlarged the passages and deposited the sediment. Because the fault is oriented perpendicular to major water flow it is not well connected to the rest of the cave. In areas of rapid uplift and uncovering of carbonates where a thick insoluble caprock is breached, the initial water table may be close to the surface and so vadose passages do not usually form. The slope above may not have been as steep as it is now during initial cave formation.

The cut part of the flowstone layer fifteen high to the right mostly ran from 117 to 120 thousand years ago. Growth decreased during the last Wisconsin, suggesting that periglacial material filled the dome pit and prevented ventilation of the carbon dioxide and some of the groundwater froze. Unlike Neptune's Grotto, growth was continuous during the last glacial, possibly because this cave was deeper than the upper parts of Oregon Caves and the groundwater therefore did not freeze.

LAST SECTION OF TUNNEL 
Tissue moths (Triphosa haesitata) in fall, winter and spring. They can hear ultrasonic cries of bats but apparently are undisturbed, likely because they are not using hunting sonar and don't feed where they sleep. However, the moths may be eaten by bats in Ape Cave in Washington. Many moths take evasive action when they hear bats, diving steeply when the calls are close and flying away from the sound when the calls are further away. Although it shares its three pheromones with other species, it is the only geometrid moth that has a particular pheromone; the amount of the other two may help males identify and fly towards females. Since, the caterpillar mostly feeds on plants not found on the Monument (cascara (Rhamnus), hawthorn) and only to some extent feeds on oaks and Oregon grape, it may go out of its way to use the cave as protection from winter cold and summer drought. One study in Manitoba indicates that 10% of the moths stay in caves throughout the year and a portion then leaves the caves the following spring. 

Pyrite: The yellow/orange/red stains is limonite, amorphous iron oxides combined with water, that, to a lesser extent than organics, color speleothems. It derives from pyrite, a pale-bronze or brass-yellow mineral FeS2 (fools gold) from igneous Hayfork rocks. Seawater moving through the buried basalts dissolved metals (gold, iron, manganese and copper) and then rose and exhaled the solutions through chimney-like black smokers. The pyrite was later dissolved and moved in a hot water solution along slickensides, polished and smoothly striated surface from friction along a fault plane, a near vertical surface low down, stained red and near the lights. Building the tunnel caused iron sulphide archae-bacteria to oxidize the pyrite to produce rust and sulfuric acid. The acid dissolves calcite flowstone (an inadvertent effect of the tunnel) and deposits thin white crusts of gypsum. Archae are microbes more different from bacteria than they are from eucaryotes (cells with nuclei) like us. Each of the three groups form a domain or superkingdom. Our domain is divided into about 17 kingdoms, two of them being plants and animals. The most divergent and, presumably oldest of archae, bacteria, and eucaryote occur today in ocean hydrothermal vents such as black smokers, suggesting life began there about 3.8 billion years ago, before life diverged into the three domains.

The sulphide archae, manganese bacteria, moonmilk actinomyces, cave slime, woodrat bacteria, and microbes that made carbonic and fulvic acids illustrates that, for biodiversity, ecosystem functions, evolution, invention of all major metabolic pathways, age, biomass, and whatever else is important, bacteria and archae are tops. Most of our cell parts (nuclei, mitochondria, chloroplasts, microtuble scaffolding, sperm tails, brain dendrites) likely come from bacteria and archae. Microbes are almost as important on the surface but are more obvious in caves. It is quite possible that most of the world's biomass is underground and is nearly all archae and bacteria. Several culturable (those that grow on agar) bacteria sampled in Oregon Caves in 2000 are undescribed species; over half in Lechuguilla Cave in New Mexico were undescribed. That's just the culturables; the ratio of culturable/ unculturable bacteria and archae may be 1/12,000.

Rapid growth: Tiny stalactites formed since the tunnel was built. Evaporation during the summer probably speeds up their growth. Rapid 
olution of calcite by sulfuric acid may have also helped increase the rate of deposition. 
EXIT
Metamorphism: Biotite and orthoclase feldspar here indicate contact metamorphism, likely from basalt intruding into limestone. Calcite is 97.1%; quartz is 1%. The lack of vesicles in the basalt also indicates recrystallization.

There is one answer to any geological question: rock movement whether by erosion, deposition or large rock masses, as in mountain uplift. The contorted marble here has large crystals, suggesting the nearby lava flow crystallized the marble and therefore made it more resistant to erosion.

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