Etchings on Cave Walls - Border Rivers Karst

The Border Rivers Karst

The Border Rivers Karst Region is a group of small impounded karst areas that crosses the Queensland - New South Wales border. The best known area, known as the Texas Caves, includes the Glenlyon stream cave (4GL), which is a meander cutoff, and the adjoining caves of Viator Hill (4VR). The Ashford Cave (2AS) lies about 60 km to the southwest.

For other pages about the Border Rivers Karst see...
Surface karren and overview
Subsoil karren

Etchings on the cave walls

Within the caves the walls of the dryer parts have smooth powdery surfaces that frequently show a finely pitted surface with hemispherical pits about 1-2mm across, and networks of narrow etch grooves 1-2mm wide and up to 5mm deep. In places the grooves widen and coalesce to form smooth or hackly areas with isolated flat-topped plateau - which suggest a case-hardening effect protecting the outer skin. In some cases beads of water are seen along the grooves which might indicate corrosion by water seepage along the cracks, or perhaps condensation corrosion?


Selected photographs and diagrams

To view full size images, click on the displayed thumbnail image.
B730306.jpg Ashford Cave: Pitted wall and etched joints.
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B810131a.jpg Ashford Cave, Lines of pits and etched grooves on wall.
Camera cap for scale.
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B730434xa.jpg
Glenlyon Cave: Bright lines and spots are reflections from beads of water that follow lines of etched grooves. Cause or effect ?
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B760106.jpg Fine pitting and etching of cracks on a cave wall.
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B760114.jpg Weathered cave wall; with etched cracks and a powdery surface.
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B750505.jpg Etching of a case-hardened cave wall.
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B750503.jpg Etching in a case-hardened cave wall.
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B750510.jpg B750511.jpg Progressive etching of a case-hardened cave wall.
ranging from fine grooves on left to broader, pitted, areas on right.
Stereopair: View cross-eyed.
File: B750510.jpg
B760111.jpg Etched pits and grooves on a cave wall.
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B760115.jpg Fine pits on a cave wall.
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B730307.jpg Ashford Cave, Finely pitted wall.
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B760117z.jpg B760118.jpg Two sizes of pits on a cave wall.
The larger pits (about 1-2cm) have much finer pits superimposed on them.
Stereopair: view cross-eyed.
File: B760117z.jpg

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