Originally uploaded by Mic2006.
In a previous post (The Water Table has Dropped and What a Pleasant Surprise; the Sound of Running Water) D told me that Marcus Buck and Steve Worthington had pushed their way along this low muddy crawlspace for around 30 metres. It supposedly joins up with the main Olmstead Cave that they had explored from a passage that we had come to know as, “the forest entrance”.
When I had first entered into the room from which this passage leads it was entirely underwater. Today after a protracted dry spell it appears as a good example of a tunnel that has formed in a bedding plane. Bedding planes appear in a massive expanse of sedimentary rock strata as a horizontal weakness. It is along this weakness that the rock typically erodes or breaks. As the rock-forming sediment had been accumulating on the bottom of an ancient ocean or lake millions of years ago, some change in the depositional circumstances would have disturbed the cohesive bond in an otherwise solid mass of stone. These eroded bedding plane passages are typically wide-low shelves such as this.