Pipe Creek Sinkhole have also been found there. Pipe Creek Sinkhole preserves an ancient wetland. It was created by the collapse of a limestone cave in a Silurian reef formation. That left a steep-sided depression about long, wide and deep. When water collected in the depression, it became the habitat of the plants and animals whose remains were preserved there when the sinkhole was buried by glacial outwash and till during the Pleistocene Epoch, two million to 11,000 years ago. While the ecology of the Pliocene in North America is well-known from fossil discoveries in other places, notably coastal sites, the Pleistocene glaciers
Sinkhole through these volcanic deposits and mechanically washed fine volcanic materials out of them, then progressively eroded and removed coarser materials. Eventually, these underground voids became large enough that their roofs collapsed to create large holes. Some of the largest sinkholes in the world are: Sinkhole A sinkhole, also known as a cenote, sink, sink-hole, swallet, swallow hole, or doline (the different terms for sinkholes are often used interchangeably), is a depression or hole in the ground caused by some form of collapse of the surface layer. Most are caused by karst processes—for example, the chemical dissolution of carbonate rocks or