Geologic History of Mammoth Cave

Abstract

Mammoth Cave is an underground part of the vast Mississippi River drainage system. Although the cave occupies a relatively small area, it has preserved about 10 million years of the drainage history of the eastern USA. It is still actively growing today. As surface rivers vary in the shape and pattern of their valleys, the cave records these events as different levels and types of underground passages. The nature and timing of those changes are well preserved in the cave. Their ages can be determined by analyzing the sand and gravel carried into the cave while it was forming. The various cave levels record the long history of the Ohio River and the influence of continental-scale glaciers on surface drainage patterns. The many changes in the erosion level of the Green River help to account for the great complexity of the cave.