A global review of solutional weathering forms on quartz sandstones

Solutional landforms in limestone have been described for over a hundred years, but landforms of similar morphology on highly siliceous sandstones and quartzites have also been identified in a wide variety of environments and generally termed pseudokarst. These include large bedrock pinnacles and towers, caves, corridors, grikes, solution basins and runnels, and even silica speleothems. Quartzites and quartz sandstones have been held to be amongst the most chemically resistant of rocks, but the similarity, both in morphology and genetic process of many landforms developed from them to features of known solutional origin on limestone, has prompted some authors to refer to these quartzose landforms as true karst. st detailed studies of quartzose karst landforms have been in present-day tropical regions, or areas believed to have been tropical in the geologically recent past. This concentration of research in hot-wet areas, allied with the long held assertion of the insolubility of silica, especially quartz, has led to a belief that tropical climatic conditions are necessary for karstic solution of these rocks. However, the existence of quartzose karst landforms in temperate and even sub-polar latitudes, especially where there is no evidence of prior tropical conditions, suggests that the requirement of tropical weathering is no longer tenable. ports of these quartzose solutional landforms are widely scattered through the geomorphological and geological literature, but a comprehensive world-wide review of the range of solutional landforms on quartzose rocks has not previously been published. Because of the increasing awareness in this karst type such a summary is sorely overdue.