The use of soils and paleosols for interpreting geomorphic and climatic history of arid regions

The study of modern surface soils, and ancient weathering zones, which occur either buried or as surface relicts, has contributed materially to understanding the complex events of the glacial and post-glacial period both in glaciated areas and in regions not influenced by glaciation. Most work of this kind in the United States has been done by geologists.

Numerous Pleistocene geologists have noted weathered zones between sheets of glacial drift or loess in the middle western United States. These include Condra, et al⁵; Frye⁷; Frye and Leonard⁸; Kay and Pearce¹³; Leighton and MacClintock¹⁵; Leverett¹⁶,¹⁷,¹⁸; Lugn¹⁹; Peltier²³; Schultz and Stout²⁶; Schultz, et al²⁷; and Simonson²⁸. Kay and Pearce¹³ interpreted the weathered zones between sheets of glacial drift as profiles of ancient soils which they referred to as gumbotil. Hseung, Marshall and Krusekopf¹⁰ have recently questioned the pedogenic character of gumbotil, but have failed to offer a satisfactory alternative explanation. Thorp, and coworkers³⁰, in a general review of buried soils, apparently consider gumbotil a product of ancient soil-forming processes.