Lamellae genesis in a semiarid environment: Grand Staircase-Escalante National Monument (Utah).

摘要

Lamellae were documented in sandstone-derived soils in a semiarid environment. Soil survey determined lamellae occurrence was related to the interfingering of the Navajo and Kayenta Formations. Ground-penetrating radar documented lamellae occurrence and showed the upper boundary of lamellae at about 1.2 m. Lamellae were shallower on the steeper of the two intensively surveyed grids, indicating a pedogenic influence.; A soil pedon and weathered bedrock sample were characterized. Soil pH was neutral to slightly acid; organic C, Fe-oxides, and CEC generally decreased with depth and were much greater in the lamellae than the surrounding soil. The lamellae contained 8% more clay than the surrounding soil; the bedrock and lamellae both contained 12.7% clay. The clay mineralogy of the lamellae was intermediate between the bedrock and soil. Lamellae thin sections exhibited well-developed argillans.; Lamellae were probably inherited from the bedrock, then altered by pedogenic processes, confirming a pedo-petrogenic origin.*; *This dissertation is multimedia (contains text and other applications not available in printed format). The CD requires the following system application: Microsoft Office.