Award Date

2009

Degree Type

Thesis

Degree Name

Master of Science in Geoscience

Department

Geoscience

Advisor 1

Brenda J. Buck, Committee Chair

First Committee Member

Debbie Soukup

Second Committee Member

Henry Sun

Graduate Faculty Representative

Brian P. Hedlund

Number of Pages

189

Abstract

The Atacama Desert is the oldest and driest desert on Earth. Hyperarid soils in this desert are dominated by rare (or exclusive) salt minerals and assemblages. Previous research details salt origins and abundance, however pedogenic processes involved in salt distribution are not adequately explained. Therefore, the main goal of this investigation was to identify and document evidence for hyperarid pedogenesis (via salt mineralogy and soil micromorphology) at a field site, Oficina Ercilla, located ~80 km northeast of Antofagasta, Chile within the Central Depression and hyperarid core of the Atacama Desert. This study presents an interpretational model for hyperarid pedogenesis, which supports the salt heave hypothesis proposed by Buck et al. (2006). Hyperarid pedogenesis incorporates many known pedogenic processes (e.g. eolian deposition, clast shatter, pressure solution). However, salt heave processes dominate with a self sustaining feed-back loop initiated and perpetuated by long term influx and retention of salt minerals.

Keywords

Atacama Desert; chile; Hyperarid soils; Patterned ground; Petrosalic; Saline soils; Salt minerals

Disciplines

Geochemistry | Soil Science

Language

English


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