Hematite Concretions from Modern Acid Saline Lake Sediments as Geochemical and Astrobiological Tombs

Abstract

Ubiquitous hematite spherules interpreted as being concretions [1] within reworked evaporite dune and interdune lake sediments [2] in the Meridiani Planum region of Mars have revealed a wealth of information about the role of acid saline waters in the planet's past. The variety of processes and conditions that could generate such deposits raises many questions about the formation of mixed iron oxide and evaporite sediments, the potential role of organisms in presumably hostile acid saline systems, and the preservation potential of organisms within this sedimentary record. Sediments from the shallow acid saline lakes in southern Western Australia (Figure 1) provide an important modern analog environment that illustrates potential early and rapid formation of hematite concretion-bearing evaporites, and the excellent astrobiological preservation potential of such deposits.

Meeting Name

7th International Conference on Mars (2007: Jul. 9-13, Pasadena, CA)

Department(s)

Geosciences and Geological and Petroleum Engineering

Second Department

Biological Sciences

Keywords and Phrases

Australasia; Australia; Lake Brown; Mars; Meridiani Planum; Western Australia; Acid Saline Lakes; Acidic Composition; Astrobiology; Chemically Precipitated Rocks; Clay Minerals; Concretions; Diagenesis; Ephemeral Lakes; Evaporites; Geochemistry; Hematite; Iron Oxides; Lacustrine Environment; Lake Sediments; Lakes; Microorganisms; Modern Analogs; Oxides; Petrography; Precipitation; Preservation; Reworking; Saline Composition; Secondary Structures; Sedimentary Rocks; Sedimentary Structures; Sediments; Sheet Silicates; Silicates; Spherules; Sulfates

Document Type

Article - Conference proceedings

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2007 Lunar and Planetary Institute, All rights reserved.

Publication Date

01 Jul 2007

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