Biogenic iron mineralization at Iron Mountain, CA with implications for detection with the Mars Curiosity rover

U.S. Environmental Protection Agency
By: , and 

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Abstract

(Introduction) Microbe-mineral interactions and biosignature preservation in oxidized sulfidic ore bodies (gossans) are prime candidates for astrobiological study. Such oxidized iron systems have been proposed as analogs for some Martian environments. Recent studies identified microbial fossils preserved as mineral-coated filaments. This study documents microbially-mediated mineral biosignatures in hydrous ferric oxide (HFO) and ferric oxyhydroxysulfates (FOHS) in three environments at Iron Mountain, CA. We investigated microbial community preservation via HFO and FOHS precipitation and the formation of filamentous mineral biosignatures. These environments included 1) actively precipitating (1000's yrs), naturally weathered HFO from in situ gossan, and 3) remobilized iron deposits, which contained lithified clastics and zones of HFO precipitate. We used published biogenicity criteria as guidelines to characterize the biogenicity of mineral filaments. These criteria included A) an actively precipitating environment where microbes are known to be coated in minerals, B) presence of extant microbial communities with carbon signatures, C) structures observable as a part of the host rock, and D) biological morphology, including cellular lumina, multiple member population, numerous taxa, variable and 3-D preservation, biological size ranges, uniform diameter, and evidence of flexibility. This study explores the relevance and detection of these biosignatures to possible Martian biosignatures. Similar filamentous biosignatures are resolvable by the Mars Hand Lens Imager (MAHLI) onboard the Mars Science Laboratory (MSL) rover, Curiosity, and may be identifiable as biogenic if present on Mars.

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Additional publication details

Publication type Conference Paper
Publication Subtype Conference Paper
Title Biogenic iron mineralization at Iron Mountain, CA with implications for detection with the Mars Curiosity rover
Year Published 2014
Language English
Publisher Lunar and Planetary Institute
Contributing office(s) California Water Science Center
Description 2 p.
Larger Work Title 45h Lunar and Planetary Science Conference
First page 1
Last page 2
Conference Title 45h Lunar and Planetary Science Conference
Conference Location Woodlands, Texas
Conference Date March 17-21, 2014
Country United States
State California
Other Geospatial Iron Mountain Mine
Online Only (Y/N) N
Additional Online Files (Y/N) N