Subsurface formation of oxidants on Mars and implications for the preservation of organic biosignatures

被引：42

作者：

Davila, Alfonso F. ^{[1
]}

Fairen, Alberto G. ^{[1
]}

Gago-Duport, Luis ^{[2
]}

Stoker, Carol ^{[1
]}

Amils, Ricardo ^{[3
]}

Bonaccorsi, Rosalba ^{[1
]}

Zavaleta, Jhony ^{[1
]}

Lim, Darlene ^{[1
]}

Schulze-Makuch, Dirk ^{[4
]}

McKay, Christopher P. ^{[1
]}

机构：

[1] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA

[2] Univ Vigo, Dpto Geociencias Marinas, Vigo 36200, Spain

[3] CSIC INTA, Ctr Astrobiol, Madrid 28850, Spain

[4] Washington State Univ, Sch Earth & Environm Sci, Pullman, WA 99163 USA

来源：

EARTH AND PLANETARY SCIENCE LETTERS | 2008年 / 272卷 / 1-2期

关键词：

Mars; organic compounds; pyrite; aqueous oxidation; hydrogen peroxide;

D O I：

10.1016/j.epsl.2008.05.015

中图分类号：

P3 [地球物理学]; P59 [地球化学];

学科分类号：

0708 ; 070902 ;

摘要：

Hydrogen peroxide can form through the interaction of pyrite and anoxic water. The oxidation of pyrite results in the precipitation of sulfates and iron oxides, high redox potentials (similar to 1000 mV) and acidic pH (3-4). The oxidative potential of the resultant solution may be responsible for the oxidation of organic compounds, as observed in the subsurface of the Rio Tinto Mars analog. On Mars subsurface migration of groundwater interacting with volcanogenic massive pyrite deposits would have mobilized acidic and oxidizing fluids through large portions of the crust, resulting in the widespread deposition of sulfates and iron oxides. This groundwater could have leached substantial volumes of aquifer material and crustal rocks, thereby erasing any organic Compounds possibly down to depths of hundreds of meters. Therefore, the preservation of organic biosignatures must have been severely constrained in the portions of the ancient Martian crust that were exposed to aqueous processes, calling for a redefinition of the future targets in the search for biomolecular traces of life on Mars. (C) 2008 Elsevier B.V. All rights reserved.

引用

页码：456 / 463

页数：8

共 49 条

[1] Extreme environments as mars terrestrial analogs:: The Rio Tinto case [J].