Metasomatic origin of quartz-pyroxene rock, Akilia, Greenland, and implications for Earth's earliest life

被引：126

作者：

Fedo, CM ^{[1
]}

Whitehouse, MJ

机构：

[1] George Washington Univ, Dept Earth & Environm Sci, Washington, DC 20052 USA

[2] Swedish Museum Nat Hist, Lab Isotope Geol, SE-10405 Stockholm, Sweden

来源：

SCIENCE | 2002年 / 296卷 / 5572期

关键词：

D O I：

10.1126/science.1070336

中图分类号：

O [数理科学和化学]; P [天文学、地球科学]; Q [生物科学]; N [自然科学总论];

学科分类号：

07 ; 0710 ; 09 ;

摘要：

A quartz-pyroxene rock interpreted as a banded iron formation (BIF) from the island of Akilia, southwest Greenland, contains C-13-depleted graphite that has been claimed as evidence for the oldest (>3850 million years ago) life on Earth. Field relationships on Akilia document multiple intense deformation events that have resulted in parallel transposition of Early Archean rocks and significant boudinage, the tails of which commonly form the banding in the quartz-pyroxene rock. Geochemical data possess distinct characteristics consistent with an ultramafic igneous, not BIF, protolith for this lithology and the adjacent schists. Later metasomatic silica and iron introduction have merely resulted in a rock that superficially resembles a BIF. An ultramafic igneous origin invalidates claims that the carbon isotopic composition of graphite inclusions represents evidence for life at the time of crystallization.

引用

页码：1448 / 1452

页数：5

共 39 条

[1] ABUNDANCES OF THE ELEMENTS - METEORITIC AND SOLAR [J].

ANDERS, E ;

GREVESSE, N .

GEOCHIMICA ET COSMOCHIMICA ACTA, 1989, 53 (01) :197-214

[2] Accretion of Moon and Earth and the emergence of life [J].

Arrhenius, G ;

Lepland, A .

CHEMICAL GEOLOGY, 2000, 169 (1-2) :69-82

[3] Distribution of yttrium and rare-earth elements in the Penge and Kuruman iron-formations, Transvaal Supergroup, South Africa [J].

Bau, M ;

Dulski, P .

PRECAMBRIAN RESEARCH, 1996, 79 (1-2) :37-55

[4] Questioning the evidence for Earth's oldest fossils [J].

Brasier, MD ;

Green, OR ;

Jephcoat, AP ;

Kleppe, AK ;

Van Kranendonk, MJ ;

Lindsay, JF ;

Steele, A ;

Grassineau, NV .

NATURE, 2002, 416 (6876) :76-81

[5] THE VIOLENT ENVIRONMENT OF THE ORIGIN OF LIFE - PROGRESS AND UNCERTAINTIES [J].

CHYBA, CF .

GEOCHIMICA ET COSMOCHIMICA ACTA, 1993, 57 (14) :3351-3358

[6] CHEMICAL-COMPOSITION AND EVOLUTION OF THE UPPER CONTINENTAL-CRUST - CONTRASTING RESULTS FROM SURFACE SAMPLES AND SHALES [J].

CONDIE, KC .

CHEMICAL GEOLOGY, 1993, 104 (1-4) :1-37

[7] CHEMISTRY, PETROLOGY AND ORIGIN OF BANDED IRON-FORMATION LITHOLOGIES FROM THE 3800-MA ISUA SUPRACRUSTAL BELT, WEST GREENLAND [J].

DYMEK, RF ;

KLEIN, C .

PRECAMBRIAN RESEARCH, 1988, 39 (04) :247-302

[8] Carbon isotope evidence for early life [J].

Eiler, JM ;

Mojzsis, SJ ;

Arrhenius, G .

NATURE, 1997, 386 (6626) :665-665

[9] EARLY ARCHEAN GRANULITE-FACIES METAMORPHISM SOUTH OF AMERALIK, WEST GREENLAND [J].

GRIFFIN, WL ;

MCGREGOR, VR ;

NUTMAN, A ;

TAYLOR, PN ;

BRIDGWATER, D .

EARTH AND PLANETARY SCIENCE LETTERS, 1980, 50 (01) :59-74

[10]

Hobbs B.E., 1976, OUTLINE STRUCTURAL G

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