In situ iron isotope analyses of pyrite and organic carbon isotope ratios in the Fortescue Group: Metabolic variations of a Late Archean ecosystem

Kazumi Yoshiya, Manabu Nishizawa, Yusuke Sawaki, Yuichiro Ueno, Tsuyoshi Komiya, Keita Yamada, Naohiro Yoshida, Takafumi Hirata, Hideki Wada, Shigenori Maruyama

Research output: Contribution to journalArticle

26 Citations (Scopus)

Abstract

The biogeochemical cycle of the Late Archean ocean is important for understanding the relationships between biological activity and oxygenation of the atmosphere and ocean. Based on the detailed geological survey of the Fortescue Group in the Redmont area in Pilbara Craton, Western Australia, we carefully selected 44 samples for iron isotope analyses, which consist of sandstones, stromatolitic carbonate rocks, alternating mudstone/sandstone rocks, mudstones and cherts. Our in situ analyses of δ 56Fe values of 210 pyrite grains in these samples show a large variation from -4.2‰ to +3.0‰. We also analyzed 128 and 40 carbon isotope compositions of organic (δ 13C org: -51.8 to -10.3‰) and inorganic (δ 13C carb: -6.1 to 0.6‰) carbons, respectively. Microscopic observations show obvious relationships between pyrite grain morphology and iron isotope ratio. Most pyrite grains with positive δ 56Fe values show hexagonal, rectangular, and parallelogram shapes, which may replace former iron-oxide crystal systems: hematite, magnetite, and goethite, respectively. In contrast, more than half the pyrite grains with negative δ 56Fe values show irregular forms. The correlation allows the possibility to solve the origin and the formation process of each grain of pyrite. The positive δ 56Fe values suggest the partial oxidation of iron in an oxygen-limited environment. Some pyrites show very lower δ 56Fe values below -2.2‰ suggesting a biological origin, probably due to microbial iron reduction. On the other hand, the pyrite is accompanied by isotopically very light organic carbon (δ 13C org: -51.8‰ to -40‰), which indicates aerobic or anaerobic methanotrophy. The coexistence of the low δ 56Fe values and low δ 13C values in the some rocks suggests anoxic oxidation of methane by iron-reduction (AOM/IR). The iron and carbon isotopes demonstrate the metabolic variations of microorganisms in a Late Archean shallow marine environment.

Original languageEnglish
Pages (from-to)169-193
Number of pages25
JournalPrecambrian Research
Volume212-213
DOIs
Publication statusPublished - Aug 2012
Externally publishedYes

Fingerprint

Iron Isotopes
Carbon Isotopes
carbon isotope ratio
Organic carbon
Ecosystems
Archean
pyrite
organic carbon
isotope
iron
ecosystem
Iron
Rocks
Sandstone
mudstone
carbon isotope
methanotrophy
sandstone
Ferrosoferric Oxide
oxidation

Keywords

  • Anaerobic methanotrophy
  • Archean
  • Carbon isotope
  • Iron isotope
  • Microbial iron reduction

ASJC Scopus subject areas

  • Geochemistry and Petrology
  • Geology

Cite this

In situ iron isotope analyses of pyrite and organic carbon isotope ratios in the Fortescue Group : Metabolic variations of a Late Archean ecosystem. / Yoshiya, Kazumi; Nishizawa, Manabu; Sawaki, Yusuke; Ueno, Yuichiro; Komiya, Tsuyoshi; Yamada, Keita; Yoshida, Naohiro; Hirata, Takafumi; Wada, Hideki; Maruyama, Shigenori.

In: Precambrian Research, Vol. 212-213, 08.2012, p. 169-193.

Research output: Contribution to journalArticle

Yoshiya, K, Nishizawa, M, Sawaki, Y, Ueno, Y, Komiya, T, Yamada, K, Yoshida, N, Hirata, T, Wada, H & Maruyama, S 2012, 'In situ iron isotope analyses of pyrite and organic carbon isotope ratios in the Fortescue Group: Metabolic variations of a Late Archean ecosystem', Precambrian Research, vol. 212-213, pp. 169-193. https://doi.org/10.1016/j.precamres.2012.05.003
Yoshiya, Kazumi ; Nishizawa, Manabu ; Sawaki, Yusuke ; Ueno, Yuichiro ; Komiya, Tsuyoshi ; Yamada, Keita ; Yoshida, Naohiro ; Hirata, Takafumi ; Wada, Hideki ; Maruyama, Shigenori. / In situ iron isotope analyses of pyrite and organic carbon isotope ratios in the Fortescue Group : Metabolic variations of a Late Archean ecosystem. In: Precambrian Research. 2012 ; Vol. 212-213. pp. 169-193.
@article{6658fbb911a740d597a435126f727520,
title = "In situ iron isotope analyses of pyrite and organic carbon isotope ratios in the Fortescue Group: Metabolic variations of a Late Archean ecosystem",
abstract = "The biogeochemical cycle of the Late Archean ocean is important for understanding the relationships between biological activity and oxygenation of the atmosphere and ocean. Based on the detailed geological survey of the Fortescue Group in the Redmont area in Pilbara Craton, Western Australia, we carefully selected 44 samples for iron isotope analyses, which consist of sandstones, stromatolitic carbonate rocks, alternating mudstone/sandstone rocks, mudstones and cherts. Our in situ analyses of δ 56Fe values of 210 pyrite grains in these samples show a large variation from -4.2‰ to +3.0‰. We also analyzed 128 and 40 carbon isotope compositions of organic (δ 13C org: -51.8 to -10.3‰) and inorganic (δ 13C carb: -6.1 to 0.6‰) carbons, respectively. Microscopic observations show obvious relationships between pyrite grain morphology and iron isotope ratio. Most pyrite grains with positive δ 56Fe values show hexagonal, rectangular, and parallelogram shapes, which may replace former iron-oxide crystal systems: hematite, magnetite, and goethite, respectively. In contrast, more than half the pyrite grains with negative δ 56Fe values show irregular forms. The correlation allows the possibility to solve the origin and the formation process of each grain of pyrite. The positive δ 56Fe values suggest the partial oxidation of iron in an oxygen-limited environment. Some pyrites show very lower δ 56Fe values below -2.2‰ suggesting a biological origin, probably due to microbial iron reduction. On the other hand, the pyrite is accompanied by isotopically very light organic carbon (δ 13C org: -51.8‰ to -40‰), which indicates aerobic or anaerobic methanotrophy. The coexistence of the low δ 56Fe values and low δ 13C values in the some rocks suggests anoxic oxidation of methane by iron-reduction (AOM/IR). The iron and carbon isotopes demonstrate the metabolic variations of microorganisms in a Late Archean shallow marine environment.",
keywords = "Anaerobic methanotrophy, Archean, Carbon isotope, Iron isotope, Microbial iron reduction",
author = "Kazumi Yoshiya and Manabu Nishizawa and Yusuke Sawaki and Yuichiro Ueno and Tsuyoshi Komiya and Keita Yamada and Naohiro Yoshida and Takafumi Hirata and Hideki Wada and Shigenori Maruyama",
year = "2012",
month = "8",
doi = "10.1016/j.precamres.2012.05.003",
language = "English",
volume = "212-213",
pages = "169--193",
journal = "Precambrian Research",
issn = "0301-9268",
publisher = "Elsevier",

}

TY - JOUR

T1 - In situ iron isotope analyses of pyrite and organic carbon isotope ratios in the Fortescue Group

T2 - Metabolic variations of a Late Archean ecosystem

AU - Yoshiya, Kazumi

AU - Nishizawa, Manabu

AU - Sawaki, Yusuke

AU - Ueno, Yuichiro

AU - Komiya, Tsuyoshi

AU - Yamada, Keita

AU - Yoshida, Naohiro

AU - Hirata, Takafumi

AU - Wada, Hideki

AU - Maruyama, Shigenori

PY - 2012/8

Y1 - 2012/8

N2 - The biogeochemical cycle of the Late Archean ocean is important for understanding the relationships between biological activity and oxygenation of the atmosphere and ocean. Based on the detailed geological survey of the Fortescue Group in the Redmont area in Pilbara Craton, Western Australia, we carefully selected 44 samples for iron isotope analyses, which consist of sandstones, stromatolitic carbonate rocks, alternating mudstone/sandstone rocks, mudstones and cherts. Our in situ analyses of δ 56Fe values of 210 pyrite grains in these samples show a large variation from -4.2‰ to +3.0‰. We also analyzed 128 and 40 carbon isotope compositions of organic (δ 13C org: -51.8 to -10.3‰) and inorganic (δ 13C carb: -6.1 to 0.6‰) carbons, respectively. Microscopic observations show obvious relationships between pyrite grain morphology and iron isotope ratio. Most pyrite grains with positive δ 56Fe values show hexagonal, rectangular, and parallelogram shapes, which may replace former iron-oxide crystal systems: hematite, magnetite, and goethite, respectively. In contrast, more than half the pyrite grains with negative δ 56Fe values show irregular forms. The correlation allows the possibility to solve the origin and the formation process of each grain of pyrite. The positive δ 56Fe values suggest the partial oxidation of iron in an oxygen-limited environment. Some pyrites show very lower δ 56Fe values below -2.2‰ suggesting a biological origin, probably due to microbial iron reduction. On the other hand, the pyrite is accompanied by isotopically very light organic carbon (δ 13C org: -51.8‰ to -40‰), which indicates aerobic or anaerobic methanotrophy. The coexistence of the low δ 56Fe values and low δ 13C values in the some rocks suggests anoxic oxidation of methane by iron-reduction (AOM/IR). The iron and carbon isotopes demonstrate the metabolic variations of microorganisms in a Late Archean shallow marine environment.

AB - The biogeochemical cycle of the Late Archean ocean is important for understanding the relationships between biological activity and oxygenation of the atmosphere and ocean. Based on the detailed geological survey of the Fortescue Group in the Redmont area in Pilbara Craton, Western Australia, we carefully selected 44 samples for iron isotope analyses, which consist of sandstones, stromatolitic carbonate rocks, alternating mudstone/sandstone rocks, mudstones and cherts. Our in situ analyses of δ 56Fe values of 210 pyrite grains in these samples show a large variation from -4.2‰ to +3.0‰. We also analyzed 128 and 40 carbon isotope compositions of organic (δ 13C org: -51.8 to -10.3‰) and inorganic (δ 13C carb: -6.1 to 0.6‰) carbons, respectively. Microscopic observations show obvious relationships between pyrite grain morphology and iron isotope ratio. Most pyrite grains with positive δ 56Fe values show hexagonal, rectangular, and parallelogram shapes, which may replace former iron-oxide crystal systems: hematite, magnetite, and goethite, respectively. In contrast, more than half the pyrite grains with negative δ 56Fe values show irregular forms. The correlation allows the possibility to solve the origin and the formation process of each grain of pyrite. The positive δ 56Fe values suggest the partial oxidation of iron in an oxygen-limited environment. Some pyrites show very lower δ 56Fe values below -2.2‰ suggesting a biological origin, probably due to microbial iron reduction. On the other hand, the pyrite is accompanied by isotopically very light organic carbon (δ 13C org: -51.8‰ to -40‰), which indicates aerobic or anaerobic methanotrophy. The coexistence of the low δ 56Fe values and low δ 13C values in the some rocks suggests anoxic oxidation of methane by iron-reduction (AOM/IR). The iron and carbon isotopes demonstrate the metabolic variations of microorganisms in a Late Archean shallow marine environment.

KW - Anaerobic methanotrophy

KW - Archean

KW - Carbon isotope

KW - Iron isotope

KW - Microbial iron reduction

UR - http://www.scopus.com/inward/record.url?scp=84861835369&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84861835369&partnerID=8YFLogxK

U2 - 10.1016/j.precamres.2012.05.003

DO - 10.1016/j.precamres.2012.05.003

M3 - Article

AN - SCOPUS:84861835369

VL - 212-213

SP - 169

EP - 193

JO - Precambrian Research

JF - Precambrian Research

SN - 0301-9268

ER -