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Enhanced microbial activity in carbon-rich pillow lavas, Ordovician, Great Britain and Ireland

Parnell, John; Boyce, Adrian J.; Brett, Davidheiser Kroll; Brolly, Connor; Bowden, Stephen and Lindgren, Paula LU (2015) In Geology 43(9). p.827-830
Abstract

There is extensive evidence for the microbial colonization of seafloor basalts in the modern ocean and in the geological record. The sulfur isotope composition of pyrite in the basalts commonly indicates marked isotopic fractionation due to microbial sulfate reduction. Sections through the Nemagraptus gracilis zone (Ordovician) in Great Britain and Ireland are characterized by both widespread pillow lavas and organic-rich seafloor sediment, allowing an exceptional opportunity to assess whether the availability of organic carbon influenced the extent of microbial activity in the basalts indeep geological time. Whole-rock data from basalts at 10 localities show that there is a relationship between sulfur isotopic composition and the... (More)

There is extensive evidence for the microbial colonization of seafloor basalts in the modern ocean and in the geological record. The sulfur isotope composition of pyrite in the basalts commonly indicates marked isotopic fractionation due to microbial sulfate reduction. Sections through the Nemagraptus gracilis zone (Ordovician) in Great Britain and Ireland are characterized by both widespread pillow lavas and organic-rich seafloor sediment, allowing an exceptional opportunity to assess whether the availability of organic carbon influenced the extent of microbial activity in the basalts indeep geological time. Whole-rock data from basalts at 10 localities show that there is a relationship between sulfur isotopic composition and the carbon content of the basalt. At two localities where organic carbon was entrained in the basalt, isotopic compositions are heavy compared to compositions in carbon-poor basalt, implying that microbial activity exhausted the supply of seawater sulfate. In most basalt, microbial activity was limited by the supply of carbon, but wherethe basalt incorporated carbon during emplacement on the seafloor, microbial activity became sulfate limited.

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author
publishing date
type
Contribution to journal
publication status
published
subject
in
Geology
volume
43
issue
9
pages
4 pages
publisher
Geological Society of America
external identifiers
  • scopus:84949499945
ISSN
0091-7613
DOI
10.1130/G36937.1
language
English
LU publication?
no
id
c66836ed-a2d8-4fe5-a94e-5044ac173a87
date added to LUP
2017-06-16 15:49:10
date last changed
2018-01-10 17:09:07
@article{c66836ed-a2d8-4fe5-a94e-5044ac173a87,
  abstract     = {<p>There is extensive evidence for the microbial colonization of seafloor basalts in the modern ocean and in the geological record. The sulfur isotope composition of pyrite in the basalts commonly indicates marked isotopic fractionation due to microbial sulfate reduction. Sections through the Nemagraptus gracilis zone (Ordovician) in Great Britain and Ireland are characterized by both widespread pillow lavas and organic-rich seafloor sediment, allowing an exceptional opportunity to assess whether the availability of organic carbon influenced the extent of microbial activity in the basalts indeep geological time. Whole-rock data from basalts at 10 localities show that there is a relationship between sulfur isotopic composition and the carbon content of the basalt. At two localities where organic carbon was entrained in the basalt, isotopic compositions are heavy compared to compositions in carbon-poor basalt, implying that microbial activity exhausted the supply of seawater sulfate. In most basalt, microbial activity was limited by the supply of carbon, but wherethe basalt incorporated carbon during emplacement on the seafloor, microbial activity became sulfate limited.</p>},
  author       = {Parnell, John and Boyce, Adrian J. and Brett, Davidheiser Kroll and Brolly, Connor and Bowden, Stephen and Lindgren, Paula},
  issn         = {0091-7613},
  language     = {eng},
  number       = {9},
  pages        = {827--830},
  publisher    = {Geological Society of America},
  series       = {Geology},
  title        = {Enhanced microbial activity in carbon-rich pillow lavas, Ordovician, Great Britain and Ireland},
  url          = {http://dx.doi.org/10.1130/G36937.1},
  volume       = {43},
  year         = {2015},
}