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4.6-billion-year-old aragonite and its implications for understanding the geological record of Ca-carbonate

Lee, Martin R. and Lindgren, Paula LU (2015) In Carbonates and Evaporites 30(4). p.477-481
Abstract

Owing to its diagenetic instability, aragonite is rare in the geological record and almost entirely absent from pre-carboniferous sedimentary rocks. The former presence of this mineral in older deposits has to be inferred from petrographic, chemical or isotopic proxies. Crystals of aragonite that formed around 4563 million years ago occur in carbonaceous chondrite meteorites, showing that under certain conditions, the orthorhombic polymorph of Ca-carbonate can survive essentially indefinitely. Together with other carbonate minerals, phyllosilicates and sulphides, this aragonite formed by low-temperature water-mediated alteration of anhydrous minerals and glass in the interior of the meteorite’s parent asteroid(s). The survival of... (More)

Owing to its diagenetic instability, aragonite is rare in the geological record and almost entirely absent from pre-carboniferous sedimentary rocks. The former presence of this mineral in older deposits has to be inferred from petrographic, chemical or isotopic proxies. Crystals of aragonite that formed around 4563 million years ago occur in carbonaceous chondrite meteorites, showing that under certain conditions, the orthorhombic polymorph of Ca-carbonate can survive essentially indefinitely. Together with other carbonate minerals, phyllosilicates and sulphides, this aragonite formed by low-temperature water-mediated alteration of anhydrous minerals and glass in the interior of the meteorite’s parent asteroid(s). The survival of aragonite for such a long time can be attributed to the loss of free water by its incorporation into phyllosilicates, and to the very low permeability of the fine-grained and organic-rich rock matrix that prevented the ingress of fresh solutions via intergranular flow. By analogy with these meteorites, terrestrial aragonite is likely to survive where it has been similarly isolated from liquid water, particularly in organic-rich mudrocks, and such deposits may provide important new evidence for deducing the original mineralogy of skeletal and non-skeletal carbonates in deep-time.

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author
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Aragonite, Carbonaceous chondrites, Marine mudrocks
in
Carbonates and Evaporites
volume
30
issue
4
pages
5 pages
publisher
Springer Heidelberg
external identifiers
  • scopus:84947491231
ISSN
0891-2556
DOI
10.1007/s13146-015-0257-2
language
English
LU publication?
no
id
fb3de988-9eb3-4597-84c4-b99033d040e4
date added to LUP
2017-06-26 10:20:12
date last changed
2018-01-10 17:10:32
@article{fb3de988-9eb3-4597-84c4-b99033d040e4,
  abstract     = {<p>Owing to its diagenetic instability, aragonite is rare in the geological record and almost entirely absent from pre-carboniferous sedimentary rocks. The former presence of this mineral in older deposits has to be inferred from petrographic, chemical or isotopic proxies. Crystals of aragonite that formed around 4563 million years ago occur in carbonaceous chondrite meteorites, showing that under certain conditions, the orthorhombic polymorph of Ca-carbonate can survive essentially indefinitely. Together with other carbonate minerals, phyllosilicates and sulphides, this aragonite formed by low-temperature water-mediated alteration of anhydrous minerals and glass in the interior of the meteorite’s parent asteroid(s). The survival of aragonite for such a long time can be attributed to the loss of free water by its incorporation into phyllosilicates, and to the very low permeability of the fine-grained and organic-rich rock matrix that prevented the ingress of fresh solutions via intergranular flow. By analogy with these meteorites, terrestrial aragonite is likely to survive where it has been similarly isolated from liquid water, particularly in organic-rich mudrocks, and such deposits may provide important new evidence for deducing the original mineralogy of skeletal and non-skeletal carbonates in deep-time.</p>},
  author       = {Lee, Martin R. and Lindgren, Paula},
  issn         = {0891-2556},
  keyword      = {Aragonite,Carbonaceous chondrites,Marine mudrocks},
  language     = {eng},
  month        = {12},
  number       = {4},
  pages        = {477--481},
  publisher    = {Springer Heidelberg},
  series       = {Carbonates and Evaporites},
  title        = {4.6-billion-year-old aragonite and its implications for understanding the geological record of Ca-carbonate},
  url          = {http://dx.doi.org/10.1007/s13146-015-0257-2},
  volume       = {30},
  year         = {2015},
}