First Discovery of Dolomite and Magnesite in Living Coralline Algae and its Geobiological Implications

Dolomite is a magnesium rich carbonate mineral abundant in ancient coral reef formations [1-3] yet very little is found forming in modern sedimentary environments. For over 150 years this conundrum has led to various theories being put forward about dolomite formation, however none have solved the so called `Dolomite Problem'[1]. It has generally been considered a post-depositional diagenetic process [2, 3], despite little experimental success at replicating dolomite formation in normal sea water conditions [4]. Here we show dolomite is in fact forming with living crustose coralline algae Hydrolithon onkodes, a species growing prolifically in coral reefs globally. Chemical micro-analysis of the coralline skeleton reveals that not only are the cell walls calcitised, but that the cell spaces are typically filled with magnesite, rimmed by dolomite, or both. Thus there are at least three mineral phases present (magnesium calcite, dolomite and magnesite) rather than one or two (magnesium calcite and brucite) as previously thought[5-7]. Both the magnesium calcite and dolomite phases comprise a continuum of magnesium to calcium compositions, whereas magnesite is near ideal composition. Using a mass balance approach we quantify potential dolomitisation of the coralline algae and can account for the total amount of dolomite found in a raised Pleistocene reef [2]. Our results are consistent with observed dolomites in coralline-algal rich environments in fossil reefs. This is the first time the presence of dolomite in living coralline algae has been confirmed.

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Date (Publication)
2011-01-01T00:00:00
Citation identifier
Geoscience Australia Persistent Identifier/https://pid.geoscience.gov.au/dataset/ga/71635

Cited responsible party
Role Organisation / Individual Name Details
Author

Nash, M.C.

 1
Author

Troitzsch, B.N.

 2
Author

Opdyke, G.N.

 3
Author

Trafford, J.M.

 4
Author

Russell, B.D.

 5
Author

Kline, D.

 6
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ED
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Commonwealth of Australia (Geoscience Australia)
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Commonwealth of Australia (Geoscience Australia)

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Topic category
  • Geoscientific information
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Unknown
Keywords

  • External Publication

  • Scientific Journal Paper

Theme

  • carbonate

Theme

  • geochemistry

Theme

  • marine

Australian and New Zealand Standard Research Classification (ANZSRC)

  • Earth Sciences

Keywords

  • Published_External

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Creative Commons Attribution 4.0 International Licence

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CC-BY

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4.0

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http://creativecommons.org/licenses/

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License

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Australian Government Security ClassificationSystem

Edition date
2018-11-01T00:00:00
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https://www.protectivesecurity.gov.au/Pages/default.aspx

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Unclassified
Language
English
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UTF8

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Commonwealth of Australia (Geoscience Australia)

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OnLine resource

Related Product

View the online abstract in Biogeosciences Vol 8, 2011, pp. 3331-3340

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Unknown

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Non geographic dataset
Other

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Title

Australian Government Security ClassificationSystem

Edition date
2018-11-01T00:00:00
Website

https://www.protectivesecurity.gov.au/Pages/default.aspx

Classification
Unclassified

Metadata

Metadata identifier
urn:uuid/a05f7893-00c5-7506-e044-00144fdd4fa6

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GeoNetwork UUID

Language
English
Character encoding
UTF8
Contact
Role Organisation / Individual Name Details
Point of contact

Commonwealth of Australia (Geoscience Australia)

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Resource scope
Non geographic dataset
Name

nonGeographicDataset

Alternative metadata reference

Title

Geoscience Australia - short identifier for metadata record with

uuid

Citation identifier
eCatId/71635

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https://ecat.ga.gov.au/geonetwork/srv/eng/catalog.search#/metadata/a05f7893-00c5-7506-e044-00144fdd4fa6

Date info (Revision)
2018-04-22T08:31:04
Date info (Creation)
2011-03-29T00:00:00

Metadata standard

Title

AU/NZS ISO 19115-1:2014

Metadata standard

Title

ISO 19115-1:2014

Metadata standard

Title

ISO 19115-3

Title

Geoscience Australia Community Metadata Profile of ISO 19115-1:2014

Edition

Version 2.0, September 2018

Citation identifier
https://pid.geoscience.gov.au/dataset/ga/122551

 
 

Keywords

carbonate geochemistry marine

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