Skip navigation
Skip navigation

First discovery of dolomite and magnesite in living coralline algae and its geobiological implications

Nash, Merinda; Troitzsch, Ulrike; Opdyke, Bradley; Trafford, J.M.; Russell, B.D.; Kline, D.I.

Description

Dolomite is a magnesium-rich carbonate mineral abundant in fossil carbonate reef platforms but surprisingly rare in modern sedimentary environments, a conundrum known as the "Dolomite Problem". Marine sedimentary dolomite has been interpreted to form by an unconfirmed, post-depositional diagenetic process, despite minimal experimental success at replicating this. Here we show that dolomite, accompanied by magnesite, forms within living crustose coralline alga, Hydrolithon onkodes, a prolific...[Show more]

dc.contributor.authorNash, Merinda
dc.contributor.authorTroitzsch, Ulrike
dc.contributor.authorOpdyke, Bradley
dc.contributor.authorTrafford, J.M.
dc.contributor.authorRussell, B.D.
dc.contributor.authorKline, D.I.
dc.date.accessioned2015-12-10T22:22:19Z
dc.identifier.issn1726-4170
dc.identifier.urihttp://hdl.handle.net/1885/52626
dc.description.abstractDolomite is a magnesium-rich carbonate mineral abundant in fossil carbonate reef platforms but surprisingly rare in modern sedimentary environments, a conundrum known as the "Dolomite Problem". Marine sedimentary dolomite has been interpreted to form by an unconfirmed, post-depositional diagenetic process, despite minimal experimental success at replicating this. Here we show that dolomite, accompanied by magnesite, forms within living crustose coralline alga, Hydrolithon onkodes, a prolific global tropical reef species. Chemical micro-analysis of the coralline skeleton reveals that not only are the cell walls calcitised, but that cell spaces are typically filled with magnesite, rimmed by dolomite, or both. Mineralogy was confirmed by X-ray Diffraction. 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. Our results are consistent with dolomite occurrences in coralline algae rich environments in fossil reefs of the last 60 million years. We reveal that the standard method of removing organic material prior to Xray Diffraction analysis can result in a decrease in the most obvious dolomite and magnesite diffraction patterns and this may explain why the abundant protodolomite and magnesite discovered in this study has not previously been recognized. This discovery of dolomite in living coralline algae extends the range of palaeo-environments for which biologically initiated dolomite can be considered a possible source of primary dolomite.
dc.publisherCopernicus GmbH
dc.rightsAuthor/s retain copyright
dc.sourceBiogeosciences
dc.subjectKeywords: carbonate; coralline alga; dolomite; fossil record; magnesite; mineral; mineralogy; paleoenvironment; reef; skeleton; X-ray diffraction; algae; Hydrolithon onkodes
dc.titleFirst discovery of dolomite and magnesite in living coralline algae and its geobiological implications
dc.typeJournal article
local.description.notesImported from ARIES
local.identifier.citationvolume8
dc.date.issued2011
local.identifier.absfor040305 - Marine Geoscience
local.identifier.absfor040310 - Sedimentology
local.identifier.ariespublicationu4047674xPUB251
local.type.statusPublished Version
local.contributor.affiliationNash, Merinda, College of Physical and Mathematical Sciences, ANU
local.contributor.affiliationTroitzsch, Ulrike, College of Physical and Mathematical Sciences, ANU
local.contributor.affiliationOpdyke, Bradley, College of Physical and Mathematical Sciences, ANU
local.contributor.affiliationTrafford, J.M., Geoscience Australia
local.contributor.affiliationRussell, B.D., University of Adelaide
local.contributor.affiliationKline, D.I., University of California, San Diego
local.bibliographicCitation.issue11
local.bibliographicCitation.startpage3331
local.bibliographicCitation.lastpage3340
local.identifier.doi10.5194/bg-8-3331-2011
local.identifier.absseo961104 - Physical and Chemical Conditions of Water in Marine Environments
dc.date.updated2016-02-24T10:32:26Z
local.identifier.scopusID2-s2.0-81355135176
local.identifier.thomsonID000298132200015
dcterms.accessRightsOpen Access
CollectionsANU Research Publications

Download

File Description SizeFormat Image
01_Nash_First_discovery_of_dolomite_2011.pdf2.31 MBAdobe PDF


Items in Open Research are protected by copyright, with all rights reserved, unless otherwise indicated.

Updated:  19 May 2020/ Responsible Officer:  University Librarian/ Page Contact:  Library Systems & Web Coordinator