Calcification by amorphous carbonate precursors: Towards a new paradigm for sedimentary and skeletal mineralization

dc.contributor.authorWang, Dongboen
dc.contributor.committeechairDove, Patricia M.en
dc.contributor.committeememberDe Yoreo, James J.en
dc.contributor.committeememberRead, James Fredricken
dc.contributor.committeememberHochella, Michael F. Jr.en
dc.contributor.committeememberRimstidt, J. Donalden
dc.contributor.departmentGeosciencesen
dc.date.accessioned2017-04-06T15:44:21Zen
dc.date.adate2011-01-11en
dc.date.available2017-04-06T15:44:21Zen
dc.date.issued2010-11-29en
dc.date.rdate2016-10-18en
dc.date.sdate2010-12-08en
dc.description.abstractA new paradigm for the formation of calcified skeletons suggests mineralization proceeds through amorphous calcium carbonate (ACC) precursors. The implications of this strategy in carbonate crystallization are widespread, particularly for understanding factors controlling impurity and isotopic signatures in calcium carbonates. The first chapter is a literature review of the biomineralization processes used by two important model organisms: the sea urchin larva and the foraminifera. Sea urchin larvae provide a thoroughly studied example of mineralization by an ACC pathway that is under biological control through regulation of protein chemistry and the local mineralization environment. A review of how foraminifera produce their test structures is also examined to explore the question of how organisms regulate the Mg content in proportion to the temperature their environments of formation. The second chapter demonstrates that acidic biomolecules regulate the composition of ACC for a suite of model carboxylated molecules. The physical basis for the systematic trend in Mg content is related to the ability of the affinity of the biomolecule for binding Ca versus Mg. The third chapter builds on these findings to explore the transformation of Mg-rich ACC precursors to calcites of exceptionally high Mg-contents that could not be produced by classical step-dominated growth processes. The data indicate that these materials are likely a result of a nucleation-dominated pathway. The final, fourth chapter develops Raman spectroscopy-based calibrations for determining Mg contents in ACC. The calibrations are based upon peak position or peak width of the carbonate υ₁ stretch.en
dc.description.degreePh. D.en
dc.identifier.otheretd-12082010-133103en
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-12082010-133103/en
dc.identifier.urihttp://hdl.handle.net/10919/77271en
dc.language.isoen_USen
dc.publisherVirginia Techen
dc.rightsIn Copyrighten
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/en
dc.subjectACCen
dc.subjectdolomiteen
dc.subjectaragoniteen
dc.subjectcalcium carbonateen
dc.subjectnucleationen
dc.titleCalcification by amorphous carbonate precursors: Towards a new paradigm for sedimentary and skeletal mineralizationen
dc.typeDissertationen
dc.type.dcmitypeTexten
thesis.degree.disciplineGeosciencesen
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen
thesis.degree.leveldoctoralen
thesis.degree.namePh. D.en
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