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dc.contributor.authorCawood, Peter Anthony
dc.contributor.authorHawkesworth, Chris
dc.contributor.authorDhuime, Bruno Philippe Marcel
dc.date.accessioned2013-05-30T12:01:02Z
dc.date.available2013-05-30T12:01:02Z
dc.date.issued2013-01
dc.identifier.citationCawood , P A , Hawkesworth , C & Dhuime , B P M 2013 , ' The continental record and the generation of continental crust ' , Geological Society of America Bulletin , vol. 125 , no. 1-2 , pp. 14-32 . https://doi.org/10.1130/B30722.1en
dc.identifier.issn0016-7606
dc.identifier.otherPURE: 42242437
dc.identifier.otherPURE UUID: 09171e7a-0fd4-40cf-87f3-a0540b96b95b
dc.identifier.otherWOS: 000313133800002
dc.identifier.otherScopus: 84872291859
dc.identifier.urihttp://hdl.handle.net/10023/3576
dc.description.abstractContinental crust is the archive of Earth history. The spatial and temporal distribution of Earth's record of rock units and events is heterogeneous; for example, ages of igneous crystallization, metamorphism, continental margins, mineralization, and seawater and atmospheric proxies are distributed about a series of peaks and troughs. This distribution reflects the different preservation potential of rocks generated in different tectonic settings, rather than fundamental pulses of activity, and the peaks of ages are linked to the timing of supercontinent assembly. The physio-chemical resilience of zircons and their derivation largely from felsic igneous rocks means that they are important indicators of the crustal record. Furthermore, detrital zircons, which sample a range of source rocks, provide a more representative record than direct analysis of grains in igneous rocks. Analysis of detrital zircons suggests that at least ∼60%–70% of the present volume of the continental crust had been generated by 3 Ga. Such estimates seek to take account of the extent to which the old crustal material is underrepresented in the sedimentary record, and they imply that there were greater volumes of continental crust in the Archean than might be inferred from the compositions of detrital zircons and sediments. The growth of continental crust was a continuous rather than an episodic process, but there was a marked decrease in the rate of crustal growth at ca. 3 Ga, which may have been linked to the onset of significant crustal recycling, probably through subduction at convergent plate margins. The Hadean and Early Archean continental record is poorly preserved and characterized by a bimodal TTG (tonalites, trondhjemites, and granodiorites) and greenstone association that differs from the younger record that can be more directly related to a plate-tectonic regime. The paucity of this early record has led to competing and equivocal models invoking plate-tectonic– and mantle-plume–dominated processes. The 60%–70% of the present volume of the continental crust estimated to have been present at 3 Ga contrasts markedly with the <10% of crust of that age apparently still preserved and requires ongoing destruction (recycling) of crust and subcontinental mantle lithosphere back into the mantle through processes such as subduction and delamination.
dc.language.isoeng
dc.relation.ispartofGeological Society of America Bulletinen
dc.rights© 2013 Geological Society of America. This is an open access article published under a Creative Commons Attribution license.en
dc.subjectQE Geologyen
dc.subject.lccQEen
dc.titleThe continental record and the generation of continental crusten
dc.typeJournal articleen
dc.description.versionPublisher PDFen
dc.contributor.institutionUniversity of St Andrews.Earth and Environmental Sciencesen
dc.contributor.institutionUniversity of St Andrews.Scottish Oceans Instituteen
dc.contributor.institutionUniversity of St Andrews.Office of the Principalen
dc.contributor.institutionUniversity of St Andrews.St Andrews Isotope Geochemistryen
dc.identifier.doihttps://doi.org/10.1130/B30722.1
dc.description.statusPeer revieweden


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