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dc.contributor.authorCawood, Peter Anthony
dc.contributor.authorHawkesworth, Chris
dc.identifier.citationCawood , P A & Hawkesworth , C 2014 , ' Earth's middle age ' , Geology , vol. 42 , no. 6 , pp. 503-506 .
dc.identifier.otherPURE: 110579489
dc.identifier.otherPURE UUID: 094169d2-43cc-4692-a15a-496e78adae9c
dc.identifier.otherScopus: 84902122156
dc.identifier.otherWOS: 000339961100013
dc.descriptionThis research was funded through Natural Environment Research Council (grant NE/J021822/1) and the APC was paid through the RCUK OA block grant.en
dc.description.abstractEarth's middle age, extending from 1.7 to 0.75 Ga, was characterized by environmental, evolutionary, and lithospheric stability that contrasts with the dramatic changes in preceding and succeeding eras. The period is marked by a paucity of preserved passive margins, an absence of a significant Sr anomaly in the paleoseawater record and in the εHf(t) in detrital zircon, a lack of orogenic gold and volcanic-hosted massive sulfide deposits, and an absence of glacial deposits and iron formations. In contrast, anorthosites and kindred bodies are well developed and major pulses of Mo and Cu mineralization, including the world's largest examples of these deposits, are features of this period. These trends are attributed to a relatively stable continental assemblage that was initiated during assembly of the Nuna supercontinent by ca. 1.7 Ga and continued until breakup of its closely related successor, Rodinia, ca. 0.75 Ga. The overall low abundance of passive margins is consistent with a stable continental configuration, which also provided a framework for environmental and evolutionary stability. A series of convergent margin accretionary orogens developed along the edge of the supercontinent. Abundant anorthosites and related rocks developed inboard of the plate margin. Their temporal distribution appears to link with the secular cooling of the mantle, at which time the overlying continental lithosphere was strong enough to be thickened and to support the emplacement of large plutons into the crust, yet the underlying mantle was still warm enough to result in widespread melting of the lower thickened crust.
dc.rights© 2014 Geological Society of America. This is an Open Access paper published under the terms of the CC-BY license.en
dc.subjectNuna supercontinenten
dc.subjectStable continental configurationen
dc.subjectAccretionary orogensen
dc.subjectGeological stabilityen
dc.subjectContinental lithosphereen
dc.subjectPassive marginsen
dc.subjectQE Geologyen
dc.titleEarth's middle ageen
dc.typeJournal articleen
dc.description.versionPublisher PDFen
dc.contributor.institutionUniversity of St Andrews.School of Earth & Environmental Sciencesen
dc.contributor.institutionUniversity of St Andrews.Scottish Oceans Instituteen
dc.contributor.institutionUniversity of St Andrews.Earth and Environmental Sciencesen
dc.contributor.institutionUniversity of St Andrews.St Andrews Isotope Geochemistryen
dc.contributor.institutionUniversity of St Andrews.Office of the Principalen
dc.description.statusPeer revieweden

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