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DOI	10.1130/B31826.1
	Two-sided accretion and polyphase metamorphism in the Haast Schist belt, New Zealand: Constraints from detrital zircon geochronology
	Cooper A.F.; Palin J.M.
发表日期	2018
ISSN	167606
起始页码	1501
结束页码	1518
卷号	130 期号:2021-09-10
英文摘要	The Haast Schist of South Island, New Zealand, consisting of the Otago, Alpine, and Marlborough Schist components, is the most deeply buried and strongly metamorphosed part of an accretionary complex above a westward-dipping subduction zone on the eastern margin of Gondwana. Conventional wisdom is that the schist formed in the Jurassic (ca. 170 Ma) by collision between Carboniferous to Triassic graywacke sequences of the exotic eastern Torlesse composite terrane and the western Caples terrane. However, extensive areas of Alpine Schist in the west, rich in metabasite, and in part overlying a metamorphosed ophiolitic sequence, have anomalously young, mid-Cretaceous, ca. 108 Ma, detrital zircon ages. Their deposition and subsequent deformation occurred approximately synchronous with the cessation of westward-directed subduction in the Eastern Province of New Zealand, the onset of regional extension, and deposition of terrestrial and volcanic sediments on the exhumed erosion surface of the eastern schist basement. These Cretaceous schist protoliths are interpreted to form the exotic Pounamu terrane, accreted and interfolded with Otago Schist on the western margin of the Haast Schist. The Alpine Schist metamorphism is dated from zircon overgrowths on detrital grains at ca. 70 Ma (although over an extended period, 98-64 Ma, regionally). This thermal event is unknown further east. The Haast Schist is therefore a polygenetic unit formed by the amalgamation of metamorphic components accreted from both the east and west sides of the SE Zealandia microplate. Existence of the Pounamu terrane requires a major revision to the Cretaceous tectonic history of southern New Zealand. © 2018 Geological Society of America.
语种	英语
来源期刊	Bulletin of the Geological Society of America
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/185089
作者单位	Geology Department, University of Otago, P.O. Box 56, Dunedin, 9054, New Zealand
推荐引用方式 GB/T 7714	Cooper A.F.,Palin J.M.. Two-sided accretion and polyphase metamorphism in the Haast Schist belt, New Zealand: Constraints from detrital zircon geochronology[J],2018,130(2021-09-10).
APA	Cooper A.F.,&Palin J.M..(2018).Two-sided accretion and polyphase metamorphism in the Haast Schist belt, New Zealand: Constraints from detrital zircon geochronology.Bulletin of the Geological Society of America,130(2021-09-10).
MLA	Cooper A.F.,et al."Two-sided accretion and polyphase metamorphism in the Haast Schist belt, New Zealand: Constraints from detrital zircon geochronology".Bulletin of the Geological Society of America 130.2021-09-10(2018).