气候变化领域集成服务门户(CCPortal): Early Ordovician to Early Devonian tectonic development of the northern margin of Laurentia, Canadian Arctic Islands

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DOI	10.1130/B35017.1
	Early Ordovician to Early Devonian tectonic development of the northern margin of Laurentia, Canadian Arctic Islands
	Dewing K.; Hadlari T.; Pearson D.G.; Matthews W.
发表日期	2019
ISSN	167606
起始页码	1075
结束页码	1094
卷号	131 期号:2021-07-08
英文摘要	Three tectonic events affected the northern margin of Laurentia between Early Ordovician and Early Devonian time. Each tectonic cycle started with an unconformity followed by rapid subsidence and an influx of clastic material, then decreasing sediment accumulation rates. The first cycle extends from the Tremadoc to late Katian (480-448 Ma), the second from late Katian to Ludlow (448- 426 Ma), and the third from Ludlow to Lochkovian (426-410 Ma). A strong geodynamic link is interpreted between the first two sedimentary cycles and tectonic events on the composite Pearya terrane on northern Ellesmere Island, Nunavut, Canada. The first cycle is interpreted as a response to crustal thickening caused by the M'Clintock Orogeny on Pearya terrane and onset of subduction dipping under Laurentia. An extensive Middle Ordovician (Darriwillian) unconformity is not associated with a change in subsidence rate or a change of facies above and below, but is normally faulted. It is interpreted as a migrating forebulge or increase in crustal buoyancy due to breakoff of a subduction slab. The second cycle is synchronous with a Late Ordovician minor faulting event on Pearya terrane and volcanic units in the deep water basin between Pearya terrane and the carbonate platform. A major platform margin stepback, along with a positive εNd shift are associated with the late Katian Irene Bay Formation. The event also introduced numerous organisms of Siberian affinity into northern Laurentia. The third cycle, starting in Ludlow time is related to the onset of deformation in the Boothia foldbelt and is not recorded as a deformational event on Pearya terrane. The presence of aerially restricted intraplatform basins that are interpreted to be synchronous with, and caused by, tectonic events on Pearya terrane implies that it was close to its current location by Early Ordovician time. © 2019 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/184944
作者单位	Geological Survey of Canada, 3303-33rd St NW, Calgary, AB T2L 2A7, Canada; Earth and Atmospheric Sciences, University of Alberta, Edmonton, AB T6G 2E3, Canada; Department of Geoscience, University of Calgary, 2500 University Dr. NW, Calgary, AB T2N 1N4, Canada
推荐引用方式 GB/T 7714	Dewing K.,Hadlari T.,Pearson D.G.,et al. Early Ordovician to Early Devonian tectonic development of the northern margin of Laurentia, Canadian Arctic Islands[J],2019,131(2021-07-08).
APA	Dewing K.,Hadlari T.,Pearson D.G.,&Matthews W..(2019).Early Ordovician to Early Devonian tectonic development of the northern margin of Laurentia, Canadian Arctic Islands.Bulletin of the Geological Society of America,131(2021-07-08).
MLA	Dewing K.,et al."Early Ordovician to Early Devonian tectonic development of the northern margin of Laurentia, Canadian Arctic Islands".Bulletin of the Geological Society of America 131.2021-07-08(2019).