气候变化领域集成服务门户(CCPortal): A review of cretaceous smooth-slopes extensional basins along the Iberia-Eurasia plate boundary: How pre-rift salt controls the modes of continental rifting and mantle exhumation

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DOI	10.1016/j.earscirev.2019.103071
	A review of cretaceous smooth-slopes extensional basins along the Iberia-Eurasia plate boundary: How pre-rift salt controls the modes of continental rifting and mantle exhumation
	Lagabrielle Y.; Asti R.; Duretz T.; Clerc C.; Fourcade S.; Teixell A.; Labaume P.; Corre B.; Saspiturry N.
发表日期	2020
ISSN	00128252
卷号	201
英文摘要	This article points out for the first time a striking correlation between the paleogeography of Upper Triassic deposits and the mode of crustal stretching around and inside the Northern Iberia plate during the Cretaceous transtensional event. First, we propose a review of the architecture of the basins, which opened during the mid-Cretaceous times along the Iberia-Eurasia plate boundary. Similarly to the emblematic Parentis basin, these basins exhibit a peculiar synclinal-shaped profile and are devoid of prominent block faulting. The top of the basement is characterized by gentle slopes, which dip symmetrically toward the center of the basins. As revealed by recent comparisons with geologically-constrained rifting models established from the North Pyrenean Zone, this architecture results from the thinning of a heterogeneous continental crust under greenschist facies conditions. Basement deformations are thus dominantly ductile and are characterized by large-scale boudinage, hyper-thinning and subsequent lateral extraction. Bulk deformation of the upper and middle crust leads to the formation of anastomosed shear zones and the development of mylonitic fabric. Tectonic lenses consisting of crustal material remain welded on top of the exhuming mantle. The common character shared by all the pre-rift sequences of the studied basins is the presence of a thick low-strength Upper Triassic evaporites and clays layer belonging to the Keuper group (i.e. pre-rift salt and clay unit). In the studied basins, efficient décollement along the pre-rift salt and clay unit triggers mechanical decoupling and gliding of the pre-rift cover that remains in the center of the basin. Thus, during the early rifting phase, the basement undergoes thinning while the pre-rift cover remains preserved in the basin center. In response to hyper-thinning and horizontal extraction of the continental crust, hot mantle is exhumed beneath the pre- and syn-rift cover. Subsequent thermal exchange (i) promotes ductile deformation of the basement and (ii) induces the development of HT-LP metamorphic conditions in the pre-rift sediments and at the base of the syn-rift flysch levels. This thermal event is well recorded in the axial portion of the Pyrenean realm (future North Pyrenean Zone) as well as in the pre-rift sediments of the Cameros basin (northern Spain). The architecture of the smooth-slopes type basins thus contrasts with the structure of Iberia-Newfoundland Atlantic margins which are characterized by (i) top-basement detachment faults accommodating crustal extension through rotation and translation of undeformed basement blocks, and (ii) the individualization of continental extensional allochthons tectonically emplaced over exhumed lower crust or mantle rocks. Finally, using recent paleogeographic reconstructions, we show that the distribution of the pre-rift salt and clay unit remarkably matches the distribution of the Pyrenean and peri-Pyrenean smooth-slopes type basins. This allows for the first time to propose a genetic link between the distribution of evaporite-bearing pre-rift sedimentary formations and the development of smooth-slopes basins. © 2019
关键词	Dominating-ductile tectonic regime Décollement layer Eurasia Iberia Sedimentary burial Smooth-slopes basins Symmetrical profile Thermal anomaly Triassic evaporites
英文关键词	Cretaceous; Eurasian plate; evaporite; exhumation; extensional tectonics; mantle structure; plate boundary; rifting; salt; temperature anomaly; Triassic
语种	英语
来源期刊	Earth Science Reviews
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/203769
作者单位	Université de Rennes, CNRS, UMR 6118 Géosciences Rennes, Campus de Beaulieu, Rennes, 35000, France; ISEA, Université de la Nouvelle Calédonie, Nouméa, 98800, New Caledonia; Géosciences Montpellier, CNRS-Université de Montpellier-Université des Antilles, Montpellier, 34095, France; Dept. de Geologia, Universitat Autònoma de Barcelona, Bellaterra, 08193, Spain; EA4592 Géoressources & Environnement, Bordeaux INP, Université Bordeaux Montaigne, 1 Allée Daguin, Pessac, 33607, France
推荐引用方式 GB/T 7714	Lagabrielle Y.,Asti R.,Duretz T.,et al. A review of cretaceous smooth-slopes extensional basins along the Iberia-Eurasia plate boundary: How pre-rift salt controls the modes of continental rifting and mantle exhumation[J],2020,201.
APA	Lagabrielle Y..,Asti R..,Duretz T..,Clerc C..,Fourcade S..,...&Saspiturry N..(2020).A review of cretaceous smooth-slopes extensional basins along the Iberia-Eurasia plate boundary: How pre-rift salt controls the modes of continental rifting and mantle exhumation.Earth Science Reviews,201.
MLA	Lagabrielle Y.,et al."A review of cretaceous smooth-slopes extensional basins along the Iberia-Eurasia plate boundary: How pre-rift salt controls the modes of continental rifting and mantle exhumation".Earth Science Reviews 201(2020).