DOI: 10.1016/j.palaeo.2014.11.008
论文题名: Three successive phases of platform demise during the early Aptian and their association with the oceanic anoxic Selli episode (Ardèche, France)
作者: Pictet A. ; Delanoy G. ; Adatte T. ; Spangenberg J.E. ; Baudouin C. ; Boselli P. ; Boselli M. ; Kindler P. ; Föllmi K.B.
刊名: Palaeogeography, Palaeoclimatology, Palaeoecology
ISSN: 0031-0182
出版年: 2015
卷: 418 起始页码: 101
结束页码: 125
语种: 英语
英文关键词: Ardèche
; Chabert Formation
; Drowning
; Early Aptian
; SE France
; Selli episode
英文摘要: A stratigraphic and depositional model, constrained by biostratigraphy, geochemistry, total phosphorus contents, and bulk-rock mineralogy, is proposed for lower Aptian sediments from the Languedoc platform in Ardèche, SE France. The upper lower Aptian is documented by the Chabert Formation (upper Deshayesites forbesi Zone to upper Dufrenoyia dufrenoyi Subzone), deposited on a discontinuity surface on top of the Urgonian platform, recording a first emersion phase and consecutive drowning event. The Chabert Formation starts with the marly Violette Member, which passes into crinoidal limestone of the Rocherenard Member. The top of this member is associated with a second discontinuity, recording a further drowning phase, which is followed by the deposition of the glauconitic and partly phosphatic Picourel Member (upper Deshayesites grandis to upper Dufrenoyia dufrenoyi Subzone). A third erosive phase is documented by a phosphatic conglomerate (upper Dufrenoyia furcata Zone), which represents a lag deposit derived from underlying sediments. The formation of this conglomerate was associated with a substantial emersion phase. This emersion was followed by a drowning event reworking the phosphatic conglomerate into the base of the upper Aptian black marls (Frayol Formation). The carbon-isotope record shows a negative excursion which coincides with the onset of the early Aptian oceanic anoxic Selli episode (OAE 1a) in the middle/upper part of the Deshayesites forbesi Zone. Emersion phases were an important factor implied in the formation of the sequence boundaries, which were transformed into drowning unconformities during subsequent phases of significant transgressions. These phases were associated with the installation of higher trophic levels, transforming or impeding carbonate production. The first drowning phase preceded the onset of the Selli episode, suggesting that rapid sea-level change and associated environmental change were already an important element of the early Aptian before the major phase of environmental change during the Selli episode. © 2014 Elsevier B.V.
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/69063
Appears in Collections: 过去全球变化的重建
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作者单位: Institute of Earth Sciences, Bâtiment Géopolis, Lausanne, Switzerland; Département des Sciences de la Terre, Université de Nice-Sophia Antipolis, 28 Avenue Valrose, Nice, France; Centre d'Etudes Méditerranéennes, Mairie, St André les Alpes, France; Département de Géologie et Paléontologie, Maraîchers A, Bureau 407,13,rue des Maraîchers, Genève, Switzerland
Recommended Citation:
Pictet A.,Delanoy G.,Adatte T.,et al. Three successive phases of platform demise during the early Aptian and their association with the oceanic anoxic Selli episode (Ardèche, France)[J]. Palaeogeography, Palaeoclimatology, Palaeoecology,2015-01-01,418