DOI: 10.1016/j.palaeo.2014.09.027
论文题名: Evidences for a Paleocene marine incursion in southern Amazonia (Madre de Dios Sub-Andean Zone, Peru)
作者: Louterbach M. ; Roddaz M. ; Bailleul J. ; Antoine P.-O. ; Adnet S. ; Kim J.H. ; van Soelen E. ; Parra F. ; Gérard J. ; Calderon Y. ; Gagnaison C. ; Sinninghe Damsté J.S. ; Baby P.
刊名: Palaeogeography, Palaeoclimatology, Palaeoecology
ISSN: 0031-0182
出版年: 2014
卷: 414 起始页码: 451
结束页码: 471
语种: 英语
英文关键词: Amazonian foreland basin
; Madre de Dios basin
; Marine incursion
; Paleogene
; Peru
; Tidal deposits
英文摘要: This article presents new biostratigraphic dating, facies analysis, organic geochemical data and Nd-Sr isotopic provenance from five outcrops of southern Amazonia (MD-85, MD-177 MD-184, MD-255 and MD-256) to document for the first time the presence of a shallow marine ingression in the Paleocene of southern Amazonia basin. The co-occurrence of a selachian assemblage encompassing Potobatis sp., Ouledia sp., and Pristidae indet. with the ostracod Protobuntonia sp. and the charophytes Peckichara cf. varians meridionalis, Platychara perlata, and Feistiella cf. gildemeisteri suggests a Paleocene age for the studied deposits (most likely Thanetian but potentially Danian). Fifteen facies have been recognized and have been grouped into three facies assemblages. Facies association A corresponds to the sedimentary filling of a tide-influenced meandering channel formed in the fluvial-tidal transition zone. Facies association B is related to more distal tidal-flats, little channelized tidal inlets and saltmarsh deposits. Facies association C corresponds to a stressed shallow marine environment such as a bay or a lagoon. The δ13CTOC value (-23.4‰) of MD-184 is enriched in 13C compared to the other samples suggesting the presence of substantial amounts of marine organic matter in MD-184. The δ13CTOC values of samples from other outcrops (-27.3 to -29.8‰) indicate a mixed organic matter origin, from terrestrial to brackish environments. The analyzed sediments have similar Nd-Sr isotopic compositions as those of the Cenozoic sediments of the Altiplano (εNd(0) values from -6.2 to -10.7 and 87Sr/86Sr compositions from 0.712024 to 0.719026) indicating a similar volcanic source. This multidisciplinary dataset documents the presence of a tide-dominated estuary sourced by the proto-Western Cordillera debouching into a shallow marine bay during Paleocene times. This transgression might be explained by subsidence created in response to the proto-Western Cordillera loading. Similar to Miocene marine incursions affecting the Pebas megawetland, Paleogene marine incursions in the Amazonian foreland basin associated with Andean uplift may have played a role in the Neotropical biodiversity dynamics in favoring biogeographical isolation and promoting allopatric speciation for terrestrial organisms. © 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/69186
Appears in Collections: 过去全球变化的重建
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作者单位: Géosciences-Environnement Toulouse, Université de Toulouse, UPS (SVT-OMP), LMTG, CNRS, IRD, 14 Avenue Édouard Belin, Toulouse, France; Bassins-Réservoirs-Ressources, Institut Polytechnique Lasalle Beauvais, Département Géosciences, 19 rue Pierre Waguet, BP 30313, Beauvais Cedex, France; REPSOL Exploración S.A., Calle Mendez Alavaro 44, Madrid, Spain; Institut des Sciences de l'Évolution (ISE-M, UMR - CNRS 5554), C.c. 64, Université Montpellier 2, Place Eugène Bataillon, Montpellier Cedex 05, France; Royal Netherlands Institute for Sea Research (NIOZ), Department of Marine Organic Biogeochemistry, Den Burg, Texel, Netherlands; PERUPETRO S.A., Luis Aldana 320, San Borja, Lima, Peru
Recommended Citation:
Louterbach M.,Roddaz M.,Bailleul J.,et al. Evidences for a Paleocene marine incursion in southern Amazonia (Madre de Dios Sub-Andean Zone, Peru)[J]. Palaeogeography, Palaeoclimatology, Palaeoecology,2014-01-01,414