气候变化领域集成服务门户(CCPortal): Integrated stratigraphy and paleontology of the lower Miocene Monte León Formation; southeastern Patagonia; Argentina: Unraveling paleoenvironmental changes and factors controlling sedimentation

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DOI	10.1016/j.palaeo.2020.109701
	Integrated stratigraphy and paleontology of the lower Miocene Monte León Formation; southeastern Patagonia; Argentina: Unraveling paleoenvironmental changes and factors controlling sedimentation
	Parras A.; Guerstein G.R.; Pérez Panera J.P.; Griffin M.; Náñez C.; Cusminsky G.; Quiroga A.
发表日期	2020
ISSN	0031-0182
卷号	556
英文摘要	Marine sedimentary rocks of the lower Miocene Monte León Formation of southeastern Patagonia (Austral Basin), Argentina are important geological archives for better understanding regional tectonics, paleoenvironments, oceanography, and climate. In this paper, we describe assemblages of invertebrates, palynomorphs, foraminifera, ostracods and calcareous nannofossils in a stratigraphical and sedimentological framework, which suggest deposition during a transgressive-regressive cycle. From base to top, the lowermost outcropping deposits of the Punta Entrada Member represent an inner shelf environment, formed during a transgressive phase. The zone of maximum flooding is marked by a high diversity of protoperidiniaceans (heterotrophic) and offshore dinoflagellate cysts, an increase in the percentage and size of planktonic foraminifera, and a decrease in shallow water benthic foraminifera. Regressive deposits in the upper part of the Punta Entrada Member exhibit a progradational stratal stacking pattern and are characterized by an upward decrease in bioturbation and in the content of marine invertebrates; the dinoflagellate cyst assemblages point toward shallower and more restricted marine conditions than in underlying deposits. The cycle ends with the Monte Observación Member, which contains an impoverished and mostly reworked fauna of invertebrates. The presence of monospecific reefs of Crassostrea orbignyi, the decrease in dinoflagellate cysts and calcareous microfossils diversity, and the increase of continental palynomorphs suggest progressively shallower conditions and increasing influence of freshwater discharge. Although eustatic controls could have contributed to the sedimentary evolution of the Monte León Formation, the upward regressive trend is interpreted as the result of tectonism linked to the Andean orogeny, which led to the uplift, exhumation, and erosion of the highlands in the west. This is supported by the abundance of pyroclastic material, together with reworked specimens of Upper Cretaceous forams and Upper Cretaceous and middle Eocene dinoflagellate cysts in the upper part of the Punta Entrada Member and in the Monte Observación Member. © 2020 Elsevier B.V.
英文关键词	Calcareous Microfossils; Calcareous Nannofossils; Invertebrates; Neogene; Paleoenvironments; Palynomorphs; Southern South America
语种	英语
scopus关键词	community composition; dinoflagellate cyst; environmental change; invertebrate; macroinvertebrate; marine environment; microfossil; micropaleontology; Miocene; paleoenvironment; palynomorph; planktonic foraminifera; reef; sedimentary rock; sedimentation; stratigraphy; Argentina; Austral Basin; Patagonia; Crassostrea; Dinophyceae; Foraminifera; Invertebrata; Ostracoda; Protoperidiniaceae
来源期刊	Palaeogeography, Palaeoclimatology, Palaeoecology
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/150369
作者单位	CONICET-Universidad Nacional de La Pampa, Instituto de Ciencias de la Tierra y Ambientales de La Pampa (INCITAP), Mendoza 109, Santa Rosa, provincia de La Pampa L6302EPA, Argentina; Universidad Nacional de La Pampa, Facultad de Ciencias Exactas y Naturales, Uruguay 151, Santa Rosa, provincia de La Pampa L6300CLB, Argentina; CONICET-Universidad Nacional del Sur-Departamento de Geología, Instituto Geológico del Sur (INGEOSUR), Av. Alem 1253, Cpo. B́, 2° P, Bahía Blanca, provincia de Buenos Aires B8000ICN, Argentina; CONICET/Y-TEC, Av. Del Petróleo s/n, Berisso, provincia de Buenos Aires B1924CKU, Argentina; CONICET-Universidad Nacional de La Plata, División de Paleozoología Invertebrados, Facultad de Ciencias Naturales y Museo, Paseo del Bosque s/n, La Plata, provincia de Buenos Aires B1900FWA, Argentina; CONICET-Servicio Geológico Minero Argentino, Av. General Paz 5445 (colectora), Edificio 25, San Martín, provincia de Buenos Aires B1650 WAB, Argentina; CONICET-Universidad Nacional del Comahue, Insti...
推荐引用方式 GB/T 7714	Parras A.,Guerstein G.R.,Pérez Panera J.P.,et al. Integrated stratigraphy and paleontology of the lower Miocene Monte León Formation; southeastern Patagonia; Argentina: Unraveling paleoenvironmental changes and factors controlling sedimentation[J],2020,556.
APA	Parras A..,Guerstein G.R..,Pérez Panera J.P..,Griffin M..,Náñez C..,...&Quiroga A..(2020).Integrated stratigraphy and paleontology of the lower Miocene Monte León Formation; southeastern Patagonia; Argentina: Unraveling paleoenvironmental changes and factors controlling sedimentation.Palaeogeography, Palaeoclimatology, Palaeoecology,556.
MLA	Parras A.,et al."Integrated stratigraphy and paleontology of the lower Miocene Monte León Formation; southeastern Patagonia; Argentina: Unraveling paleoenvironmental changes and factors controlling sedimentation".Palaeogeography, Palaeoclimatology, Palaeoecology 556(2020).