气候变化领域集成服务门户(CCPortal): Ediacaran paleoenvironmental changes recorded in the mixed carbonate-siliciclastic Bambuí Basin; Brazil

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DOI	10.1016/j.palaeo.2018.12.022
	Ediacaran paleoenvironmental changes recorded in the mixed carbonate-siliciclastic Bambuí Basin; Brazil
	Uhlein G.J.; Uhlein A.; Pereira E.; Caxito F.A.; Okubo J.; Warren L.V.; Sial A.N.
发表日期	2019
ISSN	0031-0182
起始页码	39
结束页码	51
卷号	517
英文摘要	Significant Ediacaran paleoenvironmental changes recorded in the mixed carbonate-siliciclastic Bambuí Basin, east-central Brazil, outcrop in one of the best-preserved sites, the Januária paleo-high. From a detailed stratigraphic and chemostratigraphic approach (carbon and oxygen isotopes, total organic carbon, total sulfur and selected elements abundances), we identified transgressive-regressive intervals and depositional settings within the Bambuí Group stratigraphy and developed a new model for the origin of the extremely positive Middle Bambuí Excursion (MIBE) present in the middle section of the basin. A post-Marinoan cap carbonate interval is recorded in the first ~10 m, preserving aragonite pseudomorph fans, barite-rich layers and negative δ 13 C anomaly. A hiatus separates the cap carbonate from the late Ediacaran succession that makes up the remaining Bambuí Group. The younger intervals preserve both siliciclastic (middle Serra de Santa Helena Formation) and carbonate (middle/upper Sete Lagoas and Lagoa do Jacaré formations) shallow-water depositional settings, requiring tectonic influence or climatic changes in source areas. The MIBE yields δ 13 C values as high as +14‰ and extends for about 350 m, from the upper Sete Lagoas Formation to the lower Serra da Saudade Formation. We suggest a model of a restricted basin setting that favored local carbon isotopic signals in the δ 13 C record of sedimentary carbonates through preferential weathering of ancient carbonate platforms on the continent and higher burial rate of authigenic carbonate. This scenario caused the global δ 13 C budget to be affected by an offset of, at least, +4‰ in sedimentary carbonates deposited on the São Francisco craton and along its margin during the terminal Ediacaran. Many previous studies suggested a restricted nature for the middle Bambuí Basin, which probably resulted from the central position of the São Francisco paleocontinent within the mosaic of collisional blocks during the SW Gondwana amalgamation. © 2019 Elsevier B.V.
英文关键词	Carbon burial; Carbon isotope excursion; Chemostratigraphy; Depositional settings; Paleogeography; West Gondwana
语种	英语
scopus关键词	aragonite; barite; burial diagenesis; carbonate; chemostratigraphy; climate variation; depositional sequence; Ediacaran; environmental change; hiatus; outcrop; paleoenvironment; paleogeography; pseudomorph; siliciclastic deposit; transgression-regression cycle; Brazil; Minas Gerais; Sete Lagoas
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/151077
作者单位	Centro de Pesquisas Manoel Teixeira da Costa, Instituto de Geociências, Universidade Federal de Minas Gerais, Campus Pampulha, Av. Antônio Carlos 6627, Belo Horizonte, MG 31270-901, Brazil; Departamento de Paleontologia e Estratigrafia, Faculdade de Geologia, Universidade do Estado do Rio de Janeiro – UERJ, Av. São Francisco Xavier, 524, Maracanã, Rio de Janeiro, RJ 20550-013, Brazil; Departamento de Geologia Aplicada, Instituto de Geociências e Ciências Exatas, Universidade Estadual Paulista, Avenida 24A, 1515, Rio Claro, SP 13506-900, Brazil; NEG-LABISE, Departamento de Geologia, Universidade Federal de Pernambuco, Av. da Arquitetura, s/n, Recife, PE 50670-901, Brazil
推荐引用方式 GB/T 7714	Uhlein G.J.,Uhlein A.,Pereira E.,et al. Ediacaran paleoenvironmental changes recorded in the mixed carbonate-siliciclastic Bambuí Basin; Brazil[J],2019,517.
APA	Uhlein G.J..,Uhlein A..,Pereira E..,Caxito F.A..,Okubo J..,...&Sial A.N..(2019).Ediacaran paleoenvironmental changes recorded in the mixed carbonate-siliciclastic Bambuí Basin; Brazil.Palaeogeography, Palaeoclimatology, Palaeoecology,517.
MLA	Uhlein G.J.,et al."Ediacaran paleoenvironmental changes recorded in the mixed carbonate-siliciclastic Bambuí Basin; Brazil".Palaeogeography, Palaeoclimatology, Palaeoecology 517(2019).