气候变化领域集成服务门户(CCPortal): Multivariate taphonomic analysis of mollusk shell concentrations in Holocene deposits of southern Brazil: An integrated approach

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DOI	10.1016/j.palaeo.2020.110085
	Multivariate taphonomic analysis of mollusk shell concentrations in Holocene deposits of southern Brazil: An integrated approach
	Pereira L.G.; Fornari M.; Erthal F.; Leme J.M.; Giannini P.C.F.
发表日期	2020
ISSN	0031-0182
英文摘要	Shell concentrations are one of the most distinctive features of the Holocene coastal stratigraphy in the southern portion of Santa Catarina State, southern Brazil. In this paper, we integrated stratigraphic, geochronological, geophysical, and taphonomic data to discuss the processes involved in the genesis of shell concentrations in a siliciclastic and subtropical setting, a useful analogy for ancient shell concentrations in semi-closed environments affected by storms. The data indicated the succession of three facies associations (FA): bay, lagoon, and back-barrier. This succession implies a grain size fining-upward trend that is representative of a gradual shallowing. Interpretation of GPR sections revealed that the passage from the bay to lagoonal deposits occurred by forming a laterally continuous, high-amplitude surface overlain by sigmoidal reflections, which characterized the progressive basinward backstepping of the lagoonal margin. Shell concentrations in bay deposits are an allochthonous product of storm flows in shallow waters. In contrast, accumulations of the bivalve Anomalocardia brasiliana had their valves reworked in the lagoonal margins and transported to the bottom, characterizing a parautochthonous accumulation. In this study, the correlation of taphonomy and grain size indicates that in bay FA, the loss of periostracum is correlated with increased gradients of fine sand, and part of the shell samples correlates to corrosion and abrasion in increased gradients of medium sand and decreased ones of fine sand. Additionally, in the lagoon FA, the loss of periostracum depends on the decrease in mud-enriched sediments and the increase in fine and medium sand, whereas brightness loss and color alteration are related to the increase in fine and medium sand, as well as margin modification. Corrosion was positively correlated to the mud-dominated fraction. © 2020 Elsevier B.V.
英文关键词	Actuopaleontology; Coastal dynamics; GPR; Holocene; Relative sea-level; Siliciclastic deposits
语种	英语
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/150709
作者单位	Institut für Geowissenschaft, Bonn Universität, Nußallee 8, Bonn, Nord Rhine Westfalia 53115, Germany; Biosciences Institute, São Paulo State University (UNESP) - Coastal Campus, Praça Infante Dom Henrique s/n. 11330-900, P.O. Box: 73601, São Vicente, São Paulo, SP ZIP Code/CEP 11380-972, Brazil; Instituto de Geociências, Departamento de Paleontologia e Estratigrafia, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Rio Grande do Sul CEP 91.501–970, Brazil; Instituto de Geociências, Programa de Pós-graduação em Geoquímica e Geotectônica, Universidade de São Paulo (USP), Rua do Lago 562, São Paulo, SP CEP 05508-080, Brazil
推荐引用方式 GB/T 7714	Pereira L.G.,Fornari M.,Erthal F.,et al. Multivariate taphonomic analysis of mollusk shell concentrations in Holocene deposits of southern Brazil: An integrated approach[J],2020.
APA	Pereira L.G.,Fornari M.,Erthal F.,Leme J.M.,&Giannini P.C.F..(2020).Multivariate taphonomic analysis of mollusk shell concentrations in Holocene deposits of southern Brazil: An integrated approach.Palaeogeography, Palaeoclimatology, Palaeoecology.
MLA	Pereira L.G.,et al."Multivariate taphonomic analysis of mollusk shell concentrations in Holocene deposits of southern Brazil: An integrated approach".Palaeogeography, Palaeoclimatology, Palaeoecology (2020).