globalchange  > 过去全球变化的重建
DOI: 10.1016/j.palaeo.2016.09.009
论文题名:
Origin and sedimentary evolution of sinkholes (buracas) in the Abrolhos continental shelf, Brazil
作者: Bastos A.C.; Amado-Filho G.M.; Moura R.L.; Sampaio F.M.; Bassi D.; Braga J.C.
刊名: Palaeogeography, Palaeoclimatology, Palaeoecology
ISSN: 0031-0182
出版年: 2016
卷: 462
起始页码: 101
结束页码: 111
语种: 英语
英文关键词: Abrolhos continental shelf ; Brazil ; Carbonate sedimentation ; Pleistocene-Holocene ; Radiocarbon dating ; Submarine sinkholes
英文摘要: Cup-shaped depressions (termed buracas by local fishermen) are common geomorphic features on the northeastern Abrolhos continental shelf (Brazil). Samples collected by technical diving from the walls of two depressions (Buraca Funda, B1, top at 59 m, and Buraca Rasa, B2, top at 26 m) and seismic profiles provide evidence of the processes leading to their formation. The top of the sedimentary succession consists of two units bounded by erosion unconformities. Unit 1 overlies an erosion surface (MR1) and is older than the radiocarbon dating limit. It is made up of packstone to rudstone accumulated on mid- to outer-shelf paleoenvironments. Voids in the limestone are filled by a meteoric cement 29,000 cal yrs BP in B2. It is assumed that Unit 1 formed in the late Pleistocene, mainly during MIS 5e. An erosion surface (MR2) carved sinkholes in Unit 1, with karstification taking place while the ACS was emergent during the last glacial period. The timing and span of subaerial exposure changes with depth within the shelf. Unit 2 accumulated on this karst surface in the Holocene, after postglacial sea level rise. At the B1 margin, Unit 2 consists of early-lithified packstone to rudstone with attached corals. In B2, the Holocene unit comprises a boundstone of encrusting invertebrates and calcareous algae similar to the living ones attached to the wall today. High productivity in the sinkholes probably promoted the growth of encrusting suspension feeders but also led to intense, multistory bioperforation of carbonates on the wall. The cup-shaped depressions are, therefore, the result of sinkhole formation during the last-glacial low sea levels and later carbonate accretion at sinkhole margins during the Holocene. © 2016 Elsevier B.V.
Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/68210
Appears in Collections:过去全球变化的重建

Files in This Item:

There are no files associated with this item.


作者单位: Departamento de Oceanografia, Universidade Federal do Espírito Santo, Avenida Fernando Ferrari 514, Vitória, Brazil; Instituto de Pesquisas Jardim Botânico do Rio de Janeiro, Rua Pacheco Leão 915, Rio de Janeiro, RJ, Brazil; Departamento de Biologia Marinha, Instituto de Biologia, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, Ilhado Fundão, CP68011, Rio de Janeiro, RJ, Brazil; Dipartimento di Fisica e Scienze della Terra, Università degli Studi di Ferrara, via Saragat 1, Ferrara, Italy; Departamento de Estratigrafía y Paleontología, Universidad de Granada, Campus Fuentenueva s/n, Granada, Spain

Recommended Citation:
Bastos A.C.,Amado-Filho G.M.,Moura R.L.,et al. Origin and sedimentary evolution of sinkholes (buracas) in the Abrolhos continental shelf, Brazil[J]. Palaeogeography, Palaeoclimatology, Palaeoecology,2016-01-01,462
Service
Recommend this item
Sava as my favorate item
Show this item's statistics
Export Endnote File
Google Scholar
Similar articles in Google Scholar
[Bastos A.C.]'s Articles
[Amado-Filho G.M.]'s Articles
[Moura R.L.]'s Articles
百度学术
Similar articles in Baidu Scholar
[Bastos A.C.]'s Articles
[Amado-Filho G.M.]'s Articles
[Moura R.L.]'s Articles
CSDL cross search
Similar articles in CSDL Cross Search
[Bastos A.C.]‘s Articles
[Amado-Filho G.M.]‘s Articles
[Moura R.L.]‘s Articles
Related Copyright Policies
Null
收藏/分享
所有评论 (0)
暂无评论
 

Items in IR are protected by copyright, with all rights reserved, unless otherwise indicated.