4.6 Article

Microbialite fields developed in a protected rocky coastline: The shallow carbonate ramp of the Aptian Romualdo Formation (Araripe Basin, NE Brazil)

期刊

SEDIMENTARY GEOLOGY
卷 389, 期 -, 页码 103-120

出版社

ELSEVIER
DOI: 10.1016/j.sedgeo.2019.06.003

关键词

Stromatolites; Microbialites; Echinoids; Bivalves; Shark Bay analogue; Lower Cretaceous

类别

资金

  1. Sao Paulo Research Foundation (FAPESP) [2016/13214-7, 2017/20803-1, 18/01750-7]
  2. Petrobras [2014/00519-9]
  3. Conselho Nacional de Desenvolvimento Cientifico e TecnolOgico (CNPq) [444070/2013-1, 401039/2013-5, 1082 30017/2015-3, 152385/2016-9, 301294/2018-6]
  4. Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP) [18/01750-7] Funding Source: FAPESP

向作者/读者索取更多资源

The Aptian Romualdo Formation is a siliciclastic-dominated sedimentary unit recording the last marine ingression within the Cretaceous interior basins of northeastern Brazil. At the western margin of the Araripe Basin, rocks of the Romualdo Formation are mainly represented by carbonates resting abruptly over the Proterozoic crystalline basement. Detailed mapping and stratigraphic analysis revealed two stromatolite fields that were described and discussed for the first time. Several bioherms, biostromes and isolated stromatolites characterized by distinct microbialite morphologies associated with echinoid-rich strata have been identified, suggesting that hypersalinity, water depth and hydraulic conditions were the main factors controlling stromatolite morphogenesis. A cm-thick amalgamated bivalve rudstone, resting directly on the basement and representing a shell concentration formed above the fair-weather wave base was also recorded. Based on the regional distribution of the stromatolite types and associated sedimentary fades, we interpret the depositional environment as a local low gradient carbonate ramp deepening to the east. Our data robustly indicated that the western rocky shorelines of the Araripe Basin during the Aptian were populated by microbial mats and stromatolites in a condition analogous to the modern world-famous Hamelin Pool, Shark Bay, Western Australia. Finally, the development of stromatolites and echinoid-bearing microbialites at the western margin of the basin may be correlated with the formation of bakevelliid- and cassiopid-rich shell beds in the upper part of the Romualdo Formation at the eastern margin. (C) 2019 Elsevier B.V. All rights reserved.

作者

我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。

评论

主要评分

4.6
评分不足

次要评分

新颖性
-
重要性
-
科学严谨性
-
评价这篇论文

推荐

暂无数据
暂无数据