Palaeoecology of the Aptian Santana Formation (Northeastern Brazil)
Palaeoecology of the Aptian Santana Formation (Northeastern Brazil)
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Aptian Santana 地层的古生态学（巴西东北部）
DOI：
10.1016/0031-0182(73)90006-0
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发表时间：
1973
期刊：
影响因子：
--
通讯作者：
I. Tinoco
中科院分区：
文献类型：
--
作者：
J. M. Mabesoone;I. Tinoco
在巴西东北部的内陆地区，存在阿普第安时代的桑塔纳地层，从岩石学上来说，它由三个部分组成：克拉托——薄石灰岩和页岩的交替； Ipubi——石膏； Romualdo——几乎是纯石灰石。该地层富含化石；花粉、植物残骸、介形类、壳介类、软体动物、海胆、鱼类和一些爬行动物。鱼类和爬行动物出现在石灰岩结核中。所有有关沉积物特征和化石的数据都被综合考虑，以解释地层的古环境。得出的结论是，在克拉托段时期，沉积发生在浅湖和沼泽中。后来（Ipubi 成员），在气候干燥期间发生了海洋入侵，导致硬石膏沉淀。与海洋的联系逐渐受阻，沉积期末期的环境再次成为淡水环境（罗穆阿尔多段）。动物群落和沉积物表明，在整个盆地沉积期间，在温暖和干燥的气候条件下，河水供应量相当大。与海洋的联系持续了相当短的一段时间。
In the interior of northeastern Brazil there occurs the Santana Formation of Aptian age, composed lithologically of three members: Crato — an alternation of thin limestones and shales; Ipubi — gypsum; and Romualdo — almost pure limestone. The formation is very fossiliferous; pollen, plant remains, ostracodes, conchostracans, mollusks, echinoids, fishes and a few reptiles. The fishes and reptiles occur in limestone concretions. All data on sediment character and on fossils have been considered together for the interpretation of the palaeoenvironment of the formation.It was concluded that at the time of the Crato Member the deposition occurred in shallow lakes and swamps. Later (Ipubi Member), a marine invasion took place during a time of dry climate, causing anhydrite precipitation. Gradually the connection with the sea became obstructed so that the environment at the end of the depositional period became once more one of fresh water (Romualdo Member). Faunal assemblages and sediments point to a fairly great supply of river water during the whole time of basin deposition, under warm and dry climatic conditions. The connection with the sea persisted for a rather short period.