Late paleocene to middle Miocene planktonic foraminifer biostratigraphy of the Ceara Rise
Late paleocene to middle Miocene planktonic foraminifer biostratigraphy of the Ceara Rise
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塞阿拉隆起的古新世晚期至中新世浮游有孔虫生物地层
DOI：
10.2973/odp.proc.sr.154.106.1997
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发表时间：
1997
影响因子：
1.9
通讯作者：
W. Chaisson
中科院分区：
文献类型：
--
作者：
P. Pearson;W. Chaisson
在154号大洋钻井项目中，在西大西洋的西阿拉隆起的五个地点（地点925、926、927、928和929）进行了深度取样。每个地点主要由远洋碳酸盐沉积物组成。浮游有孔虫在整个层序中都很丰富，除了在深度较深的位置有强烈溶解的间隔。动物群是低纬度地区的典型，它们种类繁多，而且在大部分记录中保存得相当完好。重结晶大多为中度，但在较大的埋藏深度则较为严重。从上古新世的P4c亚带到中新世中期溶蚀最强烈的N12亚带，形成了地层段下部的生物地层格架。这项研究取代了先前发表的船上浮游有孔虫生物地层学。它包含许多额外的数据和一些修订。本文还介绍了在西阿拉隆起的整个地层区间内所有已知物种的完整范围图。从古新世到全新世，高原上的沉积几乎是连续的。虽然在个别地点发现了一些小裂缝，但没有一个延伸到整个高原，因此可以构建一个非常完整的地质历史。这些记录的大部分以米兰科维奇时间尺度上的沉积旋回性为特征。这表明，西阿拉隆起将是轨道年代学未来发展的一个关键领域，其中浮游有孔虫生物地层学将是一个重要组成部分。
During Ocean Drilling Program Leg 154, five sites (Sites 925, 926, 927, 928, and 929) were drilled as a depth transect on the Ceara Rise in the western Atlantic Ocean. Each site consists mainly of pelagic carbonate sediments. Planktonic foraminifers are abundant throughout the sequences except in intervals of intense dissolution at the bathymetrically deeper sites. Faunas are typical of the low latitudes, and they are diverse and reasonably well preserved for much of the record. Recrystallization is mostly moderate, but it is severe at the greater burial depths. A biostratigraphic framework is presented for the lower part of the stratigraphic interval, from Subzone P4c in the upper Paleocene to Zone N12 immediately below the most intensely dissolved level in the middle Miocene. This study replaces the previously published shipboard planktonic foraminifer biostratigraphy. It contains many additional datums and some revisions. Complete range charts of all the species recognized are also presented for the entire stratigraphic interval on the Ceara Rise. Sedimentation on the plateau was almost continuous from the Paleocene to the Holocene. Although several small hiatuses are identified at individual sites, none extends across the whole plateau, so a remarkably complete geological history can be constructed. Much of this record is characterized by sedimentary cyclicity on Milankovitch time scales. This suggests that the Ceara Rise will be a key area for future advances in orbital-based chronology in which planktonic foraminifer biostratigraphy will be an important component.