• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Stratigraphy >Earliest Miocene calcareous nannofossil biostratigraphy from the low-latitude Pisco Basin (Peru)
【24h】

Earliest Miocene calcareous nannofossil biostratigraphy from the low-latitude Pisco Basin (Peru)

机译：来自低纬度Pisco盆地（秘鲁）的最早内科钙质钙质诺坎辛斯生物科学照片

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Stratigraphic studies, based on lithology, diatoms, and mollusks, have suggested different chronostratigraphic placements for formations in the Pisco Basin. This study focusses on a stratigraphically important, calcareous nannofossil-bearing unit between the Chilcatay and Pisco formations. The Eocene-Pliocene Pisco Basin is located at low latitude (-14 degrees S) in a forearc basin in central coastal Peru. The objective of this study is to use nannofossil biostratigraphy to constrain the age of an interval for ongoing stratigraphic work in the region. We analyzed nannofossils from two sections located on the northern end of the Cerros Yesera de Amara trend and in Cerro Las Tres Piramides. A tuff bed above the top of the section is dated to 17.70 +/- 0.24 Ma based on a single Ar-Ar age from biotite. Analysis of productive samples from the two locations show rare to common calcareous nannofossil occurrence with poor to moderate preservation. Nannofossils show strong dissolution and/or overgrowth in almost all samples. Based on the first occurrence (FO) of Helicosphaera carteri in association with Cyclicargolithus abisectus, Reticulofenestra bisecta, and Triquetrorhabdulus carinatus, we suggest that the assemblage recovered represents an age of earliest Miocene, Zone NN1 (CN1b). Studies from the equatorial Pacific region indicate rare and discontinuous occurrence of Reticulofenestra bisecta (<10 mu m) in late Oligocene and earliest Miocene (NN1), making it difficult to determine if its occurrence in the assemblage is caused either by low productivity or by reworking. The absence of Discoaster druggii might suggest that the assemblage is not younger than NN1, although Discoaster druggii tends to be rare and difficult to findd even in well preserved sediments.
机译：基于岩性，硅藻和软体动物的地层研究已经提出了Pisco池中的形成的不同计时器展示。本研究侧重于慈昔士和比克地层之间的地层重要性，钙质诺诺辛斯单元。何世丙烯酰基斯科盆地位于中央沿海秘鲁的前臂盆地的低纬度（-14度）。本研究的目的是使用Nannofossil BioStraTigraphy来限制该地区正在进行的地层工作的间隔的年龄。我们分析了位于甲克罗斯北端的两段部分的Nannofossils·斯科拉趋势和Cerro Las Tres Piramides。基于来自Biotite的单个Ar-AR年龄，截面上方的凝灰岩床以上的颗粒为17.70 +/- 0.24 mA。两个地点的生产样品分析罕见的普通钙质NannoFossil罕见与中度保存差。 Nannofossils在几乎所有样品中都显示出强烈的溶解和/或过度生长。基于螺旋磷酸的第一次出现（FO）与环菌胆管脱落，reticulofenestra Bisecta和Triquetrorhabdulus carinatus相关联，我们建议恢复的组合代表最早的中医区，区域NN1（CN1B）。来自赤道太平洋地区的研究表明晚寡烯和最早的氨基烯（NN1）中罕见且不连续的近连蛋白酶Bisecta（<10μm）的发生，使得难以确定其在组合中的发生是通过低生产率或通过再加工来引起的。没有探医者药物可能表明组合的不是比NN1更年轻，尽管即使在保存完好的沉积物中，探测剂药物往往罕见且难以发现。

著录项

  • 来源
    《Stratigraphy》 |2019年第2期|共19页
  • 作者

    Belia Emilia R.; Nick Kevin E.; Bedoya Agudelo Erika; Watkins David K.;

  • 作者单位

    Loma Linda Univ Dept Earth &

    Biol Sci Griggs Hall Room 101 Loma Linda CA 92350 USA;

    Loma Linda Univ Dept Earth &

    Biol Sci Griggs Hall Room 101 Loma Linda CA 92350 USA;

    CADIC Bernardo Houssay 200 RA-9410 Ushuaia Tierra Fuego Argentina;

    Univ Nebraska Dept Earth &

    Atmospher Sci Lincoln NE 68588 USA;

  • 收录信息
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类 地质学;
  • 关键词

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号