• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Brazilian Journal of Geology >New sedimentological and palynological data from surface Miocene strata in the central Amazonas Basin area
【24h】

New sedimentological and palynological data from surface Miocene strata in the central Amazonas Basin area

机译：亚马逊河盆地中部地区中新世地层的沉积学和孢粉新数据

获取原文
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

ABSTRACT The scarcity of stratigraphic data has hindered the demarcation of the outcropping area of Miocene deposits of the Amazon Basin, represented informally by the Novo Remanso Formation. Moreover, this unit is characterized by a sparse and irregular geographic distribution due to its sedimentological features and rare fossil content. Miocene deposits cropping out in central Amazonas Basin area were described in sedimentological terms and analyzed palynologically. All analyses were undertaken in samples collected at the -Uatum? River banks (Itapiranga and S?o Sebasti?o do Uatum? cities). Lithostratigraphic data shows that Novo Remanso Formation consists of sandstones, with subordinate conglomerates and pelites, characteristic of a meandering fluvial paleosystem, with fluvial channel, point bar, floodplain and crevasse splay facies. The palynoflora retrieved from five samples consists exclusively of continental-origin palynomorphs dominated by angiosperms species. Trilete spores are well represented, while gymnosperms pollen grains are minor components. The presence of Psilastephanoporites tesseroporus, Syncolporites poricostatus, Jandufouria seamrogiformis and Polypodiaceoisporites potoniei ensure these deposits fits into the Grimsdalea magnaclavata palynozone (Regali et al. 1974a, b), and the Grimsdalea magnaclavata/Crassoretitriletes vanraadshooveni palynozones of Jaramillo et al. (2011) considered Middle Miocene age. This age is confirmed by the zonation of Jaramillo et al. (2011), based on the LADs of Bombacacidites baumfalki (11.57Ma) and Crototricolpites annemariae (12.91Ma); and the FAD of Psilastephanoporites tesseroporus (14.00Ma). With these new data presented herein, it is possible to assume that the Miocene strata represented by the Novo Remanso Formation covers a larger area in the basin than previously considered, and that it may be extended for about 300 km until the Manacapuru village, indicating a Miocene subsidence phase.
机译：摘要地层数据的稀缺性阻碍了以新诺曼素组非正式代表的亚马逊盆地中新世露头地区的划分。此外，由于其沉积学特征和稀有的化石含量，该单元的特征是稀疏和不规则的地理分布。用沉积学术语描述了在亚马逊河盆地中部地区中新世形成的沉积物，并进行了孢粉学分析。所有分析均在-Uatum收集的样品中进行。河岸（Itapiranga和S？o Sebasti？o do Uatum？城市）。岩石地层学资料表明，诺曼·雷曼索地层由砂岩组成，下有砾岩和贝利特岩，具有蜿蜒的河流古系统的特征，河流河道，点坝，洪泛区和缝隙呈张开相。从五个样本中检索到的古植物仅由被子植物种占主导的大陆起源的古植物组成。 Trilete孢子很好地代表，而裸子植物的花粉粒是次要成分。 Psilastephanoporites tesseroporus，Syncolporites poricostatus，Jandufouria seamrogiformis和Polypodiaceoisporites potoniei的存在确保了这些沉积物适合于Grimsdalea magnaclavata palynozone（Regali等人1974a，b）和Grimsdaleeni magnaclavatatri。 （2011年）考虑了中新世中期。 Jaramillo等人的分区证实了这一年龄。 （2011），基于Bombacacidites baumfalki（11.57Ma）和Crototricolpites annemariae（12.91Ma）的LADs;以及Psilastephanoporites tesseroporus（14.00Ma）的FAD。利用此处提供的这些新数据，可以假设以Novo Remanso地层为代表的中新世地层覆盖盆地的面积比以前考虑的要大，并且可能会延伸约300 km直到Manacapuru村庄，表明中新世沉降阶段。

著录项

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