...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Sedimentary geology >Palaeoredox conditions and sequence stratigraphy of the Cretaceous storm-dominated, mixed siliciclastic-carbonate ramp in the Eastern Cordillera Basin (Colombia): Evidence from sedimentary geochemical proxies and facies analysis
【24h】

Palaeoredox conditions and sequence stratigraphy of the Cretaceous storm-dominated, mixed siliciclastic-carbonate ramp in the Eastern Cordillera Basin (Colombia): Evidence from sedimentary geochemical proxies and facies analysis

机译：东科迪勒拉盆地（哥伦比亚）白垩纪以暴雨为主的混合硅质碳酸盐岩斜坡的古氧化还原条件和层序地层：来自沉积地球化学代理和相分析的证据

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

The Cretaceous black shales of Colombia are among the most important successions in the north of South America and have attracted the attention of many geoscientists and exploration companies over the last few decades, because of their high hydrocarbon potential and the presence of emerald deposits. However, many uncertainties still remain with regard to their tectonic setting, sequence stratigraphy, depositional environments, palaeoxygenation conditions, and organic matter preservation. In order to develop a more integrated picture of these different processes and conditions, we conducted a detailed sedimentological, inorganic geochemical (U, V, Ni, Zn, Mn, Fe, Ti, Mo, Cu, Cr, Cd, Ba) and sequence stratigraphic analysis of the Cretaceous black shales in the Magdalena-Tablazo Sub-Basin (Eastern Cordillera Basin) of Colombia. Eleven lithofacies and five lithofacies associations of a storm-dominated, siliciclastic-carbonate ramp were identified, which range from basin to shallow inner ramp environments. These facies were grouped into six third-order stratigraphic sequences showing high-order cycles of marine transgression with constrained regressive pulses during the late Valanginian to early Coniacian. The black shales succession represents deposition under anoxic bottom water with some intervals representing dysoxic-suboxic conditions. The evolution of the sedimentary environments and their palaeoxygenation history reflect tectonic and eustatic sea-level controls that 1) produced a variable orientation and position of the coastline throughout the Cretaceous; 2) conditioned the low-gradient ramp geometry (0.3 degrees) and 3) modified the oxygenation conditions in the Magdalena-Tablazo Sub-Basin. An improved understanding of the sedimentary setting during deposition of the Cretaceous black shales in the Magdalena-Tablazo Sub-Basin assists in highlighting the interplay between the mechanism of sedimentation and continuum anoxic conditions prevailing in a basin, as well the important role of nutrient input from continental runoff as a trigger of high productivity and extended anoxia conditions. (C) 2018 Elsevier B.V. All rights reserved.
机译：哥伦比亚的白垩纪黑色页岩是南美洲北部最重要的演替之一，并且在过去的几十年中，由于它们的高碳氢化合物潜力和翡翠矿床的存在，吸引了许多地球学家和勘探公司的关注。然而，关于其构造背景，层序地层学，沉积环境，旧加氧条件和有机物的保存，仍然存在许多不确定性。为了更全面地了解这些不同过程和条件，我们进行了详细的沉积学，无机地球化学（U，V，Ni，Zn，Mn，Fe，Ti，Mo，Cu，Cr，Cd，Ba）和序列哥伦比亚马格达莱纳-塔布拉索次盆地（东部科迪勒拉盆地）的白垩纪黑色页岩地层分析。确定了一个以风暴为主的硅质碳酸盐岩斜坡的11个岩相和5个岩相组合，范围从盆地到浅的内部斜坡环境。这些相被分为六个三阶地层层序，显示了在Valanginian晚期至Coniacian晚期海侵的高阶循环和受约束的逆冲脉冲。黑色页岩层序代表缺氧底水下的沉积，某些间隔代表缺氧-缺氧条件。沉积环境的演变及其旧的加氧历史反映了构造和欢乐的海平面控制，这些控制是：1）在整个白垩纪产生了不同的海岸线取向和位置； 2）调节低梯度坡道几何形状（<0.3度），3）修改Magdalena-Tablazo子盆地的充氧条件。对马格达莱纳-塔布拉索次盆地中白垩纪黑色页岩沉积过程中沉积环境的更好理解有助于强调沉积机理与盆地普遍存在的连续缺氧条件之间的相互作用，以及来自营养物输入的重要作用大陆径流是高生产力和缺氧条件的触发因素。 （C）2018 Elsevier B.V.保留所有权利。

著录项

相似文献

  • 外文文献
  • 中文文献
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