Lithofacies architecture and depositional environment of Late Cretaceous Lameta Formation, central India
Lithofacies architecture and depositional environment of Late Cretaceous Lameta Formation, central India
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DOI：
10.1007/s12517-013-1192-y
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发表时间：
2013
影响因子：
--
通讯作者：
A. Srivastava;Rupesh S. Mankar
中科院分区：
文献类型：
--
作者：
A. Srivastava;Rupesh S. Mankar
在一个有三个相邻暴露的新区，对Lameta组进行了岩相建立和沉积环境解释。总体而言，层序大致可分为三个主要单元，即下部的砂质、中部的泥质和上部的钙质，它们或多或少地构成了三个岩相组合。每个组合由各种岩相组成，这些岩相是在野外观察的基础上确定和建立的，并添加了重要的岩石学细节。砂质组合包括块状砂岩相、绿色砂岩相、薄层、黄橙子、灰棕色砂岩相、粗粒砂岩相和深棕色生物扰动砂岩相5种岩相。泥质岩相组合由黄褐绿粘土-粉砂岩岩相和浅灰色粉质粘土-结核岩相组成，钙质岩相组合由钙质结砾岩岩相、结核灰岩岩相、硅化灰岩岩相和层内角砾岩岩相组成。相分析表明，晚白垩世Lameta沉积发生在半干旱条件下的河湖相环境中。
Establishment of lithofacies and interpretation of depositional environment of the Lameta Formation have been carried out for a new area having three nearby exposures. Overall, the successions are broadly differentiable into three major units, i.e. arenaceous in the lower part, argillaceous in middle and calcareous at the top, which more or less serve as three lithofacies associations. Each association consists of various lithofacies which are identified and established on the basis of field observations, added with significant petrological details. The arenaceous association includes five lithofacies, viz. massive sandstone lithofacies; green sandstone lithofacies; thinly bedded, yellowish orange and greyish brown sandstone lithofacies; coarse-grained sandstone lithofacies and dark brown bioturbated sandstone lithofacies. The argillaceous lithofacies association consists of yellowish-brownish-greenish clay–siltstone lithofacies and light grey silty–clay with concretions lithofacies, whereas the calcareous lithofacies association is represented by calcrete lithofacies, nodular limestone lithofacies, chertified limestone lithofacies and intraformational breccia lithofacies. The facies analysis reveals that the deposition of Late Cretaceous Lameta sediments took place in fluvial–lacustrine environments in semi arid condition.