Abstract The Lower Rewa Sandstone of the Rewa Group exposed in Drummondganj ghat area is about 15 m thick; it shows well developed features of tidal and wave origin. The sandstone succession characterized by Inclined Heterolithic Strata (IHS) is composed of three lithofacies associations namely, i) Sandstone lithofacies association (A), ii) Siltstone lithofacies association (B) and iii) Shale lithofacies association (C). These three lithofacies associations are repetitive and signify vertically stacked parasequences, which are further divisible into smaller hemicycles showing fining upward in terms of grains size and lithology. The studied section is characterized by heterolithic facies, lateral accretion elements (LA surfaces) with tide generated features such as cross-beddings with mudstone drapes, lenticular and wavy bedding, often of wave origin, suggesting a tidal point bar of a sinuous estuarine channel formed along coast line having momentous tidal action, superimposed by significant wave action. The upper part of the section, characterized by erosionally based cross-bedded sand-bodies with occasional mudstone drapes and current modified wave ripples, indicates translation of river-dominated inner part of an estuarine channel over the mixed-energy zone of the estuary based on estuarine facies models proposed by Dalrymple et al. (1992). The complete Lower Rewa Sandstone represents a 3rd order Highstand Systems Tract (HST). Palaeocurrent pattern is polymodal suggesting subtidal to intertidal sedimentation whereby sediment was moved mainly by tidal action with intermittent wave activity. Petrographic study reveals that the fine to very-fine grained sandstone is quartzarenite, which has been derived from a stable cratonic uplifted basement.

中文翻译：

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印度北部 Vindhyan 盆地新元古代 Rewa 群的异石下 Rewa 砂岩：潮点坝的一个例子

摘要 Drummondganj ghat 地区出露的Rewa Group 下Rewa 砂岩厚约15 m；它显示了潮汐和波浪起源的发达特征。以倾斜异石岩地层（IHS）为特征的砂岩系列由三个岩相组合组成，即i）砂岩岩相组合（A），ii）粉砂岩岩相组合（B）和iii）页岩岩相组合（C）。这三个岩相组合是重复的，表示垂直堆叠的准层序，它们可以进一步分为更小的半圈，在晶粒尺寸和岩性方面显示向上细化。研究剖面的特征为异岩相、横向增生元素（LA 面），具有潮汐生成特征，如泥岩披覆交错层理、透镜状和波浪状层理，通常起源于波浪，表明沿着海岸线形成的蜿蜒河口通道的潮汐点棒具有重大的潮汐作用，叠加有显着的波浪作用。该剖面的上部，以侵蚀为基础的交错层砂体为特征，偶尔有泥岩褶皱和电流修正波波纹，表明河口河道内部以河流为主的部分在河口混合能源带上的平移Dalrymple 等人提出的河口相模型。(1992)。完整的下雷瓦砂岩代表了三阶高位系统区域 (HST)。古洋流模式是多峰的，表明潮下至潮间带沉积，其中沉积物主要通过潮汐作用和间歇性波浪活动移动。