Occurrence of slump folds and associated faults generated by soft-sediment deformation from the Paleoproterozoic Vempalle Formation, southwestern Cuddapah basin, India, is being reported here for the first time. The slump horizon is preserved within a more or less undeformed shallow to deep-water carbonate unit in the Cuddapah basin exposed near Parnapalle village, Andhra Pradesh, India. The stratigraphic framework includes the Gulcheru Quartzite, lowermost unit of the Cuddapah basin succession, deposited in an alluvial to shallow marine shelf environment, and the overlying Vempalle Formation, representing a ramp-type stromatolitic carbonate platform. The synsedimentary sliding along a steepened ramp is evidenced by northeast-verging kink-like folds with wavelength up to 400 m and an overprinting set of thrusts with ramp-flat geometry, fault-cored folds or small break-thrusts showing top-to-southwest displacement, and smaller congruent folds. From the isolated occurrence within a generally undeformed succession, association of structures, and the stratigraphic context, we suggest soft-sediment deformation at the toe of a large (kilometer-scale) slump, with the prevalent bedding-parallel anisotropy exploited for common flexural slip and ramp-flat geometry. In addition, the bedding-parallel slickensides in the Gulcheru Quartzite immediately below the Vempalle Formation indicate a top-to-east-northeast, normal sense of slip representing extensional slip at the slump head. Northeast-verging large folds in the Parnapalle slump horizon possibly represent structures formed during the translation phase of slumping. As the large northeast propagating slump was halted, the backthrust-like structures and associated folds developed at the slump toe.

中文翻译：

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印度南部Cuddapah盆地古元古代Vempalle组大坍塌地层的变形结构

印度库达帕盆地西南部古元古代Vempalle组软沉积物变形产生塌陷褶皱和相关断层的报道首次在此报道。在印度安得拉邦Parnapalle村附近暴露的Cuddapah盆地中，塌陷层保留在一个或多或少未变形的浅水至深水碳酸盐岩单元中。地层框架包括Gulcheru石英岩，Cuddapah盆地演替的最低单元，沉积在冲积到浅海架环境中，以及上覆的Vempalle地层，代表了斜坡型叠层碳酸盐岩台地。沿陡峭斜坡的同滑滑动由波长达400 m的东北向扭结状褶皱和斜面几何形状的一组逆冲叠印证明，断裂带褶皱或小断裂冲断，显示出自上而下的西南位移，较小的全褶皱。从通常未变形的演替，构造的关联以及地层环境中的孤立事件来看，我们建议在大（千米级）坍落度的脚趾处进行软沉积变形，并利用普遍的顺应层状平行各向异性来进行普通挠曲滑移和斜面几何。此外，在Vempalle组正下方的Gulcheru石英岩中，与顺层平行的光滑滑石表明了从上到东向东北的正常滑移感，代表坍落度头处的伸展滑移。在Parnapalle坍塌地平线中，东北向的大褶皱可能代表着坍塌的平移阶段形成的结构。随着东北大萧条的停止，