The Palghat Cauvery Shear Zone (PCSZ), which dissects the Southern Granulite Terrane (SGT), evoked much attention for last two‐three decades as it offers an enticing opportunity to understand Precambrian tectonics. Many studies suggest that it is a suture zone or a terrane boundary, but tectonic evolution is mainly derived from structural and geochronological evidences. The present gravity‐magnetic study provides insight into both shallow and deeper crustal architecture and addresses the issues related to validation/modification of the existing tectonic realm. A total of 3,650 gravity and magnetic measurements were made covering ~8,640 km² area, represented by high‐grade metamorphic rocks and acid intrusives of Archean to Neoproterozoic age. Representative rock samples were also collected for determination of petrophysical properties (density and susceptibility) which have augmented the understanding of gravity‐magnetic signature. The gravity anomaly map and subsequent modelling suggest an occurrence of a high‐density batholith at mid‐crustal level at the central part of the area. The magnetic anomaly map reveals that ENE‐WSW trending linear magnetic low zone is coincident with a residual gravity high, which probably indicates the fossil of an oceanic crust. The horizontal gradient of gravity‐magnetic data reveals the shallow crust, which is bounded by Palghat Cauvery Shear Zone (PCSZ) and Dharapuram Shear Zone (DSZ), and separates two terranes in terms of density and susceptibilities. The study suggests N‐S verging compressional tectonics had led to closure of an ocean, imprints of which is well manifested in gravity and magnetic maps.

中文翻译：

---

通过对重力和磁数据的综合分析，深入了解印度Palghat Cauvery剪切带的地壳建筑和构造

帕格哈特切瓦尼剪切带（PCSZ）解剖了南部的花岗岩颗粒（SGT），在过去的二十三年中引起了人们的极大关注，因为它提供了一个诱人的机会来了解前寒武纪构造。许多研究表明，它是缝合带或地层边界，但构造演化主要来自结构和年代学证据。当前的重力磁性研究提供了对浅层和深层地壳结构的洞察力，并解决了与现有构造领域的验证/修改有关的问题。总共进行了3,650次重力和磁测量，覆盖〜8,640 km ²以高等变质岩和太古代至新元古代的酸性侵入体为代表。还收集了具有代表性的岩石样品，以确定岩石物性（密度和磁化率），这加深了对重力磁特征的理解。重力异常图和随后的建模表明，在该区域的中部地壳中部出现了高密度的岩基。磁异常图显示，ENE-WSW趋势线性磁低区与剩余重力高重合，这很可能说明了海洋地壳的化石。重力磁数据的水平梯度揭示了浅层地壳，其边界为Palghat洞穴剪​​切带（PCSZ）和达拉普拉姆剪切带（DSZ），并根据密度和磁化率将两个地层分开。该研究表明，N‐S压缩构造构造导致了海洋的封闭，其烙印在重力和磁图上得到了很好的体现。