Abstract This study presents an overview of Mesozoic transgressions that influenced the palaeogeography of central India, and offers an analysis of the existing evidence for the interpretation of the depositional record of infra- and inter-trappean sequences. These data are then used to understand the respective palaeogeographic settings of the Narmada and the Godavari master valleys, leading to a reappraisal of the paths suggested thus far for a Cretaceous-Tertiary (K-T) seaway. Major rift related discontinuities have been subjected to reactivation episodes during the Mesozoic. These tectonic events caused the initiation of several pericratonic basins. The riftogenic valley systems have been affected by transgressions from the western margin of India through the Narmada valley; and/or from the eastern margin through the Godavari valley. However, for the most part, these continent-scale valley systems have hosted mainly Mesozoic fluviatile and lacustrine sediment successions. Besides, a marine incursion from the west in the lower reaches of Narmada Valley is widely recognised on the basis of the Late Cretaceous Bagh Beds. Additionally, the Maastrichtian palaeogeography of these valley systems of central India have been strongly influenced by the uplift resulting from the thermo-magmatic flux associated with the Deccan volcanism. This resulted in major topographic readjustments within the Godavari and Narmada-Tapti palaeovalleys resulting in turn, in major basinal depressions as revealed from the reconstruction of the palaeo-digital elevation model. Significantly removed from the eastern and western coastal margins of India, isolated occurrences of marine biota such as foraminifera, marine algae and palm fossils have been found in infra- and inter-trappean (Maastrichtian and Danian) sequences of central India. Their presence in these inland basins is enigmatic and three hypotheses have been proposed to explain the presence of marine environments in these basins: (a) “Trans Deccan Strait”, connecting both the margins of India through pre-existing rift systems; (b) an ~800 km long seaway through the Narmada valley; and (c) a marine incursion through the Godavari valley. This palaeogeographic analysis supports a marine incursion through the Godavari rift and presents arguments against the other two.

中文翻译：

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印度中部的二叠纪-白垩纪陆上海道：白垩纪-第三纪侵入的纳尔马达与戈达瓦里裂谷的争论

摘要 本研究概述了影响印度中部古地理的中生代海侵，并对现有证据进行了分析，以解释下圈层和圈层间层序的沉积记录。然后将这些数据用于了解纳尔马达和戈达瓦里主山谷各自的古地理环境，从而重新评估迄今为止建议的白垩纪-第三纪 (KT) 航道路径。在中生代期间，与裂谷相关的主要不连续性经历了再激活事件。这些构造事件导致了几个周边盆地的形成。裂谷系统受到了从印度西部边缘到纳尔马达河谷的海侵的影响；和/或从东部边缘穿过戈达瓦里山谷。然而，在大多数情况下，这些大陆尺度的山谷系统主要承载着中生代河流和湖泊沉积层序。此外，在晚白垩世巴格床的基础上，人们普遍认识到纳尔马达河谷下游西部的海侵。此外，印度中部这些山谷系统的马斯特里赫特古地理受到与德干火山活动相关的热-岩浆通量引起的隆起的强烈影响。这导致了 Godavari 和 Narmada-Tapti 古河谷内的主要地形重新调整，进而导致了从古数字高程模型重建中揭示的主要盆地洼地。明显远离印度东部和西部沿海边缘，孤立的海洋生物群，如有孔虫、海藻和棕榈化石已在印度中部的下层和圈层（马斯特里赫特和大年）层序中发现。它们在这些内陆盆地的存在是个谜，已经提出了三个假设来解释这些盆地中海洋环境的存在： (a) “跨德干海峡”，通过预先存在的裂谷系统连接印度的两个边缘；(b) 一条约 800 公里长的海道穿过纳尔马达山谷；(c) 一次通过戈达瓦里河谷的海洋入侵。这种古地理分析支持了通过戈达瓦里裂谷的海洋入侵，并提出了反对其他两个的论点。它们在这些内陆盆地的存在是个谜，已经提出了三个假设来解释这些盆地中海洋环境的存在： (a) “跨德干海峡”，通过预先存在的裂谷系统连接印度的两个边缘；(b) 一条约 800 公里长的海道穿过纳尔马达山谷；(c) 一次通过戈达瓦里河谷的海洋入侵。这种古地理分析支持了通过戈达瓦里裂谷的海洋入侵，并提出了反对其他两个的论点。它们在这些内陆盆地的存在是个谜，已经提出了三个假设来解释这些盆地中海洋环境的存在： (a) “跨德干海峡”，通过预先存在的裂谷系统连接印度的两个边缘；(b) 一条约 800 公里长的海道穿过纳尔马达山谷；(c) 一次通过戈达瓦里河谷的海洋入侵。这种古地理分析支持了通过戈达瓦里裂谷的海洋入侵，并提出了反对其他两个的论点。