Provenance, Tectonic Setting and Palaeoclimate of the Neogene Sandstones in the Naga Schuppen Belt, Indo‐Myanmar Range, India

ABSTRACT In this study, mineralogy and modal components of sandstones from the Neogene Surma and Tipam Groups in the Assam‐Arakan Basin were analysed to understand their provenance, tectonic setting, and palaeoclimate. Petrographic composition and heavy mineral assemblages suggest that most of the sandstones have been supplied by a mixed provenance. However, an increase in the metamorphic detrital input has been observed in the overlying sandstones of the Tipam Group, suggesting more contribution from a metamorphic source. Modal analysis of the Neogene sandstones also suggests a mixed provenance where most of the sandstones were supplied from a recycled orogeny comprising collision suture, fold‐thrust belt, arc orogen, and subduction complex sources. With changing tectonics and the upliftment of the Shillong Plateau and/or Karbi Anglong massif, the supply of sediments from the Indian Craton and Eastern Himalayas into the Assam‐Arakan Basin decreased. Though the supply of sediments from the Eastern Himalayas continued until the end of the deposition of the Tipam Group, the detrital input from the uplifted Naga Ophiolites and Naga Metamorphics had increased significantly. Palaeoclimate analysis for the sandstones reflects a semi‐humid climate during the deposition of both marine Surma and fluvial Tipam Groups, which coincides with the Miocene Climatic Optimum.