Petrotectonic setting of the provenance of Lower Siwalik sandstones of the Himalayan foreland basin, southeastern Kumaun Himalaya, India

Abstract

Detailed petrography and modal analysis of 35 sandstone thin sections was carried out to determine petrotectonic setting of the provenance of the Lower Siwalik molasse of southeastern Kumaun Himalaya. The sandstones are fine‐ to coarse‐grained (0.14–0.63 mm), poorly‐ to moderately‐sorted and comprise lithic arenites, sublithic arenites and lithic greywackes. The sandstones invariably belong to the quartzolithic QtFL (Qt, total quartz; F, feldspar; L, lithic grains) and QmFLt (Qm, monocrystalline quartz; Lt, lithic grains plus polycrystalline quartz) petrofacies, and indicate their derivation from a quartzose‐ and transitional‐recycled orogen provenance under sub‐humid climatic conditions. The framework composition of the sandstones comprises abundant monocrystalline and polycrystalline quartz and low‐ to high‐grade metamorphic rock fragments, along with subordinate feldspar, characterized by low ratios of plagioclase to total feldspar, and accessory minerals. The framework composition and petrofacies characters of these texturally submature sandstones suggest their derivation mainly from the nearby located Great Himalaya terrane and subordinately from the Tethys and Lesser Himalayan terranes. A comparison of the data presented here with the previous similar data from Lower Siwalik of northwestern Pakistan, northwestern India, south‐central Kumaun, western Nepal and southeastern Nepal reveals that like the Lower Siwalik rivers in other sections, the Lower Siwalik rivers of the southeastern Kumaun too drained large parts of the Great Himalayan terrane and some parts of the Tethys and Lesser Himalayan terranes.

Autogenic and allogenic controls on the temporal palaeographic evolution of the Himalayan foreland basin: Insights from facies analysis of the lower Siwalik succession, Kumaun Himalaya, India

“…It was influenced by monsoonal precipitations that intensified during the Middle–Late Miocene as the rising up of the Tibeto‐Himalayan zone drastically changed the heat budget of the region (Amano & Taira, 1992; Burkle, 1989; Harrison et al, 1993; Hoorn et al, 2000; Patnaik et al, 2005; Schrader, 1974). Bivariate log–log plots of Q t / F + L versus Q p / F + L (where Q t is total quartz, Q p is polycrystalline quartz, F is feldspar, and L is lithic fragments) of the sandstones (Suttner & Dutta, 1986) reveal sub‐humid climate in the catchments of Lower Siwalik rivers of the study area and neighboring south‐eastern Kumaun (Bora & Shukla, 2005, figure 11; Goswami & Deopa, 2018b, figure 7). Moreover, the sedimentary record of the Bengal fan brings out that a substantial amount of sediment was deposited in the distal fan during the Early to Middle Miocene due to faster erosion in the Himalayan orogen in response to significant pulse of rapid tectonic uplift (Copeland & Harrison, 1990).…”

Petrography and Lithofacies of the Siwalik Group in the Core of Hazara-Kashmir Syntaxis: Implications for Middle Stage Himalayan Orogeny and Paleoclimatic Conditions

“…The Paleogene deposits of the basin are exposed only along a few sectors of the HFB and have different names in different areas. However, the Neogene alluvial strata are well exposed continuously throughout the length of the HFB, from the Indus Valley (Pakistan) in the west to the Irrawaddy Valley (Myanmar) in the east, and these deposits are known as the Siwalik Group [7]. sectors of the HFB and have different names in different areas.…”

“…sectors of the HFB and have different names in different areas. However, the Neogene alluvial strata are well exposed continuously throughout the length of the HFB, from the Indus Valley (Pakistan) in the west to the Irrawaddy Valley (Myanmar) in the east, and these deposits are known as the Siwalik Group [7]. [8], Avouac, et al [9], Greco [10], Baig and Lawrence [11], Calkins, et al [12] and Wadia [13]).…”

Provenance of the Middle Siwalik sandstones of the Himalayan foreland basin (south central Kumaun, India): Implications for tectonics and paleoclimate of the source area

“…Petrographic analysis is a powerful tool for determining lithological assemblage, tectonic setting, location, and climate of the provenance of sand(stones) (Critelli, ; Haughton, Todd, & Morton, ; Weltje & von Eynatten, ). In general, reliable inferences on these aspects are drawn by integrating the information on assemblages and characters of major as well as accessory framework constituents of sand(stones) with that on the modal composition of their major framework constituents (Basu, ; Caracciolo, Critelli, Innocenti, Kolios, & Manetti, ; Castillo, Lacassie, Augustsson, & Hervé, ; Critelli et al, ; Critelli & Ingersoll, ; Dickinson & Suczek, ; Garzanti, Critelli, & Ingersoll, ; Goswami & Deopa, ; Ingersoll, ; Ingersoll & Suczek, ; Lee, Yi, & Choi, ; Suttner & Dutta, ; Zhang et al, ; and references therein). Moreover, petrographic analysis of synorogenic sand(stones), such as those deposited in foreland basins, provides additional information on the tectonic developments and unroofing‐erosion history of the hinterland (e.g., Critelli, ; Critelli et al, ; Critelli, Muto, Perri, & Tripodi, ; DeCelles et al, ; Najman et al, ; Qayyum, Niem, & Lawrence, ).…”

“…Sandstone petrography along these lines has been applied by many workers to determine lithotectonic and climatic characters and unroofing‐erosional patterns of the source areas for the discrete sectors of the Himalayan foreland basin's fill (e.g., Chaudhri, ; Critelli & Garzanti, ; Critelli & Ingersoll, ; Garzanti et al, ; Goswami & Deopa, ; Kundu, Matin, & Eriksson, ; Kundu, Matin, & Mukul, ; Mughal et al, ; Najman et al, , ; Parkash, Sharma, & Roy, ; Singh, ; Singh, ; Singh, Pawar, & Karlupia, ; Tandon, ; and references therein). However, the studies carried out so far are insufficient to clearly portray the spatio‐temporal variations in these characters of the hinterland, for the reason that many sectors of this laterally and temporally vast basin are still unstudied, probably owing to dense forest cover and intense deformation.…”