Integrated provenance and tectonic implications of the Cretaceous–Palaeocene clastic sequence, Changla Gali, Lesser Himalaya, Pakistan

Abstract

This study documented the field relationship and integrated provenance of a clastic sequence exposed at the Mesozoic–Cenozoic boundary located in Changla Gali section, Lesser Himalaya, Pakistan, to provide an insight into Cretaceous tectonics of the northern Indian margin. This boundary sequence is represented by the Early Palaeocene Hangu Formation, which consists of shales in the lower part and sandstone in the upper part. The contact relationship of the Early Palaeocene Hangu Formation with the underlying Late Cretaceous Kawagarh Formation is marked by an angular unconformity. The detrital zircons extracted from the shale and sandstone samples shows a major age cluster, which varies between ~700 and ~1,100 Ma (45%), ~1,600 and ~1,900 Ma (15%), and ~480 and ~590 Ma. Additionally, two minor age clusters of the detrital zircons are identified, that is, ~2,300–2,500 Ma and ~600–700 Ma. The younger detrital zircon grains have ages of 298 ± 4 Ma, 297 ± 4 Ma and 116 ± 3 Ma. This age pattern reflect the major source area as the Indian Plate. The two younger Permian zircon grains may be derived from the Panjal mafic volcanic rocks exposed in the vicinity of the study area. However, a single Cretaceous grain may be attributed to ophiolites, as well as Tethyan Himalayan (TH) volcanic rocks. Similarly, the sandstone petrographic results show that the sandstones are quartz‐rich, which show derivation from the craton interior provenance, which is likely the Indian Plate. However, the trace element data suggest a mixed source consisting of felsic and mafic rocks. The contribution of the mafic source is likely associated with the Panjal mafic rocks exposed along the northern Indian margin. The field relationship shows that the underlying Mesozoic sequence is folded prior to the deposition of the Hangu Formation. This folding suggests that the northern Indian margin experienced a regional compression during the Late Cretaceous time, which folded the Mesozoic sequence before the resumption of sedimentation during the Palaeocene. Furthermore, the detrital zircon provenance suggests that the sediments were mainly derived from the Indian Plate. Combining the results, it can be concluded that the compressional event is likely associated with the Late Cretaceous ophiolite obduction onto the leading edge of the Indian Plate. However, the absence of the major ophiolitic age component in the detrital record may suggest that the ophiolites were emplaced over the northern Indian margin but remained submerged during Early Palaeocene time.

Indian plate paleogeography, subduction and horizontal underthrusting below Tibet: paradoxes, controversies and opportunities

“…The Lesser Himalaya consists of a Proterozoic to Paleozoic, low-grade metasedimentary, and discontinuous Cretaceous-to-Paleocene clastic sedimentary rocks, in places overlain by Eocene and Miocene foreland basin clastics [ 57 ]. Upper Cretaceous-to-Eocene clastic sedimentary rocks become more prominent towards the west, in Pakistan, where Eocene and younger foreland basin clastics are also found on the undeformed Indian continent [ 65 , 66 ]. The provenance of Upper Cretaceous and Eocene foreland basin clastics in the Lesser Himalayas and on the northwest Indian continent reveal erosion of Indian margin rocks and ophiolites that signal Eocene or older obduction, and is commonly interpreted to reflect collision recorded in the Tethyan Himalaya to the north [ 33 , 57 , 65 , 66 ].…”

“…Upper Cretaceous-to-Eocene clastic sedimentary rocks become more prominent towards the west, in Pakistan, where Eocene and younger foreland basin clastics are also found on the undeformed Indian continent [ 65 , 66 ]. The provenance of Upper Cretaceous and Eocene foreland basin clastics in the Lesser Himalayas and on the northwest Indian continent reveal erosion of Indian margin rocks and ophiolites that signal Eocene or older obduction, and is commonly interpreted to reflect collision recorded in the Tethyan Himalaya to the north [ 33 , 57 , 65 , 66 ]. However, the western margin of India was also the locus of orogenesis due to ophiolite emplacement in a Late Cretaceous and an Eocene phase, but this obduction was governed by convergence between the Indian and Arabian plates and the collision of the Kabul microcontinent with west India [ 67 ].…”

Multiphase Diagenetic Processes and Their Impact on Reservoir Character of the Late Triassic (Rhaetian) Kingriali Formation, Upper Indus Basin, Pakistan

“…It, therefore, represents a comparable analogue for age-equivalent carbonate reservoirs in North Africa [18]. Detailed investigation of these dolostones of the Kingriali Formation is essential for their correlation with the same multiphase dolomitized hydrocarbon reservoirs around the world and in the Indus basin of Pakistan [19,20]. Multiphase dolomitization may increase or decrease the porosity and permeability characteristics and modify the reservoir quality accordingly [19].…”

First U-Pb Detrital Zircon Ages from Kamlial Formation (Kashmir, Pakistan): Tectonic Implications for Himalayan Exhumation

“…Sedimentary rocks in the basin hold information about fluctuations in sea level, origins of sedimentary rocks, and the tectonic history of the basin [3]. The sedimentary archives of the foreland basins are extensively analyzed using modern techniques such as U-Pb dating [4][5][6][7][8] to estimate the maximum depositional ages and constrain the sediment provenance. This is a powerful tool in identifying the precise information about the sediment provenance, which is very important in explaining the paleogeographic reconstructions of the terranes in geological history [9][10][11].…”