Gangdese arc detritus within the eastern Himalayan Neogene foreland basin: Implications for the Neogene evolution of the Yalu–Brahmaputra River system

2009 ◽  
Vol 285 (1-2) ◽  
pp. 150-162 ◽  
Author(s):  
Sara E. Cina ◽  
An Yin ◽  
Marty Grove ◽  
Chandra S. Dubey ◽  
Dericks P. Shukla ◽  
...  
Keyword(s):  
Foreland Basin ◽  
River System ◽  
Brahmaputra River

Multiproxy records on the fluvial successions of Assam-Arakan Basin: Implication for paleo-drainage evolution

2020 ◽  
Author(s):  
Priti Rai ◽  
Biraj Borgohain ◽  
George Mathew
Keyword(s):  
Detrital Zircon ◽  
Drainage System ◽  
Foreland Basin ◽  
River System ◽  
Heavy Mineral ◽  
Heavy Minerals ◽  
Brahmaputra River ◽  
Electron Probe Micro Analyzer ◽  
Fluvial Sedimentation ◽  
Namche Barwa

<p>Assam-Arakan Basin comprises Cenozoic sedimentary successions, located in northeastern India is juxtaposed to both the Himalaya and Indo-Burman Ranges (IBR). The Upper Miocene-Pliocene (Tipam sandstone) and the overlying younger Upper Pliocene-Pleistocene units (Dupi-Tila/Namsang/Dihing) of this foreland basin are fluvial successions. Heavy mineral as detritus provenance indicator has been used as one of the multiproxy records on the fluvial sequences of Assam-Arakan Basin to unravel the drainage system that deposited the same in this basin. Previous workers have advocated that the paleo-Brahmaputra river had initially flowed east of Shillong Plateau before being deflected northwesterly taking the present-day course parallel to the Plateau. However, unequivocal evidence of paleo-Brahmaputra remains enigmatic. The study demonstrates the provenance for the fluvial sedimentary units of the above foreland basin using petrography and heavy mineral distributions. X-ray Diffraction (XRD) and Electron Probe Micro Analyzer (EPMA) analyses were employed to correctly identify the heavy mineral species and support the semi-quantitative analysis of heavy minerals in the basin. The outcome of the study provides new insights towards the paleo-drainage evolution of the river course accountable for the fluvial sedimentation in the Assam-Arakan Basin. Clast petrography and heavy mineral observations indicate the probable source from Lohit- Dibang valley. Initial analysis of detrital zircon U-Pb ages from studied samples reveals major age peaks at around 500 Ma and 1025 Ma with young ages between 16 Ma and ~140 Ma. These samples do not provide ages < 10 Ma, signifying the sediments not derived from Namche Barwa massif, eroded by the Tsangpo-Siang-Brahmaputra river system. It is in contrast to similar sediments in the Siwaliks of NE Himalaya. The data supports our observation that the paleo-Brahmaputra seems not the cause for these deposits, at least during the Pleistocene. If Paleo-Brahmaputra got diverted during this period, it requires scanning the detritus from Tipam units and additional samples from Dupi-Tila/Namsang/Dihing units across the entire Assam-Arakan range to infer source and drainage system for these deposits. We tentatively propose that the Tipam and the younger Dupi-Tila/Namsang/Dihing units in the Assam-Arakan Basin were deposited by drainage flowing from Dibang-Tezu valley, that was initially linked to the Irrawaddy river system. The uplift along Naga thrust caused drainage migration, eventually meeting the present-day Brahmaputra course.</p><p>Keywords: Heavy mineral; Detrital zircon U-Pb ages; Paleo-Brahmaputra; Assam-Arakan Basin</p>

scholarly journals Downstream and seasonal changes of lithium isotope ratios in the Ganges‐Brahmaputra river system

2017 ◽  
Vol 18 (8) ◽  
pp. 3003-3015 ◽  
Author(s):  
Takuya Manaka ◽  
Daisuke Araoka ◽  
Toshihiro Yoshimura ◽  
H. M. Zakir Hossain ◽  
Yoshiro Nishio ◽  
...  
Keyword(s):  
Seasonal Changes ◽  
River System ◽  
Isotope Ratios ◽  
Lithium Isotope ◽  
Brahmaputra River ◽  
The Ganges

scholarly journals Lithofacies and depositional environment of the Siwalik Group in Samari-Sukaura River area, Central Nepal

2013 ◽  
Vol 16 ◽  
pp. 53-64 ◽  
Author(s):  
Dev Kumar Syangbo ◽  
Naresh Kazi Tamrakar
Keyword(s):  
Depositional Environment ◽  
Foreland Basin ◽  
River System ◽  
Nepal Himalaya ◽  
Meandering River ◽  
Fine Grained ◽  
Architectural Elements ◽  
Central Nepal ◽  
Eastern Zone ◽  
Siwalik Group

Thick sedimentary sequence deposited in the foreland basin of the Nepal Himalaya is represented by the Siwalik Group. The Siwalik Group is well exposed in the Samari-Sukaura River area. The present study is focused in southern portion of the MBT around the Samari-Sukaura area for its depositional environment. The Middle Siwaliks of the Sukaura Road sections is overlained by the Lower Siwaliks which is separated by the Karki Khola Thrust. Extension of the Lower Siwaliks in the Jyamire Khola and the Bundal Khola becomes wider in the eastern Zone. Repetition of the Lower Siwaliks along the southern margin of the MBT is recognized. Depending on lithofacies assemblage and facies analysis, the two broad facies assemblages FA1 and FA2 have been distinguished. FA1 shows SB, FF, LA, LS and CH architectural elements and is interpreted as a product of the fine-grained meandering river system. FA2 shows SB, FF, LA, DA and CH architectural elements and is interpreted as a product of sandy mixed-load meandering river system. DOI: http://dx.doi.org/10.3126/bdg.v16i0.8884   Bulletin of the Department of Geology Vol. 16, 2013, pp. 53-64

Re-Os isotope systematics of sediments of the Brahmaputra River system

2003 ◽  
Vol 67 (21) ◽  
pp. 4101-4111 ◽  
Author(s):  
Sunil K. Singh ◽  
Laurie Reisberg ◽  
Christian France-Lanord
Keyword(s):  
River System ◽  
Brahmaputra River ◽  
Isotope Systematics ◽  
Os Isotope

scholarly journals Paleocurrents, Paleohydraulics, and Palaegeography of Miocene-Pliocene Siwalik Foreland Basin of India

2015 ◽  
Vol 2015 ◽  
pp. 1-14
Author(s):  
Zahid A. Khan ◽  
Ram Chandra Tewari
Keyword(s):  
Indian Subcontinent ◽  
Foreland Basin ◽  
River System ◽  
Bimodal Distribution ◽  
Flood Plain ◽  
North India ◽  
Morphological Attributes ◽  
Gangetic Plains ◽  
Braided Rivers ◽  
Middle Siwalik

Early Miocene-Pliocene Middle Siwalik Subgroup of Kuluchaur area, Uttarakhand, North India, comprises sheet-like, coarse to medium grained, cross bedded sandstone bodies and multistoreyed variegated mudstones. Paleocurrent study shows commonly unimodal and locally bimodal distribution and displays a high magnitude of resultant (R*=0.7337) oriented towards south-southwest (206°  ±  42.27°). Palaeochannel morphological attributes suggest that the depositing river system was about 230 m wide and 4.5 m deep. These broad, shallow, and low sinuous channels with extensive flood plain flowed on a steeper slope (0.00043 degrees) with flow velocity of 60–140 cm/sec. It is visualized that the immature Middle Siwalik rocks were deposited by southward flowing braided rivers transverse to the Himalayas, predominantly in the form of overlapping alluvial fans similar to those depositing sediments at present in the Indo-Gangetic plains. Fairly consistent fluvial palaeoslopes, together with enormous thickness of sediments, are evidences of rapid subsidence of the basin. We conclude that the paleogeography of Indian subcontinent established at the onset of Miocene-Pliocene Siwalik sedimentation is continuing till today.

scholarly journals Stable Strontium Isotopic Compositions of River Water, Groundwater and Sediments From the Ganges–Brahmaputra–Meghna River System in Bangladesh

2021 ◽  
Vol 9 ◽  
Author(s):  
Toshihiro Yoshimura ◽  
Shigeyuki Wakaki ◽  
Hodaka Kawahata ◽  
H. M. Zakir Hossain ◽  
Takuya Manaka ◽  
...  
Keyword(s):  
River Water ◽  
Chemical Weathering ◽  
Drainage Basin ◽  
Dissolution Kinetics ◽  
River System ◽  
Ganges River ◽  
Brahmaputra River ◽  
Terrestrial Water ◽  
Stable Strontium ◽  
The Ganges

The Sr isotopic composition of rivers and groundwaters in the Bengal Plain is a major contributor to the global oceanic Sr inventory. The stable strontium isotope ratios (δ88Sr) provide a new tool to identify chemical weathering reactions in terrestrial water. In this study, we investigated the spatiotemporal variations of δ88Sr in samples of river water, bedload sediment, and groundwater collected from the Ganges–Brahmaputra–Meghna drainage basin in Bangladesh, which is known to strongly influence the 87Sr/86Sr ratio in seawater. The average δ88Sr values of waters of the Ganges, Brahmaputra, and Meghna rivers were 0.269, 0.316, and 0.278‰, respectively. Our data showed little difference between seasons of high and low discharge. The δ88Sr values measured in sequential leaching fractions of sediments varied from –0.258 to 0.516‰ and were highest in the silicate fraction, followed in turn by the carbonate fraction and the exchangeable fraction. Both 87Sr/86Sr and δ88Sr of these waters are primarily controlled by the inputs of Sr in weathering products from the Bengal Plain and Sr from the Himalayan rivers (Ganges and Brahmaputra). Values of δ88Sr and Sr/Ca were higher in the Brahmaputra River than in the Ganges River, a difference we attribute to greater input from silicate weathering. The variations of δ88Sr and 87Sr/86Sr were greater in groundwater than in river waters. Mineral sorting effects and dissolution kinetics can account for the large scatter in 87Sr/86Sr and δ88Sr values. The depth profile of δ88Sr showed wide variation at shallow depths and convergence to a narrow range of about 0.31‰ at depths greater than 70 m, which reflects more complete equilibration of chemical interactions between groundwater and ambient sediments owing to the longer residence time of deeper groundwater. We found that δ88Sr values in the groundwater of Bangladesh were almost identical to those of river water from the lower Meghna River downstream of its confluence with the Ganges–Brahmaputra river system, thus confirming that the δ88Sr composition of the groundwater discharge to the Bay of Bengal is very similar to that of the river discharge.

Sign in / Sign up

Export Citation Format

Share Document