IMPLICATIONS OF OROGENIC WEDGE GROWTH, INTRAPLATE STRESS VARIATIONS, AND EUSTATIC SEA-LEVEL CHANGE FOR FORELAND BASIN STRATIGRAPHY—INFERENCES FROM NUMERICAL MODELING

Abstract The Siwalik Group, ranging from the Early Miocene to Pleistocene, is believed to be controlled by contemporary Himalayan tectonics and climate. In this study, we established the fluvial system responsible for the deposition of the Siwalik succession along the Muksar Khola section and its controlling factors. Five sedimentary facies associations are identified which are interpreted as the deposits of flood plain dominated fine-grained meandering river (FA1), flood dominated overbank environment (FA2), sandy meandering river (FA3), anastomosing river (FA4), and debris flow dominated gravelly braided river (FA5). These change in fluvial style occurred around 10.5 Ma, 10.0 Ma, 5.9 Ma and 3.5 Ma due to the effects of hinterland tectonics, climate and sea-level change. The thick succession of intraformational conglomerate reveals the intensification of monsoon started around 10.5 Ma in the eastern Nepal Himalaya. The present study show asynchronous exhumation of the Himalaya east to west brought significant difference on the fluvial environment of the Neogene foreland basin. Moreover, this study also reveals continuous drifting of the foreland basin towards the hinterland concerning depositional age.

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Sedimentary facies analysis of the fluvial environment in the Siwalik Group of eastern Nepal: deciphering its relation to contemporary Himalayan tectonics, climate and sea-level change

Progress in Earth and Planetary Science ◽

10.1186/s40645-021-00444-5 ◽

2021 ◽

Vol 8 (1) ◽

Author(s):

Lalit Kumar Rai ◽

Kohki Yoshida

Keyword(s):

Sea Level ◽

Foreland Basin ◽

Sea Level Change ◽

Sedimentary Facies ◽

Nepal Himalaya ◽

Meandering River ◽

Level Change ◽

Siwalik Group ◽

Himalayan Tectonics ◽

And Sea Level

AbstractThe Siwalik Group, ranging from the Early Miocene to Pleistocene, is believed to be deposited in the fluvial environment and controlled by contemporary Himalayan tectonics and climate. In this study, we established the fluvial environment and its controlling factors responsible for the deposition of the Siwalik succession along the Muksar Khola section in the eastern Nepal Himalaya. Five sedimentary facies associations are identified; these are interpreted as the deposits of flood plain-dominated fine-grained meandering river (FA1), flood-dominated overbank environment (FA2), sandy meandering river (FA3), anastomosing river (FA4), and debris flow-dominated gravelly braided river (FA5). These changes in the fluvial system occurred around 10.5 Ma, 10.0 Ma, 5.9 Ma and 3.5 Ma, defined by existing magnetostratigraphy constraints, due to the effects of hinterland tectonics, climate and sea-level change and continuous drifting of the foreland basin towards the hinterland concerning depositional age. The thick succession of an intraformational conglomerate reveals intensification of the monsoon started around 10.5 Ma in the eastern Nepal Himalaya. The present study also shows asynchronous exhumation of the Himalaya from east to west brought a significant difference in the fluvial environment of the Neogene foreland basin.

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Significant continental ice volumes on mid-Paleocene Antarctica? Latitudinal temperature gradients, sea level change and the carbon cycle

Rendiconti online della Società Geologica Italiana ◽

10.3301/rol.2014.30 ◽

2014 ◽

Vol 31 ◽

pp. 31-32

Author(s):

Peter Bijl

Keyword(s):

Carbon Cycle ◽

Sea Level ◽

Sea Level Change ◽

Temperature Gradients ◽

Level Change

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Phanerozoic Oxygen

10.23943/princeton/9780691145020.003.0011 ◽

2017 ◽

Author(s):

Donald Eugene Canfield

Keyword(s):

Oxygen Consumption ◽

Organic Carbon ◽

Sea Level ◽

Time Scale ◽

Atmospheric Oxygen ◽

Sea Level Change ◽

Oxygen Production ◽

Level Change ◽

History Of ◽

Geologic Processes

This chapter discusses the modeling of the history of atmospheric oxygen. The most recently deposited sediments will also be the most prone to weathering through processes like sea-level change or uplift of the land. Thus, through rapid recycling, high rates of oxygen production through the burial of organic-rich sediments will quickly lead to high rates of oxygen consumption through the exposure of these organic-rich sediments to weathering. From a modeling perspective, rapid recycling helps to dampen oxygen changes. This is important because the fluxes of oxygen through the atmosphere during organic carbon and pyrite burial, and by weathering, are huge compared to the relatively small amounts of oxygen in the atmosphere. Thus, all of the oxygen in the present atmosphere is cycled through geologic processes of oxygen liberation (organic carbon and pyrite burial) and consumption (weathering) on a time scale of about 2 to 3 million years.

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