Stratigraphy of Assam Valley, India

Bhandari, Laxminarayan; Fuloria, R. C.; Sastri, V. V.

doi:10.1306/819a4310-16c5-11d7-8645000102c1865d

Cited by 17 publications

(7 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Moreover, the overlying braided river sediments of the middle Siwalik subgroup (Subansiri Formation) and alluvial fan deposits of the upper Siwalik subgroup are reported to both bear paleobotanical evidences of brackish water or near coastal environments [e.g., Chirouze et al, 2012;Mehrotra et al, 1999;Singh and Tripathi, 1990]. We speculate that these brackish water to shallow marine paleoenvironments are linked to those observed to the northeast of the Shillong Plateau in the foreland of the Naga Hills of Assam [e.g., Bhandari et al, 1973;Reimann and Hiller, 1993] and to the south in the well-dated Surma Basin of northern Bangladesh [e.g., Alam et al, 2003;Najman et al, 2012;Worm et al, 1998] (Figure 1).…”

Section: Depositional Environments and Paleogeographymentioning

confidence: 77%

“…In the foreland of the Naga Hills in Assam, paleoenvironmental data indicate marine influence during the Neogene, although the chronological constraints on sediment deposition remain poorly constrained [Bhandari et al, 1973;Evans, 1932;Mallet, 1876;Reimann and Hiller, 1993]. The Miocene Surma Group displays fossil assemblages pointing toward shallow marine to brackish water environments, whereas the overlying Mio-Pliocene Tipam Group is characterized by lithologic characteristics and floral assemblages symptomatic of a fluvial environment in a subtropical to temperate climate [e.g., Bhandari et al, 1973;Reimann and Hiller, 1993].…”

Section: Depositional Environments and Paleogeographymentioning

confidence: 99%

See 1 more Smart Citation

Late Miocene-Pleistocene evolution of India-Eurasia convergence partitioning between the Bhutan Himalaya and the Shillong Plateau: New evidences from foreland basin deposits along the Dungsam Chu section, eastern Bhutan

et al. 2016

View full text Add to dashboard Cite

The Shillong Plateau is a unique basement‐cored uplift in the foreland of the eastern Himalaya that accommodates part of the India‐Eurasia convergence since the late Miocene. It was uplifted in the late Pliocene to 1600 m, potentially inducing regional climatic perturbations by orographically condensing part of the Indian Summer Monsoon (ISM) precipitations along its southern flank. As such, the eastern Himalaya‐Shillong Plateau‐ISM is suited to investigate effects of tectonics, climate, and erosion in a mountain range‐broken foreland system. This study focuses on a 2200 m thick sedimentary section of the Siwalik Group strategically located in the lee of the Shillong Plateau along the Dungsam Chu at the front of the eastern Bhutan Himalaya. We have performed magnetostratigraphy constrained by vitrinite reflectance and detrital apatite fission track dating, combined with sedimentological and palynological analyses. We show that (1) the section was deposited between ~7 and 1 Ma in a marginal marine deltaic transitioning into continental environment after 5 Ma, (2) depositional environments and paleoclimate were humid with no major change during the depositional period indicating that the orographic effect of the Shillong Plateau had an unexpected limited impact on the paleoclimate of the Bhutanese foothills, and (3) the diminution of the flexural subsidence in the basin and/or of the detrital input from the range is attributable to a slowdown of the displacement rates along the Main Boundary Thrust in eastern Bhutan during the latest Miocene‐Pleistocene, in response to increasing partitioning of the India‐Eurasia convergence into the active faults bounding the Shillong Plateau.

show abstract

Section: Depositional Environments and Paleogeographymentioning

confidence: 77%

Section: Depositional Environments and Paleogeographymentioning

confidence: 99%

Late Miocene-Pleistocene evolution of India-Eurasia convergence partitioning between the Bhutan Himalaya and the Shillong Plateau: New evidences from foreland basin deposits along the Dungsam Chu section, eastern Bhutan

et al. 2016

View full text Add to dashboard Cite

show abstract

“…A generalized lithostratigraphy framework of the basin is presented in Figure 2. The Precambrian basement of the basin consists of crystalline metamorphic rocks (Figure 2), which include gneisses, granites and quartzite (Bhandari et al, 1973; Naidu & Panda, 1997; Nandy, 2017). The overburden Palaeogene–Neogene–Quaternary deposits comprise of the Lakadong, Prang and Narpuh Formations (Palaeocene to Mid‐Eocene), Kopili Formation (Upper Eocene), Barail Formation (Oligocene), Tipam and Girujan Formations (Miocene), Namsang and Dhekiajuli Formations (Pliocene to Pleistocene) and the alluvium cover (Pleistocene to Recent).…”

Section: Geological Settings Of the Basinmentioning

confidence: 99%

Delineation of oil–water contact within Tipam reservoir: A study from Upper Assam Basin, North‐East India

Kumar

Sain

2023

Geological Journal

View full text Add to dashboard Cite

Fluid contacts within a reservoir can vary either because of compartmentalization by faults, lithological variations, hydrocarbon fill history or changes in the hydrodynamic activity of fluids. Their detailed interpretation is significant for estimating potential reserves and developing an explored hydrocarbon field. This study uses high‐quality three‐dimensional (3D) seismic reflection data to decipher the fluid contact zones and their types from the well‐known Tipam reservoir in the petroliferous Upper Assam foreland basin. Different seismic attributes are used to understand the seismic response of fluids and associated structures that structurally control the reservoir geometry. Fluid contact analysis is performed by amalgamating these responses within the target interval. The analysis indicates that the south‐west part of the reservoir is a promising hydrocarbon‐bearing zone and consists of oil–water contacts. These contacts possess a dominant trend of NE–SW within the reservoir. Further, a decreasing trend in the density, velocity and an increasing trend in the resistivity and porosity logs of the wellbore SC‐2 calibrates these inferences and confirms the presence of oil‐bearing zones underlain by water in the SW part of the Tipam reservoir. Thus, the Upper Assam foreland basin is a promising area for hydrocarbon exploration, in which Mid‐Miocene sequences are the potential leads that can be unlocked. The analysis presented through this research could be efficiently and similarly carried out in onshore basins worldwide.

show abstract

“…The Sylhet Limestone, which is exposed in the Mikir, Garo, Khasi and Jaintia Hills, was deposited in a shallow, open marine, warm water environment (Bhandari et al, 1973; Dutta, 1982). It consists of alternating limestones and sugary, white sandstones with mineable coal seams.…”

Section: Geological Backgroundmentioning

confidence: 99%

First report of Eocene echinoids from the Sylhet Limestone, Mikir Hills of Assam, India: palaeontological, palaeogeography and palaeoenvironmental significance

Lokho,

Carrasco,

Biswal

et al. 2023

Journal of the Palaeontological Society of India

View full text Add to dashboard Cite

This article reports two echinoid taxa viz. Ilarionia sindensis Duncan and Sladen (1884) and Porocidaris schmidelii Münster in Goldfus (1830) from the middle Eocene Sylhet Limestone of Mikir Hills, Assam. P. schmidelii is found from the Lutetian (middle Eocene) to the Priabonian (upper Eocene) in the following regions: NE of Spain, Biarritz (Southwestern France), Angoumé (Southern Aquitaine, France), Carinthia (Southern Austria), Venetian region of Italy Provence, Southern Alps of French, Istria (Croatia), Persian Gulf, Oman and Egypt. I. sindensis was first reported from the Eocene of Sindh province from the Khirthar Series (Pakistan) and Madagascar. It is also recorded from the Bartonian–Priabonian in the following regions: NE Spain, Biarritz in Southwestern France, Angoumé in Southern Aquitaine-France, Carinthia in Southern Austria, Italian region of Veneto, Provence and southern French Alps, Persian Gulf, Oman, Egypt and Istria. They are systematically described to know their stratigraphic, palaeoenvironment and palaeogeographic distribution. The material studied herein represents the first report from the middle Eocene of India, and it significantly expands the geographical extension of Eocene marine echinoids in the northeastern part of India.

show abstract

Stratigraphy of Assam Valley, India

Cited by 17 publications

References 1 publication

Late Miocene-Pleistocene evolution of India-Eurasia convergence partitioning between the Bhutan Himalaya and the Shillong Plateau: New evidences from foreland basin deposits along the Dungsam Chu section, eastern Bhutan

Late Miocene-Pleistocene evolution of India-Eurasia convergence partitioning between the Bhutan Himalaya and the Shillong Plateau: New evidences from foreland basin deposits along the Dungsam Chu section, eastern Bhutan

Delineation of oil–water contact within Tipam reservoir: A study from Upper Assam Basin, North‐East India

First report of Eocene echinoids from the Sylhet Limestone, Mikir Hills of Assam, India: palaeontological, palaeogeography and palaeoenvironmental significance

Contact Info

Product

Resources

About