| 1. |
- Misra, Satabdi, et al.
(författare)
-
Multi-proxy approach on the hydrocarbon generation perspective of Barjora Basin, India
- 2020
-
Ingår i: Marine and Petroleum Geology. - : Elsevier. - 0264-8172 .- 1873-4073. ; 112
-
Tidskriftsartikel (refereegranskat)abstract
- Barjora Basin in India is a small basin characterized by a high organic richness of early mature nature. The present study aims to find the source of organic matter (OM) and hydrocarbon generation potential of Barjora Basin. Systematically collected coal and shale samples from R-II seam of the basin were used for proximate and ultimate analyses, Rock Eval pyrolysis along with total organic carbon (TOC) content, organo-micropetrographic framework, thermal maturity, carbon isotopic signature, biomarker composition, functional group studies and estimation of relative aliphaticity and aromaticity through Fourier Transform infrared spectroscopy (FTIR). The novelty of the present work lies in the application of multiple proxies such as stable isotope ratio of organic carbon (delta C-13), biomarker signatures, thermal maturity parameters, organo-micropetrography and estimation and quantification of functional groups for palaeoenvironmental reconstruction and to assess the hydrocarbon productivity of the basin. A dominant terrestrial OM input in Barjora Basin is indicated by the TOC to total nitrogen ratio (C/N), delta C-13 and biomarker compositions. High gelification index (GI), tissue preservation index (TPI), and carbon preference index (CPI) values indicate that coals are deposited in wet swamp forest regime under high rainwater conditions and shales are formed in upper delta plain regime under high groundwater activity. In addition, large liptinite content, TPI and GI designate short transportation of the OM before burial leading to organic richness of the Barjora Basin. Moreover, high liptinite content, type II-III admixed kerogen input, S-2/S-3 ratio, TPI and index for hydrocarbon generation (I-HG) signify higher potential of the basin for hydrocarbon generation.
|
|
| 2. |
- Ray, Sumit Kumar, et al.
(författare)
-
Modern analogue to past coseismic ground uplift in North Andaman, India
- 2021
-
Ingår i: Catena (Cremlingen. Print). - : Elsevier. - 0341-8162 .- 1872-6887. ; 205
-
Tidskriftsartikel (refereegranskat)abstract
- Dynamics of surface geological processes, triggered by coseismic ground uplift following the 2004 Sumatra-Andaman earthquake (M-w > 9.2), provide a modern analogue for assessing the paleoseismic significance of an enigmatic subsurface peat occurrence within beach sands in the western coast of North Andaman Island. The megathrust earthquake uplifted vast stretches of coastal intertidal zones to supratidal levels. As a result, intertidal flora, including mangroves, desiccated and perished. Mass mortality of the flora continued even three years after the earthquake and generated a large volume of forest debris. Coastal waves pushed the debris to the high tide line where the accumulated debris would be gradually buried, and would subsequently transform into linear peat bodies keeping a record of the seismic event in 2004. Accordingly, we have interpreted a linear strand-parallel peat occurrence in beach sand as a record of earlier mass mortality of plants likely associated with a coseismic ground uplift. Stable isotope studies indicate that local intertidal flora is the source of the peat organic matter. Moreover, the 1817 CE calibrated mean AMS radiocarbon age of the peat suggests recurrence of a megathrust earthquake in the Andaman subduction zone about 200 years ago.
|
|
