The unequivocal identification of soft-sediment deformation structures(SSDS)is a significant attribute to constrain the effect of transient geological events in the spatio-temporal evolution of ancient sedimentary bas...The unequivocal identification of soft-sediment deformation structures(SSDS)is a significant attribute to constrain the effect of transient geological events in the spatio-temporal evolution of ancient sedimentary basins.This paper reports and discusses,for the first time,the occurrence of several cm-to dm-scale SSDS within sandstone successions of the Mesoproterozoic Kaimur Group(Vindhyan Supergroup),exposed at the Hanumandhara Hill of Chitrakoot-Satna border region,Madhya Pradesh State,India.The SSDS are confined to a deformed interval comprising seven individual sedimentary units of variable composition and texture,which are sandwiched between nearly horizontally undeformed sandstone beds.The SSDS consist of load structures(load casts,flame structures,pseudonodules and ball-and-pillow structures),contorted lamination,convolute lamination,boudins and pinch-and-swell structures,deformed cross-stratification,slump structures,clastic injections,fluid escape structures,and syn-sedimentary fractures/faults.The pre-sent study suggests that the formation of these SSDS is essentially related to a combination of processes(gravitational instability,liquefaction,fluidization,and fluid escape)predominantly induced by seismic shocks.In addition,the restricted occurrence of fractures/faults in these deformed layers emphasizes the passage of seismically-induced Rayleigh waves.Considering the observed types of SSDS,their lateral homo-geneity and geographic distribution along with the geodynamic framework of the Vindhyan Basin,the whole area can be tentatively attributed to having experienced moderate-to high-magnitude(M≥5)seismicity.The present study combined with earlier reports of seismically-induced SSDS,from other regionally disposed formations belonging to the Lower(e.g.,Kajrahat Limestone,Chopan Porcellanite,Koldaha Shale,Rohtas Limestone,and Glauconitic Sandstone of the Semri Group)and Upper(e.g.,Bhander Limestone of the Bhander Group)Vindhyan Supergroup,respectively,provides evidence for the constant regional-scale seismo-tectonic activity within the Paleo-Mesoproterozoic Vindhyan Basin.Importantly,this observation further suggests that the intracratonic basins can be active tectonically contrary to the earlier propositions.展开更多
Remote sensing, one of the most important reconnaissance and feature identifying tools generally applied for surface and groundwater investigation, was used for water resources mapping for the lower Son Valley in this...Remote sensing, one of the most important reconnaissance and feature identifying tools generally applied for surface and groundwater investigation, was used for water resources mapping for the lower Son Valley in this study. The mapping was done with the help of Indian Remote Sensing (IRS) satellite imagery IRS-LISS- 1-B1 for January 29, 1991 obtained during the day transit time. The area under study comprises adjoining parts of Uttar Pradesh and Bihar states of India and extends over the seven districts, namely Bhojpur, Rohtas, Patna, Jahanabad, Aurangabad, Ballia and Chapra. Geology of the study area is quite complex, tectonically disturbed and shows four major cycles of depositions after erosions during last one billion years (since Cretaceous). Two lineaments mapped by GSI (Geological Survey of India) in western side of river Son in the Bhojpur district can also be identified by the satellite imagery. In the present study, apart from these lineaments, two new lineaments have been investigated, which run almost parallel to river Ganga in northwest parts of the area in Ballia district. The lineaments may play a very vital role in groundwater monitoring in the area. The detailed study of geomorphology, vegetation and geology of the Lower Son valley on the basis of photo-interpretation techniques for surface features, drainage pattern and density, and drainage texture has been carried out to determine alluvial type, permeability, tributary, etc. These studies and Darcy velocity analysis show that the prospect of water is very good for entire lower Son valley. The Bhojpur district is most prospective for groundwater exploitation.展开更多
基金the Council of Scientific and Industrial Research, New Delhi, Government of India, for awarding him Shyama Prasad Mukherjee Fellowship [SPM-09/001(0328)/2020-EMRI]the Department of Science and Technology, Government of India, for the INSPIRE Fellowship [IF170168]
文摘The unequivocal identification of soft-sediment deformation structures(SSDS)is a significant attribute to constrain the effect of transient geological events in the spatio-temporal evolution of ancient sedimentary basins.This paper reports and discusses,for the first time,the occurrence of several cm-to dm-scale SSDS within sandstone successions of the Mesoproterozoic Kaimur Group(Vindhyan Supergroup),exposed at the Hanumandhara Hill of Chitrakoot-Satna border region,Madhya Pradesh State,India.The SSDS are confined to a deformed interval comprising seven individual sedimentary units of variable composition and texture,which are sandwiched between nearly horizontally undeformed sandstone beds.The SSDS consist of load structures(load casts,flame structures,pseudonodules and ball-and-pillow structures),contorted lamination,convolute lamination,boudins and pinch-and-swell structures,deformed cross-stratification,slump structures,clastic injections,fluid escape structures,and syn-sedimentary fractures/faults.The pre-sent study suggests that the formation of these SSDS is essentially related to a combination of processes(gravitational instability,liquefaction,fluidization,and fluid escape)predominantly induced by seismic shocks.In addition,the restricted occurrence of fractures/faults in these deformed layers emphasizes the passage of seismically-induced Rayleigh waves.Considering the observed types of SSDS,their lateral homo-geneity and geographic distribution along with the geodynamic framework of the Vindhyan Basin,the whole area can be tentatively attributed to having experienced moderate-to high-magnitude(M≥5)seismicity.The present study combined with earlier reports of seismically-induced SSDS,from other regionally disposed formations belonging to the Lower(e.g.,Kajrahat Limestone,Chopan Porcellanite,Koldaha Shale,Rohtas Limestone,and Glauconitic Sandstone of the Semri Group)and Upper(e.g.,Bhander Limestone of the Bhander Group)Vindhyan Supergroup,respectively,provides evidence for the constant regional-scale seismo-tectonic activity within the Paleo-Mesoproterozoic Vindhyan Basin.Importantly,this observation further suggests that the intracratonic basins can be active tectonically contrary to the earlier propositions.
文摘Remote sensing, one of the most important reconnaissance and feature identifying tools generally applied for surface and groundwater investigation, was used for water resources mapping for the lower Son Valley in this study. The mapping was done with the help of Indian Remote Sensing (IRS) satellite imagery IRS-LISS- 1-B1 for January 29, 1991 obtained during the day transit time. The area under study comprises adjoining parts of Uttar Pradesh and Bihar states of India and extends over the seven districts, namely Bhojpur, Rohtas, Patna, Jahanabad, Aurangabad, Ballia and Chapra. Geology of the study area is quite complex, tectonically disturbed and shows four major cycles of depositions after erosions during last one billion years (since Cretaceous). Two lineaments mapped by GSI (Geological Survey of India) in western side of river Son in the Bhojpur district can also be identified by the satellite imagery. In the present study, apart from these lineaments, two new lineaments have been investigated, which run almost parallel to river Ganga in northwest parts of the area in Ballia district. The lineaments may play a very vital role in groundwater monitoring in the area. The detailed study of geomorphology, vegetation and geology of the Lower Son valley on the basis of photo-interpretation techniques for surface features, drainage pattern and density, and drainage texture has been carried out to determine alluvial type, permeability, tributary, etc. These studies and Darcy velocity analysis show that the prospect of water is very good for entire lower Son valley. The Bhojpur district is most prospective for groundwater exploitation.
