Study of lapse time dependence coda Q in the Andaman Islands using the aftershocks of the 2002 earthquake (M w 6.5)     

Chandrani Singh  Sagarika Mukhopadhyay  Sagar Singh  Pranab Chakraborty  J. R. Kayal 《Natural Hazards》2015,75(1):779-793

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Assessing the feasibility of CO<Subscript>2</Subscript>-enhanced oil recovery and storage in mature oil field: A case study from Cambay basin     

Shib Sankar Ganguli  Nimisha Vedanti  Idar Akervoll  V. P. Dimri 《Journal of the Geological Society of India》2016,88(3):273-280

The utilization of anthropogenic CO₂ for enhanced oil recovery (EOR) can significantly extend the production life of an oil field, and help in the reduction of atmospheric emission of anthropogenic CO₂ if sequestration is considered. This work summarizes the prospect of EOR and sequestration using CO₂ flooding from an Indian mature oil field at Cambay basin through numerical modelling, simulation and pressure study based on limited data provided by the operator. To get an insight into CO₂-EOR and safe storage process in this oil field, a conceptual sector model is developed and screening standard is proposed keeping in mind the major pay zone of the producing reservoir. To construct the geomodel, depth maps, well positions and coordinates, well data and well logs, perforation depths and distribution of petrophysical properties as well as fluid properties provided by the operator, has been considered. Based on the results from the present study, we identified that the reservoir has the potential for safe and economic geological sequestration of 15.04×10⁶ metric ton CO₂ in conjunction with a substantial increase in oil recovery of 10.4% of original oil in place. CO₂-EOR and storage in this mature field has a bright application prospect since the findings of the present work could be a better input to manage the reservoir productivity, and the pressure field for significant enhancement of oil recovery followed by safe storage.  相似文献   

Experimental studies to constrain parental magma of Malangtoli volcanics from Singhbhum craton of the eastern Indian shield     

Mousumi Banerjee  Jyotisankar Ray  Nupur Adhikary  Sandip Nandy  C. Manikyamba  Madhuparna Paul  Dola Chakraborty  Alireza Eslami 《Journal of the Geological Society of India》2016,88(2):245-255

Malangtoli volcanics of the Singhbhum craton of the eastern Indian shield is one of the important Proterozoic lava suites. Experimental studies on 1 atmosphere pressure constrain the parental magma type and temperature range of crystallization of the parent magma (deduced to be in the range of 1500°C to 1200°C). The experimental studies show that at 1500°C, plagioclase is the first phase to crystallize, followed by few opaques which join along with plagioclase at 1450°C. At subsequent lower temperature (1400°C-1300°C), plagioclase and opaque continue to crystallize. At 1250°C plagioclase and opaque still persist while pyroxene appears first and liquid (glass) still remains. Appearance of opaque minerals (magnetite and illmenite) at both ~1400°C and ~1300°C indicate oscillation of oxygen fugacity in the parent magma, petrographically documented by coarser phenocrysts as well as finer or peripheral tiny grains. Use of tectonic discrimination diagrams (based on discrimination factors F₁-F₂ and FeO^t/MgO vs. TiO₂) shows an island arc tholeiitic affinity for Malangtoli volcanic, suggests that the role of proto-plate convergence in Singhbhum architecture played an important role to build up Malangtoli volcanics during Proterozoic.  相似文献   

Low-frequency intraseasonal variability in a zonally symmetric aquaplanet model     

Surajit Das  Debasis Sengupta  A. Chakraborty  Jai Sukhatme  Raghu Murtugudde 《Meteorology and Atmospheric Physics》2016,128(6):697-713

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Texture Measurement Through Local Pattern Quantization for SAR Image Classification     

Debasish Chakraborty  Dibyendu Dutta  Jaswant Raj Sharma 《Journal of the Indian Society of Remote Sensing》2016,44(3):471-477

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Index-based groundwater vulnerability mapping using quantitative parameters     

Satiprasad Sahoo  Anirban Dhar  Amlanjyoti Kar  Durjoy Chakraborty 《Environmental Earth Sciences》2016,75(6):522

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Elemental geochemistry and mineralogy of coals and associated coal mine overburden from Makum coalfield (Northeast India)     

Binoy K. Saikia  Ananya Saikia  Rahul Choudhury  Panpan Xie  Jingjing Liu  Tonkeswar Das  Hari P. Dekaboruah 《Environmental Earth Sciences》2016,75(8):660

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Geochemical constraints on the tectonic setting of the Sonakhan Greenstone Belt,Bastar Craton,Central India     

S. D. Deshmukh  K. R. Hari  P. Diwan  M. P. Manu Prasanth 《中国地球化学学报》2018,37(3):489-499

The Neo-Archean Sonakhan Greenstone Belt (SGB) located in the north-eastern fringes of Bastar craton, Central India, is dominated by Basalts, Andesites, Dacites and Rhyolites association. Partial melting modeling on the SGB metabasalts indicates that these rocks were derived by 20% melting of spinel peridotite. Fractional crystallisation modeling with REE reveal that the most evolved samples represent the product of fractional crystallization of least evolved magma with 35% plagioclase, 35% clinopyroxene, 20% olivine, 5% magnetite and 5% ilmenite as fractionating minerals with 40% remaining magma. Depletion of HFSE with reference to the LILE and LREE/HFSE ratios and Nb, Zr anomalies in the multi-element diagram of the mafic rocks of SGB indicate Island arc magmatic setting. The enriched Th/Yb values further substantiate that the mantle arrays were modified by subduction-related fluids or melts. The general conclusions drawn indicate that the metabasalts from the SGB were formed as a result of subduction of an intraoceanic lithosphere in a fore-arc suprasubduction zone environment.  相似文献   

Syn-sedimentary tectonics and facies analysis in a rift setting: Cretaceous Dalmiapuram Formation,Cauvery Basin,SE India     

Nivedita Chakraborty  Subir Sarkar 《古地理学报》2018,(2)

The Cretaceous(Albian-Cenomanian) Dalmiapuram Formation is one of the economically significant constituents in the hydrocarbon-producing Cauvery rift basin, SE India that opened up during the Late Jurassic e Early Cretaceous Gondwanaland fragmentation. The fossil-rich Dalmiapuram Formation,exposed at Ariyalur within the Pondicherry sub-basin of Cauvery Basin, rests in most places directly on the Archean basement and locally on the Lower Cretaceous(Barremian-Aptian) Basal Siliciclastic Formation. In the Dalmiapuram Formation, a facies association of tectonically-disturbed phase is sandwiched between two drastically quieter phases. The early syn-rift facies association(FA 1), records the first carbonate marine transgression within the basin, comprising a bar-lagoon system with occasionally storms affecting along the shore and a sheet-like non-recurrent biomicritic limestone bed on the shallow shelf that laterally grades into pyrite e glauconite-bearing dark-colored shale in the deeper shelf. Spectacular breccias together with varied kinds of mass-flow products comprise the syn-rift facies association(FA 2). While the breccias occur at the basin margin area, the latter extend in the deeper inland sea. Clast composition of the coarse clastics includes large, even block-sized limestone fragments and small fragments of granite and sandstone from the basement.Marl beds of quieter intervals between tectonic pulses occur in alternation with them. Faulted basal contact of the formation, and small grabens filled by multiple mass-flow packages bear the clear signature of the syntectonic activity localized contortions, slump folds, and pillow beds associated with mega slump/slide planes and joints, which corroborates this contention further. This phase of tectonic intervention is followed by another relatively quieter phase and accommodates the late syn-rift facies association(FA 3). A tidal bar-interbar shelf depositional system allowed a transgressive systems tract motif to grow eventually passing upwards into the Karai Shale Formation, whose contact with the Dalmiapuram Formation is gradational.  相似文献   

Hybrid Gaussian-cubic radial basis functions for scattered data interpolation     

Pankaj K. Mishra  Sankar K. Nath  Mrinal K. Sen  Gregory E. Fasshauer 《Computational Geosciences》2018,22(5):1203-1218

Scattered data interpolation schemes using kriging and radial basis functions (RBFs) have the advantage of being meshless and dimensional independent; however, for the datasets having insufficient observations, RBFs have the advantage over geostatistical methods as the latter requires variogram study and statistical expertise. Moreover, RBFs can be used for scattered data interpolation with very good convergence, which makes them desirable for shape function interpolation in meshless methods for numerical solution of partial differential equations. For interpolation of large datasets, however, RBFs in their usual form, lead to solving an ill-conditioned system of equations, for which, a small error in the data can cause a significantly large error in the interpolated solution. In order to reduce this limitation, we propose a hybrid kernel by using the conventional Gaussian and a shape parameter independent cubic kernel. Global particle swarm optimization method has been used to analyze the optimal values of the shape parameter as well as the weight coefficients controlling the Gaussian and the cubic part in the hybridization. Through a series of numerical tests, we demonstrate that such hybridization stabilizes the interpolation scheme by yielding a far superior implementation compared to those obtained by using only the Gaussian or cubic kernels. The proposed kernel maintains the accuracy and stability at small shape parameter as well as relatively large degrees of freedom, which exhibit its potential for scattered data interpolation and intrigues its application in global as well as local meshless methods for numerical solution of PDEs.  相似文献