Correlation analysis of geothermal data for the sedimentary basins of India     

Janardan G. Negi  Pramode K. Panda  Om Prakash Pandey 《Earth and Planetary Science Letters》1974,21(2):143-148

Correlation coefficients are calculated from the available geothermic data for the sedimentary basins of India to reveal some significant association between: (1) heat flow and thermal conductivity, (2) heat flow and geothermal gradient, (3) geothermal gradient and thermal conductivity, and (4) heat flow and related crustal thickness. The observed negative correlationship between heat flow and thermal conductivity for all Indian sedimentary basins suggests corresponding changes in crustal thickness.  相似文献   

Concentrations of Trace Elements in Carbonate Reference Materials Coral JCp-1 and Giant Clam JCt-1 by Inductively Coupled Plasma-Mass Spectrometry   总被引：1，自引：0，他引：1  

Mayuri Inoue  Masato Nohara  Takashi Okai  Atsushi Suzuki  Hodaka Kawahata 《Geostandards and Geoanalytical Research》2004,28(3):411-416

Trace elements in the Geological Survey of Japan carbonate reference materials Coral JCp-1 and Giant Clam JCt-1 were determined by inductively coupled plasma-mass spectrometry after digestion with 2% v/v HNO₃. A standard addition method was adopted in this determination in order to neutralise the Ca matrix effect. In addition, Sc, Y, In and Bi were used as internal standards to control the matrix effect and correct instrumental drift. Of the eighteen elements measured in JCp-1, precisions for fourteen elements, including Cu, Cd and Ba, were better than 10% RSD and concentrations ranged from 0.002 μg g^-1 (Cs) to 8.02 μg g^-1 (Ba). The concentrations of measured trace elements in JCt-1, except for Cu, were lower than those in JCp-1. Precisions for all elements with concentrations higher than 0.04 μg g^-1 in JCt-1 were also better than 10% RSD and concentrations were found to be between 0.001 μg g^-1 (Cs) and 4.84 μg g^-1 (Ba). The concentrations of more than fifteen trace elements in the aragonite reference materials are reported here for the first time. Both reference materials are suitable for use in geochemical studies of environmental reconstruction based upon biogenic carbonate materials.  相似文献   

Changes in the source and transport mechanism of terrigenous input to the Indian sector of Southern Ocean during the late Quaternary and its palaeoceanographic implications     

M. Thamban  S. S. Naik  R. Mohan  A. Rajakumar  N. Basavaiah  Witty D’Souza  Sarita Kerkar  M. M. Subramaniam  M. Sudhakar  P. C. Pandey 《Journal of Earth System Science》2005,114(5):443-452

Changes in the terrigenous sediment source and transport mechanisms during the late Quaternary have been investigated using four sediment cores within the Indian sector of Southern Ocean, using the magnetic susceptibility (MS) and sedimentological records. Sediments deposited during the Holocene and other interglacial periods were characterised by low MS, low sand content, reduced ice-rafted detritus (IRD) input and increased illite possibly transported via hydrographic advection from the south. The glacial intervals are characterised by high MS, high sand content, increased IRD input and reduced illite clays, derived from both local as well as Antarctic sources. Significant reduction in clay fraction and illite content during glacials suggests that the erosive and transporting capabilities of the deep and bottom waters could have reduced compared to the interglacial times. The changes in terrigenous influx to this region were significantly influenced by the rhythmic glacial-interglacial fluctuations in bottom circulation and the position of the Polar Front.  相似文献   

Geomorphological study of sundarban deltaic estuary     

Dipnarayan Ganguly  Anirban Mukhopadhyay  Rahul Krishna Pandey  Debasish Mitra 《Journal of the Indian Society of Remote Sensing》2006,34(4):431-435

Study of landforms in Sundarbans deltaic estuary is necessary in regular basis due to its importance and impact on ecology, climate and economy. Remote sensing has proved as an important tool to study this. Multi-temporal satellite data helps to delineate the various geomorphic classes in different time domain and also provide inputs to study the coastal erosion and accretion. Finer spatial and better temporal resolution will be an added adventure for this kind of study.  相似文献   

Deleterious effects of Malathion on survivality and growth of the fingerlings of Channa punctatus (BLOCH.), a freshwater murrel     

J. P. Shukla  M. Banerjee  K. Pandey 《洁净——土壤、空气、水》1987,15(6):653-657

The LC₅₀ of Malathion for Channu punctatus is determined for 24… 96 h of exposure as 10.95… 3.22 mg/l. At exposure to 2.5 mg./l Malathion, growth–measured by increase in weight–is significantly reduced from the 19th day and reduced by 10 % till the 31st day. During the same period of time, the RNA and protein contents of the muscle is lowered by 10 and 15 %, respectively, as compared with the control. In addition to an acute toxic effect, in sublethal concentrations Malathion has also pronounced effects on growth and metabolism.  相似文献   

Altered Nucleic Acids Metabolism in the Ovary Exposed under Arsenic Stress in a Fresh-water Fisch,Colisa fasciatus (BL u. SCH.)     

J. P. Shukla  K. Pandey 《洁净——土壤、空气、水》1984,12(2):217-220

  相似文献   

Probing non-Gaussian features in the H i distribution at the epoch of re-ionization     

Somnath Bharadwaj  Sanjay K. Pandey 《Monthly notices of the Royal Astronomical Society》2005,358(3):968-976

  相似文献   

Study of indices for drought characterization in KBK districts in Orissa (India)     

R. P. Pandey  B. B. Dash  S. K. Mishra  Ranvir Singh 《水文研究》2008,22(12):1895-1907

Drought is a temporary, random and regional climatic phenomenon, originating due to lack of precipitation leading to water deficit and causing economic loss. Success in drought alleviation depends on how well droughts are defined and their severity quantified. A quantitative definition identifies the beginning, end, spatial extent and the severity of drought. Among the available indices, no single index is capable of fully describing all the physical characteristics of drought. Therefore, in most cases it is useful and necessary to consider several indices, examine their sensitivity and accuracy, and investigate for correlation among them. In this study, the geographical information system‐based Spatial and Time Series Information Modeling (SPATSIM) and Daily Water Resources Assessment Modeling (DWRAM) software were used for drought analysis on monthly and daily bases respectively and its spatial distribution in both dry and wet years. SPATSIM utilizes standardized precipitation index (SPI), effective drought index (EDI), deciles index and departure from long‐term mean and median; and DWRAM employs only EDI. The analysis of data from the Kalahandi and Nuapada districts of Orissa (India) revealed that (a) droughts in this region occurred with a frequency of once in every 3 to 4 years, (b) droughts occurred in the year when the ratio of annual rainfall to potential evapotranspiration (Pae/PET) was less than 0·6, (c) EDI better represented the droughts in the area than any other index; (d) all SPI, EDI and annual deviation from the mean showed a similar trend of drought severity. The comparison of all indices and results of analysis led to several useful and pragmatic inferences in understanding the drought attributes of the study area. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   

Relocation of aftershocks of the 2001 Bhuj earthquake: A new insight into seismotectonics of the Kachchh seismic zone,Gujarat, India     

Prantik Mandal  O.P. Pandey 《Journal of Geodynamics》2010,49(5):254-260

In view of an anomalous crust–mantle structure beneath the 2001 Bhuj earthquake region, double-difference relocations of 1402 aftershocks of the 2001 Bhuj earthquake were determined, using an improved 1D velocity model constructed from 3D velocity tomograms based on data from 10 to 58 three-component seismograph stations. This clearly delineated four major tectonic features: (i) south-dipping north Wagad fault (NWF), (ii and iii) south-dipping south Wagad faults 1 and 2 (SWF₁, SWF₂), and (iv) a northeast dipping transverse fault (ITF), which is a new find. The relocated aftershocks correlate satisfactorily with the geologically mapped and inferred faults in the epicentral region. The relocated focal depths delineate a marked variation to the tune of 12 km in the brittle–ductile transition depths beneath the central aftershock zone that could be attributed to a lateral variation in crustal composition (more or less mafic) or in the level of fracturing across the fault zone. A fault intersection between the NWF and ITF has been clearly mapped in the 10–20 km depth range beneath the central aftershock zone. It is inferred that large intraplate stresses associated with the fault intersection, deepening of the brittle–ductile transition to a depth of 34 km due to the presence of mafic/ultramafic material in the crust–mantle transition zone, and the presence of aqueous fluids (released during the metamorphic process of eclogitisation of lower crustal olivine-rich rocks) and volatile CO₂ at the hypocentral depths, might have resulted in generating the 2001 Bhuj earthquake sequence covering the entire lower crust.  相似文献   

Probing molecular and isotopic features of meteoritic insoluble organic matter by solid‐state nuclear magnetic resonance spectroscopy with sub‐milligram sample     

M. K. Pandey  Y. Nishiyama  P. Tekely 《Meteoritics & planetary science》2019,54(2):321-327

We recorded one‐ and two‐dimensional solid‐state nuclear magnetic resonance spectra of meteoric insoluble organic matter with unprecedented sensitivity and resolution permitting us to reveal unambiguous spectroscopic fingerprints relevant to its molecular and isotopic features. Two‐dimensional ¹H‐¹H and ¹H‐¹³C correlation experiments have unveiled the spatial proximity between aliphatic and aromatic groups proving a highly branched character of a rigid macromolecular network composed of short aliphatic chains linking together small aromatic units. One‐dimensional ²H and two‐dimensional ¹H‐²H correlation spectroscopy delivered evidence of significant reduction in the deuterium enrichment of aromatic species relevant to interstellar processes, proto‐planetary disk chemistry, and to determining the origin of the meteoritic insoluble organic matter. The experimental approach developed in this work opens new perspectives for systematic and nondestructive analysis at the molecular level of meteoritic insoluble organic matter even with a very small amount of sample from some particularly rare chondrites.  相似文献