Occurrence of Nummulitic coralline limestone from offshore Palar Basin,Bay of Bengal,India     

S. Ramesh  K. Nvv Murthy  S. M. Hussain  S. Ramasamy  G. A. Ramadass 《Marine Georesources & Geotechnology》2020,38(1):57-63

Abstract

Palar basin is located between Pennar and Cauvery sedimentary basins of East coast of India in Bay of Bengal, northeast Indian Ocean. Sea floor drill (Wire-line Autonomous Coring System – WACS) with operational capability of up to 3000?m water depth was developed to collect long cores from deep sea floor for geotechnical and ocean resource assessment studies. During the drilling operation it encountered Nummulitic coralline limestone of Lower Eocene age at 18 meters below the seafloor (mbsf) at 850?m water depth indicating carbonated platform presence for the first time at the study region. Bathymetry contour from Naval Hydrography Chart and General Bathymetric Chart of the Oceans (GEBCO) has revealed the presence of shallow mounds from 50 to 200?m depth closure contour near the sampling site at 850?m water depth which might be a submerged carbonated structure. Since, Nummulites are shallow water dwelling fauna (<20?m depth) but its occurrence at 18 mbsf in 850?m water depth is recorded because of the advancement in technology tool for long core sampling by means of sea floor drill.  相似文献   

Use of remote sensing in lineament analysis for tectonic evolution and resource study of a part of Vindhyan Basin,Jhalawar area,India     

S. M. Ramasamy  P. C. Bakliwal  K. L. V. Ramana Rao 《Journal of the Indian Society of Remote Sensing》1988,16(1):63-71

Synoptivity and the exemplified fracture systems exhibited by the space borne imagery data has helped in solving many of the geological enigma in various parts of the world. The study conducted, using such remotly sensed data, in Jhalawar anticline, part of Proterozoic Cratonic Vindhyan Basin, Rajasthan, India, led to infer the history of tectonic evolution of peribasinal deformation which has been a matter of controversy for a century and more. In Landsat MSS data the Jhalawar region displays a panorama of lineaments and their analysis through azimuthal frequency diagrams, isofracture, lineament incidence and lineament intersection incidence density maps shows that the mean orientation of the lineaments fall in NW-SE and NE-SW and the shape of the various lineament density contours also show NE-SW and NW-SE orientations. In aerial photographs the area exhibits four sets of lineaments in NE-SW, NW-SE, N-S and E-W directions. Amongst these the former two sets are expressed as wide open master fracture systems with prolific vegetation fills along them and the latter two sets are characteristically observed as thin vegetation linears with frequent strike slip faulting along them. The further analysis of these fracture/lineament systems derived from multi-level remote sensing data shows that the Jhalawar anticline, which followed the pattern of flexural slip fold mechanism, was evolved by horizontally disposed σ1 (greatest principal stress) and 3σ (least principal stress) with the former oriented in NE-SW and the latter aligned in NW-SE directions with vertically disposed 2σ. The inference of such palaeostress environment of the Jhalawar region lead in the identification of a buried rigid basement high southwest of Jhalawar anticline, beneath the Deccan pile and loci of ground water, silica sand and probable igneous plug.  相似文献   

Pre-and post-construction status of panam reservoir and its environs using remotely sensed and ancillary data     

R Nagarajan  S D Shah  V K Yadav 《Journal of the Indian Society of Remote Sensing》1993,21(1):29-35

The success of water-resources projects can be evaluated by using remotely sensed and ancillary data supported by ground-based information. Surficial features in the vicinity of Panam reservoir of the Mahi-Kadana river-valley project, have been demarcated using IRS data of 1991 (post-commission) and 1969 topographic sheet information (prior to commission) and have been evaluated. Observed positive and negative changes indicate that the project maintains its environment-friendly function.  相似文献   

Franck-condon factors and -centroids for certain band systems of astrophysical molecular ions CN+ and N+2     

N. Rajamanickam  K. Nagarajan  V. Raja 《Astrophysics and Space Science》2000,274(4):725-731

The Franck-Condon factors and r-centroids, which are very closelyrelated to relative vibrational transition probabilities, have beenevaluated by the more reliable numerical integration procedure forthe bands of c ¹ - a ¹ and f ¹ - a ¹ systems of CN ⁺ and C ^{2 +} _u- X ^{2 +} _g and D ² _g- A ² _u systems of N ⁺ ₂ molecular ions of astrophysical interest,using a suitable potential.  相似文献   

Assessment of groundwater potential zones using GIS technique   总被引：1，自引：0，他引：1  

M. Nagarajan  Sujit Singh 《Journal of the Indian Society of Remote Sensing》2009,37(1):69-77

A case study was conducted to find out the groundwater potential zones in Kattakulathur block, Tamil Nadu, India with an aerial extent of 360.60 km². The thematic maps such as geology, geomorphology, soil hydrological group, land use / land cover and drainage map were prepared for the study area. The Digital Elevation Model (DEM) has been generated from the 10 m interval contour lines (which is derived from SOI, Toposheet 1:25000 scale) and obtained the slope (%) of the study area. The groundwater potential zones were obtained by overlaying all the thematic maps in terms of weighted overlay methods using the spatial analysis tool in ArcGIS 9.2. During weighted overlay analysis, the ranking has been given for each individual parameter of each thematic map and weights were assigned according to the influence such as soil −25%, geomorphology − 25%, land use/land cover −25%, slope − 15%, lineament − 5% and drainage / streams − 5% and find out the potential zones in terms of good, moderate and poor zones with the area of 49.70 km², 261.61 km² and 46.04 km² respectively. The potential zone wise study area was overlaid with village boundary map and the village wise groundwater potential zones with three categories such as good, moderate and poor zones were obtained. This GIS based output result was validated by conducting field survey by randomly selecting wells in different villages using GPS instruments. The coordinates of each well location were obtained by GPS and plotted in the GIS platform and it was clearly shown that the well coordinates were exactly seated with the classified zones.  相似文献   

Enrichment pattern of leachable trace metals in roadside soils of Miri City,Eastern Malaysia     

R. Nagarajan  M. P. Jonathan  Priyadarsi D. Roy  M. V. Prasanna  A. Elayaraja 《Environmental Earth Sciences》2014,72(6):1765-1773

This article presents the results on distribution and enrichment pattern of acid-leachable trace metals (ALTMs) from roadside soil of Miri city, Sarawak, East Malaysia. The city is one of the fastest developing in the Malaysian region with huge petroleum resources. ALTMs Fe, Mn, Cr, Cu, Ni, Co, Pb, Zn and Cd along with organic carbon and carbonates (CaCO₃) were analyzed in 37 soil sediments collected from roadside. The enrichment of ALTMs [especially Cu (0.4–13.1 μg g^?1), Zn (9.3–70.7 μg g^?1), Pb (13.8–99.1 μg g^?1)] in the roadside soils indicate that these metals are mainly derived from sources related to traffic exhausts, forest fires and oil refineries. The comparative study and enrichment pattern of elements indicates that Mn, Cu, Zn and Pb are enriched multi-fold than the unpolluted soil and Ni, Pb, Cd in some samples compared to Sediment Quality Guidelines like Lowest Effect Level (LEL) and Effects Range Low (ERL) in the region which is mainly due to the recent industrial developments in the region.  相似文献   

Remote sensing- and GIS-based runoff modeling with the effect of land-use changes (a case study of Cochin corporation)     

M. Nagarajan  George Basil 《Natural Hazards》2014,73(3):2023-2039

A study was conducted to estimate the runoff in urbanized zone using Soil Conservation Services Curve Number (SCS-CN) method through remote sensing and GIS techniques. In this study, the region was identified as Cochin Corporation (Kerala State, India) with an aerial extent of 96.44 km². The spatial and non-spatial data were collected from different sources, and the thematic layers of soil hydrologic group and land-use maps were prepared and overlaid with one other. The overlaid output results were assigned by curve numbers with respect to soil and land-use categories, and the CN map was prepared with the help of Visual Basic (VB) language in ArcGIS platform. Through supervised classifications, 13 different land-use classes were identified from Quickbird data for the year of 2005 and 2010. The most prominent land-use classes were water bodies, residential, mixed crops, commercial and industrial, and 3 types of soil hydrologic groups were identified namely A, B, and C categories. The B group is most prominent occupying 60 km² of the study area. The CN map shows the ranges that 92–100 is the major CN area with high runoff potential zone of the study region. At the final stage, the runoff was estimated by the maximum successive rainfall received in this study area in two different years—2005 and 2010 along with their land-use pattern. The runoff model is applied for temporal variation in land-use change, and impact of runoff was studied. The study area showed significant changes in land-use pattern between 2005 and 2010 particularly in the land-use change from agricultural into industrial, commercial, and residential (high density). The area covered by the highest runoff depth with the range of 92–100 CN values increased from 43.87 to 45.32 km² from 2005 to 2010. The volume of runoff was increased from 135.56 to 141.49 Mm³ from 2005 to 2010 due to the land-use change pattern.  相似文献   

Changes in Climate Extremes Over the Australian Region and New Zealand During the Twentieth Century   总被引：10，自引：0，他引：10  

Neil Plummer  M. James Salinger  Neville Nicholls  Ramasamy Suppiah  Kevin J. Hennessy  Robert M. Leighton  Blair Trewin  Cher M. Page  Janice M. Lough 《Climatic change》1999,42(1):183-202

Analyses of high quality data show that there have been some interesting recent changes in the incidence of some climate extremes in the Australian region and New Zealand.  相似文献   

Tectonic evolution of early precambrian south indian shield (rocks) using remotely sensed data     

S M Ramasamy  S Balaji  C J Kumanan 《Journal of the Indian Society of Remote Sensing》1999,27(2):91-104

The interpretation of satellite imagery of part of South India falling South of 15 degree North latitude shows that the regional anticlines, synclines, domes and basins of the Precambrian group of metamorphites are aligned in three major hill ranges/domains such as Chitra-durga domain in the north, the Mangalore-Ootacamund-Bangalore domain in the centre and the Cochin-Cape Comorin-Madurai-Chittoor domain in the south. These hills are crescent shaped with their axes of elongation oriented in NNW-SSE direction. The lineaments with ENE-WSW, NE-SW/WNW-ESE and NNW-SSE azimuthal frequencies respectively exhibit extensional, shear and release geometries. Such deformational fabric shows that the tectonic evolution of South India was controlled by two major compressive forces, the first one aligned in N-S direction and the second in ENE-WSW direction.  相似文献   

Groundwater and surface water interactions in an alluvial plain, Tuul River Basin, Ulaanbaatar, Mongolia     

Maki Tsujimur  Koichi Ike  Tadashi Tanak  Lunten Janchivdorj  BadamgaravErdenchimeg  Damdinbazar Unurjargal  Ramasamy Jayakumar 《寒旱区科学》2013,5(1):0126-0132

Drinking water supplies in Ulaanbaatar, the capital of Mongolia, are completely dependent on groundwater sourced from pumping wells located in an alluvial plain of the Tuul River which flows through Ulaanbaatar. The interaction between groundwater in the alluvial plain and river surface water was investigated using a hydrological and multi-tracers approach. The observed groundwater contour map clearly shows that the Tuul River recharges the floodplain groundwater and groundwater flows from east to west. The similarity of chemical and stable isotopic compositions suggests that groundwater is mainly recharged by Tuul River water in the vicinity of the river. In addition, considering groundwater contours and chemical composition, groundwater in the northern and southern mountain sides contribute to floodplain groundwater. Stable isotopic information suggests that winter season precipitation also contributes to the groundwater, because groundwater in a specific region has a considerably lower isotopic ratio. Using the End Member Mixing Analysis applying oxygen-18, SiO₂ and HCO₃ ^- as tracers, the contribution ratios of the Tuul River, groundwater in the northern and southern mountain regions, and winter season precipitation to floodplain groundwater are estimated to be 58% to 85%, 1% to 54%, 0% to 16%, and 0% to 12%, respectively.  相似文献