Informatics Publishing Limited

A. B. Narayanpethkar ¹, V. V. S. Gurunadha Rao ², K. Mallick ²

Affiliations
1 Geology Department, Shivaji University PG Centre, Solapur, IN
2 National Geophysical Research Institute, Hyderabad, IN

Abstract

Aquifer parameters have been estimated through pump tests conducted on large diameter wells at 40 locations well distributed in the basin. The pre- and post-monsoon groundwater levels during 1988 and 1989 have been measured at 40 observation wells. (1) Total groundwater input of 23.8 MCM to aquifer system consists of 23.2 MCM of recharge due to rainfall and 0.6 MCM of seepage from canal network. (2) Total output stresses include groundwater draft of 14.6 MCM from about 1300 open wells and borewells, and groundwater effluence of 9.2 MCM to the Adila stream. (3) The regional transmissivity (T) values in the basin range from 10 to 235 m²/day.

Keywords

Ground Water Adila Basin, Maharashtra, Deccan Trap Transmissivity.

Full Text

     

B. S. Rathor ¹, M. Devanandam ¹, K. Mallick ¹

Affiliations
1 National Geophysical Research Institute, Hyderabad - 500 007, IN

Abstract

Finite-difference numerical technique has been in use for over two decades in solving elastic wave equation for the interpretation of seismic response of complex 2-D and to a limited extent, 3-D oil bearing geological structures. The present communication consists of two parts. In the first part, synthetic seismograms have been obtained under plane wave as well as line source excitations for a gas cap structure and over a salt dome/basement undulation. In the second part, seismogram under plane wave conditions has been computed for a geological structure from the Gujarat coast. Some of the faults confining the pay zone between 1800 ms and 1900 ms in the time section are highlighted.

Keywords

Seismology, Structure, Hydrocarbon, Gujarat.

Full Text

     

K. K. Sharma ¹, V. K. Rao ², K. Mallick ²

Affiliations
1 Department of Applied Geology, University of Madras, Chennai, IN
2 National Geophysical Research Institute, Hyderabad, IN

Abstract

The separation of the regional gravity anomaly by any of the existing techniques has one common drawback, i.e. the Bouguer gravity values over the anomalous zone enter into the computations. In order to overcome this, a new scheme, based on the finite element approximation, is suggested to compute the regional anomaly. The uniqueness of this approach is that except a few discrete gravity values coinciding with the nodes of the element superimposing the map space, often very large, no other gravity data are invoked to compute the regional anomaly. As a case study, regional - residual anomaly separation has been carried out for the north west Ganga Basin. This area is chosen as it is tectonically very active, and based on the regional and residual gravity anomalies, we can unfold the imprints of various tectonic episodes along the lndo - Eurosian plate boundary. While the regional gravity anomaly shows possible association with deep-seated faults along the rivers Yarnuna and Chambal, the seismicity appears to be correlated with the residual gravity anomaly around Delhi.

Keywords

Geophysics, Finite Element Analysis, Regional Gravity, Ganga Basin.

Full Text

     

A. B. Narayanpethkar ¹, A. Vasanthi ², K. Mallick ²

Affiliations
1 Department of Geology, Solapur University, Solapur, Maharashtra, IN
2 National Geophysical Research Institute, Hyderabad, IN

Abstract

No Abstract.

Full Text

     

A. B. Narayanpethkar ¹, A. Vasanthi ², K. Mallick ²

Affiliations
1 Geology Department, Solapur University(Formerly Shivaji Univ., PG Centre), Solapur, IN
2 National Geophysical Research Institute, Uppal Road, Hyderabad - 560 007, IN

Abstract

More than 250 resistivity soundings with Wenner array have been conducted in the basaltic terrain of the Adila basin with an area of about 585 sq km around Solapur, Maharashtra. The resistivity sounding curves have been interpreted in two phases first, by curve matching and later by computer-Aided techniques. Some of the sounding points were chosen near the existing boreholes so as to correlate the sounding results with the borehole lithologs. The potential zones for groundwater accumulation in different horizons were identified by preparing the structure contour maps for the first, second and third interfaces and correlating them with geology and water table contour maps. The earth-sections obtained by interpreting the resistivity soundings are shown as three profiles along NE-SW, NW-SE and E-W directions. The numbers of successful borewells in different villages are also shown in these profiles. In all, 100 locations for the purpose of irrigation were recommended for drilling and 85 of them proved successful.

Keywords

Groundwater, Electrical Resistivity, Flow Pattern, Basaltic Terrain, Maharashtra.

Full Text

     

A. Vasanthi ¹, K. Mallick ²

Affiliations
1 National Geophysical Research lnstitute Uppal Road, Hyderabad - 560 007, IN
2 National Geophysical Research lnstitute Uppal Road, Hyderabad - 560 007

Abstract

No Abstract.

Full Text

   

K. Mallick ¹

Affiliations
1 CSIR Emeritus Scientist, NGRI, Hyderabad, IN

Abstract

No Abstract.

Full Text

   

A. Vasanthi ¹, K. Mallick ¹

Affiliations
1 National Geophysical Research Institute, Hyderabad - 500 007, IN

Abstract

Bouguer gravity data over a large central part of the Cuddapah basin have been obtained by digitising the 5-mGal contour map. The regional and residual components have been separated by a newly developed finite element scheme, contoured with colour scale and residual anomalies are modelled for the basement structure in several profiles. The data is thereby rendered more attractive and easily visualised. The thickness of the sediments derived by gravity modelling has been compared with that along two deep seismic sounding (DSS) profiles. The thick columns(˜ 9 km) of sedimentary formations in the Proterozoic Cuddapah basin are likely to interest the organizations dealing with hydrocarbon exploration.

An interesting relationship has been brought out among the three mantle-Derived rocks, i.e. the volcanics of the western margin, the kimberlite emplacement and the dyke swarms. These three features seem to share a common gravity field.

Based on the correspondence between the locations of kimberlite pipes and lamproites and the regional gravity anomalies we suggest the kimberlites and the lamproites to occur along two concentric rings with the centre lying approximately in the southwest region of the Cuddapah basin. Further, the occurrences of kimberlite pipes and lamproites at Vijayawada and Ramannapet on northeast, Narayanpet on the west and Kalyandurg on the southwest led to suggest a third ring. In fact, three new kimberlite pipes have been reported at Siddanpalli between Gadwal and Raichur that lie on the third ring. The gravity studies also indicate the Cuddapah Front on the east to form a possible collision boundary.

Keywords

Bouguer Gravity Modelling, Finite Element Approach, Hydrocarbon, Diamond Fields, Collision Contact, Cuddapah Basin.

Full Text

     

A. Vasanthi ¹, K. Mallick ¹

Affiliations
1 National Geophysical Research Institute, Hyderabad - 500 007, IN

Abstract

Kimberlite pipes of Wajrakarur-Lattavaram region in Andhra Pradesh follow some definite patterns depending on regional geology, structure and tectonics. The lithotectonic units with contrasting physical properties often find expression in geophysical measurements. Although direct detection of buried kimberlite pipes by geophysical methods is often difficult, judicious integration of geology, tectonics, and geophysics may suggest favourable zones for detailed investigations.

Based on the distribution of 13 kimberlite pipes discovered so far in the Wajrakarur-Lattavaram region, and on the regional and residual Bouguer gravity and residual magnetic maps derived by a finite element approach, we have attempted to recognize patterns of occurrence of kimberlite pipes. A few potential regions are identified mainly at the intersections of the NE-SW trending faults and the contacts of granites and country rocks.

Keywords

Gravity, Magnetic Anomalies, Kimberlite Pipes, Wajrakarur, Lattavaram, Andhra Pradesh.

Full Text

     

K. Mallick ¹

Affiliations
1 National Geophysical Research Institute Hyderabad - 500 007, IN

Abstract

No Abstract.

Full Text

   

A. Vasanthi ¹, K. Mallick ¹

Affiliations
1 National Geophysical Research Institute, Hyderabad - 560 007, IN

Abstract

The Cuddapah, Kaladgi and Bhima basins have generated renewed interest in the recent past among the petroleum geologists for possible hydrocarbons in Proterozoic environment. As regards the Kaladgi basin, besides favourable structural settings such as a series of plunging anticlines and synclines, buried domal structures and thick columns of sedimentary formations, optimism for possible success stems from the surface gas seepage and gas shows in drilled wells in coeval Vindhyan Basin in Rewa and recent discovery in Shahdol near Jabalpur in the Narmada basin in India and oil fields in equivalent formations in Amadeus basin of Australia, Sichauan and Bohai bay of China and Lena- Tunguska basin of Siberia.

It is therefore tempting to apply the new finite element technique to compute the regional and residual gravity fields of the Kaladgi-Badami basin, and to model the residual anomalies with two objectives, first to estimate the sediment thickness, and secondly to know the northern extent of basin under the Deccan Traps. In the first step, the gravity effect of the overlying basalt was removed from the Bouguer gravity data and then the regional-Residual separation was carried out. The resulting residual anomaly was interpreted in terms of basement depths. The maximum depth of the basin is of the order of 36 kilometers which is well comparable to the estimates by geological observations.

Keywords

Bouguer Gravity Modelling, Finite Element Approach, Hydrocarbons, Basement Configuration, Kaladgi-Badami Basin, Karnataka, Maharashtra.

Full Text

     

K. R. P. Rao ¹, S. Viswanathan ², A. Vasanthi ³, K. Mallick ³

Affiliations
1 Geological Survey of India Training Institute, Hyderabad - 500 068, IN
2 10, Bapuji Apts., Rajendra Prasad Road, Dombivli (East) Mumbai - 421 201, IN
3 NGRI, Hyderabad - 500 007, IN

Abstract

No Abstract.

Full Text