Contents
of January 2003 - Vol. XXIV No.1
INTEGRATION
OF GEOLOGICAL, GEOPHYSICAL AND GEOCHEMICAL STUDIES TO IDENTIFY NEW POTENTIAL
TARGET AREAS FOR LEAD-ZINC AND COPPER MINERALISATION IN COVERED TERRAINS
OF RAJPURA-DARIBA GROUP, WITH SPECIAL EMPHASIS TO BETHUMBI-BHUPALSAGAR
AREA, SOUTHERN RAJASTHAN
PRESENCE
OF ANOMALOUS CRUSTAL ROOT BENEATH SAURASHTRA PENINSULA - INFERENCE FROM
GRAVITY MODELLING
GEOELECTRICAL
IDENTIFICATION OF PALAEOCHANNELS OF RIVER YAMUNA FOR FRESH GROUNDWATER
IN PARTS OF MATHURA AND AGRA DISTRICTS, UTTAR PRADESH
SEISMIC
TOMOGRAPHY FOR EARTHQUAKE SOURCE AREAS
INTEGRATION
OF GEOLOGICAL , GEOPHYSICAL AND GEOCHEMICAL STUDIES TO IDENTIFY NEW POTENTIAL
TARGET AREAS FOR LEAD-ZINC AND COPPER MINERALISATION IN COVERED TERRAINS
OF RAJPURA-DARIBA GROUP, WITH SPECIAL EMPHASIS TO BETHUMBI - BHUPALSAGAR
AREA, SOUTHERN RAJASTHAN
K.N.Mathur*, R.S.Goyal** and Dinesh Gupta**
*Geological
Survey of India, NRO, Aliganj, Lucknow
**Geological Survey of India, Jhalana Doongri Jaipur
Abstract
Rajpura-Dariba
Group of rocks is linearly spread between Satdhudhia in the north to Bhinder
in the south, over an area of 100 km long (North-South) and on an average
3 km wide (east-west). The belt is endowed with rich lead-zinc mineralisation
at Dariba-Rajpura, Sindesar, Bamania; copper mineralisation at Satdhudhia,
Dariba-Rajpura, Bari-Lunera, Akola and Tana-Bhagol and silver mineralisation
at Baghera (Bharak). Some of the lead zinc deposits are under active exploitation,
whereas, others are in various stages of development for mining. The belt
in the central part got faulted and displaced into two with a movement
of about 15 km. As a result, now there are two belts namely Dariba-Rajpura-Sindesar-Bamania-Bethumbi-Bharak-Satdhudhia
being northern belt- Belt-1 (names are from south to north) and Chhatrikhera-Jashma-Bhupalsagar-Akola-Tana-Bhinder
is southern belt- Belt-2, which is an autochthonous (names from north
to south). Owing to the presence of gossans and ancient mining at Rajpura-Dariba,
the northern belt is very well explored, resulting in rich Pb-Zn deposits,
whereas southern belt being soil covered could not be explored in detail,
except in small ancient old mining zones meant for copper, such as at
Bari-Lunera, Rawatiya, Pari, Akola and Tana. The integrated studies have
revealed that before faulting the two belts were contiguous and Dariba-Rajpura
of Belt-1 was in contact with Chhatrikhera of Belt-2, hence mineralisation
similar to that of Dariba-Rajpura is also expected at Chhatrikhera-Jashma.
This thesis is further supplemented by detailed geological, structural,
airborne and surface geophysics, geochemistry and aerial photography data.
The study is a successful case of integration of all the branches of earth
sciences resulting into delineation of new potential target areas for
further detailed exploration by drilling, in the covered terrain.
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PRESENCE
OF ANOMALOUS CRUSTAL ROOT BENEATH SAURASHTRA PENINSULA - INFERENCE FROM
GRAVITY MODELLING
Bijendra
Singh, S. K. Prajapati and D. C. Mishra
National Geophysical Research Institute, Hyderbad
Abstract
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GEOELECTRICAL
IDENTIFICATION OF PALAEOCHANNELS OF RIVER YAMUNA FOR FRESH GROUNDWATER
IN PARTS OF MATHURA AND AGRA DISTRICTS, UTTAR PRADESH
P.C.
Chandra, B.B. Trivedi, M.M. Srivastava, Mohd. Adil and M.K. Bhowmick
Central Groundwater Board, Northern Region, Lucknow
Abstract
Districts Mathura and Agra are replete
with brackish to saline groundwater. About 525 electrical resistivity
soundings conducted over an area of 2200 sq.kms in the western and southeastern
parts of these districts respectively, that is towards west of river Yamuna,
helped define the spatial disposition of the palaeo-channels as elongated
resistive bodies. In Mathura district it is oriented in a general NNW-SSE
direction, almost parallel to the present day course of river Yamuna,
while in Agra it is quite wide and oriented in NNE-SSW. The palaeo-channel
delineated towards east and south of Agra hold material of better granularity
as compared to those in Mathura district. Also, the channel in Agra district
is deeper. These conform with the palaeo-course/abandoned channels of
the eastward migrating river Yamuna picked up from satellite imageries.
The area covered by these inferred palaeo-channels is about 260 sq.kms.
Water wells could be constructed upto a depth of 30-40m in parts of Mathura
and upto about 100m in Agra in the succinctly defined coarse-grained sediments
in the channels containing fresh groundwater zones to suitably cater to
the drinking water demand of these cities.
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SEISMIC
TOMOGRAPHY FOR EARTHQUAKE SOURCE AREAS
J.R.
Kayal
Geological Survey of India, Central Geophysics Division, 27 J.L. Nehru
Road, Kolkata
Abstract
Seismic tomography structures of source
areas of the two recent damaging earthquakes, the 1993 Killari earthquake
(mb 6.3) in central India and the 2001 Bhuj earthquake (MW 7.6) in western
India are presented. Large number of aftershocks followed the main shocks.
The seismic phases (P and S arrivals) of the aftershocks are used for
the tomography study. The tomography images revealed lateral heterogeneities
in velocity structure; the earthquakes occurred in the high velocity zones
at the fault ends.
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MT SURVEY
OVER THE GEOTHERMAL REGION OF BAKRESHWAR FOR INVESTIGATION OF DEEPER GEO-ELECTRICAL
STRUCTURE
Bimalendu
B. Bhattacharya*, Rajib K. Sinharay** and Shalivahan*
* Department of Applied Geophysics, Indian School of Mines, Dhanbad.
** Geophysics Division, Central Water and Power Research Station, Pune
Abstract
Bakreshwar
geothermal system is one of the most promising geothermal resourse in
India. The surface manifestation of this system is a cluster of hot springs
with temperature of the thermal fluid varies from 350C to 880C (Majumdar
et al., 2000). Bakreshwar (23052'48" N; 87022'40" E) is located in Birbhum
district, West Bengal. (Fig. 1). The heat flow of the area is very high
with values vary from145 mW/m2 to 200 mW/m2. This is more than double
of the average global heat flow and similar to the young oceanic ridges.
The geothermal gradient near the hot spring is 900C/km (Chandrasekharan,
2000). The area shows a considerable gravity high with highest anomaly
+40 mgal. Several investigations have been made over that region but failed
to locate any probable reservoir for geothermal fluid and source of the
heat. Detailed audio magnetotelluric (AMT) survey was carried out by Indian
School of Mines over the close vicinity of the hot spring (Sinharay et
al., 2000). The results showed the absence of any probable reservoir or
source below the hot spring. In present study, magnetotelluric (MT) survey
has been carried out along approximately a 12 km long profile to study
the distant and deeper subsurface geoelectrical structure to study the
geothermal system broadly.
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