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sulphides due to reducing conditions (AMSE, 1979). 
Basu (1971) has 
given the following sequence for this area — 
*  Pegmatite and quartz vein 
e  Metabasic rock 
Calc-silicate rocks with minor bands of marbles 
Samodi quartzite 
Ferruginous quartzite 
Calc-silicate rocks with minor marbles 
Pur quartzite 
e  Garnetiferous mica-schists 
*  Hornblende-schists with bands of granitised mica- 
schists 
The ferruginous quartzite is the mineralized horizon in the area 
and is gossanised at places. The grade of metamorphism 
transgresses from green-schist to almandine-amphibolite facies 
(AMSE, 1979). 
Structurally, these rocks constitute a part of the eastern limb of 
northeasterly plunging Banera-Bhinder syncline, the closure of 
which is exposed near Bhinder in the south (Raja Rao, 1972). 
The general strike of the formations in the study area ranges 
from N5° to N60° with moderate to steep dips from 30? to sub- 
vertical towards SE and NW. There are two northeasterly 
plunging major synforms — Pansal synform and Pur synform. 
The closure of Pansal synform is exposed near Lakshmipura 
and that of the Pur synform is exposed near Pur. The 
intervening antiform is sheared off by a prominent NE-SW 
trending lineament. Apart from these two major synforms, there 
a number of tight/overturned mesoscopic folds, which have 
been observed in the Pur quartzite and ferruginous quartzite 
horizons. These folds plunge at'40? to 75° towards N355° to 
N60°. A number of longitudinal and transverse lineaments are 
present in the area. The transverse lineaments have probably 
dislocated the mineralized horizon at few places (AMSE, 
1979). 
S. MINERALIZATION 
The base metal mineralization of zinc (Zn), lead (Pb) and 
copper (Cu) occurs in the ferruginous quartzite horizon in this 
belt. The ferruginous quartzite is gossanised at places. The 
mineralization is known to have stratigraphic-cum-structural 
control and shows bedded geometry (Basu, 1971 and Patel, 
1987). The main sulphide minerals are sphalerite, galena, 
chalcopyrite, pyrite and pyrrhotite. About 35 million tones of 
ore reserves have already been proved in this mineralized belt 
by the GSI. 
A number of old workings and slag heaps have been observed 
at Tiranga hill, Pur-Dariba and Raningpura. There are 
essentially two mineralized zones — (i) the eastern zone 
extending from Malikhera in the north to Tiranga in the south 
for about 34 km and (ii) the western zone extending from 
Manpura in the north to near Gurla in the south for about 40 
km. These two mineralized zones are discontinuous presumably 
due to tectonic disturbances (Patel, 1987). 
6. APPLICATION OF REMOTE SENSING 
6.1 Image Processing and Interpretation of Satellite Data 
The satellite data obtained from the IRS PAN and Landsat TM 
have been digitally processed and interpreted with a primary 
view to map the ferruginous quartzite, which is the mineralized 
horizon in the study area. It essentially involved the following 
steps — 
(i) Georeferencing of IRS PAN data with reference 
to topographic map of Survey of India (SOI) on 
1:50,000 scale, ; 
(ii) Co-registration of IRS PAN data with the 
Landsat TM data, 
(iii) Digital image enhancement using different 
techniques, 
(iv) Interpretation of enhanced satellite data and 
(v) Ground follow-up. 
Out of all the digital image enhancement techniques, colour 
ratio composite of TM (3/1 5/4 5/7 2 R G B) has given the best 
result (Figure-1). It shows a distinct reddish brown colour for 
the ferruginous quartzite horizon. In order to reduce the 
subjectivity in picking up these spectral signatures based on 
visual interpretation, the above TM colour composite has been 
digitally classified. Based on the classified output and also the 
visual interpretation of the enhanced image, a spectral anomaly 
map has been prepared. A typical elliptical-shaped spectral 
anomaly pattern was noticed in Sanganer-Suwana-Akola area 
on the northern and southern sides of the Kothari river, east of 
Bhilwara town apart from along the main NE-SW trending 
known mineralized belt of Pur-Banera. The ground follow-up 
subsequently revealed the presence of an outcrop of ferruginous 
quartzite in the eastern outskirts of Bhilwara town along the 
Bhilwara-Suwana road (latitude 25? 20.91' N and longitude 74? 
39.84’ E). This outcrop of ferruginous quartzite is surrounded 
by the quartz biotite schist. The preliminary analysis of a rock 
sample collected at this location shows high values of Pb (>1%) 
and Zn (>800 ppm). The geological maps and literature 
available with the authors indicate the presence of calc silicate 
rocks and amphibolites in this area. AMSE (1979) has indicated 
the presence of strong magnetic and electromagnetic anomalies 
in this area. In other areas, where spectral anomalies were 
  
  
  
  
erg ey E 
Figure-1 Landsat TM FCC (3/1 5/4 5/7 = R G B) of the study 
area covering 22 km x 19 km approx. Red circle shows the 
491