) DATA
Actual
yield
(in
Ipm)
1820
1820
1592
1365
‘1668
1510
758
758
793
793
1008
793
1160
793
505
190
505
130
80
24
nent
ach
with
the
and
rent
ical
f an
and
UP,
on
ide
are,
and
ter
nal
ing
ial
19,
IAPRS & SIS, Vol.34, Part 7, “Resource and Environmental Monitoring", Hyderabad, India, 2002
GEOSCIENTIFIC EVALUATION OF CORUNDUM IN AND AROUND
KONIJERLA MANDAL OF KHAMMAM DISTRICT , ANDHRA PRADESH.
Author's Name: NARAYAN SANGAM
Senior Research Fellow
Geosciences Group, Geology Division, National Remote Sensing Agency
Dept of space, Govt. of India., Balanagar, Hyderabad, A.P.
Ph. (Off) 040- 3884224
(Res) 040- 7038173.
KEY WORDS: Geology, Remote Sensing, Exploration, Forestry, Research & Analysis.
ABSTRACT:
Corundum in the form of *Ruby" of Gem Quality is found to be associated with the Anorthosites & Amphibolites of Khammam
Schist Belt, an area East of Khammam Town, in Andhra Pradesh. Exploitation of gem quality "Ruby" has been going on for over
years at Lakshmipuram and areas surrounding the wyra lake. Examinations indicate that the occurrence of Corundum is principally
controlled by its lithology and petrogenesis.
INTRODUCTION
The Khammam district forms a part of the Indian peninsular
shield, which has remained stable since the formation of the
crust. They are exposed in the western & Eastern parts of the
district.The geosynclines during the archaean era consisted of
khondalite & Dharwarian suite of rocks.
OBJECTIVES
e To evaluate geoscientifically the occurances of corundum
in Konijerla Mandal of Khammam District , along the
KSB
e To identify the petrogenetic controls of formation of
corundum.
e To evaluate the feasibility of corundum.
e To identify the scientific parameters that cause its gem
quality.
e To identify the method of exploration for corundum in
Konijerla Mandal.
e To study the Environmental Problems associated with the
corundum exploitation.
APPLICATIONS OF RS & GIS IN TERRAIN
EVALUATION.
CHIMALPAHAD ANORTHOSITE- GABBRO
COMPLEX:
Remote sensing has provided an important tool for resource
evaluation at local, regional & global scales. An example of the
Applications of RS in terrain evaluation is being cited for the
Chimalpahad Anorthosite Gabbro Complex. The CAGC is
considered to be one of the largest archaean metamorphosed
layered complex in India. It occupies an area of approx over
200 Sq km in Khammam District . Most part of the CAGC
occurs within the chimalpahad Reserved Forest which is
inaccessible wherein, the science of remote sensing as a
scientific tool for study is used to know the details. The CAGC,
mostly covered with forest has been studied through satellite
imagery in the past and is also presently in use. The CAGC was
syntectonically emplaced (with respect to the main N- S
trending fold) into migmatites, gneisses and high grade schists
of KSB . The CAGC has an arcuate shape and the main
intrusive body constitutes the Chimalpahad Hill Range. Smaller
bodies occur around Lingannapeta Jonnaram, Yenkur — Tallada
and Konayyapalem. The host rocks are chiefly biotite — schists/
gneisses, hornblende biotite- gneisses with basic enclaves.
Garnet occurs in these basic enclaves as scattered crystals,
streaks & patches. The layered complex is made up of
Ultramafic assemblage comprising pyroxenite, dunite,
websterite and mafic anorthosite association of gabbro / leuco
gabbro and anorthosite.
KHAMMAM SCHIST BELT
Studies have revealed that the Khammam schist belt is in the
continuity of the Nellore schist belt across Guntur & Krishna
Districts thus making the KSB a single continous trans —
cratonic supracrustal belt.
LITHOLOGY
KSB is composed of metamorphosed pelitic, psammitic &
calcareous sediments represented by garnetiferous biotite
muscovite chlorite schists, calc silicate rocks, quartzities. The
metasedimentary unit is placed below a meta- volcanic unit
made up of quartz-chlorite schists, hornblende schists&
gneisses.
The rocks of the KSB are intensely migmatised with the
development of streaky biotite gneisses & hornblende gneisses.
Amphibolites, ^ Meta-Ultramafics, meta-dolerites and
metagabbros are the other rock types. Meta-Gabbro anorthosite
complex and pinkgranites are the intrusive phases into the KSB
assemblage.
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