KOVANDAKURICHI LIMESTONE MINE
OWNER- M/s. Dalmia Cement (Bharat) Limited
The topography and general geology and local/mine geology of the mineral deposit including drainage pattern-
The limestone deposit is located at about 40 Kms. North East of Tiruchirapalli and represented by topo sheet No. 58 J/13 of Survey of India. The Proposed lease area fall between Latitude N10°57’00″ and Longitude E78°55’40″. The limestone deposit of the mining lease area is a gentle sloping terrain. The slope about is about 10° towards East. There is no national monument, places of public interest, lake or reservoir near this area.
The rocks in these region form part of the marine sedimentary formation of cretaceous age referred to Uttathur stage. The Uttathur formation is the oldest stage among the cretaceous formation. The Uttathur stage is widely spread all along the southwest boundary over 9 to 10 Kms. The general strike of the occurrence is North-South and width is ranging about 200 to 300 m. The observed depth of occurrence isabout 40 meters. The basement rocks are Achaeans with granite and granites gneiss. The order of super position of the rocks has the Achaeans as the basement with conglomerate and sandstone.
The limestone deposit of the proposed lease area in Kovandakurichi mine is of sedimentary origin and referable to Uttathur stage of upper cretaceous formation and are of marine transgression series. From the field relationship it is surmised that the sedimentary process involved could be tectonics upheaval resulted in faulting which is clearly manifested in Kovandakurichi and Kallakudi quarries as two sets of almost E-W and NNE-SSW trending normal fault system. The basement rocks are of Archean with granite and granites gneiss. The order of superposition of the rocks have the Archean as the basement with conglomerate and sandstone, the massive coral limestone followed by bedded clastic limestone and bedded marl and soft marl with black clay or red earth as top soil.
Geological succession in the Kovandakurichi Limestone deposit:
|Geological Age||Litho log / Rock type|
|Recent||Alluvium, soil and Moorrum|
|Upper cretaceous||Marl and Marly limestone|
|Clastic-bedded limestone and Marl|
|Massive pink coral limestone|
|Lower cretaceous||Grey Shale|
|Upper Gondwana||Conglomerate and sandstone|
The above deposit dip at an angle of upto 25° dip towards NNW with NNE-SSW strike at Kovnadakurichi area.
Mine will be worked by Conventional system of mining, i.e., by carrying out deep hole drilling and blasting operations. During the plan period, it has been decided to mine 25,000 tones of limestone from this area. The height of benches is maintained at 7.5m. The width of the bench is always maintained higher than the height of the bench. Pneumatically operated wagon drills of 100 -115 mm diameter holes are, engaged for carrying out drilling operations. The drills are operated with the help of diesel operated screw compressors. Slurry explosives and ANFO are used for carrying out deep hole blasting in mines. Loading of blasted limestone is carried out with the help of wheel Hydraulic excavators of 1.50m 3 bucket capacity. The limestone is transported to the plant by 10-ton tippers. Thus this type of mining would be classified as mechanized operations. A proper sump will be formed in order to dewater the storm water collected during the rainy season.
There are no sources of surface streams and rivers within the area or within the buffer zone of 5Kms. The only water source in the area is the precipitation during the monsoon and underground waters. Rainfall is about 883 mm per annum.
FLORA & FAUNA
The area is devoid of any large trees. It contains only thorny bushes, natural vegetation like grasses and wild shrubs grown during the monsoon, which are useful for grazing and in the summer, they dry out.
FAUNA The fauna that is obtained within the buffer zone are common varieties like Foxes, jackals, mongoose and rats etc.