SILICATE - CARBONATE REACTIONS OF SOME HIMALAYAN ROCKS

Abstract

The Himalaya is a large orogenic belt which mainly consist of Shiwalik sediments, Higher Himalayan crystalline rocks, and some igneous intrusions. The chief lithology of Himalayan belt comprise of sandstone, Quartzite, Phyllite, Dolomite, limestone, Schist, Granite, Gneiss, Basalt, meta basalt etc. Most of these are deformed into various folds and are transected by faults of various sizes. They are mix of carbonate and silicate rocks formed in different environments. The behavior of these rocks to changing environment is always a point of debate. How the Himalayan rocks behave under different environmental conditions and what are the impacts on them are the subjects to be understood from the present study. The rocks interact with different kind of solutions in nature and the environment of interaction can vary with space and time. Hence different environmental conditions leads to different chemical reactions to occur. The nature of chemical reactions depends on the composition of the solution and the compostion of the rocks. Dissolution, precipitation, absorption, expansion, Contraction are some of the processes continuously going on in water-rock interaction. In nature, different chemical Constituents are available in solution to react with rocks like Na, K, Ca, Mg, HCO3, CO3, Cl, SO4 etc. The composition of rocks determined the way they behave towards a particular environment. Hence the change in composition of these rocks are need to be studied under different pH conditions to understand the rock-water interaction and the resultant chemical reactions