On Some Calc-Silicate Rocks Around Sitarampuram, in Visakhapatnam District, Andhra Pradesh

Occurrence of a few bands of calc-silicate rocks is found to be restricted to an area bounded by lats. 18°13'-18°16'N and longs. 83°7'-83°10'E around Sitarampuram. These bands are characterised by the assemblage of minerals like clinopyroxene, calcic plagioclase, wollastonite, scapolite, grossularite and sphene. besides secondary minerals like epidote-clinozoisite and chlorite.

The close association and gradational relationship of (bands 2 and 3) the calcsilicate rocks with the khondalite and charnockite points to the identical condition of metamorphism attained by all the three concerned litho units i.e, under the pyroxene granulite facies condition. Retrograde metamorphism, perhaps, is responsible for the formation of the secondary minerals like epidote clinozoisite and chlorite.

The field evidences, petrological studies and chemical analyses, suggest that the calc-silicate bands are products of metamorphism of sediments, varying in composition from calcareous sha limestone.