Bøger af Baiju Kalathilparambil Rajappan

¿¿¿¿¿They were first found in full variety at St. Thomas¿ Mount and Plallavaram, 10 miles south of Madras city; from quarries in these localities large quantities of rocks have been obtained for building and ornamental purposes in Madras. Subsequently the same rocks were found to make up the mountain masses of the Shevaroys, Nilgiris, the Palnis and the great ridge of high ground forming part of the Western Ghats, stretching southwards as far as Cape Comorin and reappearing above the sea level in Cylone¿.- the words by Thomas Holland on charnockite. The book is all about charnockites and associated gneisses from the Madurai Granulite Block of the Southern Granulite Terrain. Looked into its association and genesis with very conventional view point of petrography, PT paths and geochronology.

Graphite is a common accessory mineral in high-grade metamorphic rocks, but it is more prominent in khondalites (garnet-biotite-silliminite gneiss) and leptinites (garnet-biotite gneiss) and very rarely in garnet bearing and orthopyroxene bearing anhydrous granulites (charnockite). This fact is more pronounced and can be noted in rocks from the Southern Granulite Terrain, especially in Kerala Khondalite Belt. Both syngenetic and epigenetic types of graphite have been reported from this area. In the Madurai Granulite Block (MGB), the presence of khondalites and leptinites are comparatively less and the major rock type is charnockite with very rare amounts of garnet. But graphites are mineralizing in many parts of the MGB mostly within the charnockites or associated gneisses. The nature and type of this graphite has not been studied much. The book is an initiation to elucidate the graphite mineralization in the terrain with an emphasis on its genesis and mineralogical characteristics.