MINERALOGICAL STUDY OF ALBITISED METASEDIMENT AND ALTERED ROCKS OF SALWARI AREA (SIKAR DISTRICT) NORTH DELHI FOLD BELT, RAJASTHAN, INDIA

Abstract

Albitised metasediment in Rohil-Jahaz in the North Delhi Fold Belt (NDFB) Sikar District, Rajasthan. The zone of albitisation in North Delhi Fold Belt is considered as potential for Metasomatite type uranium mineralisation. Exploration is being carried out along the albitite line of NDFB to prove uranium deposits similar to Rohil and Jahaz. In Rohil, it is a metasomatite type deposit located in Sikar district, Rajasthan. The deposit occurs along an NNE-SSW trending zone of extensive albitisation in the North Delhi Fold Belt. The host rocks are albitised biotite schist and quartzite of Ajabgarh Group (Delhi Supergroup). The ore bodies occur over 1,850m strike length and extend up to a vertical depth of 650m. Exploration in contiguous blocks is in progress. Jahaz, it is located in Jhunjhunu district, Rajasthan, about 120 km NNW of Jaipur. This deposit also lies along the albitite line of North Delhi Fold Belt. Exploration is progressing in contiguous areas of Jahaz. My dissertation is on Mineralogical Study of Albitised Metasediment and Altered Rocks of Salwari Area (Sikar District) North Delhi Fold Belt, Rajasthan. Salwari is near to Rohil, Khetri, and Saladipura. In this region we have found uranium occurrence closely associated with the albite line. The host rock quartz-biotite schist and albite contain uraninite as the primary uranium mineral. Albitite is a brick red coloured, medium to coarse grained rock and is exposed at Salwari. The presence of newly formed minerals due to metasomatism, mainly albite and quartz is the characteristic feature. Chief mineral constituents of albitite in order of decreasing abundance are albite, quartz, hornblende, biotite, allanite and opaque minerals. Titanite, chlorite, rarely K feldspars, muscovite, zircon, fluorite, apatite and rarely monazite and uranothorite are the minor mineral phase. Prominent feature of albitite is the occurrence of chessboard twining which is considered to have formed by the complete replacement of microcline by albite during albitization.