GEOLOGY AND GEOCHEMISTRY OF GRANITIC AND DIORITIC ROCKS OF THE SÃO JOSÉ DO RIBEIRÃO INTRUSIVE MASSIF, MOUNTAIN REGION OF RIO DE JANEIRO STATE, BRAZIL

MENDES, J. C., JUNHO, M. B., GHIZI, A. Geology and Geochemistry of granitic and dioritic rocks of the Sao Jose do Ribeirao intrusive massif, moun- tain region of Rio de Janeiro State, Brazil. Revista Universidade Rural, Serie Ciencias Exatas e da Terra, v. 21, n. 2, 2002, p. 01-11 Medium-grained granite, dioritic and gabbroic rocks occur associated in the Sao Jose do Ribeirao district, Bom Jardim town, mountain region of Rio de Janeiro State. Geological, petrographic and geochemical re- sults are discussed and compared with similar rocks within the post-collisional granitic province of Rio de Janeiro (PCGRJ), as well as with gabbros elsewhere.The granite and the microdiorites are close related and show mingling structures. They are here inter- preted as part of the PCGRJ. They are calc-alkaline, metaluminous rocks, with high rare-earth elements content. Similarities between the microdiorites and the quartzdioritic to dioritic microgranular enclaves found elsewhere in the PCGRJ are strongly suggestive of a widespread andesitic episode in this province.