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Geology And Structure Of The Serra Do Mar In Eastern Sao Paulo, Brazil, Peter Rideg
Geology And Structure Of The Serra Do Mar In Eastern Sao Paulo, Brazil, Peter Rideg
Graduate Dissertations and Theses
Detailed geologic mapping in the Serra do Mar region of eastern São Paulo, Brazil, enables the definition of two northeasterly trending Precambrian lithologic complexes in heretofore undifferentiated crystalline complex rocks. These two complexes are the Suzano Complex and the Itatinga Complex, separated one from the other by the large Cubatão fault zone.
The Suzano Complex is divided into three formations: the Oropó schist, the Iupeba gneiss, and the Paranapiacaba gneiss. The Itatinga Complex is divided into four formations: the Biritiba-Mirim migmatite, the Jurubatuba migmatite, the Itapanhaú gneiss, and the Guarujá migmatite. Numerous late and post-tectonic granitic bodies occur intrusive into …
Geology Of The Suapure River Area, Nw Guiana Shield, Venzuela, Vicente Mendoza
Geology Of The Suapure River Area, Nw Guiana Shield, Venzuela, Vicente Mendoza
Graduate Dissertations and Theses
In the Suapure River area, NW Guiana Shield (Venezuela), crops out the Cedeño Supergroup which is a Precambrian lithologic volcanic-plutonic unit that includes the Cuchivero Group (Caicara Formation rhyolitic rocks, Santa Rosalía biotite granites and San Pedro leucogranites) and the Suapure Group, (Pijiguao leucogranites and Parguaza rapakivi granites). Radiometric ages by Rb-Sr whole rock isochron method (Hurley and others, 1973) for these rocks are as follows: 1490 m.y. for Parguaza rapakivis; 1875 m.y. for Santa Rosalía and San Pedro granites; and >1750 m.y. for Caicara rhyolitic rocks. Ortho-quartzites of Roraima Group and Cinaruco Formation unconformably overlie the Parguaza rapakivis.
The …