Produção Nacional
Aspectos petrograficos e vulcanologicos da provincia alcalina-carbonatitica de santo antonio da barra, sudoeste de goias
1981; Sociedade Brasileira de Geologia; Volume: 11; Issue: 2 Linguagem: Inglês
10.5327/rbg.v11i2.212
ISSN2317-4889
AutoresJosé Carlos Gaspar, José C.M. Danni,
Tópico(s)Geochemistry and Geologic Mapping
ResumoThe volcanic province of Santo Antonio da Barra located in the southwestern portion of Goias is of Cretaceous age (± 85,8 m.y.), and comprises a heterogeneous sequence of analcitic rocks (pyroclastic and flows), locally capped by flows, tuffs, and agglomerates of silicocarbonatitic composition. Rests of volcanic structures and a great number of pypes and vents formed by fourchites and melamonchiquites are found tectonically controlled by NW-trending faults. They are regarded as differentiated hypoabyssal products of continental volcanism of nefelinitic type. It is reported in Brazil for the first time the occurrence of carbonatitic volcanoclastics related to the terminal stage of analcimitic volcanism.
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