REVISÃO DA EXTENSÃO AREAL E DO VOLUME DA FORMAÇÃO SERRA GERAL, BACIA DO PARANÁ, AMÉRICA DO SUL

In the discussion of the origin of continental flood basalt provinces, one of the most important constraints is the volume of the mobilized magma. Concerning the Serra Geral Formation in the Parana Basin (South America), most authors cite an actual areal extent of 1,200,000 km 2 and a volume of approximately 800,000 km 3 . The same volume is often used for the Parana-Etendeka Continental Flood Basalt Province, from which the Serra Geral Formation is the major part. We investigated the precision of these numbers through a complete historical review of their origin. We found that the areal extent cut off of 1,200,000 km 2 is only an estimate made in 1934, and that the volume cut off of 800,000 km 3 aroused using this areal extent estimate and an estimate of a mean thickness of 650 m of the flows made in 1966. Using a new map, we found that the area covered by the volcanic rocks in the Parana Basin is of only 917,000 km 2 (+- 15,000 km 2 ). With isopach maps of 1987 and 1990, we calculated the volume of the extrusive rocks to be of at least 450,000 km 3 and of the intrusive sill-type bodies to be of at least 112,000 km 3 . With these estimates, the volume of the Serra Geral Formation should be considered to be of more than 600,000 km 3 . For the Parana-Etendeka Continental Flood Basalt Province as a whole, a volume of at least 1,700,000 km 3 should be considered.