Santa Marta II
This is an approximately circular trachyte plug 1 km in diameter, cutting Precambrian granite. Santa Marta I, lying 2 km southwest of Fazenda do Toninho, is gabbroic.
This is an approximately circular trachyte plug 1 km in diameter, cutting Precambrian granite. Santa Marta I, lying 2 km southwest of Fazenda do Toninho, is gabbroic.
A lava flow with a maximum thickness of 20 m outcrops over a semicircular area less than 1 km in diameter, 4.5 km southeast of Volta Redonda. It is associated with sediments of the Resenda Formation.
A major concentration of circular structures occurs in northeastern Brazil in the states of Maranhao and Piaui with one in Goias. Most show evidence of doming and they are thought probably to be underlain by alkaline intrusions. Those listed are taken from Rodrigues and Lima (1984).
A major concentration of circular structures occurs in northeastern Brazil in the states of Maranhao and Piaui with one in Goias. Most show evidence of doming and they are thought probably to be underlain by alkaline intrusions. Those listed are taken from Rodrigues and Lima (1984).
A major concentration of circular structures occurs in northeastern Brazil in the states of Maranhao and Piaui with one in Goias. Most show evidence of doming and they are thought probably to be underlain by alkaline intrusions. Those listed are taken from Rodrigues and Lima (1984).
A major concentration of circular structures occurs in northeastern Brazil in the states of Maranhao and Piaui with one in Goias. Most show evidence of doming and they are thought probably to be underlain by alkaline intrusions. Those listed are taken from Rodrigues and Lima (1984).
A major concentration of circular structures occurs in northeastern Brazil in the states of Maranhao and Piaui with one in Goias. Most show evidence of doming and they are thought probably to be underlain by alkaline intrusions. Those listed are taken from Rodrigues and Lima (1984).
A major concentration of circular structures occurs in northeastern Brazil in the states of Maranhao and Piaui with one in Goias. Most show evidence of doming and they are thought probably to be underlain by alkaline intrusions. Those listed are taken from Rodrigues and Lima (1984).
A major concentration of circular structures occurs in northeastern Brazil in the states of Maranhao and Piaui with one in Goias. Most show evidence of doming and they are thought probably to be underlain by alkaline intrusions. Those listed are taken from Rodrigues and Lima (1984).
Perambu is a peralkaline granite intrusion which cuts Precambrian gneisses and migmatites along its northern margin, but in the south is in contact with molasse-type sediments and associated volcanics. The granite contains biotite, aegirine and a little riebeckite.