Page:The origin of continents and oceans - Wegener, tr. Skerl - 1924.djvu/70

46 Paulo. In Africa, the Erongo granite in the land of the Hereros and the Brandberg granite in the north-western portion of Damaraland correspond to it, as well as the granites of the “Bushveld Igneous Complex” in the Transvaal. The alkaline rocks are found exactly on the corresponding stretches of coast: on the Brazilian side, at different places in the Serra do Mar (Itatiaya, Serra do Gericino near Rio de Janeiro, Serra de Tingua, Cabo Frio); on the African side, on the coast of Lüderitzland, near Cape Cross north of Svakopmund, and again in Angola. At a greater distance from the coast, each with a diameter of about 30 km., are the eruptive regions of Poços de Caldas in the south of the province of Minas Geraes and of Pilandsberg in the Rustenburg district of the Transvaal. These alkaline rocks are very striking in the absolutely similar development of the plutonic, dyke, and volcanic facies. Brouwer says in reference to the fourth group (Jurassic volcanic rocks and intrusive dolerite): “Just as in South Africa, a thick series of volcanic rocks is developed in the lowest portion of the Santa Catharina System, corresponding approximately to the South African Karoo System; these can be considered as Jurassic in age, and cover large areas in the provinces of Rio Grande do Sul, Santa Catharina, Parana, São Paulo and Matto Grosso, and even in Argentina, Uruguay and Paraguay.” Here, in Africa, belongs the Kaoko Formation developed between the latitudes of 18° and 21° S., which corresponds to the similar rocks in the provinces of Santa Catharina and Rio Grande do Sul of Southern Brazil. Finally, the last rock group (kimberlite, alnöite, etc.) is very well known, since its members yield the matrix in which diamonds are to be found, in Brazil as well as South Africa. In both areas the peculiar form of deposits known as “pipes” occurs. “White” diamonds