Chapter 10 Proterozoic orogenic granitoid rocks

Abstract

Publisher Summary The classification of plutonic rocks with respect to orogeny originated in Finland. Pentti Eskola classified plutonic rocks in southern Finland as synkinematic, late kinematic, and postkinematic using the degree of deformation and compositional differences as criteria. In the same year, J. J. Sederholm divided the Precambrian rocks of Fennoscandia into four sedimentation cycles, each with distinct plutonism. The plutonic rocks of the first and second cycles mainly correspond to the synkinematic rocks of Eskola (1932). Some granite stocks in southern Finland and Lapland (northern Finland) belong to the third cycle, and the rapakivi granites in southern Finland are part of the fourth cycle. Later, Simonen (1960) distinguished synkinematic granodiorite, trondhjemite, charnockite, and granite provinces as well as a belt of latekinematic microcline granites. In 1980, Simonen divided the Svecofennian plutonic rocks into synorogenic, lateorogenic, and postorogenic and considered that the rapakivi granites are anorogenic.