Saturday, November 7, 2009
The Baltic Shield (sometimes referred to as the Fennoscandian Shield) is located in Fennoscandia (Norway, Sweden and Finland), northwest Russia and under the Baltic Sea. The Baltic Shield is defined as the exposed Precambrian northwest segment of the East European Craton. It is composed mostly of Archean and Proterozoic gneisses and greenstones which have undergone numerous deformations through tectonicactivity (see Geology of Fennoscandia map ). The Baltic Shield contains the oldest rocks of the European continent with a lithospheric thickness of about 50 km. During the Pleistocene epoch, great continentalice sheets scoured and depressed the shield's surface, leaving a thin covering of glacial material and innumerable lakes and streams. The Baltic Shield is still rebounding today following the melting of the thickglaciers during the Quaternary Period.