Swedish granitoids of S- and I-type and their lithophile element distribution

Abstract

Abstract Three groups of Swedish granitoids, early, late and postorogenic, have been studied with respect to how S- or I-type granite models might be useful in the classification of these rocks. An attempt has also been made to determine which relationships, reflected in the distribution of lithophile ore elements, best characterize S- and I-types. The model is presented as a probability diagram based on two variables, the mole fraction Al2O3/(Na2O + K2O + CaO) and the degree of oxidation Fe3+/Fetot. It is shown that most of the postorogenic granites are I-type granites. These include the Karlshamn, Smaland, Dala, Ratan, Sorsele, Lina and Aland granites. The primorogenic granites of central Sweden, as well as the serorogenic Fellingsbro granite, are also I-type granites. The primorogenic granites of southern Sweden are of S-type character. Some granites, e.g. the serorogenic Revsund granite, cannot be classified using the above model. The intensity of I-type characteristics increases from primorogenic to ...