ABSTRACT
A number of giant boron and magnesite ore deposits occur in the eastern Liaoning and Jilin Provinces of China. These deposits located within a thick metamorphosed volcanic-sedimentary sequence of Proterozoic age along a NE-SW striking belt of ∼300 km long. The boron isotope analyses of Mg-borate and magnesite minerals from the deposits reveal high positive δ11B values of 9.6 to 12.1′ and 16 to 18′, respectively. The boron isotope data, together with sulfur isotope data and other geological evidence, suggest that these deposits are of metamorphosed marine evaporites in origin.
