METALLOGENIC REGULARITY AND PROSPECTING OF BORON DEPOSITS IN EASTERN LIAONING-SOUTHERN JILIN METALLOGENIC BELT

The eastern Liaoning-southern Jilin metallogenic belt is the leading site of hard rock-type boron deposit in China. Based on the previous research results of Precambrian geology, Jiao-Liao-Ji orogenic belt, as well as metallogenesis, the paper summarizes the coupling relationship between Paleoproterozoic orogeny and boron metallogenic events in eastern Liaoning region, and establishes the metallogenic model of boron deposits in eastern Liaoning-southern Jilin metallogenic belt. With the field survey on the typical boron deposits of Houxianyu, Wengquangou and Zhuanmiao-Yangmugan, the previous B and Mg isotopic data of the deposits are summarized and drawn for analysis. The results show that the boron deposits have experienced three main processes, i.e. early enrichment, mineralization during Paleoproterozoic orogeny and later reformation. Mg-rich marble and initially enriched B are the main ore-forming material sources. The basic and ultrabasic rocks play an important role in trapping B-rich fluids during orogenic metamorphism and contribute some ore-forming materials. The late metamorphism destroys orebody and partially improves the grade of ores. Finally, the paper also analyzes the main factors restricting boron prospecting in eastern Liaoning region, suggests that more attention be paid on the Paleoproterozoic formation and structure mapping, structural analysis and choice of suitable exploration means. The idea of further boron ore prospecting is also discussed.