Geochemistry and boron isotopic compositions of tourmaline from the Paleoproterozoic amphibolites, NE China: Implications for the origin of borate deposit

The Paleoproterozoic metasediments and metavolcanics in the Jiao-Liao-Ji belt, northeastern China, host a large number of borate deposits. To trace the source of boron in these borate deposits, we carried out in situ chemical and boron isotopic studies on tourmalines of amphibolites from the Lieryu Formation of the Liaohe Group in the Jiao-Liao-Ji belt. The petrology and the chemical compositions of tourmalines of amphibolites show that these...