Petrological and Mineralogical Characteristics of the Skarnoid in No.2 Mining Area of the Gongchangling Iron Deposit, Liaoning, China

Located in Anshan-Benxi area, the No.2 mining area of the Gongchangling iron deposit is the most important producer of high-grade Fe ores in Anshan-type diagenetic-metamorphic banded iron formation. Unlike the widespread low-grade iron ores hosted in other banded iron formations of the Anshan-Benxi area, there is a large amount of skarnoid occurring close to the high-grade ores in the No.2 mining area of the Gongchangling iron deposit. The high-grade ore bodies have a close genetic relationship with skarnoid. In order to investigate the mineralization of high-grade ore, this study presents the petrological and mineralogical characteristics of the skarnoid. The skarnoid was divided into four types, including garnet-rich type, chlorite-rich type, garnet chlorite-rich type and magnetite-actinolite-rich type. Electron microprobe data shows that the garnet member is dominated by almandite, the amphibole is tremolite in series with calci amphiboles and the chlorite is prochlorite. The skarnoid and high-grade ores were formed by hydrothermal interaction with low-grade ores, which were products of the same hydrothermal activity.