A geochronological and geochemical study on 10 samples of seafloor massive sulfides (SMS) from the inactive Peterburgskoye hydrothermal field at the Mid-Atlantic Ridge (MAR) was carried out. The 230 Th/U ages of the SMS are the oldest for the Quaternary hydrothermal ores ever found at the ocean floor. According to them the hydrothermal activity at Peterburgskoye field started at least 170 ka and continued down to 63 ka. The oldest hydrothermal ores from this field consist mainly of pyrite and chalcopyrite and have geochemical properties typical for SMS associated with basalts.
The paper presents the detailed mineralogical and petrographic study of spinel-bearing marbles at the Luc Yen deposit, North Vietnam. The LA-ICP-MS analysis of 74 spinel grains, combined with mineralogical data, allows us to discriminate them into fve types according to mineral assemblages and trace element geochemistry. Forty seven minerals are identifed as inclusions in spinel grains and 38 minerals are described at Luc Yen deposit for the frst time including leonardsenite, tintisite, manasseite, chalcoalumite, cobaltite and spherocobaltite. The mineral assemblages, trace element pattern, and specifc mineral inclusions indicate the involvement of hydrothermal fuids related to magma intrusions in the formation of, at least, two of fve spinel types at the deposit.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.