Mineralogy and geochemistry of ferromanganese oxide deposits from the Chukchi Sea in the Arctic Ocean

Abstract

Abundant ferromanganese oxide deposits were recovered from the Chukchi Sea in the Arctic Ocean during the 7th Chinese Arctic Scientific Expedition in August 2016. Representative samples were collected to perform a mineralogical and geochemical analysis and elucidate their origin. Their mineral phases consist of todorokite, buserite, and birnessite, along with a small quantity of detrital minerals (quartz, feldspar, serpentine, kaolinite, and illite). Their elemental composition is rich in Ni and Mn compared to ferromanganese oxide deposits from other locations in the Chukchi Sea. The total rare earth element (REE) concentration varied from 138.95 to 207.23 μg/g with an average of 164.75 μg/g. The post-Archean Australian shale-normalized REE patterns have a slightly negative Ce anomaly and a positive Eu anomaly. The comprehensive geochemical and mineral data show that they have a mixed hydrothermal and diagenetic origin.

Discriminating formation and accumulation processes of some strategic metals in Fe-Mn deposits of the Atlantic Ocean

“…For past several decades, a large number of publications on the mineralogical and chemical composition as well as textural features of FMD of the World’s Ocean have been published (Baturin, 1988; Koschinsky et al , 1997; Hein et al , 2000, 2013; Blokhin et al , 2014; Hein and Koschinsky, 2014; Mikhailik et al , 2014; González et al , 2016; Marino et al , 2017; Mikhailik et al , 2017; Konstantinova et al , 2018; Marino et al , 2018; Mikhailik et al , 2018; Ivanova et al , 2019; Mikhailik et al , 2019; Benites et al , 2020; Cui et al , 2020). Not much data on the composition of FMD is known for the Atlantic Ocean.…”