TY - JOUR

T1 - Ferro-manganese nodules from the Kara Sea: Mineralogy, geochemistry and genesis

AU - Vereshchagin, Oleg S.

AU - Perova, Elena N.

AU - Brusnitsyn, Aleksey I.

AU - Ershova, Victoria B.

AU - Khudoley, Andrey K.

AU - Shilovskikh, Vladimir V.

AU - Molchanova, Elena V.

PY - 2019/3/1

Y1 - 2019/3/1

N2 - Sixteen ferromanganese nodules collected from a large area in the Kara Sea were studied by optical and scanning electron microscopy, X-ray powder diffraction, X-ray fluorescence analysis, inductively coupled plasma mass spectrometry, and electron microprobe analysis. The geological setting, chemical and mineralogical features suggest that Fe-Mn concretions of the Kara Sea mainly were formed by diagenetic process, while hydrogenetic process is secondary if present. The studied nodules are characterized by the alternation of Mn- and Fe-P-enriched laminae. The Fe-P-rich laminae are almost completely composed of an amorphous phase under X-ray. We consider that the phosphatization process did not occur during formation of the Fe-Mn crusts and nodules from the Kara Sea. Several Mn-bearing phases are present in the studied samples (buserite-1, birnessite and X-ray amorphous phase). All studied nodules have similar contents of the main chemical elements. In all cases, the samples are depleted in light REE, enriched in heavy REE, and have negative Ce and Y anomalies. Our data indicate that diagenetic crusts and nodules differ significantly in terms of chemical composition from other types of Fe-Mn concretions. Based on their Co, Ni, Cu, Ce, Zr and Mo contents, we could differentiate diagenetic concretions from hydrogenetic and hydrothermal (both high and low-temperature) concretions

AB - Sixteen ferromanganese nodules collected from a large area in the Kara Sea were studied by optical and scanning electron microscopy, X-ray powder diffraction, X-ray fluorescence analysis, inductively coupled plasma mass spectrometry, and electron microprobe analysis. The geological setting, chemical and mineralogical features suggest that Fe-Mn concretions of the Kara Sea mainly were formed by diagenetic process, while hydrogenetic process is secondary if present. The studied nodules are characterized by the alternation of Mn- and Fe-P-enriched laminae. The Fe-P-rich laminae are almost completely composed of an amorphous phase under X-ray. We consider that the phosphatization process did not occur during formation of the Fe-Mn crusts and nodules from the Kara Sea. Several Mn-bearing phases are present in the studied samples (buserite-1, birnessite and X-ray amorphous phase). All studied nodules have similar contents of the main chemical elements. In all cases, the samples are depleted in light REE, enriched in heavy REE, and have negative Ce and Y anomalies. Our data indicate that diagenetic crusts and nodules differ significantly in terms of chemical composition from other types of Fe-Mn concretions. Based on their Co, Ni, Cu, Ce, Zr and Mo contents, we could differentiate diagenetic concretions from hydrogenetic and hydrothermal (both high and low-temperature) concretions

KW - Birnessite

KW - Buserite

KW - Classification

KW - Ferromanganese mineralization

KW - Ferromanganese nodule

KW - Kara Sea

KW - Nodules

UR - http://www.scopus.com/inward/record.url?scp=85061063527&partnerID=8YFLogxK

UR - http://www.mendeley.com/research/ferromanganese-nodules-kara-sea-mineralogy-geochemistry-genesis

U2 - 10.1016/j.oregeorev.2019.01.023

DO - 10.1016/j.oregeorev.2019.01.023

M3 - Article

AN - SCOPUS:85061063527

VL - 106

SP - 192

EP - 204

JO - Ore Geology Reviews

JF - Ore Geology Reviews

SN - 0169-1368

ER -