TY - JOUR
T1 - Geochemistry and uranium mineralogy of the Black slate in the Okcheon Metamorphic Belt, South Korea
AU - Kim, Youngjae
AU - Seo, Jieun
AU - Kang, Sue A.
AU - Choi, Seon Gyu
AU - Lee, Young Jae
N1 - Funding Information:
Acknowledgments—This work was supported by the National
Funding Information:
This work was supported by the National Research Foundation of Korean (NRF) Grant funded by the Korean Government (MSIP) (NRF-2011-0029101 and NRF-2014R1A2A2A01007294). We also wish to thank the personnel at Korea Resources Corporation (KORES).
Publisher Copyright:
Copyright © 2015 by The Geochemical Society of Japan.
PY - 2015
Y1 - 2015
N2 - Black slate in the Okcheon Metamorphic Belt (OMB) has been considered the perspective uranium ore in South Korea. In this study, three representative areas were selected for better understanding on the uranium-mineralogy and geochemistry of black slate in the OMB. It is found that the OMB black slate is highly enriched with metals such as U (∼0.03%), V (∼0.3%), Ba (∼1.4%) and Mo (∼0.04%). It is also notable that an average content of total organic carbon (TOC) is as high as 21.2%. Upon relationships between metals and TOC, Ba shows a weak correlation with TOC whereas the correlation is not clear for U, Mo, Cu, P, and V. In the comparison of the study areas, the average concentrations of metals such as Ba, U, and Mo and organic carbon decrease in the order of Goesan > Geumsan > Miwon. Four uraniumbearing minerals in the OMB black slate are identified. Tetravalent uranium (U4+) minerals such as uraninite and brannerite are found, whereas francevillite and Ba-bearing torbernite containing hexavalent-uranium (U6+) are observed. It is shown that uraninite and brannerite are less than 100 μm in dimension. In contrast, the size of francevillite or torbernite is larger, and the scaly texture with cracks is shown in their morphology. We note that uraninite is the most common uranium mineral throughout the black slate bed in OMB. It is demonstrated that the formation of U-bearing minerals in the bed is greatly affected by diversity of geochemical environments in the OMB, Korea.
AB - Black slate in the Okcheon Metamorphic Belt (OMB) has been considered the perspective uranium ore in South Korea. In this study, three representative areas were selected for better understanding on the uranium-mineralogy and geochemistry of black slate in the OMB. It is found that the OMB black slate is highly enriched with metals such as U (∼0.03%), V (∼0.3%), Ba (∼1.4%) and Mo (∼0.04%). It is also notable that an average content of total organic carbon (TOC) is as high as 21.2%. Upon relationships between metals and TOC, Ba shows a weak correlation with TOC whereas the correlation is not clear for U, Mo, Cu, P, and V. In the comparison of the study areas, the average concentrations of metals such as Ba, U, and Mo and organic carbon decrease in the order of Goesan > Geumsan > Miwon. Four uraniumbearing minerals in the OMB black slate are identified. Tetravalent uranium (U4+) minerals such as uraninite and brannerite are found, whereas francevillite and Ba-bearing torbernite containing hexavalent-uranium (U6+) are observed. It is shown that uraninite and brannerite are less than 100 μm in dimension. In contrast, the size of francevillite or torbernite is larger, and the scaly texture with cracks is shown in their morphology. We note that uraninite is the most common uranium mineral throughout the black slate bed in OMB. It is demonstrated that the formation of U-bearing minerals in the bed is greatly affected by diversity of geochemical environments in the OMB, Korea.
KW - Black slate
KW - Okcheon metamorphic belt
KW - South Korea
KW - Total organic carbon
KW - Uranium minerals
UR - http://www.scopus.com/inward/record.url?scp=84962428658&partnerID=8YFLogxK
U2 - 10.2343/geochemj.2.0369
DO - 10.2343/geochemj.2.0369
M3 - Article
AN - SCOPUS:84962428658
SN - 0016-7002
VL - 49
SP - 443
EP - 452
JO - Geochemical Journal
JF - Geochemical Journal
IS - 4
ER -