Composition and characteristics of the ferromanganese crusts from the western Arctic Ocean |
| |
| Institution: | 1. Saint-Petersburg State University, St. Petersburg 199034, Russia;2. Institute for Geology and Mineral Resources of the Ocean (VNIIOkeangeologia), St. Petersburg 190121, Russia;3. U.S. Geological Survey, Santa Cruz, CA 95060, USA;4. The Laboratory HERCULES, University of Evora, Évora 7000-809, Portugal;5. Estrutura de Missão para a Extensão da Plataforma Continental, Paçod''Arcos 2770-047, Portugal;6. Universidade de Évora, Instituto de Ciências da Terra, Dep. de Geociências, Évora 7000-671, Portugal;1. CSIRO Mineral Resources, Australian Resources Research Centre, 26 Dick Perry Avenue, Kensington, WA 6151, Australia;2. Department of Applied Geology, Curtin University, Perth, WA 6845, Australia;1. Kochi University, B200 Monobe, Nankoku, Kochi 783-8502, Japan;2. Research Institute of Geology and Geoinformation, Geological Survey of Japan, AIST, Central 7, 1-1-1 Higashi, Tsukuba 305-8567, Japan;1. Department of Geology, Graduate School of Integrated Arts and Sciences, Kochi University, Japan;2. Department of Geology, Kochi University, Japan;3. Sumiko Resources Exploration and Development, Co., Japan;4. Center for Advanced Marine Core Research, Kochi University, Japan;1. Geological Survey of Spain, (IGME), C/Ríos Rosas, 23, 28003 Madrid, Spain;2. Crystallography and Mineralogy Department, Complutense University of Madrid, C/Jose Antonio Novais, 2, 28040 Madrid, Spain;3. Instituto de Geociencias IGEO (CSIC, UCM), Madrid, Spain;4. Instituto Español de Oceanografía, C.O. de Málaga, Puerto Pesquero s/n, 29649 Fuengirola, Spain |
| |
| Abstract: | Layered ferromanganese crusts collected by dredge from a water depth range of 2770 to 2200 m on Mendeleev Ridge, Arctic Ocean, were analyzed for mineralogical and chemical compositions and dated using the excess 230Th technique. Comparison with crusts from other oceans reveals that Fe-Mn deposits of Mendeleev Ridge have the highest Fe/Mn ratios, are depleted in Mn, Co, and Ni, and enriched in Si and Al as well as some minor elements, Li, Th, Sc, As and V. However, the upper layer of the crusts shows Mn, Co, and Ni contents comparable to crusts from the Atlantic and Indian Oceans. Growth rates vary from 3.03 to 3.97 mm/Myr measured on the uppermost 2 mm. Mn and Fe oxyhydroxides (vernadite, ferroxyhyte, birnessite, todorokite and goethite) and nonmetalliferous detrital minerals characterize the Arctic crusts. Temporal changes in crust composition reflect changes in the depositional environment. Crust formation was dominated by three main processes: precipitation of Fe-Mn oxyhydroxides from ambient ocean water, sorption of metals by those Fe and Mn phases, and fluctuating but large inputs of terrigenous debris. |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
