The Cyclops Ophiolite as a Source of High-Cr Spinels from Marine Sediments on the Jayapura Regency Coast (New Guinea, Indonesia)
| Autor: | Irena Górska, Karol Zglinicki, Krzysztof Szamałek |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
lcsh:QE351-399.2
010504 meteorology & atmospheric sciences cyclops ophiolite Geochemistry Weathering 010502 geochemistry & geophysics Cyclops Ophiolite 01 natural sciences Placer deposit New Guinea Island 0105 earth and related environmental sciences Limonite Basalt lcsh:Mineralogy biology Heavy mineral Geology Geotechnical Engineering and Engineering Geology biology.organism_classification heavy minerals chromian spinels placer deposits Andradite visual_art visual_art.visual_art_medium chromian garnet |
| Zdroj: | Minerals Volume 10 Issue 9 Minerals, Vol 10, Iss 735, p 735 (2020) |
| ISSN: | 2075-163X |
| DOI: | 10.3390/min10090735 |
| Popis: | The first detailed mineralogy, geochemistry and origin of heavy minerals in marine sediments along the Jayapura Regency coast on the Indonesian part of New Guinea Island are reported as part of a larger set of investigations conducted since 2009. In these sediments, the following heavy minerals were identified: high-Al and high-Cr spinels, chromian andradite, Mg-olivine, magnetite, mixture of iron (III) oxyhydroxides (limonite) and minerals from serpentine-group minerals (lizardite, antigorite). The heavy mineral fraction of marine sediments contains increased concentrations of metals, including W (up to 257.72 ppm) and Ag (up to 1330.29 ppb) as well as minor amounts of Ni (7.1&ndash 3560.9 ppm) and Cr (68.0&ndash 5816.0 ppm). The present state of geological knowledge suggests that there are no known prospects for rich Ti, Ni, Co, Cr, Au deposits along the examined part of the Jayapura coast. However, the average content of Ag and W is high enough to provide an impulse for suggested further deposit research. The source of marine sediments is Cyclops ophiolite, which contains a typical ophiolite sequence. Cyclops Mountain rocks have undergone intense chemical weathering processes and the resulting eroded material has been deposited on the narrow continental shelf. The chemical composition of chromian spinels indicates that their source is depleted peridotites from the SSZ (supra-subduction zone) environment of the Cyclops ophiolite. A detailed geochemical examination indicates that the evolution of parental melt of these rocks evolved towards magma with geochemical parameters similar to mid-ocean ridge basalt (MORB). |
| Databáze: | OpenAIRE |
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