11:00 〜 13:00
[HRE13-P01] Geology and geochemistry of the metavolcanic host rocks at the mugomo gold prospect, Tete province, Mozambique
キーワード：Mesoproterozoic, Shear zone, Mozambique, Volcanic arc, Ore minerals
The Mugomo gold prospect is located close to N-S trending fractures and is associated with shear zones. The studied area belongs to the southern part of Irumide Belt consisting of the Proterozoic Mualadzi Group and Furancungo Suite.
A mineralization model for Mugomo prospect has not been understood and the processes of mineralization remain unknown. Hence, the goal of this study is to characterize the geology, type of mineralization, hydrothermal alteration, veins and ore minerals related to it. In the Mugomo prospect, metavolcanic rocks, schist, and quartizite are crosscut by quartz veins as well as epidote veins and veinlets.
Pyrite, chalcopyrite, sphalerite, galena and bornite with minor Ag-Te and Bi-Te minerals occur within the quartz-epidote veins, as well as dissemination in the metavolcanic rocks and quartzite. Petrographic observations and ICP-MS analysis revealed elevated concentrations of Ag, Au, Bi and Te in metavolcanic rocks, quartzite, and epidote-quartz veins.
Primary minerals in the metavolcanic rocks are epidote, albite, and calcite. The schist is composed of medium-fine-grained, biotite and quartz, which form the foliation, and the quartzite is mainly composed of quartz and minor biotite minerals.
The metavolcanic rocks are classified as a calc-alkaline rhyolite in composition based on the alkali and SiO2 contents and are characterized by their significant enrichment of LREE and depletion of HREE and Eu. The trace element data plotted on the Rb and Y+Nb discrimination diagram suggest that the rhyolite was formed in the volcanic arc setting.
A mineralization model for Mugomo prospect has not been understood and the processes of mineralization remain unknown. Hence, the goal of this study is to characterize the geology, type of mineralization, hydrothermal alteration, veins and ore minerals related to it. In the Mugomo prospect, metavolcanic rocks, schist, and quartizite are crosscut by quartz veins as well as epidote veins and veinlets.
Pyrite, chalcopyrite, sphalerite, galena and bornite with minor Ag-Te and Bi-Te minerals occur within the quartz-epidote veins, as well as dissemination in the metavolcanic rocks and quartzite. Petrographic observations and ICP-MS analysis revealed elevated concentrations of Ag, Au, Bi and Te in metavolcanic rocks, quartzite, and epidote-quartz veins.
Primary minerals in the metavolcanic rocks are epidote, albite, and calcite. The schist is composed of medium-fine-grained, biotite and quartz, which form the foliation, and the quartzite is mainly composed of quartz and minor biotite minerals.
The metavolcanic rocks are classified as a calc-alkaline rhyolite in composition based on the alkali and SiO2 contents and are characterized by their significant enrichment of LREE and depletion of HREE and Eu. The trace element data plotted on the Rb and Y+Nb discrimination diagram suggest that the rhyolite was formed in the volcanic arc setting.