Tectonics of Volcanogenic Massive Sulphide (VMS) Deposits at Flores Back Arc Basin: A Review

Abstract

The bathymetry, petrology, marine magnetic, and seismic-SBP data have identified the northwest-southeast direction submarine ridge that shows hydrothermal activity. This activity occurred through Mount Baruna Komba, Abang Komba, and Ibu Komba. The volcanic rocks are andesite basaltic lava flows, tuff, and pumice. The andesite basaltic lava shows porphyritic, intergranular, intersertal to glomeroporphyritic textures. The rock composes anhedral minerals of k-feldspar, plagioclase, and pyroxene. These minerals present in small-sized, short prismatic dispersed in very fine groundmass minerals or glasses. Most of the volcanic rocks have experienced various degrees of alteration. The k-feldspar and plagioclase are most dominantly transformed into sericite, clay mineral, carbonate, epidote and oxide mineral, opaque mineral, and secondary plagioclase through the albitization process, while pyroxene replaced by chlorite. Other minerals are biotite and quartz, and base metals are present Cu, Zn, Ag, As, Pb, and gold. Mineralization categorizes as the phyllic zone, sub-prophylithic zone, and phyllic-potassic zone that formed at a temperature range of 250-400oC. The submarine hydrothermal alteration in the Komba Ridge is associated with a volcanogenic sulphide deposit controlled by crust thinning due to the crust rifts in the back-arc tectonic setting.

Stereographic for Development of Stricture Pattern of Geological Alteration Zone in Atauro Island, Timor-Leste

“…The mineralised zone develops on a northeast-northeast trending left horizontal fault plane. In contrast, the silica-alkali alteration zone develops on a southwest-northeast trending strike-slip and left horizontal fault plane (Aryanto & Kurnio, 2020).…”

Quaternary Seabed Sediment Characteristics as an indication of VMS-mineral deposits at the South Banda Basin and its surroundings, Indonesia

“…The study location due to geological control factors has the potential for the presence of volcanic massive sulfide (VMS) deposits, such as those found at the Ibu Komba submarine volcano [4] in the The purpose of this paper is to analyze and relate morphometric aspects to the Quaternary seabed sediment deposits deposited in an active tectonic basin in the Banda Sea area, including information on the type of sediment or its characteristic, and its distribution as well as its relation to volcanic hostedmassive sulfide (VHMS) or volcanogenic massive sulfide (VMS) mineral deposits (VHMS/VMS).…”