⁴⁰Ar/³⁹Ar Geochronology of Volcanic and Intrusive Rocks in the Papandayan Metallic Prospect Area, West Java, Indonesia

Abstract

This study presents new 40Ar/39Ar ages on the volcanic and intrusive rocks from the Papandayan metallic district in West Java, Indonesia. The vein system in the Arinem area, one of the prospective areas in the district, has been considered as an epithermal gold–silver–base metal deposit, however, no published age results are available for the host volcanic rocks in the district. The ages of these rocks are critical in terms of their association with mineralization and are important to understand the evolution of volcanism in the region, which has implications for mineral exploration in the district. 40Ar/39Ar plateau ages of two typical basalt and one andesite samples of the Jampang Formation volcanic rocks yielded ages of 11.65 ± 0.52 Ma, 18.15 ± 0.46 Ma and 7.69 ± 0.05 Ma, respectively. 40Ar/39Ar ages of three intrusive rock samples from Gunung Halang diorite, Gunung Lingga diorite, and Gunung Buligir fine‐grained quartz diorite yielded ages of 12.98 ± 0.20 Ma, 10.81 ± 0.15 Ma, and 7.37 ± 0.05 Ma, respectively. The age of the youngest fine‐grained diorite (Gunung Wayang dike) is 3.95 ± 0.03 Ma. An 40Ar/39Ar age obtained from adularia in the Arinem mineralized vein (18.30 ± 0.20 Ma) is older than the age of altered basalt sample of this study (11.65 ± 0.52 Ma) and the K–Ar illite ages of the Arinem vein (9.4 ± 0.3 Ma and 8.8 ± 0.3 Ma) which resulted from a previous study. The age results suggest that the Papandayan district may have experienced multiple hydrothermal and mineralization events. This study, therefore, provides crucial age data to support future mineral exploration in the district.

Java and Sumatra segments of the Sunda Trench: Geomorphology and geophysical settings analysed and visualized by GMT

“…Necessarily, numerical methods of data processing are required to model the specifics and reconstruct the past Sumatra and Java tectonic movements, as presented in previous studies, for instance, geodetic and paleogeodetic measurements (Chlieh et al, 2008). Other approaches include, for example, used tsunami modelling (Saito & Kubota, 2020), method of the r40Ar/39Ar geochronology of volcanic and intrusive rocks was applied for analysis of the geological prospects in the West Java (Titisari et al, 2017). Development of the mapping methods is presented in marine cartography and visualization, as well as automatization approaches in the GIS techniques (Schenke & Lemenkova, 2008;Lemenkova, 2019e, 2020e, 2020g).…”