Open AccessSpatial and temporal constraints of leached Cu-Au porphyry shoulder high-sulfidation epithermal deposit: insight from new discovered Kumbokarno Prospect, Trenggalek District, East Java
Author(s) -
Finlan Adhitya Aldan,
Arifudin Idrus,
Ryohei Takahashi,
Genki Kaneko
Publication year - 2019
Publication title -
journal of physics. conference series
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.21
H-Index - 85
eISSN - 1742-6596
pISSN - 1742-6588
DOI - 10.1088/1742-6596/1367/1/012037
Subject(s) - hypogene , sulfidation , geochemistry , geology , paragenesis , microprobe , electron microprobe , hydrothermal circulation , mineralogy , hematite , pyrite , materials science , metallurgy , sulfur , metamorphic rock , sphalerite , seismology
We conduct microscopic and microprobe quantitative analyses to confine characteristics of the newly found Cu-Au high sulfidation deposit which interestingly seems to highly associate with the presence of iron oxide-hydroxide complex. The resulting paragenesis shows four generation phases, which are magmatic, deep hypogene, shallow hypogene, and supergene. The alteration pattern suggests presence of a concealed intrusion which ascends the hypogene mineralization forming-fluid. Quantitative microprobe analysis shows enrichment of copper and gold in various types of iron oxide-hydroxide texture. A unique repetitive pattern of high and low copper concentration is found overlaps with goethite-hematite band of colloform texture. An interesting pattern between gold and titanium is also found as gold is almost exclusively located inside or near Fe-rich leucoxene. We propose a model of leached Cu-Au porphyry shoulder high-sulfidation epithermal deposit system to explain the prevalent condition of Kumbokarno Prospect where intensive late oxidation acts as the main process of metal concentration.