The Setting and Timing of Copper Mineralization in the Timna Igneous Complex, southern Israel.
- 1Ben-Gurion University, Earth and Environmental Sciences, Israel (alonelh@post.bgu.ac.il)
- 2Ilse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of the Negev, Beer-Sheva, Israel (brelisha@gmail.com)
- 3Department of Earth Science, University of California Santa Barbara, USA (kylander@geol.ucsb.edu)
The absence of primary sulfides challenges the interpretation of metal ore genesis, particularly where ore is hosted within several separate stratigraphic horizons. In the Timna Valley, S Israel, copper ore bodies occur mostly in Cambrian and Cretaceous sandstones and rarely in the underlying late Neoproterozoic Timna igneous complex (TIC), as secondary Cu-sulfides in veins and nodules and more abundantly as Cu-hydroxides. The timing and setting of copper mineralization in the TIC and its relation to the sedimentary ore are unknown. Quartz phenocryst-hosted fluid inclusion assemblages (FIA) in quartz porphyry (QP) stock and dykes are associated with sulfide inclusions of pyrite, chalcocite, and chalcopyrite, indicating a magmatic-hydrothermal genetic relationship. Mineralization-associated fluid inclusion assemblages (FIAs) in QP are: (FIA.a) <12 wt% NaCl eq., CO2 vapor-rich arrays with and homogenization temperatures (Ths) of 270–500°C; (FIA.b) immiscible 30–35 wt%. NaCl eq. aqueous liquid and a CO2 vapor-rich fluid trapped at 193–266°C; (FIA.c) secondary H2O liquid-rich arrays (0-11 wt% NaCl eq.), Th of 115–256 ⁰C. Mineralization-associated zircon and rutile in QP yielded U–Pb ages of ~595 Ma, overlapping alkaline felsic dykes in S Israel. Rapid cooling below 220°C is evident by average rutile (U–Th)/He age of 595 ± 46 Ma found in QP and adjacent quartz monzonite and porphyritic granite. Zircon (U–Th)/He ages record Carboniferous heating at 180 ⁰C ≤ T ≤ 220 ⁰C and hydrothermal alteration. This indicates temperatures in the TIC did not exceed ~180 ⁰C after the Carboniferous. Primary copper mineralization in the TIC is attributed to QP emplacement, during A-type granite intrusions, possibly scavenging copper and other metals from earlier calc-alkaline crust. This was followed by lower temperature (<220°C) hydrothermal events.
How to cite: Elhadad, A., Bar, E., Vapnik, Y., Haviv, I., Kylander-Clark, A., Golan, T., and Katzir, Y.: The Setting and Timing of Copper Mineralization in the Timna Igneous Complex, southern Israel., EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-11597, https://doi.org/10.5194/egusphere-egu24-11597, 2024.