The Teena Zn-Pb Deposit (McArthur Basin, Australia). Part II: Carbonate Replacement Sulfide Mineralization During Burial Diagenesis—Implications for Mineral Exploration

Abstract The Teena Zn-Pb deposit is located in the Carpentaria Zn Province (Australia), which contains some of largest clastic dominant (CD-type) massive sulfide deposits world. timing main stage hydrothermal mineralization subbasin constrained to midstage burial diagenesis, during a period short-lived regional extension. To distinguish alteration from spatially and temporally overlapping diagenetic alteration, establish primary controls on mass transfer, it necessary evaluate various foot- hanging-wall assemblages that formed between early- (eogenesis) late- (mesogenesis) diagenesis. achieve this, we have statistically evaluated large lithogeochemistry dataset (n >2,500) selected subset = 65) representative samples for detailed mineralogical (X-ray diffraction, illite crystallinity) petrographic (scanning electron microscopy) analyses; hyperspectral core imaging data were then used upscale key paragenetic observations. We show was predated by multiple assemblages, including stratiform pyrite, dolomite nodules cement, disseminated hematite authigenic K-feldspar. These eogenesis subbasins across broader McArthur Basin are not part synmineralization footprint. Whereas pyrite primarily situ degradation organic matter, feldspar authigenesis product K metasomatism focused along permeable coarse-grained volcaniclastic sandstone beds within host-rock sequence. immature input broadly siliciclastic compositional end member subbasin, protolith phyllosilicate (illite, phengite, chlorite) formation There no evidence extensive any geochemical, (illite crystallinity), or datasets, despite K-feldspar replacement sphalerite Lower Main mineralized lenses. Rather, high grades via replacement, resolvable chemical balance analysis consistent with significant exploration implications associated carbonate-replacement mesogenesis: (1) capacity secondary porosity generation host rock as important its sulfate-reducing capacity; (2) has short-range cryptic lateral vertical footprint due acid neutralization carbonate-rich protolith; (3) distribution chemistry premineralization phases (e.g., nodules) cannot be directly related footprint, localized 4th-order scale. Future this style should therefore identifying units contain mixture carbon carbonate protolith, at favorable stratigraphic redox boundaries, proximal feeder growth faults.