Nabenia Zinc Prospect
The Nabenia Zinc Prospect is located on the south east margin of the Tiebele Dome within a sequence of north east trending, steeply north west dipping mafic volcanics, meta sediments with manganese and graphite horizons, sericitised felsic lavas and sericite-chlorite-rich schists.
Overlying the ore position (Hanging wall) are mafic-rich volcanoclastic and finally coherent mafic lavas. Cross-cutting the stratigraphy are a series of late mafic dykes (gabbros) which may have intruded along the original hydrothermal feeder conduits. Future exploration programs will benefit greatly by undertaking structural architecture investigations (Basin Architecture) of the volcanic succession associated with VHMS mineralisation as this will highlight the exact location of major hydrothermal conduits associated with VHMS zinc mineralisation.
At the Nabenia Prospect Ampella drilled 4 reverse circulation holes for 380 metres and 8 reverse circulation holes with diamond tails for an additional 1637 metres. Re-logging of drilling on cross-section 739200E confirmed the presence of volcanic hosted massive sulphide (VHMS) zinc mineralisation. It also identified the nature of the footwall and hanging wall successions as well as the type of alteration mineralogy associated with zinc sulphides. Currently the historical drilling at Nabenia is being re-logged to assist in undertaking a basin analysis reconstruction. Such information will assist targeting and identification of additional sources of VHMS mineralisation.
The footwall to mineralisation consists of quartz-rich felsic volcanics (rhyodacites) which are overlain by volcanoclastics and interbedded shales. The ore position is marked by thinly developed and inconsistent silica breccias, hydrothermal carbonate and manganese horizons. The silica (chert) horizons contain overprinting magnetite veinlets. These are not true base metal gossans but they do highlight hydrothermal seafloor positions.