The Karari deposit is located in a syntectonic sedimentary basin dominated by volcanoclastic sedimentary rocks that lie in the hanging wall of the regional scale Kilkenny shear zone.
Karari is a structurally complex deposit and is bound by several post mineralisation faults. Mineralisation is principally hosted in volcanoclatic sandstones and to a lesser extent intermediate intrusives. Gold is strongly associated with albite, K-Feldspar, silica, haematite, carbonate and pyrite alteration. Mineralisation is dominated by two key orientations; (i) sub-parallel to lithological contacts, striking NNW and dipping moderately to the NE, and (ii) a WNW striking and shallowly NE dipping with a northerly plunge.
With the current resource remaining open at depth, opportunity exists to extend the drilling coverage at depth to delineate additional mineralisation.
An intensive underground drill program is underway comprising over 37,000m during FY17. The program will substantially add to the confidence of the Resource at depth and also test ~300m below the lower extents of the current Resource.
The Saracen Board recently approved a dual decline mine design for Karari. A dedicated decline will access the northern stoping horizons of the Hangingwall and A1 Lodes, and a second decline will access the southern stoping horizons of the Dhoni Lode.
Total ore tonnes mined have the potential to ramp up from current levels of ~750ktpa to in excess of 1.2Mtpa (~75kozpa to ~115kozpa) due to a combination of the dual decline access increasing stoping horizons, improved equipment utilisation and mining efficiencies, as well as increased strike lengths and widths of both the Dhoni and A1/Hangingwall lodes at depth. This could have a significant impact on the annual production from FY18 onwards and improve the overall profitability and efficiency of the Carosue Dam operations.
Karari North and Karari South (Juba)
Karari North is a high priority exploration target immediately north of the mine. This area has never been adequately tested. Recent underground drilling has highlighted that further potential exists to the north between the mine and where the stratigraphy is truncated by the Osman Fault. Recent drilling results from KRRD118 (27.6m @ 2.5g/t) highlight that the mineralisation remains open to the north. A surface drilling program is planned in H2 FY17 to test this opportunity. Surface drilling was preferred over underground due to the orientation of the projected mineralisation.
Karari South has recently been reviewed in detail and a number of key targets have been defined. The review included reconnaissance field mapping, reinterpretation of the geochemical dataset in light of recent developments in knowledge from mine geology observations, and integration of improved structural and lithological boundaries defined by the 2015 detailed gravity survey. The gravity survey was conducted from Yilgangi in the north down to the southern limits of the Carosue Dam tenements in the south. The survey successfully defined the prospective corridor of late basin volcanoclastic sediments which host the major deposits in the Carosue Dam corridor. The key stratigraphy is defined in the gravity data by a gravity low. Many of the deposits in the Carosue district are hosted in this gravity low and are generally proximal to north south striking faults.
The Juba target to the south of Karari and less than 3km from the Carosue Dam mill, is located within the gravity low corridor and is also coincident with interpreted north south striking faults. Importantly the target is also mapped by a soil anomaly of the same scale as the anomaly identified over Karari.
The limited drilling over the Juba prospect is very shallow and in some cases has not penetrated the known depletion zone. Surface drilling is planned for the Juba prospect during June half 2017.