Mulwarrie Gold Project
The Mulwarrie Gold Project is located 150km north-west of Kalgoorlie in the Ularring District of the North Coolgardie Mineral Field. The project encompasses two contiguous tenements, M30/119 (68 Ha) and M30/145, which lie 10km north-west of the Davyhurst Mining centre.
Figure1: Location, Mulwarrie project
The two tenements lie within a 10km wide greenstone belt which forms the north-west extension of the Coolgardie Line. The structurally dominant, north-trending Mt Ida fault lies approximately 4km east of the Mulwarrie Mining Centre. Most of the lithologies within this greenstone belt are steeply-dipping and well foliated along a NNW/SSE trend.
Mulwarrie tenements and simplified geology
In the late 1980’s, Callion Mining Pty Ltd mined the Mulwarrie Central West Pit extracting 24,344 tonnes @ 3.88g/t Au for 94.5 kg (3,037 ounces) of gold. The waste-to-ore stripping ratio was 5.25:1, with gold ore extracted to a maximum depth of 36 vertical metres over a strike length of 150m. Outside of this figure historical underground production in the Mulwarrie District, including the Mulwarrie Project area, has a recorded production of 26,344 ounces of gold from 19,728 tonnes for an average grade of 41.5g/t Au.
RC drilling during 2017 outlined several mineralised zones over 1.2km south and east of the Mulwarrie Central West Pit. Spitfire has drilled 75 RC holes for 9,212m and 1 diamond hole for 99.6m. This Mineral Resource Estimate (MRE) was based on all new information and historical information. Spitfire has completed the MRE using independent consultancy group Trepanier Pty Ltd.
Following the three phases of Spitfire drilling, a maiden Mineral Resource Estimate has been completed for the Mulwarrie Gold Deposit. The Mineral Resource Estimate is 880,800t at 2.8g/t Au for 79,000oz, as summarised by category in Table 8 below. Grade estimation was by Ordinary Kriging for Au using GEOVIA Surpac™ software.
The resource is classified as inferred only primarily due to a lack of oriented diamond core holes to assisting in supporting the structural model. In addition, very limited bulk density data is available to date. (See ASX releases dated for all details regarding drill hole information and assays; 16 May 2017, 3 July 2017, 27 September 2017 and the 30 January 2018).
Gold mineralisation has been found in two distinct settings at Mulwarrie: –
- In narrow shear zones with only minor or no quartz veining, with limited calcsilicate alteration haloes and with erratic but occasionally high gold values. These zones of mineralisation may be up to 2m wide but are generally less than 50cm. They are conformable to the stratigraphy and foliation; and
- The second and most important type of gold mineralisation is associated with quite flat-dipping, often massive quartz reefs with strong diopside, biotite, epidote and carbonate alteration haloes. Pyrrhotite and pyrite development is also strong within and adjacent to the quartz reefs. Minor amounts of chalcopyrite, galena and sphalerite are also associated with gold mineralisation. Gold is found within quartz reefs, within biotite selvages to the quartz veins and also in the associated country rocks.
Mulwarrie 3-D vein model – oblique view looking down 15° to Local Grid North