Explaurum’s key asset is the 90% interest in the Tampia Gold Project, located approximately 300km east of Perth in the wheat belt of Western Australia. A 2012 JORC Inferred resource of 4.7 million tonnes (MT) grading 2.0g/t Au (cut) or 2.5g/t Au (uncut) containing 310,000 – 380,000 ounces of gold, including 1.6 MT at 3.4 g/t Au (cut) or 4.6g/t Au (uncut) containing 170,000 – 237,000 ounces gold announced in April 2015 (Table 1).
BHP Minerals (‘BHP’) discovered gold mineralisation at Tampia in 1987 from follow up of regional BLEG stream sampling program. BHP and subsequent owners in the 1990s established the following features of the mineralisation:
The property received only minor exploration attention from the mid-1990s until Explaurum acquired an 80% (now 90%) interest in April 2012. At that time, although the Project is located within an under-explored greenstone belt, technical aspects of the deposit such as geology, structure, controls on mineralisation and metallurgy were poorly understood, but what was known regarding the mineralisation (open-pittable resource with near surface, high grade mineralisation open in all directions) was highly attractive to the Company. Some of the notable previous drilling intercepts include 19m at 9.2g/t Au from 15m, 12m at 13.4g/t Au from 41m, 25m at 10.7g/t Au from 0m, 25m at 10.4g/t Au from 0m, 9m at 16.49g/t Au from 16m, 18m at 24.6g/t Au from 7m and 13m at 23.6g/t Au from 21m. Since acquiring the Project in 2012, the Company has:
Notable historic drill intercepts included:
Explaurum completed a Scoping Study (“Study”) based on the Inferred mineral resource at its 90% owned Tampia Gold Project (“the Project”), located approximately 300km east of Perth in the wheat belt of Western Australia.
Explaurum was assisted by the following reputable industry consultant groups; Kenex Pty Ltd (3D geological modelling), Entech Pty Ltd (resource estimation and mining), Mintrex Pty Ltd (process flow sheet and plant design), ALS Metallurgy Pty Ltd (metallurgical test work), Mintap Services Pty Ltd (metallurgical program), Martinick Bosch Sell Pty Ltd (MBS Environmental) (baseline environmental, heritage) and Rockwater Pty Ltd (groundwater).
The results of the study were positive and importantly provides strong encouragement for the Company to commit to the next stage of its exploration and development program.
Significant Increase for Tampia Mineral Resource to 700,000oz Gold
The new Mineral Resource estimate is an increase of 125% in contained gold compared to the estimate in 2015, containing 11,318,000 tonnes at 1.91 g/t Au for 695,500 ounces of gold at a 0.5 g/t Au cut off. The new Resource estimate comprises 620,500 ounces in the Indicated category and 75,000 ounces in the Inferred category, exceeding the target Mineral Resource assumed for the Scoping Study announced in September 2016. The new Mineral Resource estimate for the Tampia project is reported at a 0.5 g/t Au cut off as this cut off more accurately reflects the economic potential of the project based on the results of the Scoping Study.
Most of the mineralisation within the Mineral Resource has been classified in the Indicated category. Material on the edges, in the deeper less well-drilled parts, as well as some areas where ground conditions led to poor sampling, were classified as Inferred (Table 1). There is no material classified as Measured.
The Resource classification has been carried out in accordance with the JORC Code (2012). The grade and densities are estimated with sufficient confidence to allow the application of Modifying Factors in sufficient detail to support mine planning and evaluation of the economic viability of the deposit. Geological evidence has been derived from adequately detailed and reliable exploration and sampling gathered through appropriate techniques, and is sufficient to assume geological and grade continuity between data points.
In the Competent Person's view, it is a realistic inventory of the mineralisation which, after preliminary evaluation of technical, economic and development conditions, might, in whole or in part, become economically extractable. In the Competent Parsons's opinion, it is more likely than not that there are reasonable prospects for eventual economic extraction of the Tampia deposit.
Portions of the deposit that do not have reasonable prospects for eventual economic extraction are not included in the Mineral Resource.
In classifying the Resource, the Competent Person has regarded several aspects that affect resource confidence:
Preliminary metallurgical test work has clearly established the gold mineralisation at Tampia is predominantly free milling, and identified that three types of gold exist: free gold, sulphide hosted gold and löllingite hosted gold. The relative proportions of each type are variable throughout the deposit. The programme has confirmed that low recoveries in some samples is due to gold hosted in löllingite (FeAs2), which the test work has shown can be recovered to a concentrate and treated to recover the gold. Estimated recoveries for each mineralisation type are:
Oxide gold, fresh sulphide gold and fresh non-sulphide and non-arsenic associated gold mineralisation are estimated to account for approximately 90% of the Tampia resource.
A full understanding of the geometallurgy of the Tampia gold deposit will not be available until all metallurgical data has been modelled, with the primary focus to establish the distribution and variability of S, As and Au. This work has started and follow-up variability test work to confirm the metallurgy to date over the entire deposit is underway. The data will be used to map the metallurgical zones in more detail for mine planning purposes.
An updated Scoping Study including optimisation and mine scheduling studies based on the new Resource will be completed in October 2017.
Drill planning has started for exploration drilling immediately around the resource area to test for extensions to gold mineralisation to the south east and at depth. This drilling should commence in early October.
Planning to test the regional gravity targets around the Tampia Gold Project is underway (Figure 1). This work will involve grid auger drilling over the entire area of each anomaly followed up by RC drilling where warranted, to establish which targets could potentially host additional Mineral Resources. This work is planned to start by the end of September and continue into 2018.
Five PQ diamond holes have been planned to provide samples for the continuing feasibility metallurgical test work program. This drilling has started and this work will provide final detailed recovery and process information and test the variability of metallurgical performance of the various ore types across the ore body and at depth. This drilling will start immediately.
Work planning to develop tasks, timelines and actions for the Feasibility Study are continuing, including discussions with relevant consultancy groups for process design and environmental studies. Work on the geotechnical aspects of the project is underway with downhole optical data being relogged to assess rock strength and competence. Mining studies will start shortly to define relevant parameters for pit optimisation for the updated Scoping Study. Hydrological data collection has started and will continue for the next quarter to assess pit dewatering requirements and to locate a suitable water source for the planned processing facility. Process design and preliminary mine site layout planning have also commenced.
The soil geochemical data collected over regional target areas defined by the recent geological mapping and gravity programs remains under review. The results from the soil sampling program will be available by mid-September 2017 once the resource estimation work is completed.
Bottle roll test work to determine the indicative gold recovery on mineralised intervals from the Leicester zone is in progress and should be available by the end of September.
Discussions are underway with relevant land owners to negotiate access agreements to the high priority regional targets from the recent gravity survey. Discussions to date have been very positive and drilling is expected to commence on a number of these targets (after harvest) in November.
Drill plan of current resource RC drill holes and gold zones (Farm building to east of resource area derelict and unoccupied).
Cross section through the Wanjalonar gold zone showing dip extension to gold mineralisation
Cross section through the Leicester gold zone showing near surface high grade gold mineralisation
Long section from the Wanjalonar gold zone through to the Leicester gold zone in the south, showing overall structure of the gold zones in relation to geology
3D Grade shells modelled in Leapfrog defining an open fold that dips and plunges to the south east
Processed regional gravity data showing gravity target areas with similar gravity data values to the Tampia gold resource area
Gold nuggets panned from the 1m at 716 g/t Au intersection in THRC344