Tampia Gold Project

Location of Explaurum Limited Projects

Tampia Gold Project

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).

Notes:
  1. about 90% of the resource (at 0.7g/t) in the upper 100m and 73% in the upper 80m
  2. details of the estimation are set out in Appendix 1
  3. oxide Resources are not significant at about 15,000 ounces at a 0.7g/t cut off.

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:

  • Gold mineralisation is high grade and near surface
  • The resource was well drilled in part to mostly shallow depth, but open in all directions and at depth.
  • The resource area has significant gaps in drilling. If infill drilling is successful, an increase in resources is anticipated.
  • There is significant potential for further discoveries within 10km radius with a number of strong geochemical and auger/RAB anomalies.
  • Tampia is located on private land close to sealed roads, power, water, accommodation, services and labour.
  • Tampia is located 135km by road from Westonia and about 185km by road from Southern Cross and Marvel Loch.

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:

  • Established a 2012 JORC compliant Inferred Resource of 695,500 gold at a grade of 1.9 g/t Au;
  • Undertaken QAQC and infill drilling campaigns that increased the confidence in the Resource and the structural controls on the mineralisation;
  • Commenced regional exploration based on gravity survey data that has resulted in significant new drill intercepts and wide scale ; and
  • Undertaken a range of metallurgical, processing, mining, baseline environmental and groundwater studies with the aim of establishing a preferred development strategy

Tampia Gold Project Mineral Resource classification

 

Tonnes

Average Grade

Ounces

Indicated

9,948,000

1.94

620,500

Inferred

1,370,000

1.70

75,000

Total

11,318,000

1.91

695,500

 Notes:

  • The Mineral Resource is classified in accordance with JORC, 2012 edition.
  • The effective date of the mineral resource estimate is 11 September 2017.
  • The Mineral Resource is contained within M70/816.
  • Estimates are rounded to reflect the level of confidence in these resources at the present time. All resources have been rounded to the nearest 0.01 million tonnes.
  • The mineral resource is reported as a recoverable resource at 6x6x3.5 SMU size, which includes dilution, and at 0.5 g/t Au cut-off grade.

Notable historic drill intercepts included:

GR028 17m at 27.5g/t from 8m including 4m at 108.9g/t Au from 9m;
NRC4 11m at 28.1g/t from 21m including 5m at 57.7g/t Au from 25m;
GDH01 9m at 18.3g/t from 19m including 1m at 55.5g/t Au from 23m and 2m at 43.5g/t from 25m and a deeper intercept of 11m at 10.1g/t from 50m including 2m at 41.9g/t Au from 50m;
GR001 25m at 11.0g/t from 0m to the end of the hole including 8m at 29.3g/t Au rom 14m;
GR003 25m at 10.1g/t from 0m to the end of the hole including 3m at 52.7g/t Au from 19m;
NRC41 5m at 34.9g/t from 79m including 1m at 165g/t Au from 79m;
GDH09 29m at 5.9g/t from 35m including 1m at 154g/t from 59m;
NRC16 4m at 19.2g/t from 33m and 6m at 16.1g/t Au from 45m  including 1m at 64.0g/t Au from 49m;
GR026 9m at 16.5g/t from 16m including 4m at 32.5g/t Au from 19m;
GR411 31m at 3.9g/t Au from 64m;
NRC6 13m at 7.6g/t from 59m including 2m at 24.8g/t Au from 67m; and
NRC15 18m at 5.3g/t Au from 67m. 

Scoping Study

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. 

Highlights

  •  The results of the Scoping Study are positive and provide confidence to advance the Project to the next level, with a significant program of infill, extension and exploration drilling to commence shortly.
  •  The results provide a clear direction for the Company to pursue as well as strongly favourable indications of the Project’s future potential.
  • A Pre-feasibility Study has also commenced and is due to be completed in late H2 2017 – which will deliver an updated mineral resource estimate.
  • The Study has highlighted the particular activities, required for planning purposes, to develop the Pre-feasibility program and budget, and to optimise both the mine and process design.
  • Near resource and regional exploration is at a very early stage - providing significant potential upside to the scale of the Project that will improve the positive findings from the Study.
  • The Study has also established a ‘checklist’ of criteria required to focus further exploration, metallurgy and mining studies required for development.
  • Immediate focus now is the undertaking of major exploration and drilling programs, scheduled to commence shortly, to unlock the significant upside potential of the known Gault deposit, which is open in all directions, and through regional exploration, of the Project.

Significant Increase for Tampia Mineral Resource to 700,000oz Gold

  • The new Mineral Resource estimate for the Tampia Gold Project, reported and classified in accordance with the JORC Code (2012), is 11.3 million tonnes at 1.91 g/t Au for 695,500 ounces of gold (0.5 g/t Au cut off), an increase of 125% over the previous 310,000oz estimate.
  • The new Resource estimate has exceeded our expectations and the target Mineral Resource assumed by the 2016 Scoping Study as required to enable development of a viable standalone single open-pit mining operation with robust financials.
  • 90% of the new Mineral Resource is in the Indicated category which, subject to the completion of a Feasibility Study, may be converted to Ore Reserves.
  • Most of the new Resource is less than 100m below surface, and comes to surface in three locations.
  • Simple resource geometry indicates future mining potential may enjoy an unusually high conversion of Indicated Resources to Reserves (+90%), and a low strip ratio.
  • This estimate is a recoverable Resource and includes assumed internal and external dilution, as well as mining losses.
  • The new estimate is based on a total 287 RC holes (36,339m), drilled on a 40m by 40m drill spacing covering an area 1,040m along strike by 550m down dip to a depth of 140m.
  • An updated Scoping Study including optimisation and mine scheduling studies based on the new Resource will be completed in October 2017 to indicate initial project economics.
  • Planning has started for 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.
  • There will be a focus on drilling all of the 24 regional targets (including three major targets) before the end of March 2018. This work will involve grid auger drilling over the entire area of each anomaly followed by RC drilling where warranted, to establish which targets could potentially host additional Mineral Resources. This drilling should commence in November.

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.

Resource Classification

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:

  • Informing sample quality. Each sample was given a data quality ranking (DQR) based on a combination of several factors (sample recovery, sample splitting quality, water issues, dust loss). These numbers were then modelled into the blocks allowing the identification of blocks or areas that are estimated by lower-quality sampling. This showed that only a small and insignificant area of clay-rich regolith provided on average poor sample quality.
  • Kriging efficiency and variography. The 40m drill spacing is adequate to determine the grade continuity in all directions, although it is clear from the indicator variography that grade continuity of very high-grade material is not always captured, with second-structure ranges ranging between 10-30m. However, even well above the average Resource grade, there are several areas where high grade zones (above 2.5 g/t) can be linked across 4-5 drill sections (~180m). Kriging efficiency (KE), as a product form the Ordinary Kriging check-estimate process) was also used as a proxy for the quality of the estimation and to support the classification. This showed that the majority of the blocks had KEs above 20%, with blocks in between sections and on the fringes showing lower and sub-zero KEs. Expectedly, low KEs were mainly driven by relatively high gamma values in semi-variograms, combined with large point-to-block distances, resulting in high Kriging Variances. Given the near-perfect grid distribution of the data, lack of clustering contributed to a lower Kriging variance and better KE.

Metallurgy

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 mineralisation – 95%
  • Fresh sulphide gold mineralisation – 92% to 94%
  • Fresh non-sulphide and non-arsenic associated gold mineralisation – unknown (test work in progress) but suggests free milling with recoveries similar to oxide gold mineralisation.
  • Fresh non-sulphide arsenic associated (löllingite) gold mineralisation – 81% (initial estimate) to be confirmed with ongoing test work.

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.

Next Steps

An updated Scoping Study including optimisation and mine scheduling studies based on the new Resource will be completed in October 2017 to indicate initial project economics.

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 November.

There will be a focus on drilling all 24 regional targets (including three major targets) before the end of March 2018. 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 in November and continue into 2018.

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.

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