THE KROUSSOU PROJECT (GABON)
The Kroussou Project is a large scale, near surface zinc-lead project with exploration to date validating province-scale base metals potential.
- Previous exploration work has resulted in the identification of 150 zinc-lead mineral occurrences over a 80km strike length of prospective geology within the project area
- The mineral occurrences are associated with 18 channels (prospects), each representing an exploration target with the potential to host significant shallow, zinc-lead mineralisation
- Only four of the 18 prospects have been drill tested to date, with all four channels intersecting zinc-lead mineralisation at very shallow depths
- Multiple opportunities for discovery with all 18 prospects remaining open and under-explored, with broader, deeper parts of the basin to the west completely untested
- Initial metallurgical test work has confirmed high recoveries and produced separate, high grade and high-quality zinc and lead concentrates
- Mining friendly jurisdiction, with Government support for expanding its mining industry
- Strong pipeline of news flow expected as Company mobilises its existing French-speaking exploration team to rapidly commence an exploration program at the Kroussou Project, including drilling to delineate the Project’s scale
- Initial exploration will focus on defining sufficient shallow (open-pittable), high grade zinc-lead mineralisation to justify commencement of feasibility studies
The Project is located in western Gabon in the Ngounié Province, and extends across nearly 1,000km2 of highly prospective ground for base metals exploration.
Figure 1 – Kroussou Project highlighting 18 Prospects
KROUSSOU PROJECT OVERVIEW
The Kroussou Project is readily accessible using a bitumen highway that runs south from the capital Libreville and all-weather unsealed roads and logging tracks that lead into the project area (Figure 2). The project area is surrounded by significant oil and gas and logging activities which facilitates good access to the Kroussou Project area and useful road, port and communications infrastructure.
A small river port at Yeno, approximately 65km to the west of the Kroussou Project along a good quality road, is used by the timber and oil industries to barge equipment and product to Gabon’s main commercial shipping base at Port Gentil, approximately three days by river to the northwest of the Kroussou Project. This barge system presents a relatively cheap logistical solution for operations within the project area to and from the main export facilities at Port Gentil.
Gabon is a mature mining jurisdiction and as such, has a supply of labour that is used to support exploration and mining operations.
Figure 2 – Kroussou Project Licence Location Plan
At the Kroussou Project, zinc-lead mineralisation is hosted in Cretaceous sediments on the margin of the Cotier Basin within preserved channels lying on unconformable Archaean and Paleoproterozoic basement rocks (Figure 3).
Exploration work carried out by previous operators identified 150 base metal occurrences along a +70km strike length of prospective geology within the project area. The zinc-lead mineral occurrences are hosted within exposed channels that offer very shallow, near surface targets close to the Archaean and Paleoproterozoic basement rocks. Only two of the 18 exposed channels were drill tested by the Bureau de Recherches Géologiques et Minières (BRGM) historically, with both channels containing significant base metal mineralisation.
As discussed below, a further two near surface targets were drilled by Trek, which also returned significant zinc-lead intervals, further validating the province scale, base metal potential of the project area.
There are multiple opportunities for the discovery of further base metal mineralisation within the remaining untested 14 channels and also further exploration westward within the broader Cotier Basin is warranted.
PREVIOUS WORK ON THE KROUSSOU PROJECT
Intermittent exploration was carried out on the Kroussou Project between 1962 and 1980, primarily by the BRGM, with latter work in partnership with the Gabonese Government organisation known as COMILOG. The BRGM carried out surface geochemistry comprising soil samples (on a grid of 50 x 50 metres), rock chip sampling (largely along the drainage network where exposures are most prominent) and minor stream sediment work, focusing largely on regional targets.
Some geophysics, including ground based induced polarization and electromagnetic programs, were completed in order to identify any potential near surface mineralisation. As a result of the compilation of the data received from this work, significant near-surface base metal mineralisation was identified where drilling was carried out. This drilling was limited to a small portion of the target area.
Approximately 400 very shallow holes (average depth of 16 metres) were drilled by the BRGM. The majority of the BRGM drilling was carried out on the Dikaki Prospect (Figure 3). Numerous shallow intersections of ore grade and width lead and zinc mineralisation were returned. At the time, the BRGM were focused predominantly on the potential for lead and therefore did not fully explore the zinc potential which is today considered highly prospective.
The BRGM drill holes confirmed multiple horizons of flat lying mineralisation. Numerous intersections of massive sulphide were reported adding to the potential for significant zinc-lead mineralisation at the Kroussou Project.
Figure 3 – Kroussou Project Prospects Detailed
Trek has recently undertaken two small drilling programs at the Kroussou Project to confirm historical results, soil surveying, mapping, rock chip sampling and a ground geophysical program. To date, results received have indicated large anomalies corresponding with potential down-dip and along strike positions to known mineralisation within the Dikaki Prospect area.
Figure 4: Dikaki Area, Kroussou Zinc–Lead Project
Recent results from 2018 drilling at the Kroussou Project include (see Trek’s ASX Releases dated 28 August 2018 and 10 December 2018):
- 8 metres @ 4.2% Zn+Pb (DKDD010, from 2.4 metres)
- 7 metres @ 4.6% Zn+Pb (DKDD012, from 25.1 metres)
- 1 metres @ 6.1% Zn+Pb (DKDD013, from 0.7 metres)
- 0 metres @ 15.2% Zn+Pb (DKDD029, from 8.1 metres)
- 8 metres @ 6.0% Zn+Pb (DKDD028, from 8.9 metres)
- 0 metres @ 4.5% Zn+Pb (DKDD033, from 37 metres)
Niambokamba (approximately 5km north of Dikaki):
- 0 metres @ 4.8% Zn+Pb (NKDD001, from 45.0 metres)
This hole was targeted at the southeastern end of a high order soil anomaly and is open.
Figure 5: Cross Section – Dikaki Channel, showing continuity of the mineralization down-dip
Figure 6: Cross Section – Dikaki Channel
Figure 7: Cross Section – Dikaki Channel
INITIAL METALLURGICAL TEST WORK
An initial metallurgical testwork program in 2018 produced separate, high-grade, high-recovery zinc and lead concentrates. The testwork predicted relatively potential low-energy costs due to low grind times to achieve target sizing (see Trek’s ASX Release dated 8 November 2018). The independent testwork, undertaken by METS Engineering in Perth, Western Australia, resulted in the production of:
- Lead concentrate up to 79% Pb (overall un-optimised lead concentrate graded >70% Pb with > 90% recovery); and
- Zinc concentrate up to 58% Zn (overall zinc concentrate graded 53% Zn at 65% recovery, with the majority of the zinc losses reporting to the lead rougher concentrate. Of the zinc reporting to the zinc rougher, 90% was recovered. Further optimisation on zinc depression in the lead rougher is expected to significantly improve the overall zinc recovery.
The initial exploration program will focus on defining sufficient shallow (open-pittable), high grade zinc-lead mineralisation to justify commencement of feasibility studies.
Exploration can commence quickly given the existence of local drilling contractors, existing site infrastructure and good access to drill targets using logging tracks.
Furthermore, the Company’s existing French-speaking team will be combined with local Gabonese teams to rapidly begin work at the Project.
The proposed work plan for the Kroussou Project includes:
- Mobilise drill rigs to conduct infill and extensional drilling program at the Dikaki Prospect before the end of the dry season in late September if possible;
- Rank and prioritise exploration targets across the project area based on historical data;
- Conduct surface exploration programs comprising soil surveying, geological mapping, rock chip sampling further assess identified prospects and to generate new targets within the broader project area;
- Conduct ground geophysics to refine identified prospects and generate new targets;
- Plan for the mobilisation of a track-mounted reverse circulation (RC) rig suitable for a rapid drilling program over multiple channels;
- Create road access to new prospects in anticipation of an aggressive drill program;
- Continue metallurgical test work over all prospective targets to assess recovery characteristics, concentrate quality, and variability;
- Estimation and reporting of a Mineral Resource in accordance with the JORC Code; and
- Commence with feasibility studies.
The Company will undertake the work program with a strong commitment to all aspects of sustainable development and responsible mining, with an integrated approach to economic, social, environmental, health and safety management.