Beefwood Project
The Beefwood project provides the Company with a prospective high risk – high return play which is partly under the cover of more recent rocks. The area has received little exploration in the past and historical drilling is limited to three shallow holes drilled by North Limited in the early 1990s which were well to the east of EPM26399. The deepest hole was 152m in depth but did not intersect basement (Reference: QDEX CR26209 – McInnes, 1994).
The limited exploration appears to reflect explorers being discouraged by Carpentaria Basin sedimentary sequences overlying and obscuring the basement geology. However, the discovery of outcropping basement rocks by Three Rivers Prospecting Pty Ltd within the tenement suggests that the thickness of cover sequences may have been historically over estimated and may in fact be quite variable. This is supported by regional AUSAEM 20km survey lines immediate North and South of the tenement and also by 3D modelling of regional magnetic and gravity data, as well as the outcropping ignimbrite formations.
The Beefwood project was originally selected due to a modelled density anomaly in the middle of the tenure (Figure 1a), in a region of complex magnetics (Figure 1b) and close to the Gamboola Fault zone which has been interpreted as a western extension to the Palmerville Fault zone – a major crustal feature. Newcrest Mining has also originally targeted this zone with its Bulimba project which is now part of the Bulimba agreement with R3D Resources. Further south the Tartana copper project, the King Vol Zinc Mine, the Mungana Copper/Gold Mine and Red Dome Gold mine all lie near the northwestern trend of the Palmerville Fault.
Figure 1. 1a. Bouger Gravity 1VD, 1b. Magnetics – RTP (red – high, blue -low) overlain by Bouger Gravity data which reinforces coincident gravity/mag high in the centre of the tenement. (Source: TRP, see ASX announcement dated 29 June 2022).
Landsat imagery combined with the identification of outcropping basement (rhyolitic ignimbrites) supports an interpretation of a series of nested calderas with a later one in the southwest corner of the Beefwood project (see Figure 2).
Figure 2. 2a Landsat enhanced bands 7/6/2 ‘Geology’. 2b. Landsat enhanced bands 7/6/2 Outcrops and inferred sub-cropping ash flow caldera’s (yellow/orange). Outcropping rhyolitic ignimbrites overlain as blue polygons in figure 5b. (Source: TRP)
Three Rivers Prospecting Pty Ltd’s structural interpretation is presented in Figure 3 and shows the potential later caldera in the southwest and high intensity of faulting proximal to the gravity/mag high complex in the centre of the tenement.
Figure 3. 1:100K GSQ Surface Geology. Overlain polygons (blue) represents mapped extents of outcropping felsic volcanic breccia and ignimbrite. Orange polylines represent sub-cropping (hypothesised) collapse cauldron with possible resurgent dome in centre. Black polylines are hypothesised sub-surface penetrative structures interpreted from combinations of remotely sensed data and field observations – particularly sub-surface influences on cover. The outcropping felsic volcanics may represent a partially exposed and structurally disrupted ring-dyke complex associated with collapse of the sub-circular feature. Landsat bands 7/6/2 and 5/6/2 highlight the outcrops and inferred sub-crops against the more extensive unconsolidated cover (Wyaaba beds and Bulimba formation) particularly well. (Source TRP).
Soil geochemistry surveys carried out by TRP have identified anomous gold values and other pathfinder elements (Figure 4) which tend to be higher tenor in the region of the gravity/mag high.
Figure 4. Soil Geochem Survey with anomalous path finder elements including gold. (Source: TRP).
The anomalous gold is particularly encouraging with crushed iron pisolite gold samples containing ragged visible gold flakes up to 2 mm in length (Figure 5).
Figure 5. Crushed Iron pisolith sample containing gold grading up to 282 g/t in iron pisolites. (Source: TRP)
TRP has also identified an array of breccias in regolith samples which are interpreted to be derived from basement lithologies. The regolith contains mineralised breccia clasts. The breccia fragments contain a haematite and goethite matrix with angular quartz and volcanic clasts and in some cases are a quartzcarbonate rich breccia with tourmaline and occasional chalcopyrite in the matrix (see Figure 6).
Figure 6. Clockwise from top left. 6a. Breccia fragments with haematite and goethite matrix with angular quartz and volcanic clasts. 6b. Quartz-rich breccia with tourmaline and chalcopyrite in the matrix. 6c. Low temp high acid steam alteration of intense silica stockwork breccia 9d. Possible leached cap vuggy silica and specimen (150mm across) with possible alunite growths in cavities. 9e. Epithermal sheeted veining clast in tourmaline shingle breccia fragment (Source TRP).
The distribution and composition of the pathfinder elements, the breccia regolith samples and the presence of outcropping ignimbrites suggest both the geophysical and geochemical anomalies could relate to mineralisation in the basement rocks which may not be excessively deep within the Beefwood project area.
Figure 7. Outcropping ignimbrites, which have previously been mapped as deep (non-prospective) cover by the Geological Survey of Queensland and Geoscience Australia. The volcanic lithologies include brecciated rhyolitic ignimbrite.
The Falcon gravity/magnetic survey flown in 2021 determined a number of coincident gravity and magnetic anomalies with the Beefwood project and which has assisted in identifying other targets within the project area.
Figure 8. 8(a) Isosurfaces from the 3D model output. Low density shown in blue, high density in yellow and high magnetic susceptibility in pink. 8(b) Depth Slice through Gravity Model at 300m below surface. Black dots indicate the presence of magnetic remanence, low density zones circled in blue, high-density zones circled in yellow and potential structures shown in yellow. Potential zones of interest circled in red and labelled 1 – 7.
In summary, the Beefwood project is highly prospective based on geophysics, geochemical surveys and its proximity to a splay of the Palmerville Fault – a major structural feature. The next phase will involve reconnaissance drilling and the Company is finalising access agreements.
