EPM 18325 - BALD HILLS

EPM 18325 is located between the Palmer River and Mitchell River, approximately 130km north of tthe township of Chillagoe, and 210km north-west of Cairns. 

Exploration is focused on the delineation of porphyry copper-gold, skarn and volcanic massive sulphide (VMS) copper-gold, lead and zinc style deposits within the highly prospective Chillagoe Formation which hosts the Mungana and Red Dome mines.

Diversified Mining and Resources also believes that the Chillagoe Formation is a potential host for polymetallic volcanic-hosted massive sulphide mineralisation. This is mostly due to its shallow-marine, mixed volcanosedimentary stratigraphy and the suite of anomalous elements found in stream sediment and soil geochemistry within the Chillagoe Formation along the northern segment for the Palmerville Fault Zone.

 1970 – 1980

CRA explored the regional area under the tenure of EPM 738.

CRA conducted a soilsampling program, consisting of 29 samples, over the Mountain Creek Prospect, which is a micro-granodiorite stock with accompanying skarn and silicified zones. The soil assay results for Mountain Creek included:

• up to 530 ppm Cu,
• 980 ppm Pb,
• 750 ppm Zn and
• 100 ppm Mo (CR 4176).
• A rock chip sample from the Mountain Creek prospect contained 1.5% Cu.

Commonwealth Aluminium Corporation Ltd explored teh general area under EMP 1472 and 1564

n 1975 Commonwealth Aluminium Corporation Ltd held EPM’s 1472 and 1564 which overlapped the footprint of EPM 18325. As part of a combined exploration program over both tenements, detailed -80#
stream sediment sampling confirmed weak anomalism in the Mountain Creek catchment (CR 5570). This regional stream sediment survey also identified a catchment in the upper Buffalo Creek with anomalous Cu values (consistently above 150 ppm (see Figure 4below) which was never followed up. Both tenements were surrendered after the first year.

1981 – 1990

CSR explored the general area under EPM 2866.

The main focus of this exploration program was for scheelite and was based on the Mittersil Model (scheelite within cherty exhalites), with a secondary focus being a potential Carlin-style Au deposit. The company collected panned concentrates and 80 stream sediment samples at 26 locations (CR 10309). The area covering EMP 18325 was relinquished in early-1983.

In 1984 BP held EPM 3551 which covered the footprint of EPM 18325.

BP engaged in a comprehensive stream sediment sampling program with over 609 samples collected which equates to an average of one sample for every 3km² (CR 13101). Some 46 rock samples of existing known prospects were collected during this program.

No anomalous results were found, and BP concluded that the area is “too remote from the mineralising intrusives at Chillagoe”. This is despite BP geologists noting that individual prospects at Mountain Creek, Kangaroo Creek, Red Bluff, Hill 211, Hill 286, and Hill 366 displayed evidence of mineralising activity (intrusives, skarns, breccias, quartz stockworks, silicification, etc).

REGIONAL GEOLOGY

Structure

EPM 18325 lies within the Middle Palaeozoic Hodgkinson Province (represented by the Mulgrave, Chillagoe and Hodgkinson Formations) and is separated from the Middle Proterozoic Dargalong Metamorphics to the west by the Palmerville Fault, a major NNW trending structure.
Extensive thrusting and push-pull tectonics during deformation episodes spanning the Late Devonian to Mid Carboniferous produced steep sub-vertical dips, tight folding and resulted in significant structural thickening to the formation. The steeply dipping thrust faults trend north-west, sub-parallel to the stratigraphy and the Palmerville Fault.

Late Carboniferous to Early Permian igneous activity resulted in intrusion of granitic rocks and extrusion of felsic volcanic rocks, plus localised emplacement of high-level rhyolitic porphyry stocks in the Chillagoe Region. Known mineralisation is typically related to this Carboniferous-Permian igneous activity.

Within the general licence area, the Chillagoe Formation trends in a north-north-westerly direction. As with the Mungana and Red Dome Mines, many of the lithological contacts within the Chillagoe tenements are potentially structural in nature.

The limestone ridges of the Chillagoe Formation can be clearly traced in satellite imagery for a strike length of more than 250km from a point roughly 60km to the north of the Limestone Creek tenements through to a point roughly 25km south of Chillagoe.

Stratigraphy

The Hodgkinson Province, which hosts the Chillagoe Project, consists of an early to middle Palaeozoic sedimentary sequence dominated by turbiditic rocks with subordinate limestone, chert, and basic volcanic rocks extending for ~500 km from Innisfail to Cape Melville and inland for ~150 km from the coast to the Palmerville Fault.

The dominant rock types are quartzo-feldspathic arenite and mudstone, which represent deep-water density current deposits interlayered with subordinate conglomerate, chert, meta-basalt, and minor shallow-water limestone. Rocks of the Hodgkinson Province (Hodgkinson Formation) host significant mesothermal quartz veinhosted gold mineralisation, which includes the Hodgkinson/Palmer goldfields. The Hodgkinson Province locally hosts significant skarn mineralisation, such as that at Red Dome, where Permian-Carboniferous granitoid bodies of the Kennedy Province intrude carbonate-rich rocks of the Chillagoe Formation.

The Siluro-Devonian Chillagoe Formation hosts the most significant mineralisation within the Chillagoe area. The formation is comprised by intercalated limestone, conglomerate, sandstone, wacke (generally upper units of the Formation) and siltstone, shale, chert, minor mafic volcanics, and basalt (generally lower units of the Formation). Sedimentary breccias are also known to occur. Bedded, locally ferruginous chert occurs as numerous thin units that typically form the crests of ridges and hills.

RECENT EXPLORATION BY NATIVE MINERALS RESOURCES

2021 Hyperspectral Response Mapping

During 2021, NMR contracted Dirt Exploration to acquire and review the publicly available SWIR/LWIR Sentinel-2 satellite imagery and develop hyperspectral imagery maps for the potential for copper, gold and antimony in the regolith over the entire Palmerville project area.

The hyperspectral results were generated for different mineral phases and were not suitably filtered for features such as roads, sandbanks which can add significant weighting and erroneous results in many cases.

The results show that the positive response for gold is partly influenced by the location of major structures, however, this is also partly influenced by the lithology and lithological controls which in turn are controlled by major structures.

Accordingly, the correlation between the three datasets (lithology, structural geometry and spectral mapping) is not surprising. However, the southern extension of the anomalous gold in spectral results corresponds approximately with the major NW-SE trending structure in the centre of EPM 18352.

Figure 6 shows the hyperspectral image for gold overlaying the 2023 TMI magnetic image, highlighting the potential for gold mineralisation related to the Palmerville fault in the north-western corner of
EPM 18325.

North Palmerville Geophysical Interpretation and Target Analysis

NMR contracted Mitre Geophysics to complete an interpretation and modelling of the airborne magnetic and radiometric data for the Northern section of NMR’s Palmerville Project focussing on the structural complexity of the area as well as the geophysical targets.

The interpretation area covered EPM 18325, as well as the surrounding NMR tenements and included all publicly available data, including historical drilling, geophysics and geochemical sampling, as well as data collected by NMR.

The interpretation highlighted 16 targets and prioritised them ranking them as high, medium or low.

Within EPM 18325 there is one medium, & one low priority target, with the medium target being centred on the Mountain Creek and Bonanza targets (Figure 7).

The interpretation also highlighted the complex structural nature of EPM 18325 with Figure 7 highlighting a number of magnetic lenses that are truncated and faulted by a series of cross cutting faults, with the medium priority target (yellow) highlighting a number of these features as well as truncated and discrete magnetic highs.

EXPLORATION PLANNING

Activities in the coming year are being planned following completion of the North Palmerville interpretation of the Airborne magnetics survey.

The first phase of work for the next reporting period will include:

• Site visit to EPM 18325 for ground truthing.
• Possible ground geophysical survey to determine size, shape and depth of the priority targets delineated in the above work.
• Possible drilling of priority targets