mallina basin projects

exciting developments in the heart of the pilbara

roberts hill

RECENT NEWS

ROBERTS HILL DRILLING UPDATE (25/8/21)
Progress update on maiden drill program at Roberts Hill

DRILLING COMMENCES AT ROBERTS HILL (2/8/21)
Progress update on maiden drill program at Roberts Hill

Mt Berghaus

regional geology

Both Roberts Hill and Mt Berghaus are located within the Central Terrane region of the Archaean Pilbara Craton, which is comprised of granite, greenstones and sediments which formed between ca. 3600Ma and 2800Ma. The Pilbara Craton appears to be unconformably overlain (at least along its southern margin) by the late Archaean-Palaeo-proterozoic volcano-sedimentary Hamersley Basin sequence. The Pilbara Craton has been subdivided into three structural terranes; the Eastern Terrane consists of large circular, domal granitoid complexes which have intruded belts of tightly folded volcaniclastic rock. In contrast, the Western Terrane is dominated by linear, northeast trending outcrop patterns which are truncated on their south-west margin by the northeast trending Sholl Shear Zone. The Central Granite-Greenstone Terrane separates the Eastern and Western Terranes and contains sediments of the De Grey Group (3015-2950Ma) and the Whim Creek Group. Within the Central Terrane lies the Mallina Basin, a tectonic, rift-like basin that is comprised of sediments of the De Grey Group. Several large granitic plutons are intruded into the Mallina Basin sequence, in addition to highly interesting extremely elevated Mg-rich diorites which appear to have a spatial association with gold and base metal mineralisation within the Mallina Basin.

Mining and Previous Exploration

There has been no recorded mining and very limited exploration over the Roberts Hill and Mt Berghaus tenements. This has probably been due to the thick (up to 40 metres) unconsolidated sands covering much of the tenement area and sparse highly weathered outcrop.

However, within 10 kilometres of the tenement boundaries are several small mining centres. Mallina and Toweranna were historical gold mining centres whilst Mallina and Peawah historically produced small amounts of antimony. Mallina was discovered in 1888 and mined up until 1918 with reported accompanying small gold production of 3.99 kg. Toweranna historically reported production of 161.7 kg Au. Stibnite and other base metals can occur with the gold.

The driving force and catalyst behind the identification of economic gold mineralisation in the Mallina Basin has been the exploration and development work of De Grey Mining Ltd over the past 5 to 6 years. In 2019, a new style of intrusion-related gold mineralisation (? high Mg-rich diorite) was identified at the Toweranna deposit. With accelerated drilling campaigns at the Toweranna resource, this has now increased to 524koz @ 2.2g/t to become the second largest and second highest grade deposit discovered by De Grey. Using good geological and geophysical extrapolation, De Grey have now identified seven new intrusive-related gold targets analogous to Toweranna. In 2020, the Hemi gold occurrence was the first of these new De Grey targets to be tested, which has since confirmed gold mineralisation across three defined Hemi zones, Aquila, Brolga and Crow. Another of these newly defined targets, still to be tested, is De Grey’s Shaggy gold occurrence, which is less than 200 metres from the Caeneus Roberts Hill tenement boundary.

Exploration programs testing the other six identified intrusion-related targets along the Berghaus and Antwerp Structural Trends are about to commence later in 2020.

With the Mallina, Berghaus and possibly new (previously unidentified) shear trends crossing the Roberts Hill and Mt Berghaus tenements, Caeneus is highly encouraged that similar intrusive related gold anomalism will be discovered within its tenements

1968-1972 Mallina Basin
Mallina Mining

Mallina Mining carried out the first modern exploration over the Au-Sb rich Mallina Shear Zone by conducting a detailed soil geochemical sampling program and diamond drilling. Results of both activities were inconclusive.

1973-1974 Mallina Basin
Utah Development Co

Utah Development Co explored for nickel mineralisation, focusing on the mafic and ultramafic intrusives that have intruded the Mallina Basin sediments. Work appeared to demonstrate geochemical interest, however, activities were abandoned. 

1981-1983 Mallina Basin
WMC

In 1981 to 1983, WMC explored for gold mineralisation across the Mallina Shear Zone using lag geochemistry (-4mm+2mm), which highlighted two gold-arsenic trends with values up to 150 ppb Au and 2000 ppm As. The original lag anomalies were later downgraded by follow up surface geochemistry and no drilling was undertaken

1981-1984 Mallina Basin
Aquitaine

Between 1981 and 1984, Aquitaine explored for alluvial Au-Sn mineralisation adjacent to the Yule River and across a portion of the Mallina Shear Zone. Several samples contained detectable Sn (maximum 600 ppm), Ta (maximum 230 ppm) and Au (0.83 ppm)

1986-1989 Mallina Basin
Hunter Resources Ltd

Hunter Resources Ltd explored for Au and PGM’s between 1986 and 1989 over exposed mafic-ultramafic lenses at the base of the Mallina Formation. RC drilling of selected lenses returned disappointing results.

1992-1993 Mallina Basin
Aztec

In 1992-1993, Aztec attempted to test the alluvial gold potential of part of the Mallina Basin area with RAB drilling. A total of 17 holes was drilled to a maximum depth of 28m, which included up to 20m of alluvial cover over Archaean bedrock. Examination of the samples revealed inconclusive and sporadic gold, with limonite-goethite grains the dominant heavy mineral with accessories magnetite, chromite, chalcopyrite and cassiterite.

1992-1993 Mallina Basin
MIM

Between 1992 and 1993, MIM explored parts of the Mallina Basin for Whim Creek style Cu-Zn mineralisation. A prospective exhalite horizon was targeted with maximum rock geochemistry of 110 ppm Cu, 225 ppm Zn and 670 ppm As, however, further exploration ceased.

2019 Mallina Basin
De Grey
In 2019, a new style of intrusion-related gold mineralisation (high Mg-rich diorite) was identified at the Toweranna deposit. With accelerated drilling campaigns at the Toweranna resource, this has now increased to 524koz @ 2.2g/t to become the second largest and second highest grade deposit discovered by De Grey

contact Us

Caeneus Minerals Ltd
Ground Floor
168 Stirling Hwy
Nedlands WA 6014