YARRAM PARK PROJECT
The Yarram Park Project in western Victoria, approximately 250 km to the west of Melbourne, comprises one exploration licence EL5478, with an area of 26 square kilometres.
The Yarram Park Project overlays the Bunnugal Belt of the Cambrian Stavely Volcanic Arc, which is considered highly prospective for intrusive related porphyry copper-gold.
First-pass air-core drilling at the Toora West prospect has returned strong indications of an underlying copper porphyry system.
The Yarram Park Project lies within the Grampians – Stavely Zone of the eastern Delamerian Orogen and hosts several belts of calc-alkaline volcanics including the Cambrian calc-alkaline Mount Stavely Belt and the Bunnagul Belt.
The Mount Stavely Belt / Bunnagul Belt lies approximately 15-20 km west of the east-dipping Moyston Fault, a regionally important fault that marks the eastern terrane boundary of the Delamerian Orogen and the western margin of the Stawell Zone in the Lachlan Orogen. The western margin of the Stawell Zone is characterised in many places by Cambrian volcanic rocks of tholeiitic and boninitic affiliation typical of the volcanic rocks exposed elsewhere in the Lachlan Orogen. These volcanic rocks and associated marine sedimentary rocks have been metamorphosed to form the Moornambool Metamorphic Complex.
Cambrian volcanic rocks of the Grampians / Stavely Zone were deformed during the Delamerian Orogeny and intruded by post-tectonic Late Cambrian granites. By contrast, the Cambrian to Ordovician volcano-sedimentary sequence of the Stawell Zone was deformed during the late Ordovician to early Silurian Benambran Orogeny and intruded by late Silurian to early Devonian post-tectonic granites.
Toora West Copper - Gold Porphyry Prospect
Maiden drilling by the Company at the Toora West prospect confirmed the presence of a “blind” porphyry intrusive complex.
Diamond holes STWD001 and STWD002, drilled in early 2017, to test a coincident gravity low with peripheral and central magnetic anomalies, encountered a sequence of andesite lavas that have been intruded by diorite and quartz diorite or tonalite. Hornblende and plagioclase in the intrusive rocks have been preferentially replaced by biotite and k-feldspar, respectively, potentially indicating local development of a proximal potassic or metasomatic alteration package. In contrast, STWD003 drilled to test an induced polarisation chargeability anomaly, intersected a steeply southwest dipping package of massive and laminated mudstone, siltstone, fine to coarse grained turbidites and narrow bedding parallel tonalite sills.
Litho-geochemical data for drill holes STWD001 and STWD002 show that the calc-alkaline diorite and quartz diorite/ granodiorite intrusives plot within the Bob Loukes Cu+Au productive field.
From the recent Stavely ARC 3D model it is considered likely that the circular aeromagnetic feature in the southern portion of EL5478 represents a drag-folded package of intermediate to mafic volcanic rocks, related to dextral offset of the Yarrack Fault. The coincident gravity and aeromagnetic low may represent a combination of intrusive and sedimentary rocks. All three diamond drill holes encountered diorite and tonalite intrusions, although STWD003 appears to be more marginal to the volcanic arc, as deep-water laminated black mudstone and turbidite deposits were observed. STWD003 was collared directly adjacent to the Yarrack Fault which explains why the bedding was steep in the hole.
Diamond hole STWD004, drilled to a depth of 372 metres to test to test a discrete magnetic anomaly in the vicinity of the previous drilling at the Toora West prospect, intersected a sequence of feldspar phyric rhyodacites and basaltic andesites, as well as fine grained basalts, trace pyrite and occasionally trace chalcopyrite. No anomalous gold and only minor anomalous base metal assays were returned from drill hole STWD004.
Drilling Confirms Substantial Extensions to High-Grade Mt Ararat VMS Copper-Gold-Zinc Deposit
Strong drilling results highlight potential for Mt Ararat deposit to form part of an expanded project based on the Cayley Lode discovery
Toora West Strong Evidence of Emerging Porphyry Discovery
Further encouraging indications from shallow air-core drilling ~15km NW of the Thursday’s Gossan prospect provide a strong target for deeper diamond drilling