Copper Hill East porphyry copper project

Overview

The Copper Hill East Project consists of two tenements (EL8556, EL8901) covering an area of around 290 km² and is located approximately 35 km north of Orange.

The geology consists of Ordovician mafic volcanics and related intrusions, Silurian felsic volcanics and associated sediments.

There are numerous historical copper and gold workings mainly concentrated in the southeast portion of the tenement. Between the tenement and the township of Molong, the Copper Hill deposit (which is located outside the current Godolphin tenement), is estimated to contain an Indicated and Inferred Resource (at 0.4% Cu cut-off) of 28 Mt @ 0.56% Cu and 0.53 g/t Au (Golden Cross Resources, 2019). The Boda discovery by Alkane Resources Ltd (ASX release, 9 September 2019), located approximately 50 km to the north, highlights the potential of this area due to the similar geological setting.

Modern exploration activities commenced around 1975 and consisted of various greenfield exploration techniques through to minor drilling. Ardea has carried out soil auger sampling over approximately seven km of strike length in the northwest portion of the tenement.

This area is prospective for porphyry hosted gold-copper, VHMS and epithermal/mesothermal gold deposits.

Background

The Copper Hill East Project has a long history of minor scale historical workings, mainly focussed in the southeast corner of the tenement (Figure 2). Most of the workings are concentrated on the margins\contacts of the Mullion Range Volcanics and the Barnaby Hill Shale and according to available data were exploited for pyrite (for the extraction of sulphur), gold (both hard rock and alluvial), copper and other base metals.

As far as can be ascertained, modern exploration activities commenced in the area in the mid-1970s. Numerous companies have been active in the area including; Kamilaroi Oil, Samedan, Aquitaine, Amoco/Shell, Tri Origin/Delta Gold JV, Alkane, Comet and Newmont.

Geology

In general, the tenement contains the north trending Early Ordovician to Early Silurian Molong Volcanic Arc (MVA), in which the western portion within the tenement consists mainly of Ordovician mafic volcanics and volcaniclastics and the eastern portion consisting of Silurian felsic volcanics and sediments.

The MVA hosts both porphyry hosted gold-copper mineralisation (Cadia-Ridgeway, Boda and Copper Hill) and skarn related deposits such as Browns Creek.

The MVA is dominated by major north-south trending strike slip fault arrays which generally mark the contact between Ordovician volcanic rocks in the west and younger geological units in the east. These are thought to be relevant to the gold and base metal mineralisation in the area.

It is thought that north-westerly trending structures have significant control on mineralised intrusive bodies (Copper Hill) and post-mineralisation deformation at the majority of known gold-copper deposits in the area.

Previous workers have noted a variety of alteration assemblages. The most notable are the sericite, hematite, epidote, quartz and carbonate within the Oakdale Formation (located in the western portion of the tenement within the Ordovician volcanics. Potassic and propylitic alteration have been observed in a monzodiorite intrusion in the northern part of the tenement.

Work from previous exploration activities indicates that this project contains VHMS, skarn and mesothermal gold type occurrences. Lithologies within the tenement are conducive to these types of deposit styles.

Exploration potential

This Project has the potential to host various types of mineral deposit including porphyry gold-copper, mesothermal gold and VHMS type deposits. The fact that traces of copper mineralisation, associated alteration and the tenements location within a similar geological setting to known porphyry gold-copper occurrences (Cadia-Ridgeway and Boda) has already been noted in this tenement, does highlight the potential of this area.

With the identification of the McPhillamy’s orogenic gold deposit along a structure to the south, the historic Calula gold workings in particular require careful analysis for comparable mineralisation styles.

A more comprehensive data compilation and further soil geochemistry will allow Godolphin to vector into more prospective targets within this tenement.

Recent work by Ardea included field observations and an approximate 7 km long soil auger sampling program carried out in the northwest corner of the tenemt. The program was spaced at 80 m × 80 m grid and results have outlined one 800 m × 800 m copper anomaly (150-500 ppm Cu) and two small anomalies of lesser extent. Field observations within the tenement have noted carbonate veining, carbonate replacement textures and silica cap material.

The main proposed exploration activities will be based on gaining land access so the current soil sampling can be extended and areas that are considered prospective can be soil sampled and mapped.

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Latest News - Copper Hill East
Copper Hill East Project: Copper and gold in rock chip samples identify drill targets
24/02/2020 2.0 MB
GRL-CopperHillEast-Geology
Figure 1 – Location of Copper Hill East tenement, geology and surrounding mineral occurrences
GRL-CopperHillEast-HistoricalWorkings
Figure 2 – Location of historical workings, prospects and interpreted geology within the Copper Hill East project
GRL-CopperHillEast-SoilAuger
Figure 3 – Soil auger copper results for Copper Hill East
GRL-NSW-Tenement
Figure 4 – Godolphin Resources tenement locations