Gold Bearing Conglomerates Identified by Previous Explorers
Released
Released
Announcement PDF
ASX ANNOUNCEMENT
Date: 27 November 2017
Number: 558/271117
GOLD-BEARING CONGLOMERATES IDENTIFIED BY PREVIOUS
EXPLORERS ON IMPACT’S PILBARA GOLD PROJECT
A review of previous exploration data and field checking indicates at least 90 kilometers of
prospective Fortescue Group conglomerates occur at or near-surface on Impact’s licence
applications which cover 1,300 sq km in the Pilbara region Western Australia
Rock chip results of up to 11.2 g/t gold occur at the Glen Herring Prospect 10 km west of
Marble Bar in a gold-pyrite conglomerate that extends for 25 kilometres.
A single diamond hole at Shady Camp Well returned 0.9 metres at 0.6 g/t gold that has not
been followed up.
Other gold-bearing conglomerates identified on or adjacent to Impact’s licences.
The conglomerates on Impact’s licences are similar to those that occur in the
Witwatersrand Basin of South Africa where the majority of the gold-bearing reefs are only
1 to 2 metres wide and easily missed.
A recent field visit to the Purdeys Reward-Comet Well area with Novo-Artemis has
highlighted the different types of conglomerate-hosted gold in the Pilbara as well as the
challenges in exploring for such deposits.
Impact is conducting on-ground reconnaissance exploration to ascertain access conditions
and to determine the best sampling approach for gold both in nugget form as well as finely
disseminated gold, both of which occur in the East Pilbara.
Earlier this year Impact Minerals Limited (ASX:IPT) applied for nine new 100% owned Exploration
Licences covering 1,300 sq km of ground prospective for conglomerate-hosted gold in the Pilbara
region of Western Australia (Figure 1).
This followed a review of the discovery of gold in conglomerates at the base of the Fortescue Group by
Artemis Resources Limited (ASX:ARV) and the subsequent joint venture with Novo Resources
Corporation.
This discovery indicated a significant breakthrough had been made in the search for conglomerate
hosted gold deposits of a similar age to the Witwatersrand Basin of South Africa in the Pilbara and
Impact was an early mover in applying for available ground considered prospective for this style of
deposit (see announcement dated 28th September 2017).
Impact is completing a review and synthesis of previous exploration data and mapping by the
Geological Survey of Western Australia (GSWA) with particular focus on the two most prospective
conglomerate horizons within the Fortescue Group:
26 Richardson Street West Perth Western Australia 6005
Tel +61 (8) 6454 6666 Facsimile +61 (8) 6454 6667
Email info@impactminerals.com.au www.impactminerals.com.au
1. Conglomerates of the Hardey Formation. These rocks host the Beatons Creek resource
(6.4 Mt at 2.7 g/t gold for 558,000 ounces of gold) held by Novo Resources Corporation near
Nullagine (Figure 1); and
2. Conglomerates at the base of the Mt Roe Basalt. The recent gold discovery at Purdeys RewardComet Well by Novo Resources and Artemis Resources Limited occurs within this unit (Figure 1).
Figure 2
Figure 1. Location of Impact’s new licences and significant conglomerate hosted gold occurrences
Field checking and previous mapping indicates that the prospective conglomerates occur over at least
90 kilometres of trend at or close to surface within Impact’s licence applications, in particular to the
west and east of Marble Bar as well as close to the Beatons Creek deposit near Nullagine.
West of Marble Bar, previous exploration in the district highlights several gold occurrences associated
with the conglomerate horizons on and along trend from Impact’s licence applications ELA45/4972 and
ELA45/4971 (Figure 2).
Here, four main gold-bearing conglomerate occurrences with similar characteristics to those that occur
within the Witwatersrand Basin have been discovered:
1. At the Glen Herring Prospect previous rock chip samples in 1989 returned assays of up to
11.2 g/t gold from a gold-pyrite bearing conglomerate within the Hardey Formation which
extends for 10 km of strike on Impact’s licence ELA44/4972 (Figure 2).
2. At the Shady Camp Well Prospect one diamond drillhole was completed by Western Mining
Corporation in 1976 to test a surface gold and uranium anomaly in conglomerate-sandstone and
returned 0.9 metres at 0.6 g/t gold from 174 metres downhole in quartz pebble conglomerate
with rounded pyrite in the matrix. The conglomerate occurs close to a carbonaceous shale unit.
Assays of up to 320 ppm uranium were also returned in places. Carbon and uranium are
signficant accessory minerals in the Witwatersrand Basin and Impact considers these results to
be significant. Further gold and uranium-bearing conglomerates in the Hardey Formation have
been identified by previous explorers for at least 10 km along strike from Shady Camp Well.
MARBLE BAR
Figure 2. Interpreted bedrock geology map surrounding two of Impact’s Licences west of
Marble Bar showing the prospective conglomerate horizons within the Fortescue Group with key
gold and uranium assay results.
The same conglomerates also extend for a further 15 km along strike to the southwest outside of
Impact’s licence where historic assays returned up to 2.1 g/t gold and 45 ppm uranium (see
Figure 2).
3. Gold-bearing pyritic quartz pebble conglomerates have been identified at the base of the Mt Roe
Formation by several previous explorers at the Contact Creek Prospect which lies 6 km west of
Impact’s licence E45/4971 with the the best rock sample result of 15.9 g/t gold by Novo
Resources in 2013 (see Figure 2). This gold-bearing conglomerate extends to the east and occurs
very close to surface over at least 4 km of strike on Impact’s licence ELA45/4971.
4. The Hardey Formation sandstones and conglomerates have been mapped by the GSWA over at
least 25 km of strike on ELA45/4971 and rock samples of conglomerate with very strong pyrite
returned up to 0.26 g/t gold by CRA Exploration in 1987 (Figure 2).
The chemistry and characteristics of the conglomerates from the four propsect areas are similar to those
observed in Witwatersrand-style conglomerate-hosted gold deposits. These characteristics include:
Widespread gold-bearing conglomerates with highly elevated uranium in places;
The identification of rounded detrital pyrite within the matrix between conglomerate clasts; and
The occurrence of black carbonaceous shale that occurs in close proximity to the conglomerates
These are significant observations and are very encouraging for further exploration on Impact’s 100%
owned Pilbara Gold Project.
Impact’s Managing Director Dr Mike Jones said: “We were recently priviliged to visit the Purdeys
Reward-Comet Well area with Novo Artemis and have seen first hand the reasons why it had not been
discovered before, the potential scale of the discovery and also the difficulties of exploring and sampling
for this style of deposit. It is evident that there is a wide range in size and distribution of gold within
these conglomerates and it is this that has hampered previous exploration for this style of
mineralisation.We are now determining the most appropriate sampling methodologies for our on-ground
exploration which will commence in earnest on grant of the licences.
Dr Mike Jones
Managing Director
The review of exploration activities and results contained in this report is based on information compiled by Dr Mike Jones, a Member of
the Australian Institute of Geoscientists. He is the managing Director of the company and works for Impact Minerals Limited. He has
sufficient experience which is relevant to the style of mineralisation and types of deposits under consideration and to the activity which he is
undertaking to qualify as a Competent Person as defined in the 2012 edition of the Australasian Code for Reporting of Exploration Results,
Mineral Resources and Ore Reserves (the JORC Code). Dr Jones has consented to the inclusion in the report of the matters based on his
information in the form and context in which it appears.
Impact Minerals confirms that it is not aware of any new information or data that materially affects the information included in the
previous market announcements referred to and that all material assumptions and technical parameters underpinning the results.
All reported data in this announcement has been taken from previous publicly available reports. Impact Minerals has no reason to doubt
the validity of these reports, which, because of their age, did not fully document techniques and procedures. Accordingly a detailed account
of these results is deemed to be immaterial at this stage.
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