Tag Archives: telemark geosciences

ECR Minerals plc (LON: ECR), the gold exploration and development company focussed on Australia, is pleased to provide the following update on the Creswick gold project in Victoria, Australia, which is 100%-held by ECR’s wholly owned Australian subsidiary Mercator Gold Australia Pty Ltd (“MGA”).

As announced by ECR on 20 February 2020, Dr Dennis Arne, through his consultancy Telemark Geosciences, was retained to stain reverse circulation (RC) drill cuttings (chips) from MGA’s 2019 drilling at Creswick to test for the presence of ferroan carbonates. The results of the study have now been received.

HIGHLIGHTS:

• Ferroan dolomite in wallrock and as quartz-carbonate composite chips has been identified in five drill holes from MGA’s 2019 RC drilling programme at the Creswick gold project;
• Ferroan dolomite is characteristic of alteration around central Victorian gold deposits and indicative of gold-related hydrothermal fluid flow;
• The strong development of ferroan dolomite in some holes can further assist to delineate auriferous shoots in those areas.

Craig Brown, Chief Executive Officer, commented:

“We are very pleased with the results of this study, which show good indications of hydrothermal fluid flow related to gold mineralisation in a number of drill holes at Creswick. Importantly, the variation in the results, with some areas ‘lighting up’ and others not, is potentially useful for identifying gold-bearing shoots.

This underlines the significant gold exploration potential we believe exists at Creswick, where our tenement position covers approximately seven kilometres of the Dimocks Main Shale (DMS) trend, of which our 2019 drilling tested only approximately 300 metres.”

DISCUSSION OF RESULTS

Ferroan dolomite in wallrock and as quartz-carbonate composite chips was identified in five drill holes from MGA’s 2019 reverse circulation (RC) drilling programme at the Creswick gold project: CSR008, 010, 012, 013 and 014.

The presence of ferroan dolomite is a positive indicator of hydrothermal fluid pathways, particularly where associated with quartz vein material, and allows metamorphic quartz to be distinguished from hydrothermal quartz veins.

As only a small proportion of the total samples from drilling at RC Creswick were reviewed for this study, the presence of ferroan carbonate elsewhere cannot be ruled out, particularly in oxide material where the staining is not effective but in which oxidised ferroan carbonates may be observed.

Given the nuggety nature of gold distribution in most typical central Victorian goldfields, reliance solely on gold assays for exploration may be misleading. While any anomalous gold will be significant in conventional assays, the presence of low values may represent false negatives that might lead to the premature downgrade of prospective structures.

Recognition of wallrock alteration independently of gold assays can be used to map the hydrothermal conduits that have potentially carried gold and provide support for mineralised structures in which gold assays are erratic. Accordingly, routine staining of RC chips to identify ferroan carbonates during logging has been recommended by Dr Arne for any future RC drilling at Creswick.

Dr Arne has also observed that if the stratigraphy is consistently dipping moderately to the west there is hydrothermal alteration and associated quartz veining stratigraphically below the Dimocks Main Shale, roughly below the historical surface workings at vertical depths between approximately 50 and 120 metres. Quartz-carbonate veining appears to be associated with sandstone units in the deeper intercepts where ferroan dolomite has been recognised through staining, and so is compatible with many other central Victorian deposits where sandstones adjacent to thick shale units behave in a brittle manner during deformation to create a host for gold mineralisation. Therefore mineralisation may not be restricted to the Dimocks Main Shale as the Company initially believed.

ALTERATION STUDY METHOD

The approach used involved staining washed RC chips with a mixture of potassium ferricyanide and Alizarin Red mixed with dilute (2%) hydrochloric acid. Ferroan dolomite and ankerite turn dark blue upon staining and ferroan calcite turns purple. Non-ferroan calcite will turn pink or red.

Siderite and magnesite do not react to this stain, so the mixed Fe-Mg carbonates observed at some Victorian gold deposits, such as Fosterville, will not react to the stain. Consequently, the amount of ferroan carbonate observed in RC chips following staining should be considered a minimum amount. The stain also does not work once the ferroan carbonates are oxidised, so samples above the logged base of oxidation were not selected.

Material from 34 one-metre intervals was tested in the study. These intervals were prioritized by MGA’s geological consultant Dr Rod Boucher based on known mineralised areas and logging of quartz-carbonate vein material in the RC chips. RC chips were sampled either from reject poly sample bags or duplicate split calico bags stored near Creswick. There was no material remaining for some samples from which elevated gold values had been obtained. Samples were washed to remove fines and then stained. After approximately a minute the RC chips were rinsed and photographed to document the staining reaction.

Review of Announcement by Qualified Person

This announcement has been reviewed by Dr Rodney Boucher of Linex Pty Ltd. Linex Pty Ltd provides geological services to Mercator Gold Australia Pty Ltd, including the services of Dr Boucher, who has a PhD in geology, is a Member and RPGeo of the Australian Institute of Geoscientists and is a Member of the Australasian Institute of Mining and Metallurgy. Dr Boucher is a Qualified Person as that term is defined by the AIM Note for Mining, Oil and Gas Companies.

MARKET ABUSE REGULATIONS (EU) No. 596/2014

The information contained within this announcement is deemed by the Company to constitute inside information as stipulated under the Market Abuse Regulations (EU) No. 596/2014 (MAR). Upon the publication of this announcement via Regulatory Information Service (RIS), this inside information is now considered to be in the public domain.

FOR FURTHER INFORMATION, PLEASE CONTACT:

ABOUT ECR MINERALS PLC

ECR is a mineral exploration and development company. ECR’s wholly owned Australian subsidiary Mercator Gold Australia Pty Ltd has 100% ownership of the Avoca, Bailieston, Creswick, Moormbool and Timor gold exploration projects in central Victoria, Australia and the Windidda project in the Yilgarn region, Western Australia.

ECR has earned a 25% interest in the Danglay epithermal gold project, an advanced exploration project located in a prolific gold and copper mining district in the north of the Philippines. An NI43-101 technical report was completed in respect of the Danglay project in December 2015 and is available for download from ECR’s website.