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A Forgotten Gold Porphyry System in Kalgoorlie - Riversgold Limited.

Coffee with Samso Episode 184 is with Julian Ford, CEO of Riversgold Limited (ASX: RGL) updating us on Riversgold's exploration activities since the last conversation in March 2023.


In our previous conversation, we discussed Riversgold Limited as a lithium explorer that I found interesting. One of the reasons I liked them is because they were among the few companies actively engaged in genuine mineral exploration for lithium. It's important for people to understand that the recent discoveries in the lithium sector have largely come from reevaluating previous exploration efforts. Companies have revisited their drill cores and discovered that the historical drilling had indeed encountered pegmatites.


Samso is not begrudging of the success of these companies, such as the Mount Holland Lithium project, which is now privately owned and operated by Covalent Lithium. Riversgold, on the other hand, continues its exploration activities in search of valuable lithium-bearing pegmatite.


What I find interesting about Riversgold is their Northern Zone project. When I was researching this topic, I initially found their release titled Farm-in to Significant Porphyry Hosted Gold Project a bit confusing because the project had yielded promising results.


The company is proceeding cautiously to ensure the reliability of these results, which I believe demonstrates prudent management. Julian, in particular, discusses the project and takes a measured view of its potential.


What does Porphyry mean?


Here is a description of what a porphyry deposit means from Earth Science Australia:


The major products from porphyry copper deposits are copper and molybdenum or copper and gold. The term porphyry copper now includes engineering as well as geological considerations; It refers to large, relatively low grade, epigenetic, intrusion-related deposits that can be mined using mass mining techniques.


Geologically, the deposits occur close to or in granitic intrusive rocks that are porphyritic in texture.


There are usually several episodes of intrusive activity, so expect swarms of dykes and intrusive breccias. The country rocks can be any kind of rock, and often there are wide zones of closely fractured and altered rock surrounding the intrusions.


As is described following, this country rock alteration is distinctive and changes as you approach mineralization. Where sulphide mineralization occurs, surface weathering often produces rusty-stained bleached zones from which the metals have been leached; if conditions are right, these may redeposit near the water table to form an enriched zone of secondary mineralization.



What is the significance of a Porphyry deposit?


Based on my experience, it is quite rare to find a fertile porphyry that contains only gold. Most porphyry deposits are typically associated with copper. However, Julian informs us that their system at the Northern Zone is devoid of any other metals and is solely a gold system. When we examine the historical drilling results, we can observe significant depth of mineralization, and the grades fall within the range of atypical mineralised porphyry gold system.


Julian has mentioned that they are currently awaiting the results from their recent drilling program. These results will help confirm the assay content and determine if there is any false enrichment present (see below).



It will be fascinating to see the assay numbers and gain a better understanding of the potential of this project. The core samples from the drilling program appear to be in excellent condition, which further adds to the anticipation of the assay results.


Listen to Julian Ford here:



Chapters:


00:00 Start

00:20 Introduction

01:03 Updates from Riversgold

02:57 The Gold Porphyry story

11:22 Metallurgical Cyanide Bottle Roll Test Results

13:37 How did the Northern Zone Project fly under the radar for so long?

19:34 Mt Weld Project

20:54 How should shareholders look at Riversgold?

23:04 Newsflow

23:50 Is the Porphyry story the main focus of Riversgold?

25:26 Why Riversgold?

26:03 Conclusion


Samso's Conclusion


The Riversgold story is an evolving narrative, and I appreciate the adventurous spirit of their projects. Julian impresses me as a composed and strategic individual who possesses a deep understanding of his work. When examining the Northern Zone project, the drilling results are remarkable and align with the expectations for a sizable deposit with low-grade bulk tonnage.


According to the Visual Capitalist, porphyry deposits are very large, polymetallic systems that typically contain copper along with other important metals. Much of today’s mineral production depends on porphyries: 60% of copper, 95% of molybdenum, and 20% of gold comes from this deposit type.


The Bingham Canyon Mine, located in Utah and owned by Rio Tinto and in production since 1906, annually produces approximately:

  • 300,000 tons of copper

  • 400,000 oz of gold

  • 4,000,000 oz of silver

  • 30,000,000 lbs of molybdenum

The value of the resources extracted to date from the Bingham Canyon Mine is greater than the Comstock Lode, Klondike, and California gold rush mining regions combined.


So as you can see above, the magnitude of finding a deposit of this nature in a Tier-1 jurisdiction like Western Australia is going to make Riversgold appreciate in market capitalisation.


PODCAST



This is a good time to download the first Ebook (FREE) from Samso as it is all about VMS (Volcanogenic Massive Sulfides).

About Julian Ford

Chief Executive Officer


Mr Ford has 30+ years experience in the mining industry with global experience including Australia, Africa, South East Asia and South America. Mr Ford has held senior positions within several major resource companies including Alcoa, British Gas, Western Metals Limited. Since 2004, Mr Ford has focused on managing a number of successful start-ups, including transitioning a number of these from concept/exploration to production.


Mr Ford holds a degree in Chemical Engineering from the University of Natal, a Bachelor of Commerce from the University of South Africa and a Graduate Diploma in Business Management from the University of Western Australia. He has been a member of the AusIMM for 20 years.


About Riversgold Limited (ASX: RGL)

Riversgold Ltd is an ASX-listed exploration company focused on discovering and developing large lithium systems in the world-renowned Pilbara and Yilgarn cratons of Western Australia.


In early 2022, the Company acquired a suite of four lithium-prospective exploration tenement applications covering 164km2 in the Pilbara region. The key Tambourah Project is underexplored and has the potential to host a major lithium-caesium-tantalum system much like the nearby Pilgangoora and Wodgina deposits.


Further, the Company has acquired a tenement package of 292km2 prospective for lithium in the Southern Cross-Marvel Loch region of Western Australia as well as securing an option to acquire 80% of tenement E77/2784 immediately to the east of the globally significant Mt Holland lithium project in the same region.


The Riversgold portfolio also offers strong exposure to gold and nickel through its large landholding at the Kurnalpi Project in the Yilgarn.

 

Disclaimer


The information or opinions provided herein do not constitute investment advice, an offer or solicitation to subscribe for, purchase or sell the investment product(s) mentioned herein. It does not take into consideration, nor have any regard to your specific investment objectives, financial situation, risk profile, tax position and particular, or unique needs and constraints. Read full Disclaimer.



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