Slievedart Project

Overview

Ownership & Location

Minco, through its wholly-owned subsidiary Minco Ireland Limited, has also entered into a JV agreement for the twelve Prospecting Licences (“PL”) of the Slievedart Block. Minco Ireland has entered into a joint venture agreement with Boliden Tara Mines on PLs 1102, 1362, 1700, 1788, 1789, 1791, 2885, 2889, 3470, 3471, 3681, and 3755. Minco can earn a 50% interest through expenditure of €385,000 in staged programmes, by 31 July 2024. Boliden Tara Mines has the right of off-take to purchase or toll process on all ore that may be produced from the licence area.

The Slievedart Block is located in County Galway, immediately north and northeast of the town of Tuam. It consists of twelve contiguous prospecting licences covering a surface area of 537.38km². The Slievedart Block is operated under the terms of a Joint Venture agreement with Boliden Tara Mines (Section 4.3.5).

Geology

The Slievedart Block covers part of the northwest Lower Carboniferous Basin. Lower Palaeozoic and Precambrian rocks form the basement to the region. Devonian Old Red Sandstone (ORS) is deposited along an unconfirmable contact with the basement. Lower Carboniferous Basal Clastics form a highly variable facies that directly overly the ORS, ranging from alluvial conglomerates to marginal marine sandstones and mudstones,. During the Lower Carboniferous a marine transgression progressed northwards across Ireland with siliciclastics giving way to carbonate deposition. Clear evidence of depositional water depth variability can be seen throughout the Lower Carboniferous indicating a complex structural history with block uplift and subsidence.

Deformation of the Lower Carboniferous rocks was manifest in a series of south to southeast dipping graben structures controlled by reactivation of existing Caledonian faults within the underlying basement. The region can be divided into a series of northeast-southwest trending synclines and the Slievedart block is located within a broad southern extension of the Carrick-on-Shannon Syncline. Small horst blocks of Lower Carboniferous and Lower Palaeozoic rocks separate the graben structures, these are know as the Castlerea and Slievedart Inliers. A third inlier, at Glenamaddy, has an anomalous trend and it has been postualted that it is controlled by a relatively shallow granitic pluton.

The Slievedart Inlier trends northeast-southwest along the northern boundary of the licence block, forming a moderate topographic high. It is interpreted to be a horst structure that is bound by the Slievedart North and South Faults. The Slievedart North Fault has a downthrow of >300m to the northwest and the Slievedart South Fault has a downthrow of >100m to the southeast. Basal Clastics outcrop on the footwall to these faults and form most of the inlier. Historic drilling has identified numerous NNE-SSW striking faults that off set the inlier and step progressively to the northeast. Waulsortian Reef development on the southern flank of the inlier appears to be partially controlled by these cross faults. The Waulsortian Reef is conformably overlain by Oakport Fm. and Visean Shelf limestones. The western end of the Glenamaddy Inlier extends across the eastern side of the licence block where it is terminated by a NNE trending structure. The geology of the Glenamaddy Inlier is dominated by Basal Clastics.

A smaller inlier is seen at Rosmearan, PL3470, with Waulsortian Reef exposed within a spatially limited, half horst structure. The Oakport Limestone outcrops along the hangingwall of the controlling faults.

The geology of the southern part of the licence block is not well constrained due to lack of outcrop. It has been mapped as underlain by undifferentiated Visean Shelf limestones. Structural modelling, based upon the limited outcrop and drilling data, has postulated a half graben structure controlled by a northerly dipping normal fault system developed along the southern margin of the licence block.

Slievedart Block – Geology

Mineralization

There are at least eight known mineral occurrences located on the Slievedart Block. All of the mineralisation is hosted by the Waulsortian Reef or stratigraphic equivalent rocks. The mineralisation is closely associated with dolomitisation and occasionally silicification. Pyrite can be present in large quantities with little or no zinc-lead mineralisation. Cadmium, arsenic and thallium are common trace elements. Styles of mineralisation include cavity lining, geopetal fill of stromatactis cavities and fracture lining. Pyrite occurs as massive bands up to 50cm thick. The style of mineralisation and setting is very similar to that described at Ballinalack where knolls of Waulsortian Reef are found in the hangingwall of normal faults and mineralisation is slightly offset from the main faults.

Slievedart Mineral Occurrences.

History

Zinc-lead exploration in the Slievedart area began in the late 1960’s during a country wide exploration boom following the discoveries of Tynagh and Silvermines. Historic work was carried out by; Irish Base Metals Ltd., Enfer Resources Holdings Ltd., Westland Exploration Ltd., Amoco Minerals Ireland Ltd., Celtic Gold Plc., Riotino Finance and Exploration Plc., Ovoca Resources Plc., Cobh Exploration Ltd., Aquitaine Mining (Ireland) Ltd. and Boliden Tara Mines Ltd.

In the Slievedart area the majority of historic exploration has been focused on the potential for Waulsortian Reef-hosted mineralisation, both sub-outcropping and to depths of up to 400 metres below surface. The region was first explored by Irish Base Metals Limited who acquired the ground in 1967. The first phase of work was standard reconnaissance geological mapping / prospecting followed up by regional scale shallow soil sampling. Extension to soil sampling grids with DOB sampling focused in areas with significant soil anomalies. Geophysical surveying, consiting of Induced Polarisation, VLF/EM16R, magnetics and gravity was carried out across areas deemed prospective and follow up drilling was focused on specific target areas.

Diamond drilling has had moderate success in the region immediately south of the Sleivedart inlier. A number of moderate grade intersections of disseminated and fracture fill sulphide mineralisation were made at the Rosmearan, Darrary North, Gortnalea and Sinking River targets. Intersections of up to 2.3m grading 6.8% Zn / Pb have been recorded within the Waulsortian Reef.

Reports

•  Blaney, D. “Technical Report on the Irish Zinc Exploration Project of Minco Exploration Limited a subsidiary of Buchans Resources Limited” dated 29 October 2019

Gallery