Gold mineralisation in the Dalradian rocks of Knapdale-Kintyre, south-west Highlands, Scotland

Gunn, A.G.; Shaw, M.H.; Rollin, K.E.; Styles, M.T.. 1996 Gold mineralisation in the Dalradian rocks of Knapdale-Kintyre, south-west Highlands, Scotland. Nottingham, UK, British Geological Survey, 70pp. (Mineral Reconnaissance Programme report 143) (Unpublished)

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Abstract/Summary

Following reappraisal of regional geochemical and geophysical data for the northern part of the Kintyre Peninsula, a brief survey was conducted by the Mineral Reconnaissance Programme (MRP) to study the distribution of gold in south Knapdale and to assess the prospectivity of known base-metal veins in the area as sources of economic gold mineralisation. A limited drainage survey, involving the collection of panned concentrates and stream sediments, identified widespread enrichment of gold in several parts of the area underlain by Argyll Subgroup Dalradian metasedimentary rocks. Associated lithogeochemical sampling confirmed the presence of elevated gold concentrations in bedrock and enabled three types of mineralisation to be distinguished. The highest tenor gold mineralisation was found around Stronchullin in the north-east of the project area. Gold concentrations up to 22 ppm are present in samples of base-metal-bearing quartz veins from spoil material at the derelict Stronchullin mine. This mineralisation is characterised by high levels of arsenic, antimony, copper, lead, zinc, barium and by an elevated gold/silver ratio. Drainage geochemical data indicate the presence of additional bedrock sources of gold in the Stronchullin area and veins carrying high levels of gold have been found elsewhere in the Stronchullin valley, in the Invemeil area in the north, and in the south of the project area near the shore of West Loch Tarbert. Low to medium tenor gold enrichment has also been identified in association with discordant copper vein mineralisation in the Meal1 Mor area, in the vicinity of the former mine workings at Abhainn Srathain. This mineralisation is distinguished by high contents of copper, gold and silver. Associated levels of arsenic, antimony, bismuth and gold/silver are low. Stratiform disseminated pyrite mineralisation, with minor attendant chalcopyrite and sphalerite, of sedimentary exhalative origin is found in a concordant elongate belt extending across the project area for at least 10 km. No gold enrichment has been found in association with this type of mineralisation. Mineralogical studies carried out on gold-bearing rock samples have provided important additional information on the metallogeny. Gold grains studied in samples from the Meal1 Mor copper mineralisation are characterised by an unusual chemistry rich in silver and mercury. In contrast, the compositions of alluvial grains studied are typical of gold derived from mesothermal lode type mineralisation. No gold grains were located in the Stronchullin vein samples, but the geochemical and morphological features of the veins indicate a likely mesothermal origin. The drainage geochemical data reflects these styles of mineralisation clearly and identifies several additional prospective zones. However, the sample coverage attained in this project was not adequate to determine the controls on the gold distribution. A broad association of metal enrichment, locally including gold, with east-west lineations is evident. The importance of north-west trending features and their intersection with east-west structures should be assessed. In the light of recent discoveries of potentially economic gold mineralisation elsewhere in the Dalradian belt in Scotland and Northern Ireland, further investigations in the south Knapdale area are recommended. Priority should be given to the Stronchullin area and the other known base-metal vein occurrences. Further research, including additional mineralogical studies, is required to investigate possible links between the gold enrichment in the Meal1 Mor area associated with discordant copperbearing veins and the post-tectonic quartz veins of the Stronchullin type.

Item Type:	Publication - Report
Programmes:	BGS Programmes > Economic Minerals
Funders/Sponsors:	Department of Trade and Industry, British Geological Survey
Additional Information. Not used in RCUK Gateway to Research.:	This item has been internally reviewed, but not externally peer-reviewed.
NORA Subject Terms:	Earth Sciences
Date made live:	30 May 2023 08:58 +0 (UTC)
URI:	https://nora.nerc.ac.uk/id/eprint/534623

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