Grampian Project
Exploration Targets near Cononish
The most favoured structures for gold mineralisation in the Cononish area are the east northeasterly-trending quartz veins including the Cononish vein itself, Coire na Sionnach, Garbh Choirean, and Beinn Dubh, together with several elongate geochemical soil anomalies including Anomaly B. Together these veins and elongate anomalies form a swarm of parallel structures and are interpreted to be of the same age. In brief the exploration targets associated with these structures and anomalies are:
Map 3 — Click to enlarge
- Cononish Deeps- mineralisation at Cononish is open at depth. Potential to significantly increase the extent of the presently known mineralisation at Cononish by deeper drilling.
- Anomaly B– displaced structure; deep overburden geochemical gold anomaly coincident with a VLF-EM anomaly; sample of ‘A mineralisation’ float assayed 8.72 g/t gold in this area. An important target for the discovery of additional gold mineralisation close to Cononish.
- Coire Na Sionnach- rock chip samples with values up to 6 g/t gold; best two trenches: 5.0m @ 3.6 g/t gold, 8.6 g/t silver and 6.0m @ 3.5 g/t gold, 12.1 g/t silver. Ready for immediate drill testing and is regarded as a high priority target.
- Bein Dubh Vein– an offset quartz vein in which a rock chip assayed more than 20g/t gold. To be tested by more extensive rock chip sampling.
- Garbh Choirean Vein- parallel to the Cononish and Coire na Sionnach Veins; only partially tested. To be tested by additional sampling.
- Deep Overburden Gold Anomalies- anomalies B, G, J, K, and L in the vicinity of the Cononish deposit are elongate and sub-parallel to the mineralised quartz veins and may reflect presence of underlying auriferous quartz veins. Represent targets for further investigation.
Exploration Targets elsewhere in the Tyndrum Mineral Field
The entire Crown Licence area currently held by Scotgold has been previously sampled by the BGS as part of a nationwide program of stream sediment sampling which commenced in 1969. The samples were assayed for a wide range of elements and the data is available as regional atlases showing areas of geochemical anomalism.
In 1989 Canadian consulting group Watts, Griffis and McOuat (WGM) carried out nondestructive neutron activation analysis of 2260 BGS samples covering much of Scotgold’s licence areas for a total of 27 elements per sample. This geochemical data, combined with their own, enabled WGM to identify five anomalous areas and eleven regional exploration targets, many of which appear to be related to northeast-southwest trending structures.
In addition:
- The geological setting around Aberfeldy has been compared to that of the giant Hemlo gold deposit in Canada, which was discovered in 1981.
- Researchers have also suggested that the Middle Dalradian with its extensive stratigraphic Pyritic Zone, high level igneous intrusives, widespread sericite alteration, and major structures, could be a good regional target for stratabound gold mineralisation.
- The Dalradian is acknowledged as a Sedex/volcanogenic-hosted massive sulphide (VMS) environment with a series of second– and third-order sedimentary basins.
Initially the Company intends to focus its exploration effort in areas of high immediate promise such as Cononish and Glen Fyne, but a systematic review of the literature and other databases combined with some field work will be used to progressively identify other targets in the Tyndrum-Pitlochry section of the Dalradian metamorphic belt.
Many other promising prospects which occur within a few kilometres of Cononish are comprehensively documented in Scotgold’s newly-acquired database. These prospects could provide additional mineralisation to supplement any future gold mining operation at Cononish itself. Several of these are advanced prospects which will be explored as a priority. In brief the targets are:
- Tom A Chro–Exceptionally high gold and high silver values were obtained from rock chip sampling at Tom a Chro in 1985 by Fynegold Exploration Ltd. The highest gold value of 257 g/t gold was a rock chip from an in situ vein but most of the anomalous samples were boulders of uncertain provenance. The prospect is on the north-facing slope of Ben Udlaidh and some downhill migration of the boulders may have occurred. The auriferous boulders occur within an area measuring approximately 750m by 250m with the long axis oriented downslope.
Table 2: Results of rock chip sampling, Tom a Chro, 1985
Sample number Type of sample Gold (g/t) Silver (g/t) 6951 Boulder 175 71.5 11176 Rock chip from vein 257 118 6952 Boulder 65.4 30 5872 Boulder 86.1 23.3 5857 Boulder 133.7 56.3 5871 Boulder 25.4 0 5859 Boulder 2.4 1.1 18823 Stream sediment 19.9 N/A As part of Scotgold Resources’ review of the extensive database acquired from Fynegold, The Company has now located and processed the results of two soil sampling surveys carried out at Tom a Chro in 1986.
Map 4 — Click to enlarge
In the first survey, soil samples were obtained along five grid lines in the vicinity of the boulders, using a power auger to reach or approach the soil/bedrock interface. The 100ppb gold contour delineates several sub-parallel zones of gold anomalism over a distance of over 600 metres, with a maximum gold value of 2.38 g/t gold. Due to the limited extent of the auger sampling grid the anomalous zones remain open in three directions.
The results of the first survey indicate that the bedrock is anomalous in the immediate vicinity of the surface boulders and these highly-anomalous boulders may therefore relate to the underlying rocks.
The second soil survey was made by taking samples near the surface and was part of a regional soil sampling program along single geographic contours (‘contour sampling’), in this case the 250m contour.
In the second (shallow) soil survey, gold values above an arbitrary cut-off of 50ppb delineate two elongate anomalous zones extending over hundreds of metres in the vicinity of Tom a Chro. These results must be interpreted with caution, particularly the shape and extent of the anomalies, as there is limited information outside the sampled contour.
Map 5 — Click to enlarge
The shallow soil contour anomalies overlap the deep soil auger anomalies but have a considerably longer strike length. Together the two sets of soil data suggest a 2km-long mineralised structure trending NE-SW, parallel to the mineralised vein which hosts the Cononish deposit located about 7 km to the south.
This information considerably upgrades the importance of Tom a Chro. The prospect is now ready for immediate drill testing and it is planned to do this as soon as land access and planning permission (if necessary) are secured.
- Beinn Udlaidh – an auriferous quartz vein sub-parallel to the Cononish Vein which intersects different rocks to those that host Cononish; initial trenching yielded 10.27 g/t gold and 241 g/t silver over 2.3m within a hematitically-altered gossanous quartz vein; eleven holes drilled gave a best result of 4m @ 1.1 g/t gold and 58.4 g/t silver at a depth of 35m; low grades ascribed to extensive and deep weathering of the rock accompanied by hematisation of the quartz. The ENE trend of the vein at Beinn Udlaidh, its pink coloration and the widespread gold anomalies from surface sampling and from drilling suggest that further drilling should be carried out at this locality.
Regional Exploration Targets
Map 6 — Click to enlarge
Map 7 — Click to enlarge
Through its acquisition of Fynegold, Scotgold Resources now has a comprehensive database of information covering a large region of the SW Grampian Highlands and includes soil sampling, rock chip sampling, deep overburden sampling, stream sediment sampling (including the collection of panned concentrates), and geophysical surveys including VLF-EM, gravity and aeromagnetic surveys. The database reveals many specific prospects on the basis of anomalous geochemistry, geophysics and geological setting and many of these merit immediate follow up.
The highest priority for exploration will be given to the outstanding series of prospects within the Tyndrum Fault Zone in Glen Fyne. Within Glen Fyne, which lies along the southern extension of the Tyndrum Fault, a linear zone of exploration potential has been identified. In this narrow valley the Tyndrum Fault intersects Green Beds of the Southern Highland Group and Ardrishaig Phyllite of the Appin Group near their contact with a granodiorite intrusion of Caledonian age. Here the Tyndrum Fault has produced a tectonic corridor in which all of these rock types are commonly strongly sheared, altered and pyritic, and contain extensive linear zones of elevated gold values. This structural corridor within the Tyndrum Fault Zone in Glen Fyne is considered to have exceptional exploration merit.
An elongate zone of geochemical anomalism parallel to the axis of Glen Fyne was first recognised from BGS stream sediment sampling, based on Cu, Pb and Zn assays. Subsequent regional rock chip sampling in this area for gold outlined a comparable elongate zone approximately 4.5km long on the basis of gold values exceeding 200 ppb gold (0.2 g/t gold). The highest value in this survey was 1.08 g/t gold and silver values were generally low.
The key exploration targets are at Inverchorachan and Tom an Biorach:
- Inverchorachan–
initial rock chip sampling program included one 500g grab sample which assayed 277,000 ppb (277 g/t gold) and a 2kg composite chip sample which assayed 9.4 g/t gold, plus numerous other high gold assays. Subsequent rock chip and deep soil sampling programs identified an anomalous zone about 500m long and 50m wide oriented approximately northeast-southwest. Four trenches excavated within anomalous zone were highly anomalous in gold; one metre panel sampling along one trench (about 35m long) gave exceptionally consistent gold grades, with 85% of samples in the range 1 to 6 g/t gold. Detailed geological mapping and sampling indicates that several rock types here contain gold, pointing to lode-style mineralization within a wide shear zone in contrast to gold mineralization confined to a discrete quartz vein as at Cononish. The 500m long anomalous zone at Inverchorachan is ready to drill and is a high priority drilling target. - Tom An Biorach–
a deep soil anomaly defined by the 25 ppb gold contour occurs as an elongate zone of gold anomalism nearly 500m long approximately co-linear with Inverchorachan; best trench sampling results were 6m averaging 1.14 g/t gold, with the mineralization occurring within chloritic-altered quartzite and Green Beds containing abundant pyrite estimated at up to 30%. This well-defined anomaly at Tom An Biorach is ready for drill testing and the target zone is similar in size to Inverchorachan.
Other Regional Targets
The entire Crown Licence area currently held by Scotgold has been previously sampled by the BGS as part of a nationwide program of stream sediment sampling which commenced in 1969. The samples were assayed for a wide range of elements and the data is available as regional atlases showing areas of geochemical anomalism.
In 1989 Canadian consulting group Watts, Griffis and McOuat (WGM) carried out nondestructive neutron activation analysis of 2260 BGS samples covering much of Scotgold’s licence areas for a total of 27 elements per sample. This geochemical data, combined with their own, enabled WGM to identify five anomalous areas and eleven regional exploration targets, many of which appear to be related to northeast-southwest trending structures.
In addition:
- The geological setting around Aberfeldy has been compared to that of the giant Hemlo gold deposit in Canada, which was discovered in 1981.
- Researchers have also suggested that the Middle Dalradian with its extensive stratigraphic Pyritic Zone, high level igneous intrusives, widespread sericite alteration, and major structures, could be a good regional target for stratabound gold mineralisation.
- The Dalradian is acknowledged as a Sedex/volcanogenic-hosted massive sulphide (VMS) environment with a series of second– and third-order sedimentary basins.
Initially the Company intends to focus its exploration effort in areas of high immediate promise such as Cononish and Glen Fyne, but a systematic review of the literature and other databases combined with some field work will be used to progressively identify other targets in the Tyndrum-Pitlochry section of the Dalradian metamorphic belt.