A very old copper mine worked since at least the sixteenth century and located on the west back of the river Tamar around the town of Gunnislake, and largely responsible for the subsidence problems this town has had for many years with shafts and gunnises (from which the town gets its name) opening up without warning from the old workings.
This adit is notable for high levels of radioactivity as well as the attractive copper staining.
HISTORY
Plagiarized from the Minedat website:
This site was right in the middle of Gunnislake village and famed for the diversity of its minerals. The site was cleared and built on in the late 1970s early 1980s. An adit level is driven from the river bank, initially in the killas heading slightly north of due west following the copper lode evidence of which is clear in the site photos. Copper mineralisation apparently stops well short of the granite killas boundary and the drive further into the granite is also barren. About 20 yards from the boundary the adit turns sharply to almost due north. The granite-killas boundary marks the re-appearance of the main lode which has been exploited to the west. This initially follows the contact but then drives into the granite. Along the drive of the original adit a second mineral vein appears about 10 yards into the granite but this has only been exploited for about 20 yards to the west.
On the main drive to the west the mineralisation quickly ends and there is then another patch of barren ground before the lode reappears, heaved slightly to the north. Here the lode is very rich in copper as well as dark purple fluorite with lenses of arsenopyrite. Wolframite appears here as blades up to 2 inches long as pegmatites in quartz. The only stoping on this adit level is at the far end of the drive where the lode is most extensive. There is then a short brick tunnel, blocked at the far end, which gave access to one of the 2 shafts which reached this level. At this point there is also a flooded winze to a lower level. The adit is quite radioactive, counts rising to about 100/ second within 50 yards of the portal and remaining so throughout the works except in the barren ground on the main drive to the west where counts in excess of 200/ second prevail. However, no localisations of radioactive sources were detected throughout the workings.
REPORT
1. The entrance is just above the River Tamar.
2. Just inside the entrance, we can see many Cave Spider (Meta menardi) cocoons. Each cocoon is about 2-3cm in length and contains about 200/300 eggs. The cocoon is laid at the end of summer and after hatching, the spiderlings will remain in the cocoon until the first molt, feeding on the yolk. They leave the cocoon in spring.
3. The mine is flooded to about knee height. On the walls are brilliant blue copper deposits.
4. I did ask my son to pose, but the little sod wouldn't stay still and he poses as if going to the toilet. (before anyone calls the NSPCC I didn't know at the time that the mine was radioactive)
5. Entering deeper into the mine.
5. The water disappears with a barren section lacking mineralization.
6. Tide marks on the walls where the mine has flooded.
7. The flooded stope.
8. Nearing the furthest point in (about 400m in)
9.
10.
11. The tidemark reappears
12. The end point, marked by a small bricked archway.
Thanks for reading.
This adit is notable for high levels of radioactivity as well as the attractive copper staining.
HISTORY
Plagiarized from the Minedat website:
This site was right in the middle of Gunnislake village and famed for the diversity of its minerals. The site was cleared and built on in the late 1970s early 1980s. An adit level is driven from the river bank, initially in the killas heading slightly north of due west following the copper lode evidence of which is clear in the site photos. Copper mineralisation apparently stops well short of the granite killas boundary and the drive further into the granite is also barren. About 20 yards from the boundary the adit turns sharply to almost due north. The granite-killas boundary marks the re-appearance of the main lode which has been exploited to the west. This initially follows the contact but then drives into the granite. Along the drive of the original adit a second mineral vein appears about 10 yards into the granite but this has only been exploited for about 20 yards to the west.
On the main drive to the west the mineralisation quickly ends and there is then another patch of barren ground before the lode reappears, heaved slightly to the north. Here the lode is very rich in copper as well as dark purple fluorite with lenses of arsenopyrite. Wolframite appears here as blades up to 2 inches long as pegmatites in quartz. The only stoping on this adit level is at the far end of the drive where the lode is most extensive. There is then a short brick tunnel, blocked at the far end, which gave access to one of the 2 shafts which reached this level. At this point there is also a flooded winze to a lower level. The adit is quite radioactive, counts rising to about 100/ second within 50 yards of the portal and remaining so throughout the works except in the barren ground on the main drive to the west where counts in excess of 200/ second prevail. However, no localisations of radioactive sources were detected throughout the workings.
REPORT
1. The entrance is just above the River Tamar.
2. Just inside the entrance, we can see many Cave Spider (Meta menardi) cocoons. Each cocoon is about 2-3cm in length and contains about 200/300 eggs. The cocoon is laid at the end of summer and after hatching, the spiderlings will remain in the cocoon until the first molt, feeding on the yolk. They leave the cocoon in spring.
3. The mine is flooded to about knee height. On the walls are brilliant blue copper deposits.
4. I did ask my son to pose, but the little sod wouldn't stay still and he poses as if going to the toilet. (before anyone calls the NSPCC I didn't know at the time that the mine was radioactive)
5. Entering deeper into the mine.
5. The water disappears with a barren section lacking mineralization.
6. Tide marks on the walls where the mine has flooded.
7. The flooded stope.
8. Nearing the furthest point in (about 400m in)
9.
10.
11. The tidemark reappears
12. The end point, marked by a small bricked archway.
Thanks for reading.
