August 4, 2003
Entrance to the Delaware Mine tour
Delaware Mine dump
After leaving the Humboldt mine, I proceeded to the site of the next field trip, the Delaware mine. I hadn’t originally signed up for this one, since I had been there previously (in 1983). I had signed up for the Drexel mine, but the organizers had to make a last-minute change due to logging on the road to the Drexel.
The Delaware is one of the better-known mines in the area because of the commercial tours conducted at the mine site. There is a large sign on US 41 for the mine. After turning at the sign there is a bend in the road. A sign points straight ahead for the mine tour, and if you bear left, the mine dump is on the right, 0.3 miles from the highway. For reference, the GPS coordinates of the dump are lat. 47 deg. 25.408’, lon. –88 deg. 06.128’.
This dump is low and easy to climb on. It appears that the county highway department has been removing rock for road ballast. The picture above was taken the day after the field trip, after I bought a new camera. In the picture, the highway department was back to remove rock already.
At this mine, most of the crystallized copper is in vugs in prehnite. The prehnite is crystalline, forming radial groups. I also collected microcline, var. adularia in red-orange crystal groups and pumpellyite in radial groups and massive “greenstone”. Silver is also known from this mine, but I didn’t find any.
All in all, a worthwhile trip, but not as good as 20 years ago.