Greenland, Ontonagon Co., MI

August 5, 2003



Knowlton Mine dump


On Tuesday morning I had no trip scheduled, so I went to the Wal-Mart in Houghton and bought a new digital camera. We also had to make a trip to Chassell to try to get Barbís sewing/embroidery machine repaired. We didnít have much luck on that score, though. The dealer couldnít get the required parts before we would head home.

On Tuesday afternoon I headed south into Ontonagon County for the Knowlton mine. Itís located on the left side of the road to the Caledonia mine, about 1.1 miles from the start of Caledonia Road. It may not be accessible at all times, since there was a large boulder blocking the access trail two days after this trip. GPS coordinates are Lat. 46 deg. 45.275í, Lon. Ė89 deg. 06.902í.

This is a fairly small dump, and one I had never heard of before. The material I collected didnít look very promising when I picked it up, but after getting it home it was very interesting. Most of the vugs are filled with calcite, and after dissolving the calcite with hydrochloric acid (diluted about 1:1) and rinsing thoroughly, the material was spectacular. Vugs lined with microcline (var. adularia) also had epidote crystals and pumpellyite fibers on top of the microcline. This makes very attractive micromounts. The microcline is red, and the yellow-green epidote and pale green pumpellyite really stand out. I also found white saponite in balls of platy crystals in some of these vugs. There are also vugs lined with prehnite that has copper crystals on it. This material was a very pleasant surprise.


On to the next field trip, the Central Mine


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