Sunday, July 11, 2010

Lunchtime Trip Underground


Rob Harris had permission to visit the Old Lead Mine inside the Raleigh Beltline. He hadn't been there since he was a little boy, but he was curious to visit again. We walked the short distance from his friends' driveway to a cool entrance on July 10, 2010.


The entrance is a few feet high and sloped down toward a shallow pool about ten feet in.


The ceiling got higher as we proceeded up the next slope, and the passage maintained its six-foot width despite small breakdown pieces along the way. Sixty feet from the entrance a very large breakdown slab covers the floor. Just beyond that a two-foot deep pool marks the back of the mine.

Rob and I surveyed and photographed the mine passage. While I was finishing the sketches, Rob investigated the rock to better understand the graphite mining.
Because all the soft walls appeared white and schist-like with quartz intrusions, we couldn't understand where the graphite was. However, stains on my hands indicated that we had indeed found the graphite. It's just a few percent of the rock. I was fortunate to find online the 1947 article "The Origin and Importance of the Raleigh Graphite" by John W. Harrington.

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