Friday, April 9, 2010

Kentucky Agate Hunting

I arrived back home on Wednesday from the Ohio and Kentucky rockhounding trip. All in all I drove just short of 2,000 miles. I was 40 miles from home when I had my third flat tire of the year. Starting with this new tire, from now on I am buying the 10 ply tires to minimize the chance for flats.

It was a great trip, especially since I learned a lot about Kentucky agates. Melina Hardy took us out in the Middle Forks River area on Easter Sunday, since her husband, Scott, had to work. I have never worn fishing waders before, so it was an adventure. The river was deep in many spots, which required us to climb up and down banks to portage around. The current was also faster than I expected.

I have not had a chance to cut open any of the 50 pounds of rocks I collected. What was interesting is that the Hardy's collect by sound. You use a rock hammer or other steel tool to bang on the rocks. The silica rocks have a higher pitch sound than the other river rocks.

The river is lined with steep banks and cliffs. The top layers are sandstone that overlie limestone, shale, and slate. Apparently the agate nodules formed in the shale layers. Because of the steep terrain, when it rains the river rises as much as 15 feet, which washes the nodules out of the shale layers.

The color of the river is amazing -- a lot like the turquoise color of the river that runs through Supai in the Grand Canyon. Below is a shot of the river as well as a couple of Melinda and friends Gerald and Jill Phillips.

Scott has sold off most of his collection, but he had a few specimens still available for sale. Here are shots of specimens that I purchased. These first three agates have dual chambers, which indicate a more complex agate genesis than I expected.

Some people have speculated that Kentucky agates form from silica gels. The following specimen has stalactite formations in a geode center. This particular agate formed at least in a fluid environment, which facilitated the stalactite growth.

This last specimen is a fantastic example of Kentucky agate that Scott generously donated to the museum.

1 comment:

  1. I just started looking for agates two days ago, and I am completely hooked. I collected about a dozen or so. Two of which are as big as a large pumpkin. I cannot wait to slice into them. I am searching in a creek that runs into the Kentucky River in Clark County (near Ft. Boonesborough).