The volcanic west

Volcanic rock formations at Jump creek, Idaho

I noticed how much the whole region of southeastern Oregon, northeast Nevada, and southwest Idaho have the same topography and geology. Its all volcanic. This region is famous for quite a few gemstone localities such as Succor creek geodes and thunder eggs, Bruneau jasper, and several other well known localities. The country rock is mostly basalt grading into rhyolite and other volcanic's. It is believed that the rock that forms the Treasure valley where Caldwell, Nampa and Boise are situated formed under an inland sea. The geologists have found formations similar to those found under the Pacific ocean. In my wanderings I have found a few rocks that would perform admirably as tools. There is a dense form of basalt, no bubbles as is typical, that knapp's out just fine. I'm sure there are some local artifacts made from the same stuff. Of course, where there is any kind of volcanic rock there is bound to be some silica minerals (quartz mainly) that form in the vesicles (bubbles). This would be premier knapping material. I saw a collection that has several local pieces that are made from quartz family rock and even some obsidian. I don't know where the closest obsidian outcrop is but it was considered primo stuff and was carried very far to trade and work. I'll definitely be keeping my eyes open and report and new finds or discoveries. I hope to find some good knapping material. Mine is all gone. Take care everyone!!