I'm already at the national GSA Meeting in Portland, but I took my time getting here, four days to be precise. Here are a few highlights from travel day two.
The lighting was great between Susanville and Klamath Falls. Here, I'm dropping into a Basin and Range valley, the valley that's home to Eagle Lake (MSRMaps link). Eagle Lake, which is reported to be a closed basin with no hydrologic outlet, is shown as being either in or out of the Great Basin, depending on whose map you use. Eagle Lake was not connected to Pleistocene Lake Lahontan.
Eagle Lake (Google Maps link), looking almost west, from Highway 139.
This is a basalt dike on the east side of Highway 139, just south of Lassen County Milepost 52 (Google Maps location), and just before you get to the Willow Creek Campground if you're driving north.
The columnar jointing in the dike is nearly horizontal, making the rock look like a bunch of stacked logs.
Looking end-on at the pile of stacked logs, the cross-section through the stacked columns shows the typical though irregular polygonal shapes common to basalt columns. Kim posted about another dike with horizontal columnar joints earlier this year, and Andrew's article on basalt columns has a great photo of a piece of basalt with an almost perfect hexagonal shape. It seems like I've seen another post more recently on columnar jointing, but I'm not finding it right now.
Closer to my KFalls destination, it started raining, but without the intensity of the previous day.
And then there was the IPA awaiting me at The Creamery Brew Pub & Grill . . .