29 January 2013

Trona Pinnacles, California

Posted by Callan

South of Searles Lake is a distinctive landform: the Trona Pinnacles. This multi-image photomosaic is too small for GigaPan, but I’ve made a medium-sized version of it that can be hosted here. You’re going to have to click through to see it large, though.

Click to enlarge

These are tufa towers (like we saw at Mono Lake), all in a cluster. If you view it from above, you can see that they are arranged in many places where multiple towers appear in a line. This linear arrangement bespeaks a network of fractures in the ground below, through with the calcium carbonate-bearing solution flowed, and emerged, presumably, at the bottom of a larger version of Searles Lake, precipitating the tufa over time. The fracture orientation is more or less the same as the basins and ranges of the surrounding landscape, which is a nice demonstration of Pumpelly’s Rule (structural orientations are scale independent):

Click to enlarge

As the climate in this area dried out, Searles Lake shrank (and got saltier!) and the tufa towers of the Trona Pinnacles were exposed in the open air, where we can see and wonder about them.