Friday folds: the Poleta folds

In the White Mountains of eastern California, just west of the Deep Springs Basin (site of my coldest camping experience ever, followed by a memorable morning walk in the playa and discovery of a bat mummified by salt), there lies a classic field mapping location, the Poleta folds. Here’s what it looks like from Google … Read more

Skolithos in the sun

Today, I share with you eight images that I took yesterday on Skyline Drive in Shenandoah National Park: Blocks of Antietam Formation quartzite (meta-quartz sandstone) of Cambrian age, used in the low rock walls of an overlook parking pull-out. They all bear lovely Skolithos trace fossils (seen end-on, and in cross-section):

Friday fold: cleaved slate in Kootenay National Park

This summer, a week or two after our wedding, my wife and I found ourselves in the Canadian Rockies for a pre-honeymoon. Part of our time was spent on a backpacking trip to Floe Lake in Kootenay National Park, British Columbia. On our hike in, we passed this outcrop of Chancellor Slate, a Cambrian aged … Read more

Cross-bedding in Flathead Sandstone, Wind River Canyon

This is a boulder of Cambrian-aged Flathead Sandstone, the unit overlying the Great Unconformity exposed in Wind River Canyon, Wyoming. Click to make it 5000 pixels wide. Swiss Army knife for scale. It shows a lovely example of multiple upside-down cross-beds. It also shows a heavy layer of caliche on what is (now) the upper … Read more

Friday fold: One from Walcott

My man Walcott contributed a lot of images to the USGS stockpile during his travels. Today, I’ll feature one from Bishop, California, from 1894: Got it from here. Rock hammer on the left for scale. The caption reads: Plicated layers of thin bedded chert in limestone etched by erosion, Lower Cambrian (?). Hill two miles … Read more

Tumbling Run: New Market/Lincolnshire contact

Here’s a gigapan I shot yesterday, looking north at the contact between the New Market and Lincolnshire Formations at the classic “Tumbling Run” outcrop south of Strasburg, Virginia: [gigapan id=”78234″] See if you can find the E. coli plush toy I included, or the cm-scale pencil! As usual, you can see it full screen, by … Read more

Champlain thrust fault

Over the summer, I went up to Vermont to visit my friends the Clearys. Joe Cleary is a college friend and a talented luthier. He and his wife Tree and their children Jasper and Juniper have settled in Burlington, a lively town with a lot of cool stuff going on. Joe took time out one … Read more