Lidar hillshade image. Giant current ripples atop a terrace surface near Omak, WA. Hwy 97 is at the center of the image. The ripple field is located on the second-highest terrace surface and is truncated on its east side by the next-lower surface. The south end of the ripple field, mostly off the image, appears partially buried by windblown sediment, likely post-glacial loess and dune sand. I discovered these giant current ripples in 2019 and emailed this image out to folks I

Geologists have long been fascinated with the high terrace that stands well above the modern Columbia River between Brewster and Chelan. Its origin, composition, extent, and connection to other flights of terraces in the region (i.e., Okanogan Valley) is still a topic of debate. To my knowledge, no one has compiled what is written about The Great Terrace in one place. So I'll do it here. In this post I compile mentions in the historical record of terraces along the Columbia R

A robust association between thick calcretes (petrocalcic horizons) and lowland alluvial deposits is a key finding of my recent work in south-central Washington. This association is hardly mentioned in previous articles that address calcretes in this region. Calcretes that post-date the Ringold Formation formed in a lowland, basinal setting near a shallow water table or in gently-sloping alluvial fan gravels on the flanks of Yakima Fold Belt ridges. This is a view looking eas

Lake Rufus Woods is a 50-mile long reservoir formed by Chief Joseph Dam. The reservoir extends from Bridgeport to Grand Coulee, WA. Access the lake by boat or via short hikes from Hwy 155/Columbia River Rd (Colville Indian Reservation land), or via gravel roads leading north from Hwy 174 (Strahl Canyon Rd). Excellent golfing can be had at nearby Gamble Sands, designed by David McClay Kidd and ranked #1 Best Course in Washington by Golf Magazine in 2021. Geology exposed in sho

Brown soil wedges follow polygonal crack networks in fine grained sediment (lakebeds) south of Browning, MT. The features formed during the Pleistocene in a periglacial region mapped by Murton (2020) and French (2017). Periglacial wedges are reported in the Lemhi Range of Idaho (Butler, 1984), the Owl Cave-Wasden Site on the Snake River Plain (Dort, 1968; Butler, 1969), Glacial Lake Missoula basin in western Montana (Chambers, 1984; Chambers and Curry, 1989; Levish, 1997; Han