You Want Complex Geology?


WC has gotten complaints that geology is too complex. Piffle. Until now, WC hasn’t tackled complex geology. Nevada’s geology is notoriously, infamously complex. WC had a glimpse of that complexity in his recent hike in the Ruby Mountains in northeastern Nevada. While Idaho has some interesting geology, for the most part everything but the volcanism…

Geology Matters: Haiti and the Enriquillo Fault


WC gets a lot of blowback from readers on his geology posts. “Who care about rocks?” one reader wrote. Yet geology really, really matters, and WC will offer one case in point, from the island of Hispaniola,1 to illustrate his claim. Hispaniola, the island divided between the Dominican Republic on the east and Haiti on…

The Batholith Meets the Overthrust


WC and Mrs. WC recently concluded a trip into North Idaho, up the Lochsa River over Lolo Pass, then south down the Bitterroot River Valley and up over Lost Trail Pass. We explored part of East Idaho for a bit, and then headed west across southern Idaho with a delightful stop on the Little Wood…

Field Notes: Long Valley, Part 3


You’re right. There were only going to be two parts in this series. But Mrs. WC, an enthusiastic paddleboarder, brought back photos from parts of Sugarloaf Point that are only accessible by water. The geology she captured in those photos is so remarkable that it deserves a blog post. The thing to remember about the…

The Pillars of Rome


It’s just a little over-hyped. Rome, Oregon – a country store in southeastern Oregon – is probably best known as a launch point for raft trips down the main stem of the Owyhee River. The place was named by William F. Stine for the nearby hoodoo formations that suggested to him the ruins of Rome, Italy. It’s a…

The Evolving Understanding of the Yakutat Terrane


Long-time readers of this blog may recall that WC has written about the Yakutat Terrane before. The terrane, one of the smallish variety sometimes called a “microplate,” is the most recent terrane to plow into the southern belly of Alaska. It has been hugely influential on the climate, hydrography and topography of the 49th state.…

Oregon Coast Notebook: Melange


The Southern Oregon Coast geology is a distinctly different beast than its more northerly neighbor. The southern coast is dominated by the Franciscan Melange. It’s the detritus scraped off the top of the subducting Juan de Fuca and Pacific Plates. Geologists call it an accretionary wedge or prism. It’s not a good place to be…

Who Do Those Hoodoos Like You Do?


In another instance of abject failure of imagination, the State of Idaho has at least three different places called some variation of “City of Rocks.” WC had a chance to visit one of them recently, the Little City of Rocks, in the Bennett Mountains. It doesn’t look very much like a “city,” it’s not “little”…

WC Answers His Mail


WC will once again dive into the Wickersham’s Conscience email. Setting aside the Nigerian unclaimed fund scams (~ 15%), invitations from putative scantily clad or unclad young ladies (~18%), dubious queries from folks who think WC is still practicing law (~30%), links to known malware (~17%) and advertisements for sexual stimulants (~19%), we’re left with…

Notes on the Geology of the Alaska Peninsula


WC promised a more thorough discussion of the geology of the Alaska Peninsula in general and the Katmai National Park region in particular. The 15 or so volcanoes in the region – collectively, the Katmai Group – get all the attention, but mostly buried under all that volcanic debris, is some pretty interesting geology. As…

The Second Biggest Freshwater Lake


Most readers know the largest freshwater lake wholly within the United States is Lake Michigan. But the second largest lake? That’s more of a puzzler. It’s Lake Iliamna (Ill-EE-ahm-nah), in southwestern Alaska, at the base of the Alaska Peninsula. Here’s a brief overview of Alaska’s biggest lake. At just over 77 miles long and 25…

Seismic Tomography and the Mid-Atlantic Ridge


WARNING: Seriously geeky geology ahead. And serious simplification will occur. Geologists have attributed most tectonic plate movement to gravity pulling down the colder, denser slabs in subduction zones. The northwesterly movement of the Pacific Plate, for example, is attributed to cold, dense ocean bottom being pulled under the North American Plate at southern Alaska and…

Notes on the Yellowstone Hot spot


At least for those of us riding on the North American Plate, the Yellowstone Hot Spot rivals the Hawai’an Hotspot as the most famous of its kind. As North America has moved westwards, shoving itself over the Pacific Plate, the fixed point of the Yellowstone Hot Spot has left an extraordinary trail of volcanic activity…

Geology 101: Greenstone


Drop a large vase on a stone floor. It shatters, of course, pieces go everywhere. Now cover the fragments with 5,000 feet of layered sand, basalt, mud and gravel. Let it sit for 20 million years. Allow tectonic forces to then fault the mile-thick pile, shifting some it vertically and some of it horizontally. Allow…

Suspect Terranes


WC thinks it was John McPhee who first said, “Most of Alaska, like most Alaskans, originally came from somewhere else.” McPhee was cleverly making a geological point: Alaska is composed mostly of accreted chunks of real estate transported by plate tectonics and welded on to Alaska. Definition note: “Suspect terrane” is a mass of fault block…

Final Notes on the Colorado Plateau


This is a slightly different interpretive poster for the Colorado Plateau, which includes better discussion of the rock layers that compose the place. Please click on the image for a larger view. You should be able to read even the finest print. Use your browser’s Back button to return here. WC’s trip hastily visited only…

Cross-bedding Explained. Sort of.


One of WC’s readers recently asked for an explanation of cross-bedding. Although many of you have had enough geology posts already to last you into the new year, WC will offer another, because the explanation is pretty cool. Here’s a bit of cross-bedding photographed in a close-up, deep in Buckskin Gulch. The Navajo Sandstone formation…

Taking a Cedar Break


If the Colorado Plateau is a metaphoric layer cake (not a metamorphic layer cake; it’s all sedimentary; this is a geologist joke), Cedar Breaks is the icing on the top layer. Here’s a reminder. You can see the Cedar Breaks in the upper left, at a breathtaking 10,000 feet. It’s something to think about: Cedar…

Geology for Psychoanalysts: Kodachrome Basin


Sigmund Freud’s ideas about human psychological and sexual development are pretty much discredited now. But if they weren’t, and if you wanted a litmus test for whether someone has moved beyond Freud’s phallic stage, you’d send them to Kodachrome Basin and see how they reacted. The attraction of Kodachrome Basin and Utah’s state park are…

Enjoying the Slots: Buckskin Gulch


What’s probably the longest slot canyon in the world runs through the Coxcomb in Grand Staircase-Escante National Monument. A “slot canyon” is defined in geomorphology as “a long, narrow and deep channel or drainageway with sheer rock walls that are typically eroded into either sandstone or other sedimentary rock, with a slot canyon that has depth-to-width ratio that…