WC recently spent a few delightful days birding in Summer Lake Wildlife Refuge, in southcentral Oregon. Because it all starts with geology, WC will start there, too. Multiple geology theses, a few books and hundreds of geology papers have been written on Summer Lake and its ancestor, Chewaucan (chee-WAU-can) Lake. WC is necessarily going to…
Long-time readers know WC gets twitchy if there isn’t a geology post for a while. The geology and geomorphology of Florida, where WC was most recently, is frankly boring. Missouri, WC’s other recent destination, was all about the ages of layers and layers of limestone. Boring.1 So WC will reach back to his trips into…
Most readers know about the Yellowstone Mantle Plume, the “hot spot” that has given us the Yellowstone caldera and, not long ago in geologic time, some very scary eruptions. The mantle plume is the source of the heat that makes Yellowstone National Park what it is today. Research on the geologic history of the mantle…
The Hagerman Formation, a layer of sand and silt compressed to fragile sedimentary rock, is part of the larger Idaho Group. It’s world famous as the source of the Hagerman fossils. A large piece of the Formation is preserved as the Hagerman Fossil Beds National Monument, which has produced thousands of fossils across more than…
WC was able to challenge Geology 101 – 103 and so missed the introductory geology courses at the University of Oregon, derisively called “Rocks for Jocks.” “Challenge”? Maybe that’s no longer a thing. But back in the late Pliocene, when WC was an undergraduate, you could meet the course requirements of any entry level science…
The most powerful earthquake to strike Turkey in the last hundred years has caused incredible damage and loss of life in southern Turkey and Syria. It’s instructive to look at the underlying geology, because it has important lessons for folks living along the San Andreas Fault. The earthquake and aftershocks are along the East Anatolian…
You probably think of sand dunes as a desert phenomenon. But you can get sand dunes wherever you have (1) a decent supply of coarse-grained sand, (2) an area where there is enough topography to create a trap for the sand, and (3) relatively equal distribution of the winds, or at least no prevailing single…
About 56 million years ago, the Earth experienced something called the Paleocene-Eocene Thermal Maximum (PETM). The Earth’s atmosphere warmed by about 6.5° C, and sea surface temperatures by about 5° C. There was serious ocean acidification, which is associated with very high CO2 levels in the atmosphere. It’s too long after the Dinosaur Killer’s cataclysmic…
WC has read two lay geology books recently, and the contrast in their approaches to the rocky science is itself instructive. Both are fine examples of cogent, readable explanation of geology, in this case the geology of the Great Basin. The first is Frank DeCourten’s The Great Basin Seafloor, which is a geologic history of…
In the late 18th and early 19th Centuries, there was a mighty struggle in the nascent science of geology. Biblical literalism had insisted on a young earth, created less than 10,000 year earlier, and a literal, world-spanning Noachian flood. As the evidence for a much older earth accumulated, and the evidence against a global flood…
It was the second strongest earthquake WC has experienced. Only the Good Friday Earthquake in 1964 was stronger. But the November 3, 2002 Denali Fault Quake was M 7.9, and the epicenter, under Susitna Glacier, was only 82 miles from Fairbanks. It’s worth marking the anniversary, and noting what geologists have puzzled out about the…
In plate tectonics, a Triple Junction occurs where three tectonic plates, all moving in different directions, touch. For example, off the west coast of the United States is the Mendicino Triple Junction, where the San Andreas Fault, a strike-slip fault and transform plate boundary, separates the Pacific Plate and the North American Plate. To the north lies the Cascadia…
WARNING: Still more geeky geology ahead. And, WC acknowledges, some pretty serious oversimplifications of complex stuff. WC has written about seismic topography before, the evolving technology that uses the seismic waves from earthquakes to analyze subsurface geologic features. The technology has even been used on Mars to study xenogeology, albeit in a more simplified form.…
WARNING! Seriously geeky geology ahead. Most folks who were exposed to even a little bit of geology in school understand vaguely the idea of plate tectonics. They get the basic idea that big chunks of the surface of the earth are somehow moving around. But there are lots of non-obvious parts of the science of…
You won’t find Lime, Oregon on a map; at least not one published in the last forty years. Lime isn’t even a ghost town; it’s obliterated, along with the cement plant that was Lime’s reason for existence. Today, Lime is a wide spot in a side road off Interstate 84, not too far from Baker…
While the State of Idaho has many fine points, it does not have glaciers worthy of the name. It has had them in the past, and they did some dramatic alteration of the terrain, but those glaciers are long gone. While the ice may have all melted, the geologic signatures of glaciers are everywhere. Among…
The place name “Secesh,” including the lovely Secesh River in central Idaho, has a romantic, American Indian sound to it. Unfortunately, it’s short for “secessionist,” and a name given by refugees from the South in the American Civil War. The territorial history of Idaho reads as a struggle between Federal, pro-Union appointed officials and popularly…
On February 20, 1943, at about 4:00 PM local time, a Mexican corn farmer named Dionisio Pulido was clearing shrubbery in his fields when a large crack opened in the ground. Suddenly, the ground nearby swelled upward and formed a fissure between 2 and 2.5 meters across. Pulido reported that he heard hissing sounds, and…
Most of Alaska, like most Alaskans, originally came from somewhere else. John McPhee, Assembling California WC’s second year geology classes at the University of Oregon – prosaically enough, Geology 201, 202 and 203 – were taught mostly by visiting professors. The second quarter class focused on structural geology, a refreshing change after the tedious and…
“Thwaites,” in this instance, is Thwaites Glacier and Ice Shelf, located in Antarctica, west and a little south of the Antarctic Peninsula and Ellsworth Land, it dumps into the Amundsen Sea. “Ribbed” is, well we will get to that in a minute. Thwaites has gotten a lot of press. Rolling Stone, back in 2017, called…
The thing about landslides is that they move in slow motion until they don’t. WC has written earlier about the potential landslide-generated tsunami in Barry Arm. This is an update. Barry Arm is a glacial fjord in northwestern Prince William Sound, Alaska. The westerly wall of Barry Arm is badly fractured rock, hanging hundreds of…
There are so many mysteries about Lake Idaho. How did it last an incredible 7.8 million years? Where did it go? Why did it go? Geologists are slowly teasing out some of the answers, but as in the case of most good science, each answer just raises more questions. This is Part 2 of 2…
There are so many mysteries about Lake Idaho. How did it last an incredible 7.8 million years? Where did it go? Why did it go? Geologists are slowly teasing out some of the answers, but as in the case of most good science, each answer just raises more questions. This is Part 1 of 2…
While WC recently answered readers’ questions, in that effort WC held one question out to address is a separate blog post. You’ll see why. Why do you write about geology so often?When WC was in undergraduate school, in the late Pleistocene, he took a minor (sorry) in Geology. One of the classes was on plate…
It’s been weeks without a geology post. How did that happen? Some background. WC, semi-immobilized by a bad knee and huddled by his air-conditioning vent to escape the current heat wave, has been sorting through slides from the days before digital photography. A recent batch of scanned slides from WC’s 2002 trip to the Galápagos…
During the Pleistocene, as recently as 12,000 years ago, central Oregon had a number of large lakes. One of them, Fossil Lake, located in south-central Oregon, in northern Lek County, was, at peak, about 30 miles wide and perhaps 250 feet deep. It’s vanished now. The last two ponds evaporated about 1877. But during the…
7,700 years go, give or take 1.5%, the 12,000 foot high stratovolcano Mt. Mazama catastrophically erupted, blasting so much ash and molten rock from its magma chamber that the whole edifice collapsed, creating an oblong caldera six miles long on the longer axis, four and a half on the shorter one, and nearly a mile…
WC cautions readers that this post is mostly WC’s speculation, geology ex cathedra WC’s bellybutton, as it were. But it is at least slightly informed speculation. Let’s talk about stream courses in the Idaho Batholith. Anyone unfamiliar with Idaho who tries to trace the course of the Salmon River on a map will find the task immensely…
In principle, at least, the use of seismic – earthquake – waves to understand the interior of a planet is less complicated than it first seems. You’re probably familiar with bats’ use of echolocation to navigate the night skies: they emit high-pitched squeaks, and then use the reflections, the echoes, to navigate and find prey.…
It’s not a desert, although the area only gets about seven inches of precipitation a year, on average. It’s a playa, the dry bed of a former lake, and it’s about 8 miles wide and 70 miles long. The surface of the dry lake bottom is absolutely, unnervingly flat, and bare of any visible trace…
Wickersham's Conscience 
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