Geobulletin alpha

Imaggeo on Mondays: Half dome at sunset 

Yosemite’s Half Dome stands, majestic, over a granite dominated terrain in the Yosemite Valley area;  one of the most beautiful landscapes in northern America, and arguably, the world – it is also an Earth scientist’ playground. Stamped into the west slope of the Sierra Nevada range, the Yosemite Valley is a collection of lush forests, deep valleys, meandering rivers and streams, all punctuated by huge domes and cliffs of ancient volcanic origin. Come and explore this part of the [...]

Megastorms that throw boulders over cliffs 

This photo shows one of the mysterious boulders on the island of Eleuthera in the Bahamas  Charles Ommanney/The Washington PostRead more . . 

Imaggeo on Mondays: Giants Causeway 

Since its discovery back in the late 1600s the origin of the spectacular polygonal columns of the Giants Causeway, located on a headland along the northern coast of Ireland, has been heavily debated. Early theories for its origin ranged from being sculpted by men with picks and chisels, to the action of giants, through to the force of nature. It wasn’t until 1771 that Demarest, a Frenchman, suggested that the origin of the world-famous headland was indeed volcanic. “The myth goes that the [...]

Vagabonding on Dangerous Ground: Putting on a Happy Face at Dismal Nitch and Cape Disappointment 

Waikiki Beach at Cape Disappointment. Yes, the cliffs are basaltic like those in Hawaii, but the spot was named for a Hawaiian sailor who lost his life here in a shipwreck (one of many). How does a place get a name? Cape Disappointment and especially Dismal Nitch seem to just scream to tourists to "please visit us". Both sites sit on the north peninsula where the Columbia River reaches

Vagabonding on Dangerous Ground: Into the Land of Sand and Exploding Whales 

The Cascadia Subduction Zone has raised mountains. The entire length of the convergent boundary, from California to British Columbia is marked by incredibly rugged cliffs and steep, forest-covered topography. There aren't a lot of sandy stretches of coast in southern Oregon, the kind that folks from Florida, south Texas, or the Atlantic seaboard would recognize. But in the central part of

Geologic Map of the Kings Peak 7.5-Minute Quadrangle, Duchesne and Summit Counties, Utah 

By: Esther M. Kingsbury-Stewart, Paul K. Link, Carol M. Dehler, and Shannon L. Osterhout The Kings Peak 7.5-minute quadrangle straddles the crest of the Uinta Mountains in the High Uinta Wilderness Area and contains Kings Peak, Utah’s highest point. The peaks and cliffs are comprised of the newly formalized formations of the Neoproterozoic (late Precambrian)

Volute Gastropod Fossil 

This Volute gastropod fossil is on display at the Mesa Verde National Park as of August 2014. The area is rich in geological history going back 2 billion years. The national park was founded in 1906 to protect the Anasazi Native American sites found on the mesa tops, cliffs, and canyons. The exposed areas found in the park are from the Mesozoic Era, Cretaceous Period (about

Prionocyclus macombi Ammonite Fossil 

This Prionocyclus macombi (Meek, 1876) ammonite fossil is on display at the Mesa Verde National Park as of August 2014. The ammonite existed in the Late Cretaceous Period (Campanian). The area is rich in geological history going back 2 billion years. The national park was founded in 1906 to protect the Anasazi Native American sites found on the mesa tops, cliffs, and canyons. The exposed

Imaggeo on Mondays: Retreating Glacier 

The Svalbard archipelago is considered to be one of the best places to study the geological history of the Earth because its rocks represent every geological period. This image shows a view from the peak of Fugleberget (569 m a. s. l.; 77º 00’ N, 15º 30’ E) on the south-western coast of the island of Spitsbergen. Glaciation of this geologically diverse area gave rise to a variety of geomorphic features. The most prominent of them, depicted in the picture, is the Hornsund Fjord that cuts [...]

Endocostea simpsoni Clam Fossil from Colorado 

This Endocostea simpsoni inoceramid clam fossil is on display at the Mesa Verde National Park as of August 2014. The clam existed in the Late Cretaceous Period (Campanian). The area is rich in geological history going back 2 billion years. The national park was founded in 1906 to protect the Anasazi Native American sites found on the mesa tops, cliffs, and canyons. The exposed areas found

The Sierra Beyond Yosemite: Where the Sierra Ends (maybe), and Gold 

In some places it is pretty clear where the Sierra Nevada ends. For a hundred miles or more there is a solid rock wall that reaches a height of two miles in the Owens Valley. There is no mistaking that the mountains end at the cliffs above Lone Pine. Likewise, it's an unmistakeable demarcation between the flat Great Valley and the Sierra Nevada foothills as well. But in the central

Cliffs of the Ruby Mountains: Some Pretty Pictures 

And while we're waiting an even longer time for me to get around to posting about the nappe in Lamoille Canyon, here are a few of my favorite pretty pics taken from our campsite at Camp Lamoille in late September. I can say that a bit of the nappe can be seen in a few of these photos, if you know where to look! Cliffs (with sunset, first night) and the U-shaped valley of South Fork

If These Cliffs Could Talk: The Ah-wah-nee, To-tau-kon-nu'-la, and a Different History of the Sierra Nevada 

The first question might be "what is that?". It's a pair of climbers, Kevin Jorgeson and Tommy Caldwell, on El Capitan (To-tau-kon-nu'-la) in Yosemite Valley (Ah-wah-nee) who are seeking to do something never before done...a free climb of the one of the most difficult rock faces in the world. Free climbing means they do the climb with their hands and legs only, not using artificial

Cliffs of the Ruby Mountains: More Views from the Hanging Valley Pullout 

While I'm gradually working my way toward posting a bit about the nappe in Lamoille Canyon, let's take a quick look at more views of the cliffs from the hanging valley pullout. A shadowed view of the cliffs to the northwest. Stunning! A view of the cliffs to the southeast. When I took this photo, it looked like I could see a recumbent fold in the upper cliffs. I'm not sure that there

If These Cliffs Could Talk: The Cliffs of the Ah-wah-nee that Never Got Legends 

Do you know these places? Would a place that has cliffs like these merit being declared a national park? Thankfully, these rocky precipices are in a national park already. But these are not the iconic features that end up in the photo collections of the millions of tourists that visit this place every year. But these cliffs contribute to the awesome scenery by serving as the backdrop

First Field Trip 

We have returned from a 9-day trip out to a few different field camps. We were finally able to start collecting our soil samples!The first place we went is called Mars Oasis. To get there, we flew on a Twin Otter airplane that landed on Utopia Glacier. We camped on the glacier for 6 days. Here’s a picture of the glacier that we landed and camped on. We set up our camp near the dark spots towards the back, where the plane had enough space to land and there were no known crevasses.We skied from [...]

If These Cliffs Could Talk: Wa-ha'-ka, the Three Brothers Who Are All Out of Joint 

Actually the Three Brothers are just full of joints, and that's the problem. If any legends exist concerning the rocks known as the Three Brothers in Yosemite Valley, they have not come to me via the anthropologists or the internet. The rocks seem have been called Wa-ha'-ka, Wawhawke, or Kom-po-pai-zes, with meanings that include leaping frogs, couples enjoying each other (to use

If These Cliffs Could Talk: Tis-sa-ack and Tu-tok-a-nu-la (A Geologic Love Story) 

Tis-sa-ack (Half Dome) from near Yosemite Falls A love story... Unnumbered snows have come and gone since The Great Spirit led a band of his favorite children into the mountains, and bade them rest in this beautiful Valley of Ah-wah-nee. They were weary and footsore, and were glad to rest after their long journey. Here they found food in abundance. The streams held swarms of

If These Cliffs Could Talk: A Sentinel People Sometimes Miss in Yosemite 

If you saw this picture out of context, perhaps in the opening frames of an adventure movie, you might think of this cliff as being an otherworldly precipice full of allure and mystery. Maybe dragons perch on its summit, maybe buried treasure lies in a cave at its base. It's an incredible rock tower. To back up and look at this cloud filled world from a distance takes away none of

The Hazards of Field Work: Distraction by Cuteness 

Okay, maybe this one wasn't cute... The perils of teaching in the field are paramount and legion: attacks by killer bees, mosquito bites, falling off cliffs, sunburn, and multitudes of other hazards. But there is something visceral with coming face to face with an animal that is capable of killing you with a swat of its claw. But it wasn't likely to be one of these fine creatures. According