So, What's Been Happening in the World? And Why is it always Florida?

Sort of like Lois Lane in Superman II, after she had her memory wiped by the Man of Steel, I re-enter the world after five days in the wilds of Death Valley blissfully ignorant of world news (the picture above is from deep in Titus Canyon; you must see this place!). I go on the internets and find that there have been elections and primaries, $100/barrel oil prices, earthquakes, and Florida education officials thinking they are cute by linking the word "theory" with the word "evolution" (as was pointed out in Princess Bride..."You keep using that word. I do not think it means what you think it means. "). Check out some of the updates on this issue at http://www.flascience.org/wp/.

The contributors at the Panda's Thumb (http://pandasthumb.org/) have been on top of the Florida evolution controversy. On the one hand, the state education standards for the first time include the words "theory of evolution", instead of the timid "change over time". This could be considered a victory of sorts, except that as always there is a huge difference in what "theory" means to scientists, and what it means to laypeople. Evolution is indeed a theory, in that it has been confirmed by loads of evidence, it explains the origin of many diverse phenomena, and competing hypotheses have fallen by the wayside over the last century or two. On the other hand, when I ask students to use the word "theory" in a sentence, I tend to get "We don't have to believe that, it's just a theory".

You can be sure that this perception will exploited by the creation-science crowd. We have a great deal of educating to do....

Death Valley - A land of many treasures

And very few of the treasures are of the monetary kind. Mosaic Canyon, at the north end of the Panamint Mountains is a treasure trove of learning opportunities at all levels. In the picture above, students witnessed a rare sight of flowing water in a desert wash (after an overnight soaking in our campsite; no one really cared, it was the last day). We could watch the pebbles rolling down the channel, and it was easy to imagine one of the large flash floods that have carved the intricate narrows just upstream.

The canyon walls are adorned with the "mosaics", chunks of yellow dolomite marble that were once cobbles in the stream bed. They were later cemented, and then eroded by later floods. Understanding their origin was the goal of the student projects while they wandered up-canyon.

The canyon lies at the edge of a metamorphic core complex, Tucki Mountain, and numerous faults are visible on the walk up the canyon, including one of the sweetest pictures of a normal fault one could ask for.

The yellowish rock forming the canyon wall is the late Proterozoic Noonday Dolomite, a carbonate shelf deposit recording the subsidence of the recently rifted passive margin of the western edge of North America. At first glance, the rocks appear simply tilted, but closer observation reveals complex folding patterns.

When the Tule Fog gets you down....

The Central Valley of California is not one of the grandest places to be in the world in February, although I am sure that my friends in snow country might disagree, but frankly, it's not very long before the fruit trees bloom, pollen fills the air, and my hay fever goes hypercritical. When this all happens, I realize I have to get out of town. So...I am dragging 15 or 20 students out of the classroom, and we are headed to Death Valley for a long weekend!

There is no place in the world quite like DV...the oldest rocks in California, evidence of the Proterozoic snowball earth, 36,000 feet of Proterozoic and Paleozoic sedimentary rocks, detachment faults, strike-slip faults, turtleback faults, thrust faults, a two mile deep fault graben, the hottest and driest place in North America, the lowest place in North America, four species of fish (?!), and that is only scratching the surface.

Blogging will be slow for a few days...they haven't installed wi-fi in the campgrounds just yet...

Picture of the Day - The Airliner Chronicles

Continuing a very short series on the Channeled Scablands, this photograph shows several isolated hills and small mesas of the Palouse Soils. It is obvious given the irrigation circles that they are arable, and are well-known for their fertility. The Palouse soils are composed of a layer of loess (wind-deposited silt) that formed during the Pleistocene ice ages. During the floods caused by the glacial dam collapse in Montana (see the previous post), these low hills were islands in the midst of widespread catastrophic flooding.

I am not sure, but I think I see some of the giant ripple marks just below the center of the picture in the widest part of the channel. Normally just inches high in a river, some of the ripples on the Scablands are 30 feet (9 meters) high. Their size is related in part to the volume and velocity of the flowing water. I will try to confirm on Google-Earth when I get a chance.

I can hardly begin to imagine what it would have been like to witness one of these floods...I live on a massive floodplain, and we had an estimated 250-year flood in 1997, and as terrifying as it was, it didn't even come close to a small fraction of a percent of the volume of water on the Scablands. Imagine if you can a flood that equaled the flow of all the rivers in the world...times 10. In some places the water was hundreds of feet deep, even more in narrow canyons, and backflow alone flooded practically the entire Willamette River Valley in Oregon. Giganitic chunks of glacial ice floated along in the flood, leaving huge dropstones here and there.

Picture of the Day - The Airliner Chronicles Part 12

Back to some normal picture blogging; there were lots of great photo-mysteries on Friday (Geopuzzles, Friday Field Fotos 1 and 2 , Weekend fun - picture time!, and of course, the Airliner Chronicles). This photo reveals part of a very famous geological mystery that has become one of the fabled geological stories of perception, persistence, and persipiration-inducing field work.

In the 1920's, geologist and teacher J. Harlan Bertz began to wonder about the strange landscape on the Columbia Plateau between the Cascades and Idaho. Termed by Bretz the Channeled Scablands, the terrain was punctuated by intricately carved channels in the basalt, where a thick covering of loess deposits had been obviously and clearly eroded way by large rivers. There are huge potholes and giant ripplemarks, and dry waterfalls with no obvious water source. Harlan Bretz realized that the features must have resulted from cataclysmic floods involving hundreds of cubic miles of water, beyond the scale of anything ever seen in previous geological studies...anywhere. Although his conclusion is easier to visualize in satellite and aerial photos, Bretz managed to do it when such technology was unavailable. He walked the outcrops, and figured it all out from ground level.

That was only the beginning of the story. Bretz figured out that giant floods had carved the Scablands, but he knew of no sources for the vast quantities of water required to produce said floods. And in a time of geological controversy over evolution (some gentleman named Scopes) and uniformitarian philosophy aligned against catastrophism, his conclusions were fiercely contested by the geological community, who proposed various less intense processes to explain the features.

The Scablands remained a controversial issue for four decades. J.T. Pardee, working in Montana, had found a source for the floods in an immense glacial dam that blocked vast amounts of water in western Montana (Pleistocene Lake Missoula). It drained catastrophically as the inherently unstable ice dam broke up numerous times. But still, the geological community had a hard time accepting such an incredible and incomprehensible hypothesis. The evidence continued to accumulate, and with advances in remote sensing (like putting satellites in space), the reality of the ice age floods became more acceptable to the scientific community.

Harlan Bretz eventually was recognized for his tenacity in the face of vigorous opposition. In 1979, the Geological Society of America awarded him the Penrose Medal for his contributions to geology. He was 97 years old at the time (he passed away in 1981).

The photo of the day was taken on a flight home from Paris in 2006. It was the first time I had seen the Channeled Scablands from above, and they were a stunning sight.

I teach by standing on the shoulders of giants (to borrow a concept from Isaac Newton)...I am awed at the perception and insight that Bretz brought to his work, and really, to the work of all the researchers who toil in the field of geology. They have done, and continue to do things that I can only barely imagine. I enjoy telling their stories, in hopes that those in my classes will be inspired to push beyond their perceived limits and discover new and wondrous things about our little planet.

Dinosaur National Monument getting the shaft?

A few days ago, I pointed out the potential role of the geoblogosphere as an avenue for disseminating information to as many people as possible on issues related to geology and politics. I came across this post from Dinochick Blogs, Help save Paleontology at Dinosaur National Monument that seems to fit the bill. It seems that our national parks are the adopted step-children of our federal government, and they seem to appear first on the chopping block when budgets have to be cut. There is an active community of paleontology bloggers who I am sure will get involved with this, but for my part, Dinosaur National Monument is an excellent field trip destination for many reasons, not just a display of dinosaur bones on a cliff (and even the building housing that display has been allowed to languish to the point of condemnation).

Check it out and be heard on this!

We have a Winner!

That didn't take long, Ron

Many of the details of Mt. Shasta's complex history are summarized nicely by Bill Hirt at http://www.siskiyous.edu/Shasta/geo/index.htm. The small hills and ponds are part of the hummocky topography produced by a giant debris avalanche that broke loose from the north flank of Mt. Shasta Version 1.0 or 2.0 (Note that the modern Mt. Shasta is something like version 5.0; Sargents Ridge, Misery Hill, and Shastina are all earlier volcanoes that preceded the young summit called Hotlum Cone). The topography, seen from the air in Picture of the Day - The Airliner Chronicles Part 11, was an enigma to geologists until 1980 when the debris avalanche thundered off of Mt. St. Helens, producing a similar topography in the Toutle River Valley. The Shasta avalanche was much larger, traveling some 55 kilometers, making it one of the biggest ever documented.

Here is one more photo showing Shasta (the two summits are Shastina and Hotlum Cone), and a portion of the debris field along Interstate 5. Good job, Ron!