Sunday, May 31, 2009
Friday, May 29, 2009
The Cenozoic Era was a time of great change in the Colorado Plateau area. Mountains rose to great heights around the margins, especially in the Rockies, and rivers carried vast amounts of sediments across the region. But the rapid warping of the crust disrupted the flow patterns of the rivers, and some ended in vast lakes that covered large parts of Utah and Wyoming. In many areas all the Cenozoic sedimentary rocks were stripped away, but in some choice locations the lake sediments were preserved. These rocks form the bedrock of two truly unique parks on the plateau: the world-renowned Bryce Canyon National Park, and the much less-known Cedar Breaks National Monument (Ah-ha! You thought the top picture was Bryce Canyon, didn't you? It's not).
Lake sediments are usually clay-rich and very soft and unresistant to erosion, so they rarely form cliffs unless they are protected by some kind of hard caprock. The Claron or Wasatch formations that make up the cliffs of the two parks include freshwater limestone which is a great deal more resistant to erosion. The rocks have been fractured by pressure from nearby faults, and vertical cracks (joints) have allowed erosion to form the unique towers of stone called hoodoos. Oxidation of iron bearing minerals in the rock led to the intense red color that dominates the attention of the observer.
Fossils are rare in these rocks, but we know from other related rocks on the plateau that a few tens of millions of years after the great extinction event that ended the reign of the dinosaurs, the survivors had evolved into a rich ecosystem that included birds, mammals, reptiles, amphibians and fish. Insects are even occasionally found as fossils in the rocks. The mammals, which emerged from the Cretaceous extinction as small rat-sized insectivores diverged into all manner of carnivores, large grazing animals, and smaller forest browsers. The biggest plant-eaters were almost dinosaurian in bulk, and some of the carnivores as intimidating as any raptor. And yet, this was a world that was coming to resemble something more familiar to us in the present day. We might not have any more of the giant browsers on this continent, but similar animals survive (barely) on the African continent. And the tigers and lions and hyenas, although a bit smaller than their ancestors, are still as capable as any of these carnivores of the geologically recent past.
Bryce Canyon National Park is well known, making part of a recreational triangle that includes Zion and the North Rim of the Grand Canyon (and which now includes Grand Staircase - Escalante National Monument). Roads traverse the tops of the cliffs from one end of the park to the other, and a series of rather spectacular trails wind among the hoodoos. Elevations range up to 8,000 feet or so.
Cedar Breaks lies to the northwest, at the edge of the Wasatch Mountains overlooking the town of Cedar City and the barren mountains and desert flats of the Basin and Range province. It sits several thousand feet higher than Bryce Canyon, so roads may be closed by snow well into May. If the hoodoos at the Breaks are maybe less in stature than those at Bryce, they also tend to be more colorful, and the forest and snow banks provide beautiful contrasts that are not often visible to the casual tourists who visit Bryce in droves.
The end of the story approaches! A project I thought would last a month or so has stretched into an entire year. Still to come: an explosion of volcanism sweeps across the region!
Sunday, May 24, 2009
Tuesday, May 19, 2009
Sunday, May 17, 2009
Saturday, May 16, 2009
In 2003, I was casting about for another international trip, and settled on a tour of Australia and New Zealand. The company offering the tour had a great line-up of sites, even though it was not directly geology-related. It was really expensive, since a company's gotta make a profit, after all, but how could one beat a tour of both islands of New Zealand (only missed the glaciers, a big "only"), BUT, once in Australia, we would see the Blue Mountains (pictured above), a north Australian rainforest, the Great Barrier Reef, and as a grand climax, we would fly to the interior of the Outback, and see the greatest inselberg in the world: Uluru, or Ayer's Rock. What a great way to end the adventure...
We got 35 students together a year in advance, got several thousand dollars of non-refundable deposits, paid the company and looked forward to our adventure. The trip material arrived a few months later, and...presto! Uluru was gone from the schedule, with no explanation. The company barely had e-mail, and an explanation was days in coming, having to do with airlines changing their schedules and bureaucratic difficulties and would you like a few days in Fiji instead?
So, non-refundable deposits have a reason. Sucker that I am, we continued on the trip, and despite many management problems from the lousy company, our students had a good time, and we did see a lot. But who knows when or if I will ever have a chance to see the Olga Rocks and Uluru?
What's the moral? If you want to see everything you want to see on an overseas field trip, well, you have to plan and conduct it yourself. Thus, the spotty blogging. I'm leaving on a field trip in a few weeks to the Hawaiian Islands (three of them), and I am running the trip myself, with the help of some gracious volunteers. It's a lot more work, but it will be a great deal cheaper, and we will be able to see everything that is great about the island's geology.
Sunday, May 10, 2009
Please also catch this important post on the need for support for a change in attitude by the University of California towards the earth sciences in their admission requirements. Earth Science has always taken a back seat to chemistry and physics, and yet is most vivid example of chemistry and physics at work in the real world. We need to support the teaching of the earth sciences at the secondary level.
Friday, May 8, 2009
The very first international field trip I led was to Scotland in 2001 to see the great geology, but especially to visit some of the famous James Hutton localities. We made special arrangements with the tour company (for a price) to deviate from their usual tour (to St. Andrews to see golf courses), so we could instead head into the southern uplands of Scotland to Siccar Point, site of the famous Hutton/Playfair unconformity* . We committed to the trip 1 1/2 years in advance, having no idea that hoof and mouth disease was about to be detected in the British Isles, including the farms around Siccar Point. So near, so far is so right! Access was impossible. In total frustration, I pulled out the topo maps, and we made our way to a campground about a mile north of Siccar Point. I read the passage from John Playfair to the students, and than I ran as far as I could along the beach cliffs to where I could see the point, but not the relationships (although we could pick up the associated rocks along the coast). The story in pictures is here.
On the same trip, we intended to visit the grave of Hutton at a church in Edinburgh, but as luck would have it, the particular section of the cemetery was locked up because of past abuse by the perpetrators of the the "Ghost Walks" in the town (yeah, yeah I did a ghost walk too, tourist that I was).
Thursday, May 7, 2009
The script and MP3/Real Audio can be seen here: http://prairiehome.publicradio.org/programs/2009/05/02/scripts/noir.shtml
Here's a bit....
BP: This is a volcanic hot spot in Hawaii. It’s for a TV special I’m writing a soundtrack for. I just can’t explain how the sight of red hot lava bubbling up from the ground — I just find it moving— the earth reforming itself.....continents shifting......earthquakes......I want to learn more and more about geology— have you ever read John McPhee’s book, Rising From The Plains?
GK: Yes, I’ve been reading it for ten years every night just before I fall asleep.
BP: I just find the science of geology so exciting....so fulfilling— I don’t want to sing about love anymore. I want to sing about the earth.
And a little ditty from "Al Gore":
Let other people hang out in bars.
I lie on the rocks and look up at the stars.
(I thought we geologists did both....)
Kudos to Prairie Home Companion!
Tuesday, May 5, 2009
It's great to see some good geology on the cover of the local news, especially when they get the general details right.
This note was also posted at the other blog I run for the National Association of Geoscience Teachers. We have some great geology field guides for the California-Nevada region you might want to check out, including a geologic tour of Yosemite Valley. Part of the Yosemite tour is posted at http://virtual.yosemite.cc.ca.us/ghayes/roadside.htm.
Sunday, May 3, 2009
I'm not going there this year. I'm headed overseas to our 50th state with 25 students instead. When I started considering a trip that involved flights and hotels and vehicle rentals, I thought of letting a travel company make the arrangements, but from experience I knew the expenses pile up rapidly and the profit margin demanded by the tour companies makes the cost prohibitive. So I made all the arrangements myself. I have found that holding and spending tens of thousands of dollars of student's money, knowing that if I screw up the trip won't work, well, it's intimidating. You can't really commit to hotel and flight reservations until you know you'll have enough people, but people like to wait to the last minute to commit because they don't know if they'll have the money or the time off, so there is a delicate balancing act. But it is working out well so far. Thank heavens for the wonderful folks who are helping me out!
In the meantime, for those of you who will be headed out to the open range this summer, especially the southwest that I love so much, I offer another bit of poetry from the archives. In honor of the Beach Boys, it can be set to the tune of "Kokomo" (thanks to our department poet laureate Vicki)
Out on the old plateau
Far away from Modesto
We're camped out on the Navajo
With no place to go
Out on the Coconino
Arches had the wind
Lovely was the Grand Canyon
Cedar Mesa was the best there'd been
It felt like Heaven
Out on the Coconino
Zoraster, disaster, drive a little faster
Chinle, please hurry, we're all a little weary
Jurassic, Triassic, we say it's just fantastic
Out on the Coconino
Just when we start to snooze
CB crackles with Garry's news,
"Hey guys? Can you name that rock,
back there at six o'clock?"
Out on the Coconino
Her Garry! It's scary!
Those cliffs were really hairy
Arches and bridges, volcanoes, faults and itches
Surprises, moonrises, this trip has had some hitches,
but best of all, we're still all
out on the Coconino!
The photo of the day takes in the view from Cedar Mesa in the Four Corners region. The Cedar Mesa Sandstone is sort of correlative to the Coconino Sandstone that is most famously exposed as the white cliff near the top of the Grand Canyon. Both units date from the late Permian, and represent coastal and desert sand dune environments. The deep canyon in the distance contains the San Juan River. The encised meanders are the famous Goosenecks of the San Juan.
Saturday, May 2, 2009
Here's some food for thought: What ten parks would best display the geological history of your country? I'll have to think on that one a bit...I live in a very big country.