I mentioned in Monday's Sand post that this was "book month" here at NOVA Geoblog. That means it's now time for a quick book review of CATACLYSM: When Human Stories Meet Earth's Faults, by Douglas W. Huigen...

When I was writing my Benchmarks piece for EARTH magazine about the Hebgen Lake earthquake and the Madison River landslide, I spoke on the phone to Doug Huigen, who was then just finishing a multiyear project learning about the geology of the Hebgen Lake area, and interviewing survivors of the event. He was very genial and shared some great information when we spoke.

Later in the year, my summer Rockies field course brought me out to the site of the landslide itself. Here's me and my students at the Earthquake Lake Visitors' Center, talking about the structure of the mountain behind us, and why it failed almost fifty years previously:


After I was done pontificating, we went inside and watched the compelling movie they show there, and then I noticed that Doug's book was for sale on the counter. I bought a copy.

Months later, I finally found the time to read it. For some reason, though, I've found it difficult to finish up with my "book review" blog posts. I started this one in late October, for instance. I'm hoping that by declaring February to be "book month," I can motivate myself to crank through these reviews.

Cataclysm is a nice introduction to the events of August 1959, viewed both through the people on the ground experiencing the earthquake and landslide, and through the perspective of modern-day geological insight. Huigen spoke to a great many survivors of the event, and relates their stories with compassion and an ear for colloquial language. The book is subdivided into three main sections: (1) stories of people during the event, (2) a bunch of photographs and graphics showing the area, the people, and the geology, and (3) a description of the geology underlying the earthquake and landslide. The story is very compelling, and I think it's worth reading this book if you're going to be visiting the Hebgen Lake landslide site.

The book is self-published by Huigen, so there's some issues with typos and formatting of photo annotations, but I guess that could also be seen as part of its charm. It's an excellent repository of a lot of information, and I learned some new things by reading it. I was particularly pleased with the image Huigen has on the inside of the front cover: a sketch of the major geological features in the area. The inside of the back cover is a gorgeous geologic map of the same terrain, but Huigen didn't include the map's explanation, so you have no idea what the various rock units actually are (unless you're already familiar with the area).

Bottom line: not the most amazing piece of literature in the universe, but an important compilation of data about the Hebgen Lake earthquake and landslide: data both of the geologic variety and the 'oral history' variety. I'm glad I read it.

Labels: books, earthquakes, mass wasting, montana

Last new year's, I stated some of my goals for the year. Here they are again; I'll bold the ones I actually accomplished, and strike through the ones that I didn't.

1. visiting the Galapagos Islands
2. visiting the high Andes (Cotopaxi, Chimborazo), Ecuador
3. finding a cool outcrop of graded beds in the Martinsburg Formation (late Ordovician turbidites in the Shenandoah Valley of Virginia) that Rick Diecchio told me about last week
4. "walking on the Moho" in Gros Morne National Park, Newfoundland (late summer)
5. seeing Snowball rocks and Ediacarans on the Avalon Peninsula, Newfoundland (late summer)
6. visiting Egg Mountain paleontological site, Montana
7. joining my colleague Ken Rasmussen's field trip to the Culpeper Basin, a Triassic rift valley in northern Virginia
8. some cool trip next winter break (2009-10): perhaps Patagonia? Or Antarctica?

I've also got some big teaching resolutions:

1. Running a successful and robust Structural Geology course for George Mason University (spring semester).
2. Running a successful and innovation Environmental Geology course for NOVA (spring semester).
3. Running a successful and safe Regional Field Geology of the Northern Rocky Mountains course for NOVA (summer semester).
4. Preparing and running a successful and groundbreaking Honors Historical Geology course linked with English Literature 242 at NOVA, where the English professor and I will bridge the two subjects with readings of Lyell, Darwin, "A Pair of Blue Eyes," and others (fall semester). (didn't get sufficient enrollment for this one; bummer!)

On other topics:

1. Finish my M.S.S.E. degree (July)
2. Buy a house
3. Put together a series of geology 'vodcasts' on local geology (though I've gathered a lot of footage that will eventually go into this series)
4. Write a few freelance articles [link]
5. Publish one cartoon per month in EARTH
6. Prepping (cutting and polishing) a backlog of rock samples from all over the place (I'll have to share the story soon of how our "Campus Safety Officer" emasculated my rock saw out of a fear of accidents and ensuing litigation: it's an absolute abomination...)
7. Successfully moving the geology department into our new building

So what's up for the coming year, 2010?

1. More structure at GMU! Bigger, better, tweaked towards greater learning.
2. Hire and train a new member of the NOVA geology team to take on some of the tasks that my colleagues and I can't currently keep up with.
3. Actually get up to Newfoundland this year. I've got a family reunion up there in early August, so hopefully that will be the catalyst. (My mom's side of the family are Newfies.)
4. Run my Rockies course (with co-instructor Pete Berquist) again.
5. Update my website's numerous mentions of "greywacke" (English spelling) to "graywacke" (American spelling).
6. Get my geoblogging under control. I'm clearly devoting too much time to this for too little recompense. Maybe an alternate would be: find a grant or some such to fund the time I spend writing this blog.
7. Continue my cartooning for EARTH. Also occasional freelance writing pieces.
8. Scan my Cartoon Guide to Geology and post it for download/printing on Lulu.
9. Take meaningful action as a "citizen scientist" to combat climate change misinformation, creationism and Intelligent Design mumbo-jumbo, and other forms of pseudoscience pertinent to my expertise as a geologist.
10. Get those geology vodcasts going.
11. Go to Antarctica. (fingers crossed)
12. Work less. Relax more. Be creative. Enjoy life.

Labels: antarctica, canada, climate change, evolution, montana, newfoundland, pseudoscience, structure, teaching

I've just submitted a list of the classes I intend to teach for summer 2010. Here they are on NOVA Geoblog, before you can access them in the official Schedule of Classes...

GOL 135 (070N) The Bedrock Geology of Washington, DC. HYBRID COURSE: pre-trip reading, field study and post-trip report. One-day field trip Saturday, June 12. Rain date: Sunday, June 13. Important pre-trip logistical information and preparatory readings located online. This trip will focus on the land upon which the capital city is built, including exposures in Rock Creek Park, Georgetown, and Adams-Morgan. Includes discussion of oceanic sediments, the Rock Creek shear zone, igneous rocks emplaced during Appalachian mountain-building, Cretaceous river gravels, dinosaur bones and recent faulting. Students will be evaluated with a field trip report which will be completed after the trip itself. NOTE: This trip involves moderately strenuous hiking on forest trails. Meet in back of the CT building at 9:00 a.m.; Return by 7:00 p.m. For information about meeting time/place or other questions call (703) 323-3276 or email cbentley@nvcc.edu
HYBRID course
Additional info online

GOL 295 (4 credits) Regional Field Geology of the Northern Rocky Mountains: July 10 to July 25, 2009. Pre-trip meetings Wed. June 9 and Wed. June 23, 6:30pm, in CS 217. Western Montana and Wyoming showcase tectonic, sedimentary, geomorphic, and volcanic features which provide world-class examples of geologic processes. Students in this course will complete field studies of locations in Yellowstone and Glacier National Parks, as well as several other field sites. The course will involve VERY STRENUOUS outdoor physical activity: Students are expected to hike several miles at high elevations in rough mountainous terrain in order to accomplish course objectives. Airfare, lodging, and transportation are covered in the approx. $1400 course fee (does NOT include tuition). For up-to-date information and a complete itinerary, see the course website or contact the instructor at cbentley@nvcc.edu or (703) 323-3276.
Extra fee
Instructor permission required
Additional info online

GOL 299 (071N) (2 credits) Snowball Earth. June 14-19, 2009. HYBRID COURSE: pre-course reading, lab, field study and post-course report. An episode of glaciation 700 million years ago, dubbed Snowball Earth, may have provided for the evolution of multicellular life. The Snowball Earth glaciations stretch our conception of the limits of climate change: the ice apparently reached from the Earth's poles to its equator! Scientists infer that the runaway freezing event was only ended due to volcano-induced global warming. This course examines the geological, chemical, and biological evidence for Snowball Earth, and includes a field trip to local "Snowball" deposits. Course meets four times: three evening sessions (6pm-9pm) in CS 217 and all day on a Saturday (9am-5pm). The schedule is: Monday June 14 (lecture), Wednesday June 16 (lab), Friday June 18 (discussion), and Saturday June 19 (field trip). For further information call (703) 323-3276 or email cbentley@nvcc.edu or go to the course website.
HYBRID course
Additional info online

Anyone in the Northern Virginia area who's interested in any of these classes, drop me a line!

Labels: dc, field trips, geology, montana, nova, snowball earth, teaching

Here we have some nice little glacial striations exposed in the Grinnell Glacier cirque in Glacier National Park, Montana. These grooves were carved by pebbles and other clasts within the glacial ice as it flowed over this outcrop of the Mesoproterozoic Helena Formation (part of the Belt Supergroup). Perhaps some of the same pebbles you see in this photo were responsible for acting as carving tools -- though the 'hand' that wielded them, Grinnell Glacier itself, melted away from this point sometime since 1939.

Also of interest to me in this photo is the lingering stain of water around the joint set in the upper right. I'm fascinated at the interplay between physical and chemical weathering, and seeing stuff like this emphasizes how even a simple hairline fracture can help funnel water, with all its destructive effects, deeper into the heart of an outcrop. Weathering is focused on these areas, and in another century this outcrop may look quite different.

Labels: glacial landforms, glaciation, joints, montana, national parks, pleistocene, proterozoic, sediment, snow, weathering

On our hike to Grinnell Glacier this past July in Glacier National Park, I found lots of cool cobbles of float, mainly of the Mesoproterozoic metasedimentary rocks that make up the bulk of the park: the Belt Supergroup. One of these formations, the Helena Formation, is intruded by a diorite sill known as the Purcell Sill. It's a prominent rock unit showing up as a black stripe within the lighter-colored Helena Formation, exposed high on the glaciated walls throughout the park. Occasionally, you'll find pieces of it as float, and I noticed that the higher we climbed up, the more of it we saw. Here's one of my favorites among these pieces of the Purcell Sill:


This cobble shows beautiful slickenlines, small gouges into the rock as neighboring rock ground across its surface, along a fault. These physical gouges are decorated with a chemical accoutrement: the metamorphic* mineral epidote, which is a gorgeous grassy green.

Labels: faults, igneous, metamorphism, minerals, montana, national parks, proterozoic, structure

Took all these images of joint surfaces this summer in Glacier National Park on my Rockies trip. Enjoy!

Appekunny Formation, with two concentric ribs:


Grinnell Formation, showing well-developed hackle fringe (rough area at bottom):


In the lovely fine-grained limestones of the Helena Formation:

Labels: montana, national parks, proterozoic, structure, weathering

(Parts 1, 2, 3, 4, & 5 of this series...)

As we were climbing up a steep snowfield, we saw something that made us rush up to the top:


Interpretive sketch:

At first, we thought this was a big isoclinal synform that was cross-cut by a ptygmatically*-folded granite dike, but closer inspection at the "axis" of the "fold" revealed that it was instead just the trailing edge of a big boudin. It pinched down and then swelled again in the downward direction, hidden in this photo by the snowpack. Not quite as cool... but still pretty cool. And I can never say no to ptygmatic* folding, regardless of the setting.

This is also kind of cool:

What you're looking at here is a gneiss, with alternating layers of coarse-grained mafic and felsic minerals. The view of the photo is orthogonal to the plane of foliation, but the boulder has been weathered so that in some places the uppermost mafic layers has been worn away. There's one spot where you can "see through" the mafic layer into the underlying felsic layer (upper right) and another spot where there's a little isolated scrap of the mafic layer where the surrounding material has been weathered away. This reminded me of a larger-scale phenomenon where the same thing happens to thrust sheets: an erosional hole through a thrust sheet into the rock beneath is a tectonic "window" or "fenster" (German for window). An erosional remnant of a thrust sheet is a "klippe." The Grandfather Mountain Window in North Carolina is an example of a fenster. Chief Mountain in Glacier National Park, Montana, is an example of a klippe. So this little boulder gives us a nice physical analogue for regional-scale tectonic/erosional features.

Ahh... what cool stuff to see and think about. But the sun was setting, and we had to head back to camp and the rest of our team... Tomorrow: the story of the long hike home.

________________________________
* Really, more of a "cuspate-lobate" fold, without the parallel limbs that make for a truely ptygmatic fold.

Labels: analogies, art, montana, national parks, north carolina, nova, structure, travel, wyoming

Over the summer the rest of the geology department and I moved into our new home, the Shuler Building (CS) on the Annandale campus of NOVA. As part of our refurbishment, I got a nice new display case which is prominently displayed in the hallway of the second floor of CS, just down from our lab. For its inaugural display, I put together a collection of photos and samples from this summer's Rockies course. I think it looks pretty good:



If you're on campus, stop by and check it out!

Labels: gear, geology, montana, nova, teaching

The Crazy Mountains are a range of mountains in south-central Montana, north of Livingston:

In this Google Map, you can orient yourself from recent posts by finding Bozeman, the Gallatin Valley, and the Bridger Range down in the southwest corner.

The Crazys are an Eocene intrusion, (Ar/Ar dates of ~50 Ma), and they are beautifully expressed on a geologic map as a radiating series of dikes around two central blobs of intrusive rocks (quartz diorites, etc.: dark pink on the map):

These igneous intrusions penetrated the Livingston Group, a series of volcaniclastic sedimentary rocks of late Cretaceous to early Paleogene age (hot pink on the map).

The day before my students arrived in Montana this summer, Lily and I took a hike in the Crazys, entering in the northern part of the range. We saw some cool dikes exposed along the road on the way in. Here's me pointing out the contact between a subvertical dike of porphyritic andesite cutting across subhorizontal layers of the Livingston Group:


Annotated version of the same photograph:


And here's a close-up of the rock making up the dike; mostly fine-grained and gray, but with some lovely big euhedral plagioclase feldspars as well:


That's about it for the geology I saw in the Crazys. Our hike kept us mostly in the forest, so clearly I'm going to have to go back some other time and spend more time there!

Labels: igneous, montana, mountains, sediment, travel, volcano

(deep voice) "Previously, on NOVA Geoblog..."

...We were looking at the structure of the Bridger Range in Montana, near Bozeman. We discussed the concept of Pumpelly's Rule, which suggests that outcrop-scale structures (meso-scale) can help us understand the regional structure (mega-scale), and that the asymmetry of certain kinds of folds can tell us where we are on that structure (vergence). [Link to post]



So the Bridgers are an anticline, overturned in the southern part of the range... but that's not the whole story!

Starting during the Miocene, the west began to widen. The Bridger anticline cracked in half along its axis and the western half slid down relative to the eastern half. The downdropped western half became buried in younger sediments, and that's the Gallatin Valley, where Bozeman is located. When the block of rock above a fault plane slides down relative to the block of rock below the fault plane, we call it a "normal fault." (It would be normal for a kindergardener to slide down a playground slide, but the reverse of normal for them to slide up it!)



A Google Map "terrain" view to show how this is expressed physiographically - Bridger Range on the east, downdropped Gallatin Valley on the west:



And, zoomed out a bit to get some more regional context on how Basin & Range extension has left its mark on the physiography of western Montana, eastern Idaho, and western Wyoming:



I've visited some of these normal faults myself (solid lines); the rest I'm just inferring from the landscape (dashed lines). Basin & Range extension is one of the main reasons the west is so beautiful: those wide open spaces with mountains rising to define the horizon...

(sigh) ...I'm glad I got to spend so much of my summer out there. I'm looking forward to it again next summer. But in the meantime, this is the first week of classes at NOVA, and I'd best get back to work!

Labels: faults, montana, structure

Rockies co-instructor Pete Berquist was quoted in a nice little article appearing recently in Thomas Nelson Community College's internal newsletter. Here it is.

Labels: field trips, montana, nova, teaching

After a post the other day, Michael wrote in to ask for clarification of "Pumpelly's Rule."

AGI defines Pumpelly's Rule thusly*: "The generalization that the axes and axial surfaces of minor folds of an area are congruent with those of the major fold structures of the same phase of deformation."

We saw some of this same idea expressed in yesterday's annotated photo series featuring parasitic folds on larger folded (and boudinaged) quartz veins. There were bigger folds there, and then those bigger folds were decorated with little parasitic folds. The idea behind Pumpelly's Rule is that you could get a sense of what the big folds are doing by looking at the little folds. But even more revealing than parasitic folds at the hinge area of a larger fold are the little folds that you sometimes see on the limbs of bigger folds.

Depending on the sense of the asymmetry of these folds, we call them either "S" or "Z" folds. The parasitic folds are more symmetrical towards the apex of the fold, but more asymmetrial along the limbs. Check out this diagram to see how small S-folds and Z-folds relate to the larger structure of the main fold. Blue arrows indicate the relative sense of shear on each limb of the main fold:


Pumpelly's Rule suggests that we don't need to see the whole picture to understand what's going on. Simply seeing the areas of the diagram highlighted in red are enough to give a sense of the bigger picture.

So how does that relate to this photo, which prompted the question?


Behind me in the photo, you can see an outcrop of the Cretaceous-aged Thermopolis Shale, exposed on Bridger Canyon Road, in the southern part of the Bridger Range, Montana. It has some sandstone layers in it. These sandstone layers, with their high color contrast against the surrounding black shale, record a series of lovely S-folds. The strata here dip moderately to the west. The S-folds relate the sense of shear on the larger structure of the Bridgers: they suggest that the bedding here is overturned, and that you're looking at the eastern side of a big north-south-striking anticline. In the southern Bridgers, therefore, the overall structure is an overturned anticline. Hiking west & uphill confirms this interpretation stratigraphically: as you go up, you go "back in time," encountering older and older strata: from the Thermopolis into the Kootenai, into Jurassic formations like the Morrison, the Swift, and the Rierdon.



Moral of the story: small observations can have large implications.

Raphael Pumpelly made this observation in 1894, presumably during his tenure as the head of the USGS New England Branch. Pumpelly sounds like he was an interesting guy, leading expeditions in Asia when that was a seriously sketchy prospect. In addition to his Rule, he is honored with a mineral named after him, pumpellyite.

* If you don't have a copy of AGI's Dictionary of Geological Terms, a good resource for looking things up online is this Dictionary of Mining, Mineral, and Related Terms sponsored by Hacettepe University in Turkey.

Labels: cretaceous, history, jurassic, montana, mountains, structure, websites

50 years and 2 days ago, the Hebgen Lake Fault slipped, and triggered the Madison River Landslide. Here's the article I wrote about it for EARTH magazine.

By the way, someone already pointed out to me that Orion's a winter constellation... d'oh!

Labels: earthquakes, mass wasting, montana

All photos in this post by Rockies student Charlie Corrick.

Obstacle in the road...


Tetons...


Charlie and Jared on Blacktail Butte:


Luke on Blacktail Butte:


Charlie, Luke, and Jared on Blacktail Butte:


Checking out the fault scarp of the Hebgen Lake Fault, north of Hebgen Lake:


Examining the Grinnell Formation for the first time:


Looking down the St. Mary Valley, Glacier National Park:


Stromatolites in the Helena Formation, Glacier National Park:


Victoria points out the contact of the Purcell Sill with the surrounding Helena Formation (limestone), Glacier National Park:


Callan points out the contact of the Purcell Sill with the surrounding Helena Formation (limestone), Glacier National Park:


Pete and Joel point out the contact of an apophysis of the Purcell Sill with the surrounding Helena Formation (limestone), Glacier National Park. Notice that the sill cuts across stratification down by Joel's legs.


At the Bozeman Airport on the way home, John entertains us with geology songs he composed, which cracked up the instructors:

Labels: glacial landforms, montana, national parks, nova, proterozoic, travel, wyoming

All photos in this post by Rockies student Charlie Corrick.

Talking S-folds, vergence, and Pumpelly's Rule in the Bridger Range:


Hiking uphill and down-sequence in the Bridger Range:


Describing the Kootenai Formation:


Jared gets eaten by Big Mike:


Joel with a few columns of basalt:


Post-M.O.R.-tour, with the guide:


Victoria and a Triceratops horn:


Group at M.O.R., with Tyrannosaurus for scale:


Calcified bat, Lewis & Clark Caverns:


Inside the cave:


Beartooth Plateau:


Amanda enjoys the view:


Camp at Pebble Creek in Yellowstone:


Watching for wolves, Yellowstone:


Bison:


Obsidian at Obsidian Cliff:


Longhorned beetle that landed on our geologic map of Yellowstone:


More to come...

Labels: arthropods, dinosaurs, fossils, glacial landforms, mammals, montana, wyoming, yellowstone

Working through my backlog of e-mails, I find that I have a few more Rockies course final projects to share with the world:

Laurie's website on Yellowstone geothermal features.

Jared explores Ringing Rocks.

Kevin suggests "more study is needed."

Ken discusses Grinnell Glacier:

Amanda reviews the Tetons:

Labels: glacial landforms, glaciation, montana, mountains, stromatolites, volcano, water resources, wyoming

Following on this morning's video from Jason, here are a few more Rockies class final projects:

Ringing Rocks (Bob)
Lewis & Clark Caverns (Charlie)
Gros Ventre Landslide (Chris)

Labels: montana, nova, teaching, websites, wyoming

This is a short film made by one of my Rockies students as his final project for the class. Enjoy!

Labels: environmental, mining, montana, movies, ore

Here's some images from my first post-master's-post-master's graduate class: "Bahama Montana," Dave Lageson's one-credit examination of carbonate sedimentology with a particular focus on some interesting features in the Bridger Range: Waulsortian-type bioherms. This field trip was on my fourth day in Montana this summer, following a two-hour lecture the previous evening. Unfortunately, the road to Fairy Lake still wasn't totally open, which meant that we had to add an additional three miles each way to our hike, which meant we didn't get to examine the bioherms themselves at close range. Oh well; next year perhaps...

The class hiking up to the summit of Sacagawea Peak:

(The green stripe on the left/west may look familiar from the satellite image I shared yesterday.)

Sacagawea Cirque, not looking especially "Death Cirque"-like* today:


The view south from Sacagawea Peak:


The class, looking east from the summit:


The elusive Waulsortian bioherms, off in the un-logistically-feasible middle distance:

...Interesting that they weather out in high relief, eh?

Dave instructs:






Some cool Columella stromatolites that I hadn't noticed on previous trips up Sacagawea:


More Columella stromatolites:


The class was a good example of how field trips have to be modified to fit local conditions. It was a bummer the road closure added six miles to our hike, but we were able to scour the talus slopes in Sacagawea Cirque for Mississippian fossils like crinoids, brachiopods, corals, and bryozoans. I got some sweet samples of fenestrate bryozoans, but saw none of the spectacular rugose corals that I collected on my first visit to this cirque 2 years earlier.

_________________________________
* The "Death Cirque" moniker is one applied by my NOVA Rockies students the following week, for reasons I shall reveal in due time...

Labels: field trips, fossils, limestone, mississippian, montana, stromatolites

My third day in Montana this summer, Lily and I took a hike in the Bridger Range, going up the west side of the range via Corbly Gulch to a cirque opposite the "usual" route up Sacagawea Peak, which starts at Fairy Lake on the east side, then goes up into Sacagawea Cirque* and south to the peak. Instead, we went up Corbly Gulch and got a whole new look at Bridger stratigraphy. First, orient yourself with this topographic map:



The Fairy Lake route brings you to the ridge crest from the upper right (northeast), wheras the Corbly Gulch route brings you to the same ridge crest from the lower left (southwest). Now take a look at some satellite imagery:



The green line at upper right is the ridge crest; Sacagawea Peak is just off-screen to the right. It will not surprise you to learn that stratigraphic contacts strike NW-SE in this area. The forested left-hand part of the screen is underlain by Mesoproterozoic LaHood Formation, a coarse-grained formation in the Belt Supergroup. Then there's a little gap of grassy area and a thin line of trees atop a light-brownish layer. This is the Cambrian Flathead Sandstone, which is chock-full of interesting sedimentary structures and trace fossils. The prominent light-colored ridge-forming layer traversing the screen from upper left towards lower right is the Cambrian Pilgrim Limestone, which shows "fossil hurricanes" in the form of limestone-chip conglomerates.

Here's some of the trace fossils in the Flathead Sandstone:


Here's a limestone-chip conglomerate from the Pilgrim Limestone, which I interpret as a paleo-hurricane deposit: rip-up clasts from a carbonate bank tumbled and re-deposited together in a big jumble:


We hiked up to the ridge, and peered down into Sacagawea Cirque (getting pummeled by the wind!), but didn't feel like we had sufficient time to attempt summiting Sacagawea, since I had to be back on MSU's campus for an evening session as part of "Bahama Montana" class. More on that tomorrow...

______________________________
* The following week, my Regional Field Geology students proposed to rename Sacagawea Cirque as "Death Cirque," for reasons I will explain in due course...

Labels: cambrian, fossils, limestone, montana, msse, primary structures, proterozoic, sediment

My second day in Montana this summer, Lily and I took a hike in the Gallatin Range, in Leverich Canyon. There, I turned over a boulder of Archean gneiss (bearing a sweet isoclinal fold) and found two little pseudoscorpions:





My apologies for the blurry, pixelated quality of the photos: these guys were small and they moved fast! Each pseudoscorpion was about 3 mm in length. These are the best two photos out of 20 or so that I shot: they were not easy to capture in digital form.

Pseudoscorpions are members of one of my favorite groups of animals: the non-spider arachnids. This is a surprisingly diverse group that includes (Wikipedia links) pseudoscorpions, tailless whip-scorpions, harvestmen, solpugids, and vinegarroons. (Mites and ticks are also arachnids, as well as a host of less common groups both extinct and extant.) I've seen examples of all of them in the wild except for the solpugids. They're really neat creatures, hints of the wide range of biodiversity in the arthropod phylum.

Labels: archean, arthropods, montana, structure

On my first day in Montana this summer, I borrowed Lily's Jeep and set off to look for petrified wood in the Tom Miner Basin, an offshoot of the Paradise Valley (which connects Livingston to Gardiner). Along the way, though, I stopped at Point of Rocks CKCK, and found some nice exposures of the lahar deposits of the Absaroka/Gallatin Volcanic Field. These Eocene-aged extrusions basically consist of a series of lava flows and volcaniclastics interlayered to a substantial thickness.

Here's a map of Point of Rocks:


Here's the view north from Point of Rocks:


Here's some images of the rocks exposed there: poorly-sorted, matrix-supported grey conglomerates that I interpret on the basis of the previous year's field notes to be lahar deposits:




I've got a big fat chunk of this stuff in the NOVA geology lab now -- thanks to Lily for giving that forty pounds of lahar a lift cross-country!

Eventually I made it into the Tom Miner Basin, an area of Forest Service land where there is some petrified wood exposed. There is an interpretive trail where people are specifically asked NOT to collect but of course people collect anyhow, so it's kind of lame, but there are some nice examples of petrified branches and what not, and some nice examples of reverse-graded-bedding in the lahar deposits.

Map of the area where the road ends (at a campsite) and the trail begins:


Reverse graded bedding:


You can climb up above the trail to some exposures of the volcanics which are harder to get to and therefore not picked-over, and with a permit you can collect a fist-sized chunk per person per year.

Here's a couple examples of petrified wood that I saw:




More volcaniclastics, this time showing normal graded bedding (coarse at the bottom, fine at the top):


And on the way out, I saw a nice example of a couple of rugose corals cross-sectioned in a boulder of presumably-Mississippian-aged Madison Group limestone:



It was a nice first day in Montana! More photos to come...

Labels: fossils, igneous, montana, plants, volcano

Two examples of plumose structure, beautifully expressed in a small boulder of the Helena Formation (Mesoproterozoic limestone from the Belt Supergroup) in Glacier National Park, Montana. Photo by Bob L'Hommedieu.

Labels: field trips, limestone, montana, national parks, proterozoic, structure

Hey there everyone,

Sorry for the unconformity in my posting. Time has been passing, and events have been occurring, even if they haven't been recorded here. I'll try and compensate for that over the coming month.

My Rockies field trip went well. I think everyone had a good time, and there was clamoring for a similar regional field course next summer. I have some ideas for what that might look like, and undoubtedly I'll start planning that in the coming months. In the meantime, though, it's summer in DC, and time for a bit of R&R.

-CB

Labels: dc, field trips, montana

Hey there,

Just a quick note to say: (1) I'm in Bozeman, Montana, and (2) I successfully presented and defended my MSSE capstone research. Thanks much to John Graves and Dave Lageson for their counsel and wisdom! Now that I have two master's degrees (one in geology, one in science education), I'm going to take a few semesters off being a student.

Looking forward to the arrival of my NOVA students on Sunday!

CB

Labels: montana, msse

It's been busy round these parts. My apologies for the lack of posts this past week.

I leave tomorrow for Montana, and I'll have limited e-mail access while out there. I'll do my best to post when I can, but it will likely be more on the ~weekly timescale rather than ~daily.

On the agenda: (1) Bahama Montana, (2) present and defend my MSSE capstone project, and (3) lead my Regional Field Geology of the Northern Rockies class for NOVA.

More later...

Labels: blogs, montana, msse, nova, travel

I'm swamped -- absolutely sodden with responsibilities, of a dozen flavors. Stressed, harried, scatterbrained, and to top it all off, no time for proper blogging. But that doesn't stop me from getting excited about a new opportunity to do something cool... Even though I don't need any more credits for my MSSE degree this summer, I just found out about "Bahama Montana," an expedition into past carbonate environments of the Big Sky state, and their fossil inhabitants. Can't wait!

Eventually I'll use this credit... right?

Labels: fossils, limestone, montana, msse

A bill working its way through the Senate right now, S-22, has some provisions you may be interested in. It's called the Omnibus Public Lands Management Act of 2009. Mainly, it sets aside a heckuva lot of wilderness areas. But the thing that brought it to my attention is that it sets aside some money to develop a "national geologic trail" focused on Glacial Lake Missoula, with an interpretive center to be located in Missoula, Montana. The Senate website describes it like this:

The Ice Age Floods National Geologic Trail Designation Act (S. 268 and H.R.
450), would create a trail to document the catastrophic flooding that stretched
across parts of Montana, Idaho, Oregon, and Washington during the last Ice Age.
The designation of an Ice Age Floods Trail follows the recommendations of a 2001
study headed by the National Park Service which found the area suitable for
addition into the National Park System.

This part of the bill carries a possible pricetag of $12 million, with $2 specifically for the visitor center. Though there's no way the trail would be done by this summer, Glacial Lake Missoula's geologic signatures will be some of the highlights planned for this summer's Regional Field Geology of the Northern Rockies class.

Read more about it in this article in the Missoulian.

Hat tip to Babak R. for letting me know about this.

Labels: glacial landforms, glaciation, lakes, montana, national parks, politics

Ed Adam's "cold lab" (which I toured this past summer as part of my "Examining Life in Extreme Environments" class at Montana State University) gets mention in an article in today's New York Times. They also profile some of Adams' experiments setting off avalanches at Bridger Bowl, in the Bridger Range north of Bozeman. Worth a read. Some cool photos, too.

Labels: ice, mass wasting, montana, msse, snow

Labels: geology, maps, montana

Here's a fossil that I have hanging around my house; it's an ammonite from the Bearpaw Shale (late Cretaceous) of eastern Montana. I collected it just south of Glendive, Montana, this summer on the "Dinosaur Paleontology of the Hell Creek Formation" class I took through the MSSE program at Montana State University.

Overall, this little fellow has a maximum diameter about the same size as a quarter:


On the back side, where the nacre has been broken off, you can see the suture patterns:


Clearly, these are ammonitic sutures (as opposed to ceratitic or goniatitic), but I haven't identified it to genus level. Any paleontologists out there able to help me out with an ID?

Labels: cretaceous, fossils, montana, msse

The Masters of Science in Science Education program at Montana State University-Bozeman recently posted their list of summer courses for next year, and they illustrated it with a photo montage of images from last year's MSSE field courses. At the top of the stack? Yours truly, ogling the Grand Prismatic Spring in Yellowstone National Park:

Labels: montana, msse, wyoming, yellowstone

One of the most interesting spots I visited this summer was the Madison River landslide area, between Hebgen Lake and Ennis, Montana. Here's a photograph of the landslide scar:


Google Map of the area:


My "Northern Rocky Mountain Geology" class (through the MSSE program) visited the area this summer. Here's the class (all science educators of one sort or another) walking up to the viewing platform:


What happened here? On August 17, 1958, a large earthquake ~10 miles to the east occurred. Known as the Hebgen Lake earthquake, it was a magnitude 7.5 on the Richter Scale, and shook much of the northern Rocky Mountain area. The earthquake's effects were most deadly where the Madison River drops down out of the mountains and into a graben to the west. There, schistose bedrock with a plane of foliation that dipped steeply into the valley was jarred loose. Sliding along the foliation's plane of weakness, and unthinkably massive amount of rock ( estimated at 70 to 80 million tons) went downhill, crushing a forest service campground and damming the Madison River. The momentum carried the rocky debris up the other side of the valley, where the Visitor Center is located today. There are some huuuuuuuge boulders there, as big as a house. 28 people lost their lives in the landslide (and related smaller-scale rockfalls further up the valley).

The Madison River began to back up behind the new dam, and it formed a "quake lake" called Quake Lake (sometimes called "Earthquake Lake," as in the Google Map above). The U.S. Army Corps of Engineers was worried that the dam would fail, draining Quake Lake rapidly and causing a catastrophic flood downstream. (They were cognizant that this had happened at the Gros Ventre landslide several decades earlier in nearby Wyoming.) So they bulldozed open a spillway, and got the lake level down to where they felt it didn't pose a huge flood risk for Ennis and other downstream communities.

But they didn't get the water back down to pre-landslide levels. Today, you can see a drowned forest along the shores of Quake Lake:


We also visited a couple of exposures of the Hebgen Fault scarp. Here's one at a campsite in the Gallatin National Forest. You can see the big dirty slope in the background: that's the actual fault scarp. Total offset here is something like 2.5 meters.


Another view of the fault scarp, looking along its trace.


Clever wayside sign, mimicing the offset in the land with offset in the sign:

Labels: landslide, mass wasting, montana, msse

Here's a quick recap of my cross-country journey, for those who are interested in such things.

I left Bozeman on Saturday morning, July 26, and drove east on the Interstate to Billings, then diverged southeast towards Little Bighorn. There, I verified a comment from a Lakota friend at MSU that with my new bushy mustache (see change in icon above), I look a wee big like George Armstrong Custer (Custer & his men were killed by Lakota and/or Cheyenne warriors). After a short picnic there, I kept driving across southeast Montana, and into northeast Wyoming. My goal for the night was Devils Tower, where I have positive memories from my "North by Northwesty" roadtrip two years ago. I got to Devils Tower in mid-afternoon, just in time for a wicked-looking thunderstorm to roll in. Pendulous looking mammatus clouds were hanging down, and the skies turned a darker grey than Lola. Rain and wind came through, and a big dead branch from one of the cottonwoods in the campground came crashing down, but not on anyone's car or tent. When the skies cleared up, I drove up to the visitor's center and took a walk around the tower. It's awesome: massive columns, some of them twenty feet across. The rock is a porphyritic phonolite, and it's quite pretty to look at: big feldspars (5mm) set in a fine-grained grey matrix. Lovely.

The next morning (Sunday), I headed for Red Bird, Wyoming (along Wyoming's eastern border), where Cruisin' the Fossil Freeway suggested there would be oodles of ammonites in concretions in the Pierre Shale, some a foot across. When I visited the Denver Museum of Nature and Science earlier this summer, Kirk Johnson reiterated to me that Red Bird was the place to go for ammonites. But once I got to where Red Bird should be (according to my road atlas), there were no highway signs indicating that the town existed. Worse, there were no outcrops, and no sign of public land. (And one thing that an amateur fossil collector does not want to do in Wyoming is trespass on a rancher's land.) So, no Red Bird ammonites for me. Oh well, no worries: I had collected ammonites from a tongue of the Pierre Shale (the Bearpaw Shale) earlier in the summer on BLM land near Glendive, Montana, and scored some good specimens there. I cruised south, stopping at the Sierra Trading Post outlet in Cheyenne, Wyoming, and dropping some cash on some new duds (STP is mainly a catalog business, famous ten years ago for their amazing deals, but the company seems to be shifting to more mainstream business nowadays, including multiple brick-and-mortar locations). Then another hour on the road brought me to Fort Collins, to the house of Larry Wiseman, where I stayed earlier in my trip. He and I got some pizza and 90-Shilling Ale (Odell's) and traded tales about our summers.


The next morning, we had coffee on Larry's front porch and watch the sun rise. I packed up and hit the road, heading for Kansas. In my rear-view mirror, the Rockies shrank and vanished from sight, a melancholy fade. Out into the plains... In mid-afternoon, I rolled into Oakley, Kansas, where I headed for the Fick Museum. The Fick Museum is interesting on multiple levels: it's got some stellar fossils from Kansas's Smoky Hill Chalk (member of the Niobrara Formation), like a Xiphactinus (massive fish) and a Tylosaurus skull (even more massive mosasaur). But it's also got some whacked-out art: the founder, Vi Fick, was into making art with local "art supplies," and so the walls show his portraits of eagles rendered entirely in rattlesnake tails (see image at right, from this online gallery), or his geometric arrangements of thousands of fossil shark teeth. There's even an oil painting Fick did of "God making the Cretaceous seas," which shows a bearded diety surrounded by flames (it kind of reminded me of Hindu art) making pleisiosaurs and pterosaurs. Not the usual way you see fossils displayed, or paleontology depicted!

At the Fick Museum, I met up with Ron Schott, doyen of the geoblogosphere, who graciously agreed to show me some cool Kansas geology. Ron and I headed south from Oakley towards Monument Rocks, an outcrop of the Smoky Hill Chalk. Ron was eager to gigapan the outcrop, and he set up the little device: essentially a robot that directs his camera to take high-resolution photos in a systematic grid. Pretty cool, really -- I guess I hadn't realized what a Gigapan really was before seeing it in action. I got to meet Ron's two little plastic elves that he uses for scale, and personally placed them on a ledge of chalk for the photograph. The grid of pictures eventually gets digitally stitched together by software, and available for sharing online.

From there, Ron and I headed back up to Oakley, stopping en route so I could collect a couple samples of the aquiferiferous Ogallala Formation, and then headed east, then south again, towards Castle Rock, another chalk outcrop. Here, we tested out my Prius' shocks on the dirt tracks, and checked out the largest cliff in Kansas (nearly getting blown off it by the intense wind), and then prospected for fossils below. I found some fish scales, and a shark tooth! Also inoceramid clam fragments, encrusted with oysters (apparently a common feature of the bottom of the Western Interior Seaway). No mosasaurs, though... Back to the road, and into Hays, Kansas, where Ron put me up in his guest room. We had dinner and a few beers at the Lb. Brewing Company, and thought about recording a PodClast, but then it slipped our minds. We discussed field trips, tenure, publications, and related topics. A good time! Thanks again to Ron for being such an excellent host.

The next two days (Tuesday and Wednesday) were essentially just driving. On Tuesday, I made it to Indianapolis, Indiana, and spent the night in a hotel there. On Wednesday, I turned north, and drove up into Michigan, and crossed into Ontario at Port Huron / Sarnia. Why go to Canada on my way from Montana to DC? Well, I'm teaching my Snowball Earth class this week at NOVA, and some of the rock samples I needed were stuck at Brock University in St. Catherines, Ontario. Usually they get shipped to educators who want to use them, but because of alleged border complications, I had to go get them myself; a five hundred mile detour! Fortunately, I have good friends who leave in Waterloo, Ontario, so I went and stayed with them. Mike and Natalie Leuty have been friends since 1996, and we had a good evening catching up. They have a sweet house in a suburb full of professorial types who teach at one of the several universities in town.

On Thursday morning, Mike and I had coffee on his front porch while his kids played in the yard, and then I packed up my kit and got rolling. I made it to Brock by 11am, and got the Snowball Suite. Because it's in a giant black case that looks suspiciously like a rifle case, I packed it under a pile of other gear in my car. At any rate, I crossed back into the United States without any static from customs officials, and rolled through Buffalo, New York (twice in one year!) I made my destination for the night Ithaca, New York, where I have a friend who's going to grad school at Cornell. I've never been to Ithaca, but I hear that it's "gorges" from many people. So I called my friend, Kathryn Werntz, and she was indeed around and accepting visitors, so I drove through the finger lakes region (five subparallel glacial troughs now filled with water), and found my way to her bungalow. Kathryn and I took a walk through Cornell's campus (two amazing gorges cutting through it), had some Indian food, and went to get dessert at Purity Ice Cream.

In the morning (Friday), I got up and we went to Gimme! Coffee for some caffeine. Thus fortified, I hit the road for my final day of driving. East to I-81, then south through Pennsylvania. At Harrisburg, I turned onto I-83, which took me to Baltimore, and from there it was a familiar zoom down the B-W Parkway into northeast DC. The dome of the Captiol was visible to my left, and then the comfortable sights of Florida Avenue and U Street. Up the hill, and a left on Harvard Street, and I was back in Adams-Morgan. Home! Finally!

Labels: appalachians, canada, chalk, colorado, field trips, glacial landforms, kansas, montana, national parks, new york, snowball earth, structure, travel, wyoming

A quick note here, just for the sake of completeness, on my final MSSE class of the summer: "Examining Life in Extreme Environments." This was a cool class, but structured in a different way from my other MSSE courses: it was set up more like a conference, with a variety of different speakers on different topics, interspersed with activities. The organizers, Susan Kelly and Monica Brelsford used a grant from NASA to help fund the course, which meant they had the money to fly speakers in from NASA Ames, the University of New Mexico, and the Wrigley Marine Science Center on Catalina Island, California. We also had a presentation piped in from Woods Hole. The goal of the class was to look at living organisms that manage to survive in 'extreme' environments, like really salty, really hot, really cold, really acidic, and so forth. Why study these bacteria and archaea? We're hoping they will give us insights into (a) the origins of life on Earth, and (b) the possibility of life on other planets or moons elsewhere in the universe. We had a field trip to Yellowstone National Park to look at microbial mats; we looked at cultures of hyperthermophiles; we listened to excellent talks by Mark Young (viruses as a source of genetic diversity), Ed Adams (new subzero lab tour), and Robert Szilagyi (thermodynamics of the origin of life). As you can see, it was pretty diverse -- all week long, always something new and interesting. I really enjoyed it!

Labels: archean, astronomy, cold, hot springs, microbes, montana, msse, wyoming, yellowstone

Got back yesterday from six days out in eastern Montana, at Makoshika State Park. I was there on one of my four MSSE classes this summer, and I learned a lot. As many of you know, I'm trained as a structural geologist, not a sedimentologist. Though I use a lot of sedimentology (and fossils) in my Historical Geology course, there is much I have left to learn. Some of those gaps got filled in this week during "Dino Camp," though. Plus we had a lot of non-geologic fun!

The Hell Creek Formation is well exposed in Makoshika, as well as the overlying Fort Union Formation. The Hell Creek is latest Cretaceous, while the Fort Union is earliest Paleocene. The boundary formerly known as "K/T" is therefore between the two, and it records the changing of the eras: from Mesozoic to Cenozoic. I say "formerly known as K/T," since Tertiary is an archaic term that has been replaced (sort of) with Paleogene. The Paleocene is the first epoch in the Paleogene period. The sedimentologically-defined boundary between the two formations is the lowermost "significant" coal layer. We found this coal, the so-called "Z Coal," and you'd think that would be the K/Pg boundary, but it ain't that simple. True, there are dinosaurs below and no dinosaurs above, and it's also true that the Z Coal has been shown (rather shoddily, by the description we got) to have an iridium anomaly at its base. But there aren't any dinosaur fossils at all for 3 meters below the Z Coal, so the dinosaurs could have gone extinct well before the Z Coal was deposited (and before the iridium-rich clay layer was deposited). And of course, there's nothing in the deposition of a layer of coal that indicates it should be contemporaneous with a mass extinction -- it's just coal. Furthermore, the coal is lake coal, and the lake wasn't necessarily regionally extensive. It's a funny way of defining a critical geochronologic boundary: by the lowermost layer of lake coal in an area -- a criterion which could vary temporally from one place to another. Tricky business!

Anyhow, we prospected for dinosaur fossils. The course had two instructors, Jim Schmitt and Frankie Jackson. Frankie is a paleontologist, and she had a permit for collecting fossils on behalf of the Museum of the Rockies here in Bozeman. We found a lot of vertebrae, some five or six inches across. Plus, we found a bunch of leg bones, some rib fragments, and one of our team actually found the top of the frill on the back of a Triceratops skull! It was all pretty impressive.

In the evenings, we discussed scientific papers about field technique, the Hell Creek Formation, taphonomy, and the extinction of the dinosaurs. All our meals were cooked for us by Frankie's cool husband Bob, and so it was really ideal: Go out and learn all day, come back to camp to a hot meal, a cold beer, and a discussion of big picture ideas. My fellow teachers and I also played a lot of horseshoes and frisbee. To top it all off, when we got back to Bozeman yesterday, a group of us rented Jurassic Park and watched it over pizza and ale.

Next up: tomorrow I begin my Wildlife Ecology of Yellowstone course. Ought to be a similar high-octane experiential blast! More at the end of the week...

Labels: dinosaurs, fossils, montana, msse, yellowstone

After I got off the river at the Grand Canyon, I drove to Moab, Utah, where I have a friend from my days working outdoor education in southern California. Pete and I went swimming in Mill Creek (water + slickrock = awesome plunge pools) and checked out the sunset from the top of a dome of the Navajo Sandstone north of town. We had dinner at the Moab Brewing Company, which was delicious. The next morning, I checked my e-mail and got an oil change, then went up to Arches National Park to pay homage to Edward Abbey by taking a hike to Delicate Arch. They even have a small exhibit in the visitor center about Cactus Ed -- a nice acknowledgment on the part of the park that his book Desert Solitaire piqued interest in the park for many people.

After my hike, I got back in the car, and headed north to the interstate, then east into Colorado. Past Grand Junction and Delta, to the little town of Montrose, where I got final supplies for a couple of days in Black Canyon of the Gunnison National Park. I pulled in relatively late in the day, so just settled into the campsite. It felt good to be camping at high elevation, with cool temperatures, again. The next day, however, July 4th, I spent in exploring the park. I was surprised to learn that there is no trail down to the bottom of the canyon from the rim, but they do let people descend via "the Gunnison Route," a steep-ass ditch full of loose scree and talus. It was pretty sketchy, and pretty exhausting: not much fun. I kept thinking "there has to be a better way to do this." The reward was at the bottom, where the Gunnison River runs cool and fast. The Gunnison has carved an incredible gorge here: steep, deep, and with a steep river profile. It's a classic case of steam superposition over a buried Laramide uplift. During the recent episode of uplift, the Gunnison cut down through overlying sedimentary strata (including the Entrada Formation's pink sandstone, visible on the north rim) and into the underlying Mazatzal-aged (~1.7 Ga) igneous and metamorphic complex. This resistant rock is what makes up most of the canyon. It looks a lot like the Grand Canyon's inner gorge, with pink ribbons of granite leaping through the amphibolite-grade metamorphics. Anyhow, the river was very refreshing. I rested there for a while, and ate some lunch (tortillas from nearby Olathe, Colorado, wrapped around mozzarella and turkey pepperoni.) The hike back up was a big slog, and about as enjoyable as the hike down ("There has to be a better way of doing this!") Up top, I drove the road along the south rim, admiring the various viewpoints into the chasm and taking small hikes.

The following morning, I packed up camp early, and drove all day. I went west back to Grand Junction, and took a cool little road (Route 139) north over Thompson Pass and through some cool BLM land, replete with pictographs. I got some GREAT gas mileage after Thompson Pass, basically crusing downhill at 100 m.p.g. for over an hour. Awesome! Then through Dinosaur, into Vernal, Utah, and then into Wyoming at Flaming Gorge.

At Rock Springs, Wyoming, I went north on 191, through Pinedale (nearby Fremont Lake is the type location for Pinedale Till, the Rocky Mountain version of the Wisconsin Glaciation), and up to Jackson. Man, Jackson's a tourist trap! Yikes! Not as bad as Vegas, but I definitely didn't linger with the sunburnt hordes there. I had a date with the Gros Ventre landslide. Just northeast of Kelly, Wyoming, this is a classic location in the study of mass wasting events. I camped on the lake created by the 1925 landslide, and spent the next morning photographing the scar and debris pile which dammed the Gros Ventre River. Unlike the Madison River's landslide and resulting "quake lake," no one was killed with the initial earth movement at Gros Ventre, but when the dam failed two years later, the resulting flood drowned six people in Kelly. I first learned about the Gros Ventre slide as an undergraduate, and I teach about it today, so it was a real pleasure to see it firsthand.

Next morning, a ho-hum commute through Grand Teton and Yellowstone National Parks and up into Bozeman.

Labels: colorado, montana, national parks, travel, utah, wyoming

I left Bozeman on Saturday morning, and drove for about seven hours. I headed south through Ennis, Montana, along the western side of the Madison Range, passing by the Madison Earthquake Site landslide (from the 1959 Hebgen Lake earthquake), and then south into Idaho. I went through Island Park, Idaho, site of the caldera of one of the three big recent eruptions of the Yellowstone volcanic center. Then into northern Utah, where I got a glimpse of the Great Salt Lake. I headed up into the Wasatch Range to spend the night, just east (and several thousand feet above) Ogden, Utah. I did some birding on the reservoir there, observing the mating rituals of both the woodcock (amazing humming noise produced during flying dives) and the western grebe (neck bobbing following by synchrnonous running across the water).

The next morning, I headed west from there, into the basin, across a range, into another basin, across another range -- you get the idea. I initially intended to go hunt for trilobite fossils in the Wheeler Shale in the House Range, but the 20-mile dirt road rattled me (quite literally) and I turned around after only four miles. I got spooked: what would happen to me if the Prius broke down out here? It's really quite desolate country. I've only ever had that feeling once before, when my Dad and I drove across the Namib Desert. It's a mix of agoraphobia and anxiety over feeling inept at repairing mechanical things, like Prii and other automobiles. I chickened out -- no trilobites for me. But there was a consolation in Great Basin National Park, which was where I headed that afternoon. I did a short hike there in the Snake Range, and toured Lehman Caverns there (my third guided cave tour in two weeks!). I had my best campsite of the trip at Great Basin: montane forest, with a gurgling stream running fifteen feet from my tent. Lovely.

When I woke up, I packed up the car and coasted downhill for eight miles into the town of Baker, Nevada, where I had a great breakfast and coffee at a little cafe there. Then up and over the Snake Range, and down the next valley to the west, south for 93 miles of some of the most empty country I've ever seen in America. In an hour and a half of driving, I saw only 20 vehicles. I crossed back into Utah, and then made my way south to the edge of the Colorado Plateau, and drove up into Zion National Park. Zion is a great canyon cut into a series of sedimentary rocks. The last time I was here, 13 years ago, I walked up the Narrows, and my first order of business was to repeat that hike. There's a new shuttle system in the park now, so after parking at my campsite, I hopped on a shuttle into the park and rode it to the end. I waded into the Virgin River and shuffled upstream. In the Narrows, the Virgin River has cut down through the Navajo Sandstone, but not quite down into the weaker underlying Kayenta Formation, and so the canyon is deep but narrow. (Downstream, when it gets deep enough to tap into the Kayenta, it undermines the sandstone cliffs, and the valley widens.) "Hiking" here is one of the more unique outdoor experiences I've had. Being immersed in the cool river, surrounded by towering rock walls -- it's magical. The further upriver you hike, the less people there are, and it's like a cathedral. I went up and around several entrenched meanders, and marvelled at the alcoves, cross-bedding, and variety of cobbles in the riverbed.

Today, I'm staying in the park and heading up to Angel's Landing, a legendary hike in its own right. Tomorrow morning, bright and early, I'm off to Las Vegas to pick up my Dad and brothers for our Grand Canyon rafting trip. Not sure if I'll be able to post again until after I get out.... late next week.

Labels: birdies, fossils, grand canyon, idaho, montana, national parks, stratigraphy, travel, utah

It's been a busy week for me. I've really enjoyed my first MSSE class of the summer, Dave Lageson's "Northern Rocky Mountain Geology." Dave led us on a series of field trips within driving distance of Bozeman: the Bridger Range, the Paradise Valley, the Spanish Peaks, the Hebgen Lake earthquake scarp and Quake Lake, and today out to Ringing Rocks, the Lahood Conglomerate, and a descent into Lewis and Clark Caverns. It's been a lot of cool geology, as well as a lot of driving! In the evenings, I've been keeping busy with Shakespeare in the Parks, seeing the B Side Players, and socializing with fellow MSSE teachers. All good stuff, but it leaves little time for blogging. Tomorrow morning, I'm off to the south. I'll be on the road for another five days or so, going to Las Vegas to pick up my father and brothers and then we're going rafting down the Grand Canyon starting next Wednesday. Along the way, I hope to visit some sites in Utah, and I hope to post some updates en route. After the Canyon float, I'll head back north, again through Utah and probably western Colorado (Black Canyon of the Gunnison), before returning to Bozeman for another three MSSE classes ("Dinosaur Paleontology of the Hell Creek Formation," "Life in Extreme Environments," and "Wildlife Ecology of the Greater Yellowstone Ecosystem"). Then back east, hopefully with some Niobrara Chalk and Pierre Shale site visits along the way.

Also, along similar "rock and road" lines, I had an article published in Geotimes this month on the roadtrip I did two years ago from DC up to Alaska and back. You can check it out here.

FYI, I got a new camera for this trip, and haven't been able to download any pictures off it yet (a stupid software issue), so that's the reason for the lack of photos lately. My apologies!

Labels: grand canyon, montana, msse, utah

Sooo.... I've been "delinquent" about posting (if five days off counts as delinquent). But the long and the short of it is that I made it to Bozeman, and started classes, and have settled into life up here. After leaving Denver, I spent a couple days in Fort Collins, Colorado, staying with my undergaduate mentor professor Larry Wiseman. When I was at William and Mary, I forged a strong relationship with Larry, and that persisted even though I defected from biology (he's a developmental biologist, and chair emeritus of the department there) to geology (basically because they had more field trips). Anyhow, he and I would gather once a month or so for coffee and talk about life, the West, Ed Abbey, art, and science.

Now he's retired and pursuing bird rock art and also teaching cell biology at Colorado State University (in Fort Collins). We drove up to Rocky Mountain National Park and toured the various microbreweries and restaurants of Fort Collins (and Lyons). It was, in short, a good time.

Departing there on Saturday morning, I drove north through Wyoming, and camped at the end of the day at Buffalo Bill State Park, on the east flank of Yellowstone. On Sunday morning, I drove through the park, marvelling at six-foot-deep snow on Washburn Pass, and cruising along past tourists and bison galore. I stopped once, to look at the single petrified tree there, and then rocked and rolled on up the Paradise Valley to Livingston, and thence westward on the interstate to Bozeman.

In Bozeman, I'm enrolled in the Master of Science in Science Education program at Montana State University. It's essentially all science educators who are taking graduate coursework to become better science educators. And it's fun! This week, I'm taking Dave Lageson's class on the geology of the northern Rocky Mountains. More on that later, perhaps, but the point for now is that I'm enjoying it, and enjoying interacting with my fellow MSSE educators.

Tonight, I had a bonus, when we had a mini-conference of geobloggers. I guess there's somewhere around 50 geobloggers out there now, but we had four of them sitting at one table in Montana Ale Works, talking rocks and fossils and blogging and whatnot. That's got to be a record for the geoblogosphere. It was a lot of fun. Thanks to Mel, Brian, and Jeannette for making it happen!

Labels: field trips, montana, msse, travel, wyoming, yellowstone

Cleaning up my hard drive today, before switching over to the laptop for my summer travels. Thought I would share a few annotated photos from my "Geology of Glacier National Park and surrounding areas" class that I took last summer.

Here's Chief Mountain:


On the trail to Firebrand Pass, here's the contact between the Altyn Formation (lowest of the Belt Supergroup exposed at Glacier) and the overlying Appekunny Formation:


The Purcell Sill is a readily recognizable feature high on the glacially-carved walls of Glacier National Park. This shot is from the trail on the way up to Grinnell Glacier:


Here's a shot from Sun River Canyon, showing one of the many imbricate thrust faults there, with some glacial till thrown in as a bonus feature:


Just outside of Sun River Canyon, we saw some nice recumbent drag folds on some thrust faults in the Cretaceous rocks:


This one was from early in the trip, on the road from Helena up north towards Glacier. Specifically, we stopped in Little Prickly Pear Canyon, near Wolf Creek, and saw these chevron folds in the Cretaceous rocks there:


Along those same lines (folded Cretaceous strata), here's a gorgeous fold just outside the park's boundary, on the road leading north from Two Medicine towards Many Glacier:


No annotations on this one, but I wanted to share it anyhow: a blind thrust / drag fold complex, in the Grinnell Formation (exposed on the trail up to Grinnell Glacier):


Lastly, some snow photos. I took this shot on my way up the trail to Grinnell Glacier, because the holes in the snow reminded me of the scary mask face from the Scream movies. But then on the way down, I realized I had the opportunity to document how much snowmelt occurs in six hours of Glacier NP summer weather. Hence, the bottom "after" shot:


That's it for today... Enjoy!

Labels: field trips, montana, msse, plutons, proterozoic, sediment, structure

Today, some shots from my time in Yellowstone National Park last summer. Here's Mammoth Hot Springs:

Close-up of the travertine deposits at Mammoth:

Me advertising my brother's company at Mammoth:

Norris Geyser Basin, slime:

Norris Geyser Basin's loneliest tree:

More slime, this time two colors:

Nasty patch of slime. Looks like snot:

Bison herd:

Columnar jointing in basalt:

Me showing you where the columnar jointing is. (I'm pointing at it...)

Strata exposed in the Tower area:

And here they are again, labelled:

Lastly, heading north out of Yellowstone back to I-90 and Bozeman, here's a weathered-out Eocene dike in the Paradise Valley. The dike is more resistant to weathering than the rock it cuts through, so it stands up as a "wall"-looking feature.

Labels: basalt, field trips, hot springs, limestone, montana, primary structures, stratigraphy, travel, yellowstone

And here's the view hiking back down the canyon to the car:

It's a classic U-shaped valley, the signature of alpine glacial topography. Here's the Google Maps "terrain" view of this valley:

View Larger Map

Labels: glacial landforms, montana, volcano

Ahhhh.... the semester's just about over. Yesterday, I gave my last lecture and delivered two lab practical exams, and now all that's left to do is give the final exams on Tuesday. Not a moment too soon! It's been a very busy time over the past couple of months. What with my regular teaching duties, my Audubon class, my online MSSE class, GSW, various talks (like Wednesday's "Geology along the C&O Canal" at NSF), supervising homeschoolers visiting the NOVA chemistry lab, grant finagling, writing projects, and just life, I'm dog tired. I'm seriously ready for a nice break.

This ought to mean I'll have more time for posting on this blog, and hopefully that the posts will be richer and more thoughtfully composed.

Anyhow, let's share some pictures today. These are photos I took last summer on Dave Lageson's "Geology of Glacier National Park and Surrounding Areas" course at Montana State University - Bozeman. Dave is a great field trip leader, and I'm looking forward to another of his courses this summer: "Northern Rocky Mountain Geology."

For the Glacier course, we loaded up the vans in Bozeman and drove northwest through Helena and up to Sun River Canyon, one of the best areas in the world to look at multiple imbricated thrust sheets. Dave's been taking students here for a long time, and in fact "wrote the book" on it as a field trip location. In the photo below, the prominent cliff is Paleozoic limestone. The gently-sloping hill in the foreground, however, is Cretaceous shale. As is often the case, tectonics trumps superposition. Compressional tectonic forces have shoved the older rocks up on top of the younger rocks. (An analogous situation in the east is the Blue Ridge's Grenvillian rocks thrust up and to the west over Cambrian and Ordovician carbonates of the Shenandoah Valley.)


Here's a map showing how the Canyon trends east-west across the north-south strike of these mutliple thrust sheets:

Next up: Waterton Lakes Park, Alberta. We slipped over the border and spent an evening drinking beer in the southernmost of the Canadian Rockies. ...Purty.


Here's us looking at the next day's field stops.


Still life with fun stuff:


The next day, crossing back into the U.S., we stopped to get a good look at Chief Mountain, another scene of thrusting older rocks on top of younger rocks. Again, the lower unit is Cretaceous, but this time the upper rocks are older, much older. They're Mesoproterozoic rocks of the Belt Supergroup, thrust eastward along the Lewis Thrust, which underlies the base of this mountain. Chief Mountain is an erosional remnant of the Lewis Thrust sheet: that is to say, erosion has cut into the thrust sheet and left behind this one isolated outpost of what was once a continuous sheet of allochthonous rock. (It's a klippe!) The thrust sheet picks up again in the mountains of Glacier National Park.


Next day: a hike up to Grinnell Glacier, a classic glacier in a park named for classic glaciers. Like all of Glacier's glaciers, however, Grinnell is melting. It's receded quite a lot, as repeat photography shows:


Here's a view looking down the Grinnell Valley at a string of pater noster lakes blue with "glacial flour."


Here's what's left of Grinnell Glacier:


Where the glacier once stood, there's now a new lake. Several of my classmates decided that they would go for a dip. Note: all these guys are from Montana...


As for myself, I stayed out of the water, amusing myself with the amazing sedimentary structures displayed by the Belt rocks. Here's an outcrop of the Grinnell Formation, showing amazing Mesoproterozoic mudcracks. (As David Byrne said, "Same as it ever was, same as it ever was...")


Glacier's Belt Supergroup rocks are reknowned for their stromatolites, fossilized cyanobacterial mats. Here, a stromatolitic layer in the Helena Formation was exposed in cross-section by glacial erosion. Penny for scale (atop middle stromatolite).


And here's another view of the same stromatolitic layer, exposed in map-view section (a horizontal slice, as opposed to the vertical outcrop above). Enthusiastic geologist for scale, imagining doing the backstroke through the Proterozoic Belt Sea.


And... that's it for today. I'm off to the Blue Ridge this weekend, so I won't be posting again until Monday or so. But hopefully I'll have some cool new images from Virginia's oldest rocks to share at that time. Be good.

Labels: canada, montana, msse, primary structures, proterozoic, structure

Tuff Cookie is posting danger signs that geologists ignore, so I'll pitch in one of my own from last summer in Montana. This is in Glacier National Park, on the trail up to Grinnell Glacier. The trail was closed due to snowfields which crossed the trail in some spots. It was a little dicey crossing them, but there was no non-litigious reason to close the trail:

Labels: geologists, geology, montana

We've had a cold week in the mid-Atlantic this week, and increasingly my thoughts turn to warmer conditions and the summer. Last year, this year, and next year, I'm scheduling time in Bozeman, Montana, to take classes at Montana State University. I'm working on a second master's degree in science education. It's a pretty cool program which mixes educational practice and "action research" with science elective courses, including plenty of geology offerings.

Today in the blog, I thought I would begin the process of share some images from my time out west last summer. I'll start with the Bridger Range, north of Bozeman. Here's a meadow where we parked the vans before hiking up into the hills on Dave Lageson's excellent Alpine Field Studies seminar:


Once we had huffed and puffed up about tree line, we started to see some pretty cool geology. Here for instance, you can see tilted, folded, faulted Mississippian-aged strata that have been carved into by a glacier. A few minutes after this photo was taken, the class walked straight down into this cirque and climbed up the other side: there's some serious gravity-fighting going on with a route like that. We had lunch on the other side at the top of that orange-colored chute in the upper left:


In the photo below, my hands bracket a tilted zone of paleo-karst in the Mississippian-aged Madison Limestone. With massive limestone above and below, this orangey zone speaks of a time when the limestone deposits of this area were exposed at the surface. Caves and sinkholes developed, as did an iron-rich paleo-soil. It probably looked a lot like modern-day Florida, without the strip malls and retirees. Later, the sea returned and deposited more limestone on top. The paleo-karst is obvious because it contains big blocks of limestone from cave-roof collapse, and is stained by hematite and limonite:


Fellow DC resident and geology educator Nez Nesbitt follows Dave Lageson (the instructor) south along the crest of the range. The drop to either side was substantial, including the headwall of a cirque to the left (east). The loose scree we were walking over added an additional challenge:

In all that scree on the slope we're walking over, there were some cool fossils, including this awesome crinoid calyx ("head" region) - front and back views:


Atop a peak, we paused for a break, and Dave unfurled his Tibetan prayer flags to flap in the wind. I was struck by how a simple little string of cloth imparted a really cool aesthetic to the mountain-top:


This is the trail leading down Sacagawea Cirque. There's some substantial switchbacking going on here:


Here's me atop the highest peak in the Bridger Range, Sacagawea Peak. The views are pretty good from up there:


The class spent the next day mapping glacial landforms in Sacagawea Cirque: it was fun, but I didn't take as many pictures then. When the mapping was over, I prowled through the lateral moraines for fossiliferous chunks of limestone, and found some awesome rugose corals and other treasures. These samples now reside in the NOVA Historical Geology teaching collection.

Labels: fossils, geology, glacial landforms, montana, msse, structure

So this weekend, as part of my ravenous Netflix consumption, I watched Libby, Montana, a documentary which explores the effects of vermiculite mining in the namesake town. The vermiculite in question is augmented with a less desirable mineral: the amphibole known as tremolite. Tremolite grows in a long, fibrous habit, which has been given the name... asbestos. So the deal with Libby is that essentially everyone in town either worked in the vermiculite mine, or was married to someone who worked in the vermiculite mine. A bunch of them inhaled tremolite fibers, both workers and family members. A bunch of them developed lung diseases like asbestosis or mesothelioma. A lot of them died. The movie ends with a moving tribute to the dead. It's some bad stuff. W.R. Grace, the company operating the vermiculite mine, is demonstrably culpable for their employees' deaths.

Tremolite is one of the nastier varieties of asbestos, but not all minerals that happen to grow in that shape are carcinogenic. Some, like chrysotile, (the variety mined at the type locality) have not been found to be as dangerous (by authorities like the USGS). But because many varieties of asbestiform minerals do cause disease, many people (particularly in the litigious U.S.) have opted to ban all minerals of the asbestiform habit. This has resulted in umpteen gazillion public buildings being stripped of their asbestiform minerals, whether or not those particular minerals have been shown to be disease-causing. It's like banning all round candy just because you think that red M&Ms are carcinogenic (which isn't even true). So this brings us to my home institution of Northern Virginia Community College (NOVA). This week, if you were to come visit me in my office in the CF building, here's what you would see (photo).

We're doing asbestos abatement. Amazingly (from a legal standpoint), I'm still allowed to keep working in my office, ten feet away from a what appears to be a major asbestos removal project. The local source is the floor tiles, which look pretty much like linoleum, but are apparently held together with the strong "asbestos" fibers. Which asbestos mineral exactly? Don't know. Probably never will. Last year, they did the same thing in a separate building, the one where my classes are held.

As a P.S., I'll mention that halfway through the day yesterday, I noticed someone put duct tape over the words "Asbestos" and "Cancer and Lung Disease Hazard." No longer that particular danger, apparently...

Labels: minerals, montana, movies, nova

It's funny how one thing leads to another. In promoting our Climate Change Symposium on Friday, I wrote to Cerphe (pronounced "Surf"), probably the best DJ in the world, who's on air in the afternoons on 94.7 The Globe, our DC-area "world-class rock" station that also features a green message. Cerphe wrote back, saying he'd get some mentions on the air this week, and also mentioned that his wife has a small business building green homes. I noticed that the business is headquartered in Bentonville, Virginia, out in the Shenandoah Valley between Massanutten Mountain and the Blue Ridge. And it occurred to me that I've looked at a bentonite layer out there in the Valley (see photo), not too far away from Bentonville. Bentonite is a common clay mineral that in stratigraphic layers is usually interpreted as weathered volcanic ash. (The one pictured above is possibly the "Big Bentonite" that accompanied the onset of the Ordovician Taconian Orogeny in eastern North America.) Could it be that bentonite is named for Bentonville, Virginia? Well, Wikipedia tells me that "The absorbent clay was given the name bentonite by an American geologist sometime after its discovery in about 1890 ...after the Benton Formation in Montana's Rock Creek area." So that took me to the entry on Fort Benton, Montana, which was named for the first 5-term U.S. Senator, Thomas Hart Benton. He was an advocate of westward expansion by the United States, the idea that later was dubbed "Manifest Destiny." So: as near as I can follow, bentonite is a mineral named for a place, which is in turn named for a man. What this has to do with world-class rock and climate change is anybody's guess.

Labels: appalachians, history, montana, volcano