As We Walk Through Fields of Lava

mpollock June 6, 2012 12:39 am

FILLMORE, UTAH – Whitney and Matt took charge today, leading us on an investigation of the lava flows that extend westward from the Miter cinder cone.

The view of Miter from its lava fields. A tiny reflective spec at its base on the right side of the photo is our van, for scale.

We picked our way across the sharp, rubbly flow surface and learned the importance of careful observation. Although we weren’t looking for bombs and xenoliths, we found both along our path.

A volcanic bomb that has been rafted or carried away from the cone by the lava flow.

Whitney had a successful day of mapping the margins and morphology of a couple of complicated lava flows.

Whitney stands on the boundary between an older, vegetated lava flow on the right and a younger, black lava flow on the left.

Matt’s productive day included finding a spectacular fault exposure, where he made lots of measurements on the fault and associated joints.

Kevin poses at the most significant fault locality, where some of the surfaces display plumose structures for joints and striae for fault motion.

Overall, it was a strong start to the field project, despite the searing sun and blinding wind storm.

A perfectly nice day in the field (if you don't mind winds that will make your hair stand straight out).

We were rewarded for all of our hard work.

For one, we made a new friend.

We also found petroglyphs that showed these radiating straight lines.

The petroglyphs also showed a hand print.

The best reward was the home-cooked meal that we were treated to by Ms. Huntsman, complete with pie.

We hope every day of our field season is just like this one (minus the wind).

 

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Orientation in Ice Springs Volcanic Field

mpollock June 4, 2012 10:45 pm

FILLMORE, UTAH – [Guest bloggers Kevin Silver and Tricia Hall]

The alarms sounded in the early morning sun, early enough for the outside air to chill the bones. After our standard yogurt and cereal breakfast, we piled into the van and made our way to the Ice Springs volcanic field, the site of our field work for Independent Study. By chance, we met the manager of the quarry along the narrow road in a near head on collision before making our way up the winding road of the cinder cone with the manager’s warnings of careless truck drivers at the forefront of our minds. Once we arrived at the top of the cinder cone, we were able to enjoy the incredible views of the surrounding valley. The first feature we came to was the Crescent crater. As we viewed the expanse of the lava flow below us, it became quite clear at this point that trying to map the entire field would take much longer than the two short weeks that we have to work in Ice Springs.

Looking northeast from the summit of Crescent Crater.

 

After becoming oriented with the area, we made our way to Miter crater and came across extensive exposures of xenoliths. We paused for a snack and to reapply sunscreen before heading out onto the lava flows, and it was here we realized a harsh reality. The lava flows are very complex, but luckily provided better footing than the cinder of the crater slopes. Assessing the lava flows led us to the flows breaching Miter crater. The ascent back up Miter crater proved to be more challenging than expected, but we were truly independent minds working together to find flat ground. Once everybody caught their breath, we wandered back toward the van to make our way back down the cinder cone. We then made an attempt at circumnavigating the volcanic field using the rather primitive roads that were more attuned to cattle herds than cars. This feat proved to be futile as nothing less than an ATV could navigate the rough terrain we encountered. Upon our misfortune, and the near loss of our bumper, we decided to head back to camp. Along the way, we all took a nap, leaving poor Dr. Judge and Dr. Pollock to navigate our group safely back to the camp site in silence.

Tricia Hall standing in front of Miter Crater.

Once back in our accommodations, the kozy kabins, we all went our separate ways for some R&R. We each met individually with the professors to discuss our project ideas once again following our initial introduction to our field site.

Around 5:30 pm, we all piled into the van once more to scavenge for nutrients at the quality establishment known as 5 Buck Pizza. We had 4 of them. They were good. Will and Matt guzzled 8 pieces of pizza each, leaving the rest of us starving.

 

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Adventures in Fillmore

mpollock June 3, 2012 11:09 pm

FILLMORE, UTAH – [Guest bloggers Matt Peppers and Will Cary]

As Dr. Wilson so kindly stated in his last blog post, the Utah group arrived safely at Salt Lake City International Airport on Saturday, June 2. After stopping briefly at a Target to get various essentials, we finished our two-hour drive at Fillmore (see here for how the drive went), the town we will reside in for the next two weeks. We are staying at a KOA Kampsite in some kozy little kabins. After getting acquainted with the campsite layout, we explored some of the finer cuisine options, finally settling on Larry’s Drive-In Diner across the road. Will tried a marshmallow milkshake that gave him enough sugar to power through the jet lag associated with the time zone change. After a filling meal, the group headed back to the campsite for a quick group meeting to go over the schedule for Sunday, which promised to be an orientation day to the Black Rock Desert and what we could expect. Following the meeting, everyone felt the effects of travel and promptly retired to their respective cabins for the evening.

Dr. Judge lays out the maps for our field site.

The next morning, the group met at 9:30 to pack lunches for the day followed by an overview of equipment and safety precautions that we would need for our fieldwork. With backpacks set up, we gathered as much water as we could carry and set out to our first meeting with the Black Rock Desert. We drove directly west out of Fillmore and, although we couldn’t get onto it, saw Ice Springs, our future field site. We drove around the flow front boundaries and were impressed by how distinct and steep the boundaries actually were. Because today was an orientation day, we set out to find some lava tubes in the Tabernacle Hill lava field. Although we were unsuccessful in locating them, we had some good experience using the GPS units. In addition, we spent a lot of time looking at pressure ridges in the lava field, which adds additional complexity to some students’ projects.

Admitting defeat in finding the lava tubes (and questioning the signage that lead us to that area), we drove on to White Mountain, a hulking mass of gypsum sand a few minutes away. Looking for a place to get out of the 93° heat to eat our lunches, we headed to the one tree we had seen in the entire trip. Stepping out of the car almost had us believing we were in the Bahamas, and the white sand proved a pleasant place to sit. As we moved under the shade of the tree, two small owls flew out from its branches. Waiting cautiously in the leaves above us were three more owls, who seemed upset that we interrupted their lunch with our lunch (3 dead mice taunted them from next to where we were sitting).

The glare of someone who's had his lunch interrupted.

Imagining we are in the Bahamas.

After getting back into the car, we asked Dr. Judge and Dr. Pollock what our next stop would be. Getting only a, “Classified” as a response, all we could do is bounce around in the back of the car down a dusty road. We were pleasantly surprised when the trip ended at a natural hot spring. We eagerly climbed out of the car and jumped in.

Nature's gift.

We continued our first full day by taking a quick stop back at the campsite for a change into dry clothes before heading to meet Dr. Wilson’s, aunt, Ms. Sylvia Huntsman. She graciously welcomed us into her house where we played with her two dogs, Zeke and Bogey and ate delicious apple cobbler. When eyes started to droop from too much time sitting in a comfortable air-conditioned house, we excused ourselves to go eat more food. The fine cuisine of Fillmore proved itself once again at the “Garden of Eat’n.”

The first day ended with a final meeting back at the campsite to set a schedule for Monday (the 7 am departure time was a harsh return to reality) and a beautiful sunset.

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Wooster Geologist on the Blue Ridge of Virginia

Mark Wilson June 3, 2012 8:13 pm

The summer field season has started for Wooster geologists. Greg Wiles is now in southern Alaska with his students doing dendrochronology and geomorphology. Meagen Pollock and Shelley Judge are running an integrated project in west-central Utah with their students doing structural geology, geochemistry, vulcanism and petrology. Watch these pages for their reports!

As for me, I’m on a short vacation. A geologically-rich vacation, of course! My wife Gloria and I are visiting the Shenandoah region of Virginia. We started today in Shenandoah National Park, driving south down Skyline Drive along the Blue Ridge. The weather is spectacular as you can tell from the above image. This is a view near Mile 61 looking west across the Valley and Ridge Province.
The Blue Ridge Province has a bedrock made of igneous and metamorphic Grenville basement rocks up to a billion years old. The Blue Ridge itself, which runs north-south from Pennsylvania to Georgia, is mostly an eroded anticline overturned westward. Directly west is the Valley and Ridge Province. In the image above, the “A” is at the spot where the top photograph was taken. You can easily pick out the physiographic and geological provinces.

Most of the rocks exposed along Skyline Drive in Shenandoah National Park are metabasalts of the Catoctin Formation (Ediacaran, about 570 million years old). A metabasalt is a basalt that has been metamorphosed (unsurprisingly). The original basalts of the Catoctin were erupted during the rifting open of the Iapetus Ocean, a precursor of the Atlantic. Many of these eruptions were on this early seafloor, forming pillows and thick flows. The total basalts in this formation piled up in layers to almost 800 meters thick.
The metabasalt of the Catoctin has a greenish color in many places, giving it the common name “greenstone”. Veins of green minerals, primarily epidote and chlorite, run through the rock, especially in the northern part of the Blue Ridge. This greenstone is occasionally mined to produced chemical-resistant lab surfaces and facing stones.

The dramatic geology was accompanied by beautiful wildflowers. The rocks, flowers, views and weather combined to make an extraordinary day of natural history. Tomorrow we’ll explore how this geology affected human history in very direct ways.

Aquilegia canadensis (Red Columbine).

Penstemon canescens (Hairy Beardtongue).

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Wooster’s Fossil of the Week: a very large clam (Upper Cretaceous of South Dakota, USA)

Mark Wilson June 3, 2012 1:31 am

Our version above of the bivalve Inoceramus is actually rather small compared to how big it can get. The record holder is a specimen 187 centimeters in diameter (over six feet) in the Geological Museum of Copenhagen. This Wooster Inoceramus is from the Pierre Shale of South Dakota, a unit my colleague Paul Taylor and student John Sime once explored in some detail.

Inoceramus means “strong pot”, which I assume must refer to its unusually thick shell with calcite prisms oriented perpendicular to the surface. They also had concentric “wrinkles” that make them easily identifiable even in small fragments. In fact, we can even recognize the isolated prisms of inoceramids in thin-sections of sedimentary rocks. This genus was widespread during the Late Cretaceous, being found from British Columbia to Germany. The had very large gill systems that enabled them to live in poorly-oxygenated waters. It makes sense that they are so common in the dark, carbon-rich sediments of the Pierre Shale.
Inoceramus was named by the dapper James Sowerby (above) in 1814, so it is a genus we have known for a very long time. Sowerby (1757-1822) was an Englishman skilled in natural history as well as scientific illustration. He named the first species of the genus as Inoceramus cuvieri to honor the French scientist Georges Cuvier. His illustration of I. cuvieri is below.
Inoceramus was one of the first invertebrate fossils to be the subject of an evolutionary study in a modern way. Woods (1912) studied various species of Inoceramus in the Cretaceous, noting that it apparently underwent rapid intervals of change. My former student Colin Ozanne and his advisor (and my friend) Peter Harries studied Inoceramus and its relatives in the Western Interior Seaway. Their study, published in 2002, showed that inoceramids were greatly stressed by parasites and predators before their final extinction in the Maastrichtian.

References:

Ozanne, C.R and Harries, P.J. 2002. Role of predation and parasitism in the extinction of the inoceramid bivalves: an evaluation. Lethaia 35: 1–19.

Sowerby, J. 1822. On a fossil shell of a fibrous structure, the fragments of which occur abundantly in the chalk strata and in the flints accompanying it. Transactions of the Linnean Society of London XIII: 453-458. Plate XXV.

Woods, H. 1912. The evolution of Inoceramus in the Cretaceous Period. Quarterly Journal of the Geological Society 68: 1-20.

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Scovel Hall lecture room renovations begin (periodically updated)

Mark Wilson May 31, 2012 3:42 pm

20120531-154554.jpg Our beloved Scovel Hall lecture rooms are finally being updated. The fixed seats in Room 105 endured by generations of student behinds are headed to the dumpster (including their 1985 color scheme) and will be replaced by tables and movable chairs. Seating capacity will go from the huge 83 to a more comfortable 50. The more flexible seating will allow us to move around more in the classroom. Scovel 205 upstairs is also being redone in a similar way.

I’ve taught in the present arrangement for 27 years. I’m anxious to teach in the new improved rooms!

Scovel Room 105 on June 6th with all seats removed.

Where those chairs and the carpet ended up!

 

The new carpet in Scovel 105 on July 31.

 

Scovel 105 in early August 2012.

First class in the new Scovel 100! (History of Life, 8:00 a.m., August 27, 2012)

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Wooster’s Fossil of the Week: a trilobite burrow (Upper Ordovician of Ohio)

Mark Wilson May 27, 2012 1:43 am

This is one of my favorite trace fossils. Rusophycus pudicum Hall, 1852, is its formal name. It was made by a trilobite digging down into the seafloor sediment back during the Ordovician Period in what is now southern Ohio. It may have been hiding from a passing predator (maybe a eurypterid!), just taking a “rest” (what I learned in college), or maybe looking for worms to eat. (There is another example on this blog from the Cambrian of western Canada.)

Rusophycus is always the first trace fossil I introduce in the Invertebrate Paleontology course because it is simple in form and complex in interpretation. It shows that a relatively straightforward process (digging down with its two rows of legs) can have had several motivations. Rusophycus even shows that more than one kind of organism can make the same type of trace. Rusophycus is also found in the Triassic, long after trilobites went extinct. (These were likely made by horseshoe crabs.) It is also good for explaining the preservation of trace fossils. The specimen above is “convex hyporelief”, meaning it is on the bottom of the sedimentary bed and convex (sticking out rather than in). This is thus sediment that filled the open trilobite excavation.

Trilobites making Rusophycus (from http://www.geodz.com/deu/d/Trilobita).

James Hall (1811–1898) named Rusophycus pudicum in 1852. The image of him above is from shortly before his death (photograph credit: The American Monthly Review of Reviews, v. 18, 1898, by Albert Shaw). He was a legendary geologist, and the most prominent paleontologist of his time. He became the first state paleontologist of New York in 1841, and in 1893 he was appointed the New York state geologist. His most impressive legacy is the large number of fossil taxa he named and described, most in his Palaeontology of New York series.

James Hall is in my academic heritage. His advisor was Amos Eaton (1776-1842), a self-educated geologist (he learned it by reading in prison!). One of James Hall’s students was Charles Schuchert (1856-1942), a prominent invertebrate paleontologist. Schuchert had a student named Carl Owen Dunbar (1891-1979) — Schuchert and Dunbar were coauthors of a famous geology textbook. Dunbar had a student at Yale named William B.N. Berry (1931-2011), my doctoral advisor. Thus I feel an intellectual link to old man Hall above.

References:

Baldwin, C.T. 1977. Rusophycus morgati: an asaphid produced trace fossil from the Cambro-Ordovician of Brittany and Northwest Spain. Palaeontology 51: 411–425.

Donovan, S.K. 2010. Cruziana and Rusophycus: trace fossils produced by trilobites … in some cases? Lethaia 43: 283–284.

Hall, J., Simpson, G.B. and Clarke, J.M. 1852. Palaeontology of New York: Organic remains of the Lower Middle Division of the New-York System. C. Van Benthuysen, New York, 792 pages.

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Forbes lists Geology as 7th in its “15 Most Valuable College Majors”

Mark Wilson May 26, 2012 12:59 pm

Sure it is intellectually stimulating, adventurous and fun, but geology is also an important field for the present and future according to the latest issue of Forbes magazine. Geology is ranked as number 7 in the most valuable college majors, with a starting median pay of $45,300 and a “mid-career” rise in pay of 84%. The projected job growth in geology is 19.3%.

Top image: Rob McConnell and Palmer Shonk in Estonia. Bottom image: Sophie Lehmann in England.

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Wooster’s Fossils of the Week: Corkscrew shells from the Pliocene of Cyprus

Mark Wilson May 20, 2012 1:15 am

Steve Dornbos (’97), now a professor at the University of Wisconsin, Milwaukee, and I found these intricate shells by the hundreds in the Nicosia Formation (Pliocene) of Cyprus during his Independent Study field work. (We published this study in 1999.) They are the gastropod (snail) species Turritella tricarinata (Brocchi 1814).

Turritellid snails are still very common today, so we know quite a lot about their ecology and physiology. They are an unusual mix of deposit-feeder and filter-feeder, eating organic particles on the sediment surface and in the water. They do it by creating a current with cilia, drawing water into their mantle cavities. There they have a complex system of tentacles that filter out the largest particles, allowing only the small, digestible goodies onto the surfaces of their gills. The organics are coated with mucus and made into a kind of sticky string that is pulled into the mouth (Graham, 1938). These snails are usually found in large aggregations, just like what we found in the Pliocene of Cyprus.
Turritella tricarinata was originally described by Giovanni Battista Brocchi in 1814 as Turbo tricarinata. Brocchi (1772-1826) was an Italian natural historian who made significant contributions to botany, paleontology, mineralogy and general geology. He was born in Bassano del Grappa, Italy, and studied law at the University of Padova. He liked mineralogy and plants much better than lawyering, though, and became a professor in Brescia. His work resulted in an appointment as Inspector of Mines in the new kingdom of Italy.

Brocchi wrote the first thorough geological assessment of the Apennine Mountains, and he included in it a remarkable systematic study of Neogene fossils. He compared these fossils to modern animals in the Mediterranean — a very progressive thing to do at the time.
Above are drawings made by Brocchi of the turritellid fossils he found in the Apennines during his extensive study published in 1814. Note that in the Continental fashion still followed today, the shells are figured aperture-up. Americans and the rest of the English-speaking world orient them in the proper way.

Brocchi was an adventurous traveler, but it eventually did him in. He died in Khartoum in 1826, a “victim of the climate” and a martyr for field science.

References:

Brocchi, G.B. 1814. Conchiologia fossile subapennina con osservazioni geologiche sugli Apennini e sul suolo adiacente. Milano Vol. I: pp. LXXX + 56 + 240; Vol. II, p. 241-712, pl. 1-16.

Dornbos, S.Q. and Wilson, M.A. 1999. Paleoecology of a Pliocene coral reef in Cyprus: Recovery of a marine community from the Messinian Salinity Crisis. Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen 213: 103-118.

Graham, A. 1938. On a ciliary process of food-collecting in the gastropod Turritella communis Risso. Proceedings of the Zoological Society of London A108: 453–463.

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Wooster’s Fossils of the Week: Intricate networks of tiny holes (clionaid sponge borings)

Mark Wilson May 13, 2012 1:28 am

The most effective agents of marine bioerosion today are among the simplest of animals: clionaid sponges. The traces they make in carbonate substrates are spherical chambers connected by short tunnels, as shown above in a modern example excavated in an oyster shell. The ichnogenus thus created is known as Entobia Bronn, 1838. I’ve become quite familiar with Entobia throughout its range from the Jurassic through the Recent (with an interesting early appearance in the Devonian; see Tapanila, 2006).
The holes in this Cretaceous oyster are the sponge boring Entobia; the cyclostome bryozoan is Voigtopora. This specimen is from the Coon Creek Beds of the Ripley Formation (Upper Cretaceous) near Blue Springs, Mississippi. (This specimen was collected during a 2010 Wooster/Natural History Museum expedition to the Cretaceous and Paleogene of the Deep South.)
This is a modern clam shell showing Entobia and several other hard substrate dwelling organisms (sclerobionts).
Entobia was named and first described by Heinrich Georg Bronn (1800-1862), a German geologist and paleontologist. He had a doctoral degree from the University of Heidelberg, where he then taught as a professor of natural history until his death. He was a visionary scientist who had some interesting pre-Darwinian ideas about life’s history.

References:

Bromley, R.G. 1970. Borings as trace fossils and Entobia cretacea Portlock, as an example. Geological Journal, Special Issue 3: 49–90.

Bronn, H.G. 1834-1838. Lethaea Geognostica (2 vols., Stuttgart).

Tapanila, L. 2006. Devonian Entobia borings from Nevada, with a revision of Topsentopsis. Journal of Paleontology 80: 760–767.

Taylor, P.D. and Wilson, M.A. 2003. Palaeoecology and evolution of marine hard substrate communities. Earth-Science Reviews 62: 1-103.

Wilson, M.A. 2007. Macroborings and the evolution of bioerosion, p. 356-367. In: Miller, W. III (ed.), Trace Fossils: Concepts, Problems, Prospects. Elsevier, Amsterdam, 611 pages.

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