Archive for April, 2010

Knowing how to pick your field day

April 27th, 2010

Compare these happy and warm Sed/Strat students to the freezing Petrology group in the previous post. It is all a matter of choosing the right part of April for fieldwork in Ohio. Comes with experience, I suppose.

Andrew Collins, Nick Fedorchuk and Travis Louvain measuring a section of the Logan Formation (Mississippian) in the Miller Lakes area of Wooster. The striped sticks are low-budget Jacob Staffs divided into tenths of meters.

Houston Hoskins, Megan Innis and Sarah Appleton also measuring and describing the Logan Formation at Miller Lakes. This is a class exercise to learn how to construct a simple stratigraphic column.

Sarah Appleton reaching high as she describes a portion of the Logan Formation with interbedded very fine sandstones and quartz-pebble conglomerates. These beds were deposited in the proximal portion of a deltaic complex with the conglomerates representing distributary channel sediments. Marine fossils such as crinoids, brachiopods and bivalves are found in both the sandstones and conglomerates.

Tough Field Trips

April 24th, 2010

I heard that the Sed-Strat field trip was canceled today due to rain. Hmm… I seem to remember a certain Wooster Geology course taking a field trip on a cold, snowy Saturday just a week ago.

Who's that out in the field on a cold, snowy Saturday in April? Petrology.

Yep. Hard Rock = Hard Core! Just saying.

Science Day and Expanding Your Horizons

April 24th, 2010

The Geology Department has been busy reaching out to the community lately. On Saturday, April 17, the College hosted its annual Science Day. GeoClub invited the community to dig for dinosaurs in a sand pit and witness an erupting volcano. See the story in the April 20 edition of the Wooster Daily Record (here’s a link if you happen to have a subscription).

After 4 years of a Wooster Geology education, senior Palmer Shonk ('10) demonstrates his ability to play in the sand.

Today, local middle school girls joined Geology faculty Meagen Pollock and Shelley Judge and several Geology majors to see if they could outrun a dinosaur. The girls measured the stride and size of dinosaur footprints to calculate the speed, then raced to see if they could beat it.

The situation: T-Rex chases Stegosaurus.

Ana helps one of the girls measure the size of the T-Rex footprint.

Melissa helps one of the girls measure the stegosaurus' stride.

Afterward, we played with rocks, minerals, and fossils. The girls got to choose one to take home.

Shelley Judge talks rocks with the Expanding Your Horizons Girls.

Polished stones and agates were today's momentos.

We even had time to demonstrate the use of a rock hammer.

And time to tell (bad) Geology jokes!

Wooster Geologists Participate in the Senior Research Symposium: A Celebration of Independent Study

April 23rd, 2010

WOOSTER, OHIO–Several of our senior geology majors gave poster and oral presentations in the 2010 Senior Research Symposium today.  We are very proud of their accomplishments and the skills they have in articulating their projects to a very diverse audience.  It was a good day for the department.

Kelly Aughenbaugh delights in answering questions about her topic: "Reconstructing Late Holocene Glacial Movement in Muir Inlet Glacier Bay, Alaska."

Colin Mennett gave an oral presentation on his project: "Decline in Alaskan Yellow-Cedar: Tree-Ring Investigations into Climatic Responses and Possible Causes, Glacier Bay, Alaska."

Bill Thomas presented: "Petrographic and Mapping Analysis of Volcanic Tuffs in the Green River Formation Cuestas, Sanpete Valley, Utah."

Palmer Shonk explains to Anna Mudd his research: "Paleoecological Reconstruction of the Late Silurian (Pridoli) Äigu Beds of Saaremaa Island, Estonia."

Rob McConnell and his poster titled: "Paleoenvironmental analysis of the Silurian Jaani Formation on the island of Saaremaa, Estonia."

Travis Brown describing his work: "Directly-controlled lichen growth curves for western Spitsbergen, Svalbard."

A pleasant spring afternoon of geology in Ohio

April 22nd, 2010

The College of Wooster 2010 Sedimentology & Stratigraphy class in Spangler Park near Wooster, Ohio. Small classes are such a delight!

WOOSTER, OHIO–I let my Sedimentology & Stratigraphy class talk me into an afternoon field trip to Spangler (or Wooster Memorial) Park just west of town. It was a perfect day of sunshine and cool breezes. While I made plans to measure sections and do other formal geological work, we ended up just enjoying the creek, birds, flowers, rocks, fossils, trees and other delights of Ohio in the spring. We could not have found a better way to celebrate Earth Day.

With the fancy nails of Megan Innis for scale, this is a granitic dropstone in a greenstone known as the Gowganda Tillite. In one of those wonderful geological twists, this rock is a glacial deposit formed in Ontario, Canada, 1.8 billion years ago. It was much later carried to Ohio by a Pleistocene glacier. The dropstone is thus at least twice-removed by ice from its original source.

The class crossing Rathburn Run which flows through the park. The creekbed has many fossiliferous pieces of sandstone, shale and limestone.

An Eastern Garter Snake (Thamnophis sirtalis sirtalis) on an oak leaf in Spangler Park.

Lava pour!

April 16th, 2010

A cauldron of lava poured onto an angled surface at Syracuse University. Photograph courtesy of Jeff Karson, Department of Earth Sciences at Syracuse.

SYRACUSE, NEW YORK–Today I gave a presentation at Syracuse University as part of the fifth annual Central New York Earth Sciences Student Symposium.  My topic was the rise of modern marine ecosystems in the Jurassic.  Exciting enough, of course, but the real fun was in an event which caught me by surprise: a “lava pour” organized by Professor Jeff Karson with the Sculpture Department at Syracuse.  (This is a type of interdisciplinarity I hadn’t seen before!)

The pour, as they call it, began with the addition of about 100 pounds of basalt (collected in Oregon where they have plenty of it) into a hardened steel cauldron.  The cauldron is then lowered into a below-ground furnace and heated for about four hours until all is incandescent.  Several people in protective gear (it would not protective enough for me, though!) open the furnace and attach a winch to the cauldron and lift it to the surface.  At this point the crowd (including me) had been pushing as close as allowed to the furnace.  We immediately backed up when the blast of heat from the cauldron — which was glowing like the sun — struck us.  Molten rock is serious stuff.

A bit of the lava was first poured into a porcelain pipe bent like an elbow with the lower part ending in a large basin of water.  The pipe had been plugged at the base with wax so the lava would build up before flowing through to the water.  The idea was to make a lava pillow, a type of flow structure made when a natural flow meets water as under a glacier, in a lake or in the ocean.  (See the natural pillow lavas studied last summer by the Wooster Iceland Team.)  The wax immediately and explosively ignited, sending a spout of flame upwards which took everyone by surprise (including the crew).  The fire was short-lived, though, as the lava flowed through into the now-boiling water.

The second pour was onto a cold rock monitored by a digital remote thermometer to record its cooling rate.  This time the lava poured out like syrup, making a flat, bubbling sheet which quickly grew a dark crust which spattered tiny glass shards as the cooling bubbles burst.

The third and final pour was onto blocks of dry ice, apparently to simulate the surface of Mars.  (Really.  Not just to “see what happens”.  This is professional geology, after all!)  The lava hit the dry ice with an extraordinary hiss and then skittered off onto the sand below.  Apparently the vapor built up immediately by the rapidly-sublimating ice did not allow the lava to stick or even stay on the ice itself.  The result was ropy strings, droplets and “angel hair” of cooled lava.

Afterwards, when the cauldron had been scrapped empty and the heat had dropped to a tolerable level, we gathered around the three pour sites and marveled.  The flow on the rock slab continued to bubble and crack, producing some exquisite brown fragments of almost-transparent glass.  We picked up a few cooled pieces and tried to imagine this process scaled up to natural proportions.

Thank you to Jeff Karson for such an innovative idea, this lava pour, and sharing it with all of us.  Way cool.  Mike Cheatham has posted a webpage of photos showing our lava pour in its stages.