mpollock December 12th, 2013
SAN FRANCISCO, CA – Today was a big day for Wooster Geologists Alex Hiatt (’14) and Mary Reinthal (’16). They presented their work on subglacial volcanic ridges, along with Ellie Was (’14, Dickinson College).
Ellie (left), Mary (center), and Alex (right) presented their posters in a physical volcanology session at AGU 2013.
You may remember these fantastic undergraduate researchers from last summer’s field season. They’ve been hard at work since then, processing the images and samples that we collected. Ellie was lead author on a poster titled, “Along-axis variations in volcanology and geochemistry of a pillow-dominated tindar: Comparison of exposures in Undirhlithar and Vatnsskarth quarries, Reykjanes Peninsula, Iceland.” She carefully traced individual pillow lavas on Gigapan images and constructed the first ever (we think) pillow-size distribution. Her work can help us understand permeability and fluid flow in pillow-dominated crust.
Alex was lead author on a poster titled, “Estimated hydrostatic/cryostatic pressures during emplacement of pillow lavas at Undirhlithar quarry, Reykjanes Peninsula, southwest Iceland.” He is conducting a high-resolution FTIR study of volatiles in the quenched glass rims of basaltic pillow lavas. His ultimate goal is to estimate quench pressures and, by extension, ice thickness. Thanks to all of those who visited his poster this morning and offered excellent suggestions for next steps!
The last four days have been packed with science, far too much to cover here. Here are some final highlights from this year’s meeting:
- SolEx: SolEx is a model that we’ll be able to use to calculate CO2 and H2O solubility in basaltic melts at low pressures. Thanks to Dr. Jacqueline Dixon for pointing us to it!
- Northeast National Ion Microprobe Facility (NENIMF): Since SolEx takes into account melt composition and total volatiles, like S and Cl, we might be interested in using the SIMS at NENIMF to analyze our glasses in the future. Thanks to Dr. Adam Soule for sending us to the NENIMF booth in the exhibit hall.
- 3-D Photogrammetry: Some researchers have used 3-D photogrammetry of oblique photos taken from aircraft to trace inaccessible lava flows near the tops of mountains in eastern Iceland. Our solution in the quarries has been to combine Gigapan with high-precision GPS and laser range finder. Perhaps the 3-D photogrammetry approach could be useful.
Mark Wilson October 29th, 2013
DENVER, COLORADO–Tricia Hall (’14) stands before her 2013 Geological Society of America poster: “Petrologic and kinematic analysis of deformation bands in the Late Cretaceous Sixmile Canyon Formation, central Utah“. She worked hard this summer with Dr. Shelley Judge pounding away at deformation bands to use them as keys to sorting through complex structural events. Kyle Burden (’14) is below with his collaborative poster: “Reconstruction of eruption conditions based on crater rim stratigraphy at Miter Crater, Ice Springs Volcanic Field, Black Rock Desert, Utah“. Michael Williams (’16), Candy Thornton (’14) and Cam Matesich (’14) are also co-authors on this presentation of summer work in the Black Rock Desert with Dr. Judge and Dr. Pollock, along with students and faculty from Albion College.
Team Utah closed out the 2013 Wooster student presentations at the Geological Society of America annual meeting in Denver. The faculty is very pleased … and not a little exhausted!
Mark Wilson October 28th, 2013
DENVER, COLORADO–Michael Williams (who chose a particularly impressive shirt and tie today) and Dr. Shelley Judge presented a poster at the Geological Society of America meeting entitled: “Evidence for inflation and deflation in lavas flows west of Miter Crater, Ice Springs Volcanic Field, Black Rock Desert, Utah.” This was the first offering from this year’s Team Utah. Michael proved to be an effective and animated communicator — and possibly the only sophomore presenting at the meeting!
mpollock July 20th, 2013
KAGOSHIMA, JAPAN – The 2013 Scientific Assembly of IAVCEI, the International Association of Volcanology and Chemistry of the Earth’s Interior, has officially started in Kagoshima, Japan.
IAVCEI leaders and local elected officials welcome delegates from ~60 countries in today’s opening ceremony.
The conference is a volcanologist’s dream, with sessions focused on every aspect of volcanology and a mid-conference field trip to Kagoshima’s own volcano, Sakurajima (currently at alert level 3). Day #1 didn’t disappoint. I’ve already co-chaired a session on Lava Flows with a fantastic group of international scientists and gave a talk on the dynamics of pillow-dominated subglacial eruptions recorded in Undirhlithar quarry on the Reykjanes Peninsula in southwest Iceland. You may remember that Lindsey Bowman (’12) and Becky Alcorn (’11) completed I.S. theses in Undirhlithar. Here are some highlights from our presentation:
Undirhlithar quarry is a unique exposure that provides insights into the internal architecture of a glaciovolcanic pillow ridge.
Most of the quarry is made of pillow lavas, which are emplaced during effusive subaqueous eruption. We’ve also identified intrusions and dikes that feed the overlying pillow lava flows.
There are also fragmental units in the quarry. The tuff, or fine ashy layers, probably represent periods of quiescence between eruptive events. The tuff-breccia, which has larger clasts, are formed during explosive activity and as a result of gravitational collapse along steep slopes.
Combined with geochemical and petrological variations, we’ve generated a model for how the units exposed in Undirhlithar were emplaced that involves a complex sequence of multiple eruptive events.
The sequence of events occurred under changing magmatic and eruptive conditions, which suggests that even small glaciovolcanic ridges can be constructed in a complicated manner.
mpollock June 20th, 2013
UTAH – Congratulations to Team Utah on completing a successful field season!
Team Utah 2013 at the end of their last day in the field. From left to right: (front) Dr. Thom Wilch (Albion), Michael Williams (’16, COW), Ellen Redner (’14, Albion), Cam Matesich (’14, COW), Adam Silverstein (’16, COW); (back) Kyle Burden (’14, COW), Dr. Meagen Pollock (COW), Ben Hinks (’14, Albion), Candy Thornton (’14, COW), Tricia Hall (’14, COW), and Dr. Shelley Judge (COW). Credit: T. Wilch
Although we’re parting ways, the students will be working on the research. They have plenty of data to analyze and lab work to do, so continue following the blog to stay updated on their progress.
Mark Wilson June 16th, 2013
CATANIA, SICILY, ITALY–The very last field trip stop — and final event — of the International Bryozoology Association Conference was a trip to the south side of Mount Etna. We drove to a spot that had significant activity in 2000 and 2001. Several lateral craters appeared on the side of the mountain, and the lava flows buried parts of a restaurant and shop complex. They threatened to destroy the base of a cable car system, but firefighters with hoses managed to divert the flow by cooling it with water.
My Belgian friend Hans De Blauwe and I decided to choose one of these smaller craters and hike to it within our allotted visit time. We picked this one in the center because of its symmetry and the flows that streamed from it. All of these features in and around this cone formed in 2001.
We soon saw that our cone was the first of at least three cones descending in a row down the slope. The lava flow shows very distinct levees on its sides where the lava lapped over its banks and cooled, creating a walled channel.
There are many car- and house-sized boulders of non-vesicular basalt scattered about. I assume these were thrown from the throats of explosive craters.
We found this very cool lava tube, indicated first by a long walled channel that apparently represents a collapsed portion of the tunnel. A lava tube is formed when the periphery of a flow cools into hard rock and the still-fluid interior empties. We explore a beautiful ancient example on our Mojave Desert field trips.
Our lava tube is open at both ends. Here Hans is crouching in the larger of the entrances.
I took a flash image of the interior. You can see small “lavasicles” (cooled drips of lava) on the ceiling, along with a white crust of some sulfurous minerals.
Here Hans is picking his way through the aa flow. In the lower right is another lava tube that extends back about three meters.
The flowers on this volcanic slopes are very interesting. Hardy pioneers, they are. There are numerous clusters of these mounds of greenery. It appears that the plants settled on a bit of ash and then grew centripetally. The surrounding ash was eroded away, but the roots of these plants held onto their patches, eventually producing mounds as the surrounding sediment was removed.
The mounds are made mostly of this spiny flowering plant. Maybe Hans will provide me with names later.
These purple flowers often form in rings around the bases of the mounds.
Nice white flowers on the 2001 ash layers.
Somehow there are always daisies around, even in the most surprising places.
Finally, here is a view from our craters toward Catania and the coast. A 2001 lava flow is directly below us. In the middle distance you can see a series of small cones, many of which were active in historical times. Catania is certainly in a volcanic hazard zone. The geologists, though, worry far more about earthquakes here than eruptions. An eruption, after all, gives you much more warning than a sudden and devastating ‘quake. Considering all this, and despite the occasional tornado and blizzard, Ohio looks like one of the safest places on Earth.
And to beautiful and much wetter Ohio I now return.
[A late addition to this post (June 23, 2013). Above is a close-up of ash erupted from Mount Etna in April 2013.]
mpollock June 16th, 2013
Zion National Park, Utah – Team Utah took a break from the volcanic field to explore some of Utah’s (more famous) sedimentary rocks. We visited Zion, Utah’s first National Park.
Zion is a geological wonderland, featuring striking sheer cliffs and narrow slot canyons.
The students hiked the Kayenta trail to the Emerald Pools. Credit: T. Hall
This is the Court of the Patriarchs, so named for figures from the Old Testament by Frederick Vining Fisher in 1916. Abraham Peak is on the far left. Isaac Peak is in the center. Jacob Peak is the white peak that can be viewed just beyond Mount Moroni on the right.
View of The Narrows, a trail that winds through slot canyons in the famously cross-bedded Navajo Sandstone.
The Wooster crew cools off in the Virgin River at the end of an awesome day in Zion. Credit: T. Wilch
Mark Wilson June 16th, 2013
CATANIA, SICILY, ITALY–Today we had our last field trip associated with the 2013 International Bryozoology Conference. We traveled to the east coast of Sicily at Castelluccio, which is south of Catania and north of Syracuse. The weather could not have been better. It was, as a commenter has said, “impossibly beautiful”.
The view above is of Early Pleistocene limestones resting on tholeitic basalt flows. As our guides said, in this place we could see the interplay of extensional tectonics, regional uplift, and glacially-controlled sea-level changes. The visuals were stunning. In the background you can see the east flank of Mount Etna.
The limestones were of shallow-water origin and very diverse. One layer was almost completed bioturbated (biologically stirred up) by crustaceans, producing a trace fossil of connected tunnels called Thalassinoides.
Fossils were abundant in some units. Here is an horizon rich in scallop shells. These shells are often preferentially preserved because they are made of hardy calcite rather than chemically unstable aragonite like most other mollusk skeletons.
The interactions between the basalt flows and the calcareous sediments were fascinated. Above you see a black basaltic dike cutting vertically through the limestones. Why there are no visible baked zones is a mystery to me.
In this image we have basalt above and sediments below. The pink color of the limestones tells us they were cooked by the hot lava that flowed over them.
There are a variety of post-depositional geological processes operating at this outcrop. One of them is the superimposition of beachrock during sea-level highstands. Beachrock is a cemented sediment formed in the surf zone by precipitation of carbonate. This particular beachrock was plastered onto an eroded limestone cliff like stucco. You can see black basalt among the diverse clasts.
Over it all rules Mount Etna, here viewed from the top of the outcrop. It was unusually smoky today, which does not show well in our photographs because of the murky haze. We headed to this behemoth for the second and last stop of our field trip.
mpollock June 13th, 2013
UTAH – Team Utah has been seriously geologizing in the Ice Springs Volcanic Field over the past two days. Here’s a photo-journal of the crew at work.
Ben Hinks (’14, Albion) examines a stack of thin pahoehoe flows in his field area. Credit: M. Pollock
Cam Matesich (’14, Wooster), Ben, and Tricia Hall (’14, Wooster) look for samples in an ‘a’a lava flow in Cam’s field area. Credit: T. Wilch
Synchronized hammering was the only way we could get samples of the tough lava. From left to right: Cam, Ellen Redner (’14, Albion), Kyle Burden (’14, Wooster), and Ben. Credit: M. Pollock
Ellen hands Ben the fruits of her labor. Kyle is ready to bag it. Credit: T. Wilch
Candy Thornton (’14, Wooster) directs the data collection at her field site. Credit: T. Wilch
Kyle, Ben, and Candy document the stratigraphy of an isolated lava pillar in the middle of a depression. Credit: T. Wilch
Adam Silverstein (’16, Wooster) makes an excellent scale. Credit: M. Pollock
Michael Williams (’16, Wooster) and Cam use the GPS to map the location of features in Candy’s field site. Credit: A. Silverstein
Tricia measures the orientation of volcanic striae. Credit: M. Pollock
mpollock June 12th, 2013
ICELAND – Team Iceland is nearly ready to return to the states, but not before we share what we’ve learned with the Icelandic community. Our home-away-from-home, the Hraunbyrgi guesthouse, is also home for the Hafnarfjörður scouts. To celebrate the end of their season, the scouts are having a large, nationwide camp-out at a site just south of the pillow quarries. So, for their final meeting, the scouts met with Team Iceland to learn about our research.
Dr. Ben Edwards shows the local scouts a sample of pillow basalt.
The scouts learned that they’ll be camping along a ridge made of pillow basalts, which formed when lava erupted under a glacier. They also heard about the kinds of information that we can learn from the pillow basalts, like how the upper portion of the ocean floor is formed and how thick the ice was that once covered the Reykjanes Peninsula. The scouts returned the favor and taught Team Iceland a few new Icelandic words. What a fantastic way to end a successful field season!