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 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.
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!
mpollock June 11th, 2013
UTAH – Field work has officially begun for Team Utah, Version 2.0. The team consists of three Wooster seniors (Kyle Burden ’14, Cam Matesich ’14, Candy Thornton, ’14) and two Wooster sophomores (Adam Silverstein ’16, Michael Williams ’16). Tricia Hall (’14) is a returning member who has graciously agreed to stay in Utah after her IS field work to help us with our data collection. This year, we’re also joined by Dr. Thom Wilch and two senior geologists (Ellen Redner ’14 and Ben Hinks ’14) from the Albion College Department of Geological Sciences. Needless to say, we’re a small army, and we’re ready to find the answers to questions raised during last year’s reconnaissance investigations of Ice Springs Volcanic Field in the Black Rock Desert.
After a morning on the cinder cones, we descended into the lava fields.
Mark Wilson June 4th, 2013
CATANIA, SICILY, ITALY–They may look like impressive sea stacks to you, but it turns out these are three huge stones thrown by the aggrieved and wounded cyclops Polyphemus at Odysseus as he escaped that infernal cave. Who knew?
This morning we traveled north of Catania to the Ciclopi Marine Protected Area near Aci Castello and Aci Trezza to look at the evidence of the ancient volcanic activity that led to Mount Etna, and to snorkel and dive on the life-encrusted rocks in the blue, blue waters.
We took a boat ride all of about 300 meters across the bay to the tiny island of Lachea, shown above. Notice that there is a crack running through the rocks seen just above the boat. This is an active fault that runs through the middle of the island. Also note that there is a mix of light and dark rocks visible.
Lachea is a combination of whitish marls and claystones above with black basalt injected from below. This is the very beginning of volcanic activity in this region as hot magma began to work its way into the overlying sediments of a shallow sea. When the lava erupted onto the seafloor, masses of pillow basalts formed (see previous post). The cyclopean rocks in the top image are eroded roots of the massive basalt flows. They show beautiful columnar jointing.
The island of Lachea and its surrounding rocks has been the site of a research station for over a century. The fauna and flora of both the island and the seafloor down to 110 meters are protected by law.
This pretty green lizard is common on Lachea and apparently endemic (found only there). It is Podarcis sicula ciclopica. Its mating season of three months is about to begin, so there was much lizardly activity.
One of the first places we visited on the island was this tiny historical grotto. Only five of us could crawl into this completely dark chamber at a time. Once inside you can carefully stand up and (at least some of us) touch your head on the ceiling. That turned out to be a mistake because the guiding biologists then show you the unique cave spiders hanging on their webs about your ears!
Finally I must show you at least one of our large Sicilians lunches, this one back in Catania after our morning marine excursion. We are eating well, if a bit later than usual — and with much more time in the process!
mpollock May 31st, 2013
ICELAND – You may remember that Team Iceland is trying to determine the origin of interesting columnar-jointed features exposed in the interior of a subglacial pillow ridge. We have several hypotheses, one of which is that they could be related to the internal magma plumbing system. There’s no better way to know what’s inside of a volcano than by actually going there. Fortunately, we’re able to explore the interior of nearby Thrihnukagigur Volcano through the Inside the Volcano Tour. If you have the chance, you should check out their amazing image and video galleries.
Thrihnukagigur has three volcanic peaks, one of which is a cinder cone with a crater that opens up into a 400 ft deep volcanic chamber. Our goal was to explore the chamber for units and structures that might be analogous to the features we observed in the quarries. The tour began with a 2 mile hike to the volcano over lava flows that were 4,000 and 10,000 years old.
It was an incredible Icelandic experience! Much thanks to the Inside the Volcano Team for their excellent knowledge, guidance, and hospitality!
mpollock May 27th, 2013
ICELAND – We spent Sunday morning discussing all of the features that we’ve seen during our reconnaissance investigations. After comparing notes, we defined several lithofacies, or mappable units with specific lithologic features. Our coherent lithofacies include pillow lavas, dikes, and intrusions while our fragmental lithofacies are units like volcanic breccia and lapilli tuff. By the end of the morning, Team Iceland was ready for their first group assignment: map a section of the quarry wall.
mpollock June 13th, 2012
SALT LAKE CITY, UTAH – On Tuesday, Team Utah visited the Core Research Center at the Utah Geological Survey. The repository includes cores and cuttings from more than 4000 wells, on-site microscope facilities, and a friendly and knowledgeable staff. We suspect that the sedimentary xenoliths that Kevin has been finding represent Lake Bonneville sediments. Tom Dempster and Peter Nielsen pulled out some cuttings for us to look at and set up the microscope. Mark Gwynn showed us some core that they recently recovered from an area near our study site.
We also had the chance to meet with Amanda Hintz, a UGS geologist with an expertise in the Black Rock Desert.
Finally, Stephanie Earls, the UGS Research Librarian, was so helpful in finding historic aerial photographs for us.
After a productive day at the research center, we visited Bingham Canyon on the way out of town.