Archive for May, 2013

A Journey Inside the Volcano

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.

View of Thrihnukagigur Cone and the Inside the Volcano hut (at the base to the right) from the surrounding lava fields. Photo Credit: Ellie Was

View of Thrihnukagigur Cone from the surrounding lava fields. The Inside the Volcano tour has a warm hut at the base of the cone. (The white structure is difficult to see against the field of snow). Photo Credit: Ellie Was

At the hut, we were fitted with safety equipment for our descent into volcano.

At the hut, we were fitted with safety equipment for our descent into the volcano. Photo Credit: Liz Plascencia

We crossed this bridge to get into the open-air basket that took us into the volcanic chamber. Photo Credit: Ellie Was

We crossed this bridge to get into the open-air basket that took us into the volcanic chamber. Photo Credit: Ellie Was

The view down the open volcanic neck from the basket. Photo Credit: Ellie Was

The view down the open volcanic neck from the basket. Photo Credit: Ellie Was

View from below of the lift descending into the chamber.

View from below of the lift descending into the chamber.

Michael Williams ('16, Wooster), Adam Silverstein ('16, Wooster), and Liz Plascencia ('16, Dickinson) in the volcano. Photo Credit: Liz Plascencia

Michael Williams (’16, Wooster), Adam Silverstein (’16, Wooster), and Liz Plascencia (’16, Dickinson) in the volcano. Photo Credit: Liz Plascencia

We saw some features that are analogous to our quarry observations. Here, on the left, we see a contact between the underlying Moberg Formation and the overlying lavas that make up much of the volcanic center. The dark black vertical rocks near the center of the photo are dikes that cut across the lava flows and have heated and altered the surrounding rocks, turning them red.

We saw some features that are analogous to our quarry observations. Here, on the left, we see a contact between the dark underlying Moberg Formation and the colorful overlying lavas that make up much of the volcanic center. The black vertical rocks near the center of the photo are dikes that cut across the lava flows. The dikes have heated and altered the surrounding rocks, turning them red.

This appears to be an irregularly shaped intrusion with an open cavity.

This appears to be an irregularly shaped intrusion with an open cavity that might have transported magma to different parts of the volcano during the eruption. Notice the person in the center bottom for scale.

I have failed to mention that we battled driving sleet and 45 mph winds to hike to and from the volcano. Here's part of our group linking arms to stay on their feet as they hike back from the volcano. Our guides were superb and made sure everyone was safe during each part of our trip.

Did I mention that we battled driving sleet and 45 mph winds to hike to and from the volcano? Here’s part of our group linking arms to stay on their feet as they hike back from the volcano. Our guides were superb and made sure everyone was safe during each part of our trip. Photo Credit: Liz Plascencia

Ellie Was ('14, Dickinson), Alex Hiatt ('14, Wooster), and Aleks Perpalaj ('14, Dickinson) after their return hike. Photo Credit: Liz Plascencia

Ellie Was (’14, Dickinson), Alex Hiatt (’14, Wooster), and Aleks Perpalaj (’14, Dickinson) after their return hike. Photo Credit: Liz Plascencia

Team Iceland warms up with hot coffee and homemade Icelandic stew.

Team Iceland warms up with hot coffee and homemade Icelandic stew. Photo Credit: Liz Plascencia

The t-shirt that says it all. Photo Credit: Liz Plascencia

The t-shirt that says it all. Photo Credit: Liz Plascencia

It was an incredible Icelandic experience! Much thanks to the Inside the Volcano Team for their excellent knowledge, guidance, and hospitality!

Exploring Reykjavik, Iceland

May 30th, 2013

ICELAND – Team Iceland had a chance to explore Iceland’s capital city of Reykjavik today. Here are the photo highlights of their day:

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Team Iceland poses with Leifur Eiriksson in front of Hallgrimskirkja, Reykjavik’s landmark church that is modeled after columnar jointed basalt. Photo Credit: Aleks Perpalaj

Interior of Hallgrinskirkja. Photo Credit: Alex Hiatt

Interior of Hallgrinskirkja. Photo Credit: Alex Hiatt

Team Iceland pauses to listen to the organ in Hallgrimskirkja. Photo Credit: Michael Williams

Team Iceland pauses to listen to the organ in Hallgrimskirkja. Photo Credit: Michael Williams

The view looking east across Kopavogur. Photo Credit: Alex Hiatt

The view looking east across Kopavogur. Photo Credit: Alex Hiatt

 

They also visited the Natural History Museum in Kopavogur. Photo Credit: Alex Hiatt

A visit to the Natural History Museum in Kopavogur. Photo Credit: Alex Hiatt

Wow! Look at the size of that tree! Photo Credit: Liz Plascencia

Wow! Look at the size of that tree! Photo Credit: Liz Plascencia

Team Iceland also documented the rock displays, of course. Photo Credit: Liz Plascencia

Of course, they also found natural history at the Volcano Museum. Photo Credit: Liz Plascencia

They found a nice cafe for lunch. Photo Credit: Michael Williams

Lunch in a nice cafe. Photo Credit: Michael Williams

A little shopping in the tourist district. Photo Credit: Alex Hiatt

A little shopping in the tourist district. Photo Credit: Alex Hiatt

A view of Reykjavik across City Pond. Photo Credit: Alex Hiatt

A view of Reykjavik across City Pond. Photo Credit: Alex Hiatt

An encounter with the local wildlife. Photo credit: Alex Hiatt

An encounter with the local wildlife. Photo credit: Alex Hiatt

A visit to the Natural History Museum of Utah

May 29th, 2013

NHMU052913SALT LAKE CITY, UTAH–On the last full day of our Utah trip, we toured the Natural History Museum of Utah in Salt Lake City. It is in a spectacular place against the red rocks of the Wasatch Mountains and looking over the Salt Lake Valley. This museum has only been open since November 2011. Its exhibits are very up-to-date and modern.  (My test for recent accuracy is whether birds are acknowledged as dinosaurs and if Australopithecus sediba is in the human evolution section.) I’d like to just share some images from the museum and encourage anyone in Salt Lake City to visit it.

EoceneLake052913Dr. Judge will be impressed with the attention paid to exhibits on the Green River Formation (Eocene). This tableau is designed to show animals in the water (below) and on the beach (above). Note the stromatolites on the shoreline representing some of the features she and her students have worked on in the Green River Formation.

585_Deinosuchus_hatcheri_052913Utah is extremely rich in Mesozoic vertebrate fossils. Here is an impressive skeleton of Deinosuchus hatcheri from the Cretaceous.

CeratopsianWall052913The dinosaur exhibit is world-class. Here is a wall of ceratopsian dinosaur skulls showing evolutionary relationships.

DinoPelvis1_052913My History of Life students are well trained in sorting out major dinosaur groups by their pelvic bones. They could tell you, for example, if this is an ornithischian or a saurischian dinosaur.

DinoPelvis2_052913And this set is of the other group. Can you see the differences?

dinohead052913It appears this dinosaur had barnacles for eyes!

PaleontologistsBehindGlass052913Here is the classic paleontologists-behind-glass exhibit of a working laboratory. (I wonder why they never put working petrologists on display?)

NHMUview052913The architects knew exactly what they were doing when it came to designing the building to take full advantage of the setting. The Salt Lake Valley is fully visible from every floor.

What a great place to end our little Utah excursion this year. The real Team Utah of Wooster Geology will be back in the state next month.

Fantastic Weather Makes Productive Field Days

May 28th, 2013

ICELAND – Team Iceland made the most of the beautiful weather over the last two days. After spending all day in the field yesterday, we went back after dinner;  the lighting was just right to take GigaPan images of the field site.

Aleks ('14, Dickinson) and Ben (Dickinson) set up the GigaPan to take a panoramic image of the quarry.

Aleks (’14, Dickinson) and Ben (Dickinson) set up the GigaPan to take a panoramic image of the quarry.

This is a simple panorama made of three images stitched together. The GigaPan system allows us to merge over 100 images to produce a high-resolution image.

This is a simple panorama made of three images stitched together. The GigaPan system allows us to merge over 100 images to produce a high-resolution image.

Our plan is to couple the high-resolution GigaPan images with elevation information from the laser range finger. Here, Michael ('16, Wooster) and Ellie ('14, Dickinson) are recording the elevations of contacts along the quarry walls.

Our plan is to couple the high-resolution GigaPan images with elevation information from the laser range finder. Here, Michael (’16, Wooster) and Ellie (’14, Dickinson) are recording the elevations of contacts along the quarry walls.

Meanwhile, the rest of us are mapping and sampling the different units. Adam ('16, Wooster) and Aleks ('14, Dickinson) are ready to sample a glassy pillow lava.

Meanwhile, the rest of us are mapping and sampling the different units. Adam (’16, Wooster) and Aleks (’14, Dickinson) are ready to sample a glassy pillow lava.

Alex ('14, Wooster) describes a volcanic breccia unit.

Alex (’14, Wooster) describes a volcanic breccia unit. Photo Credit: Aleks Perpalaj

Liz ('16, Dickinson) carefully describes the mineralogy and vesicularity of a sample.

Liz (’16, Dickinson) carefully observes the mineralogy and vesicularity of a sample. Photo Credit: Aleks Perpalaj

Ben and I are having a blast working in the quarry (no pun intended).

Ben and I are having a blast working in the quarry (no pun intended). We’ve seen a number of interesting features that have our minds racing. Photo Credit: Aleks Perpalaj

We're currently puzzled over these large, light gray, columnar jointed features.

We’re currently puzzled by these large, light gray, columnar jointed features.

 

The puzzling features are associated with these steeply dipping pillow lavas, which might lead to some insights into their origin.

The puzzling features are associated with these steeply dipping pillow lavas, which might lead to some insights into the origin of the features and enhance our understanding of the formation of subglacial pillow ridges.

Ancient islands

May 27th, 2013

BonnevilleIsland1

LOGAN, UTAH–Today we explored the area around Promontory, in northern Utah. Among the many beautiful sites were these rocky, faceted hills that several thousand years ago. This particular hill was intriguing although inaccessible. (It is on a vast tract of land owned by the rocket company ATK. Trespassing is discouraged and no doubt at times very discouraging!) You can see this feature on Google Maps at 41° 37′ 21.11” N and 112° 21′ 42.28” W. Note the cone shape of the top that appears to be sitting on a flat layer beneath. That flatness is a beach terrace of ancient Lake Bonneville. It was formed 14,500 to 16000 years ago by wave action eroding away the hillsides, with the pinnacle exposed above water. (I love wave-cut terraces. Wooster Geologists have noted them before in this blog.)

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Here is a Google Earth view of the scene from the south and above. You can see the terrace cut deeply into the hill and extending to the sides. The highway below is where we stopped for the top photograph. Now note that curvy structure of rocks in the lower right of the above image. A close-up of it is shown below.

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This is a plunging fold. I can’t tell if it is a plunging anticline or syncline because I couldn’t visit it. You can make it out on the lower right of my photograph at the top of the page. These rocks are mantled with sediments from Lake Bonneville. In this case the sediments are coarse sand and gravels because of the lake energy at this shoreline. The exposed rocks are limestones, probably from the Paleozoic.

WellsvilleTerraces052713

On the other side of the valley, on the northwest end of the Wellsville Mountains, two terraces can be seen. The top one against the mountain is the 14500-16000 year-old one we saw throughout the Promontory region. The lower one is younger and made after lake levels dropped precipitously following a catastrophic flood through Red Rock Pass in southern Idaho (which I visited three years ago and recorded in this blog). Note on the lower left that it is being mined for sand and gravel. We see this throughout the area because these terrace deposits are so well sorted and useful in making concrete, building roadbeds, and the like. I learned recently that these kinds of deposits are in a category called “alloformations” because they are laid on top and against much older units.

Oh yes, and what else happened in Promontory, Utah? May 10, 1869!

Promontory052713

Mission Possible: Mapping the Quarry Walls

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.

The students worked diligently to record comprehensive field notes.

The students worked diligently to record comprehensive field notes.

Image of a pillow lava that shows some of the features the students were looking for: radial columnar joints, glassy rind, interbedded hyaloclastite.

Image of a pillow lava that shows some of the features the students were looking for: radial columnar joints, glassy rind, and interbedded hyaloclastite.

The students celebrated the completion of their mission with lunch by large mining equipment.

The students celebrated the completion of their mission with lunch by large mining equipment.

 

 

The Lodgepole Limestone Formation

May 26th, 2013

585_LodgepoleLimestoneFormationLoganCanyonUtah052613

LOGAN, UTAH–Today we hiked up part of Logan Canyon along the south side of the Logan River. Towering above us on either side were massive limestone cliffs, as shown above. The thickest unit is the Lodgepole Limestone Formation (Lower Carboniferous, Tournaisian — about 350 million years old), which is well known throughout the northern Rocky Mountains. I’ve long admired its extent and consistency. It testifies to a shallow carbonate platform that extended from what is now Utah, and Colorado up into central Montana. In fact, correlative carbonates by other names are found from Arizona (the Redwall Limetone) well into Canada. I’ve also been impressed with those many paleontologists over the past century and a half who have managed to pry fossils out of its concrete-like matrix. When they do they have beautiful bryozoans, brachiopods and rugose corals. Some of the best are silicified and removed by dissolving the calcitic matrix from around them.

View of the northern side of Logan Canyon, Utah. The Lodgepole Limestone Formation makes up the major cliff on the right.

View of the northern side of Logan Canyon, Utah. The Lodgepole Limestone Formation makes up the major cliff on the right.

The Lodgepole Limestone Formation is part of the Madison Group of mostly limestones and dolomites. Most of these rocks are affected by karstic weathering, so the terrain often has disappearing streams, sinkholes and caverns.

While the carbonates of the Lower Carboniferous were being deposited in western North America, mixed siliciclastics dominated the east. Last semester’s Sedimentology & Stratigraphy class studied some of those rocks on their field trip to Lodi and the southern edge of Wooster, Ohio. It is always fascinating to look at very different sediments deposited at the same time in different places.

Theory to Practice (Classroom in the Quarry)

May 26th, 2013

ICELAND – Team Iceland is investigating the formation of subglacial pillow lavas on the Reykjanes Peninsula in southwest Iceland.

We are working on a an elongated pillow ridge, which erupted along a fissure system when the peninsula was glaciated.

Google Earth image showing the elongated pillow ridge that we are working on. The pillow ridge erupted along a fissure system when the peninsula was glaciated. 

Quarries along the ridge expose the internal structure of the subglacial deposits, revealing complex sequences of pillow lavas, intrusions, and fragmental units.

One of the active quarries graciously allowed us to use their break room for a morning overview.

Ben Edwards discusses the  geological goals of the project.

Ben Edwards discusses the geological goals of the project. Photo Credit: Jim Ciarrocca

We spent most of the rest of the day working in the inactive part of the quarry.

Team Iceland examines the base of a wall of pillow lavas and discusses the formation of hyaloclastite, the glassy fragmental material that spalls off the pillow rims.

Team Iceland examines the base of a wall of pillow lavas and discusses the formation of hyaloclastite, the glassy fragmental material that spalls off the pillow rims.

As we explored the walls, we found a lava cave. Alex Hiatt ('14) snapped a photo of the hibernating lava bears for Dr. Wilson.

As we explored the walls, we found a lava cave. Alex Hiatt (’14) snapped a photo of the hibernating lava bears for Dr. Wilson.

Aleks ('14, Dickinson) uses a GPS and a laser range finder to "shoot" the quarry walls.

Aleks (’14, Dickinson) uses a GPS and a laser range finder to “shoot” the quarry walls.

Adam Silverstein ('16) points out features on the wall for Aleks to shoot.

Adam Silverstein (’16) points out features on the wall for Aleks to shoot.

The day ended with some reconnaissance work in the active parts of the quarry after the workers had left.

Team Iceland poses with a a fantastic columnar jointed basalt they found on their reconnaissance investigation.

Team Iceland poses with a a fantastic columnar jointed basalt they found on their reconnaissance investigation.

 

 

 

Wooster’s Fossils of the Week: Mackerel shark teeth from the Eocene of the Atlas Mountains, Morocco

May 26th, 2013

OtodusCombined_585This week we highlight another gift to the Wooster Geology Department from George Chambers (’79). Among the many fossils that arrived in three delightful boxes were these shark teeth. They are from the extinct Mackerel Shark Otodus obliquus Agassiz, 1843. They were collected from the Eocene of the Khouribga Plateau in Morocco.
Otodus obliquus multiple 021313_585These shark teeth are rather common, although they are not often available in such fine preservation as these. What intrigues me is how they are collected and placed on the market. The Khouribga Plateau, west of the Middle Atlas Mountains, has some of the largest phosphate deposits in the world. These phosphorites (phosphate-bearing rocks) are mined in open pits by dynamite. After a blast, local commercial collectors rush in to gather fossils in the rubble before large processing machines arrive to process the ore. That can be a matter of minutes. They find many, many fossils in this phosphatic debris, mostly of reptiles and fish.
mackerelsharkThe lamnoid shark Otodus obliquus, a reconstruction of which is above, was a very large animal with some teeth over 10 centimeters in length. It may have been up to 9 meters long. Otodus obliquus was a “macro-predator”, meaning it was at the top of the food chain with a likely diet of marine mammals, fish, and other sharks. Its remains are found throughout the world in Paleocene and Eocene sediments. The fossil evidence suggests that this shark is an ancestor of the massive Carcharocles (“Megalodon”).

Thank you again, George, for these beautiful fossils!

References:

Agassiz, L. 1843. Recherches Sur Les Poissons Fossiles. Tome III (livr. 15-16). Imprimérie de Petitpierre, Neuchatel, p. 157-390.

Arambourg C. 1952. Les vertébrés fossiles des gisements de phosphates (Maroc-Algérie-Tunisie). Notes et Mémoires du Service Géologique du Maroc (Rabat) 92: 1-372.

MacFadden, B.J., Labs-Hochstein, J., Quitmyer, I. and Jones, D.S. 2004. Incremental growth and diagenesis of skeletal parts of the lamnoid shark Otodus obliquus from the early Eocene (Ypres) of Morocco. Palaeogeography, Palaeoclimatology, Palaeoecology 206: 179- 192.

Pizza on the Pillows

May 25th, 2013

ICELAND – Team Iceland has arrived! We have been joined by our collaborators from Dickinson College and now number 9 strong. The Dickinson crew arrived early on Friday morning, so we spent much of the day recovering from our overseas travel and preparing for fieldwork. In addition to obtaining vehicles and food, we met our Icelandic collaborator, Steinunn Hauksdóttir, at the Iceland Geosurvey (ISOR) to discuss logistics. (Steinunn also showed us their latest geological map of the northern volcanic zone. We promptly offered to map the rest of Iceland for them in exchange for bread and Skyr).

When the group awoke from their jet-lagged slumber, they were hungry for food and geology. So, we thought we’d try a twist on the introduction to the field area: Pizza on the Pillows. In a spur of the moment decision, we thought it might be fun to have an informal dinner at the quarries where we’ll be studying the formation of subglacial pillow lavas. We picked up pizzas and headed to the field.

Unfortunately, when we arrived at the field, the weather was perfectly Icelandic. Although you can't see it, the wind and rain would have made our pizzas soggy.

Unfortunately, when we arrived at the field site, the weather was perfectly Icelandic. Although you can’t see it, the wind and rain would have made our pizzas soggy. We got the cliff notes version of the overview instead.

We are creative bunch, though, and were still able to have a different kind of Pizza on the Pillows back at the hostel.

Team Iceland and their "Pizza on the Pillows" in the dry hostel dining room. Pictured from left to right: Michael ('16, Wooster); Aleks ('14, Dickinson); Ellie ('14, Dickinson); Liz ('16, Dickinson); Dr. Ben Edwards; Alex ('14, Wooster); Adam ('16, Wooster); Jim Ciarrocca (GIS, Dickinson).

Team Iceland and their “Pizza on the Pillows” in the dry hostel dining room. Pictured from left to right: Michael (’16, Wooster); Aleks (’14, Dickinson); Ellie (’14, Dickinson); Liz (’16, Dickinson); Dr. Ben Edwards; Alex (’14, Wooster); Adam (’16, Wooster); Jim Ciarrocca (GIS, Dickinson).

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