Team Utah 2015

August 6th, 2015

Guest bloggers: Julia Franceschi and Mary Reinthal

What do you get when you have zero cloud coverage, 90-degree heat, and a desert? Aside from the start of a bad joke, you get a snippet of the College of Wooster geology’s 2015 expedition to Black Rock desert Utah. It was here that some of the College’s senior geology students—Krysden Schantz, Michael Williams, and Kelli Baxstrom—collected some sunburns and samples for their Senior Independent Studies. These research projects range anywhere from trying to figure out the date of the lava flow to mechanisms of emplacement (e.g., channelized vs. inflated flows). Some of the students that went, however, went because they were able-bodied field assistants who could handle the heat. Geology major Julia Franceschi said this about her field assisting experience:

“Utah was extremely hot and there were some days (and by some days I mean everyday) where 3 liters of water were not enough. But we managed to get a lot of good data, even though my boots took a beating (R.I.P). ”

Chloe Wallace and Julia Franceschi use the Trimble GPS to make cm-scale measurements of the topography.

Chloe Wallace and Julia Franceschi use the Trimble GPS to make cm-scale measurements of the topography.

When the plane finally landed in Salt Lake City, Utah, a 2 ½ hour drive took the crew to Fillmore, the location of their field site. The first day, Friday, started around 11AM, but the crew learned quickly that the earlier they started, the less intense the sun (and heat) was.

Team Utah meeting to distribute equipment and plan the field day.

Team Utah meeting to distribute equipment and plan the field day.

Like for most groups, the first day was devoted as a get-accustomed-to-the-field day, that entailed some reconnaissance and exploration. The rest of the week was spent doing eight hours a day of research and studies. According to Dr. Meagen Pollock, walking on a’a is “nonsense” and more often than not, each day was faced with new challenges. Chloe Wallace and Julia conducted high resolution GPS location and elevation data. Dan Misinay took photographs and helped Krysden conduct transects to record vegetative cover. Michael and Kelli spent most of their days mapping the area and attempting to understand volcanic features. Some days, however, were graced with the occasional snake or rainbow to change up the scenery. It was a successful trip.

One of our lizard friends.

One of our lizard friends.

A snake friend, warming itself in the morning sun. Photo credit: Dan Misinay

A snake friend, warming itself in the morning sun. Photo credit: Dan Misinay

Kelli and Dr. Judge measuring striae.

Kelli and Dr. Judge measuring striae.

Krysden is in her element among the lavas.

Krysden is in her element among the lavas. Photo Credit: Dan Misinay

Contemplating lava emplacement clearly brings joy to Michael.

Contemplating lava emplacement clearly brings joy to Michael. Photo Credit: Dan Misinay

Dan helps Krysden with her vegetation survey.

Dan helps Krysden with her vegetation survey.

We were treated to a double rainbow over our field site after a light sprinkle in the desert.

We were treated to a double rainbow over our field site after a light sprinkle in the desert.

And a show of wild flowers! Photo Credit: Kelli Baxstrom

And a show of wild flowers! Photo Credit: Kelli Baxstrom

Team Utah proudly representing Wooster Geologists!

Team Utah proudly representing Wooster Geologists!

Wooster’s Fossil of the Week: A Middle Jurassic trace fossil from southwestern Utah

April 17th, 2015

1 Gyrochorte 2 CarmelTime for a trace fossil! This is one of my favorite ichnogenera (the trace fossil equivalent of a biological genus). It is Gyrochorte Heer, 1865, from the Middle Jurassic (Bathonian) Carmel Formation of southwestern Utah (near Gunlock; locality C/W-142). It was collected on an Independent Study field trip a long, long time ago with Steve Smail. We are looking at a convex epirelief, meaning the trace is convex to our view (positive) on the top bedding plane. This is how Gyrochorte is usually recognized.
2 Gyroxhorte hyporelief 585A quick confirmation that we are looking at Gyrochorte is provided by turning the specimen over and looking at the bottom of the bed, the hyporelief. We see above a simple double track in concave (negative) hyporelief. Gyrochorte typically penetrates deep in the sediment, generating a trace that penetrates through several layers.
3 Gyrochorte Carmel 040515Gyrochorte is bilobed (two rows of impressions). When the burrowing animal took a hard turn, as above, the impressions separate and show feathery distal ends.
4 Gyrochorte 585Gyrochorte traces can become complex intertwined, and their detailed features can change along the same trace.
5 Gibert Benner fig 1This is a model of Gyrochorte presented by Gibert and Benner (2002, fig. 1). A is a three-dimensional view of the trace, with the top of the bed at the top; B is the morphology of an individual layer; C is the typical preservation of Gyrochorte.

Our Gyrochorte is common in the oobiosparites and grainstones of the Carmel Formation (mostly in Member D). The paleoenvironment here appears to have been shallow ramp shoal and lagoonal. Other trace fossils in these units include Nereites, Asteriacites, Chondrites, Palaeophycus, Monocraterion and Teichichnus.

So what kind of animal produced Gyrochorte? There is no simple answer. The animal burrowed obliquely in a series of small steps. Most researchers attribute this to a deposit-feeder searching through sediments rather poor in organic material. It may have been some kind of annelid worm (always the easiest answer!) or an amphipod-like arthropod. There is no trace like it being produced today.

We have renewed interest in Gyrochorte because a team of Wooster Geologists is going to Scarborough, England, this summer to work in Jurassic sections. One well-known trace fossil there is Gyrochorte (see Powell, 1992).
6 Heer from ScienceOswald Heer (1809-1883) named Gyrochorte in 1865. He was a Swiss naturalist with very diverse interests, from insects to plants to the developing science of trace fossils. Heer was a very productive professor of botany at the University of Zürich. In paleobotany alone he described over 1600 new species. One of his contributions was the observation that the Arctic was not always as cold as it is now and was likely an evolutionary center for the radiation of many European organisms.


Gibert, J.M. de and Benner, J.S. 2002. The trace fossil Gyrochorte: ethology and paleoecology. Revista Espanola de paleontologia 17: 1-12.

Heer, O. 1864-1865. Die Urwelt der Schweiz. 1st edition, Zurich. 622 pp.

Heinberg, C. 1973. The internal structure of the trace fossils Gyrochorte and Curvolithus. Lethaia 6: 227-238.

Karaszewski, W. 1974. Rhizocorallium, Gyrochorte and other trace fossils from the Middle Jurassic of the Inowlódz Region, Middle Poland. Bulletin of the Polish Academy of Sciences 21: 199-204.

Powell, J.H. 1992. Gyrochorte burrows from the Scarborough Formation (Middle Jurassic) of the Cleveland Basin, and their sedimentological setting. Proceedings of the Yorkshire Geological Society 49: 41-47.

Wilson. M.A. 1997. Trace fossils, hardgrounds and ostreoliths in the Carmel Formation (Middle Jurassic) of southwestern Utah. In: Link, P.K. and Kowallis, B.J. (eds.), Mesozoic to Recent Geology of Utah. Brigham Young University Geology Studies 42, part II, p. 6-9.

Wooster’s Fossil of the Week: Star-shaped crinoid columnals from the Middle Jurassic of southern Utah

February 27th, 2015

Isocrinus nicoleti Kane County 585Just a quick Fossil of the Week post. Above we see isolated columnals (stem units) of the crinoid Isocrinus nicoleti (Desor, 1845) found in the Co-Op Creek Member of the Carmel Formation (Middle Jurassic), Kane County, southern Utah. Greg Wiles recently received them as part of a donation to our department collections. They have such perfect star shapes that I had to share them here. For the full analysis, see my previous entry on columnals like these preserved in a limestone from the same location.


Baumiller, T.K., Llewellyn, G., Messing, C.G. and Ausich, W.I. 1995. Taphonomy of isocrinid stalks: influence of decay and autotomy. Palaios 10: 87-95.

Tang, C.M., Bottjer, D.J. and Simms, M.J. 2000. Stalked crinoids from a Jurassic tidal deposit in western North America. Lethaia 33: 46-54.

Wooster’s Fossil of the Week: An early bryozoan on a Middle Ordovician hardground from Utah

October 10th, 2014

ORBIPORA UTAHENSIS (Hinds, 1970) 072014Last week I presented eocrinoid holdfasts on carbonate hardgrounds from the Kanosh Formation (Middle Ordovician) in west-central Utah. This week we have a thick and strangely featureless bryozoan from the same hardgrounds. It is very common on these surfaces, forming gray, perforate masses that look stuck on like silly putty. Above you see one on the left end of this hardground fragment. (The circular object to the right is another eocrinoid holdfast.)
Kanosh bryo eo 072014Here is a closer view of the bryozoan, again with one of those ubiquitous eocrinoids encrusting it. The holes are the zooecial apertures. Each zooecium is the skeletal component of a living bryozoan individual (zooid). Note that the walls are thick and granular between the zooecia. All the zooecia look pretty much the same, and there are no other structures like spines, pillars or maculae. This is about as simple as a bryozoan gets.

It is impossible to be certain without a thin-section or acetate peel showing the interior, but I’m pretty sure this Kanosh bryozoan is Orbipora utahensis (Hinds, 1970). It matches fairly well the description in Hinds (1970), who named it Dianulites utahensis, and it fits within the redescription by Ernst et al. (2007).

Several years ago we would have called this a trepostome bryozoan and left it at that. These are, after all, the “stony bryozoans” with thick calcite skeletons and long zooecia. However, the group to which Orbipora belongs is unusual because they have no polymorphs (small zooecia different from the primary zooecia) and have granular skeletal textures rather than laminated. We think the granular walls may be because the original skeletons were made of high-magnesium calcite that later altered to low-magnesium calcite and dolomite, losing details of the microstructure. Orbipora is thus in an as yet undescribed new order of bryozoans. [Update: See comment below from Paul Taylor.]

The Kanosh hardgrounds and their attaching faunas are important in geological and biological history because they are telling us something about the geochemical conditions of the seawater when they formed. We think this was a peak time of Calcite Seas, when low-magnesium calcite was a primary marine precipitate and carbon dioxide levels were high in the atmosphere and seawater. Hardgrounds would have formed rapidly because of early cementation, and aragonite and high-magnesium skeletons would have altered soon after death. The abundant Kanosh communities and substrates are critical evidence for these conditions that were superimposed on the Great Ordovician Biodiversification Event (GOBE). We thus have a delightful combination of seawater geochemistry (and, ultimately, the tectonics that controls it) and evolution intertwined in the history of these rocks and fossils.


Ernst, A., Taylor, P.D. and Wilson, M.A. 2007. Ordovician bryozoans from the Kanosh Formation (Whiterockian) of Utah, USA. Journal of Paleontology 81: 998-1008.

Hinds, R.W. 1970. Ordovician Bryozoa from the Pogonip Group of Millard County, western Utah. Brigham Young University Research Studies, Geology Series 17: 19–40.

Marenco, P.J., Marenco, K.N., Lubitz, R.L. and Niu, D. 2013. Contrasting long-term global and short-term local redox proxies during the Great Ordovician Biodiversification Event: A case study from Fossil Mountain, Utah, USA. Palaeogeography, Palaeoclimatology, Palaeoecology 377: 45-51.

Wilson, M.A., Palmer, T.J., Guensburg, T.E., Finton, C.D. and Kaufman, L.E. 1992. The development of an Early Ordovician hardground community in response to rapid sea-floor calcite precipitation. Lethaia 25: 19-34.

Wooster’s Fossils of the Week: Eocrinoid holdfasts on a Middle Ordovician hardground from Utah

October 3rd, 2014

Kanosh Hardground 072014 smBack in the late 1980s and early 1990s, several students and I did fieldwork in the Middle Ordovician Kanosh Formation in west-central Utah. One year we were joined by my friend Tim Palmer of the University of Aberystwyth. Together, Chris Finton (’91), Lewis Kaufman (’91), Tim and I put together a paper describing the carbonate hardground communities in this remarkable formation (Wilson et al., 1992). At top is an image of one of the surface of one of these hardgrounds. It is covered with holdfasts of rhipidocystid eocrinoids, a kind of primitive echinoderm.
Fossil Mountain UtahMost of the hardgrounds we studied in the Kanosh Formation were found here at Fossil Mountain near Ibex, Utah. (If you want to consider Ibex a place, at least.) It was a beautiful place to work, and it is still highly productive for geologists and paleontologists (see Marenco et al., 2013, for the latest investigation).

Kanosh eocrinoid 2The encrusters on the Kanosh hardgrounds are dominated by two groups: bryozoans (which we’ll highlight next week) and stemmed echinoderms (this week’s subject). The echinoderms are represented by thousands of these small attachment structures called holdfasts. The stem of the echinoderm was attached here to the hardground. The entire skeleton of the echinoderm, including the hardground, is made of low-magnesium calcite, so they are very well preserved. Surprisingly, the hardground communities in the Kanosh have very few sponges or borings.

Kanosh eocrinoid 3 072014The holdfasts come in a few varieties with subtle morphological differences. Here we have one with a tri-radiate center.

Kanosh eocrinoids 1Sometimes the holdfasts blended together on the hardground surface, which was probably the result of competition for attachment space. Note the tri-radiate centers.

Mandalacystis diagramFrom a few plates we found, it appears that the rhipidocystid eocrinoid holdfasts are from a creature like Mandalacystis, which is pictured above from Figure 1 of Lewis et al. (1987). We can’t tell for certain without more of the skeleton, but the holdfasts are very similar to what has been described for the genus.

These Middle Ordovician hardgrounds were formed at an interesting time in the chemistry of the oceans and the development of marine invertebrate faunas. More on that next week!


Ernst, A., Taylor, P.D. and Wilson, M.A. 2007. Ordovician bryozoans from the Kanosh Formation (Whiterockian) of Utah, USA. Journal of Paleontology 81: 998-1008.

Lewis, R.D., Sprinkle, J., Bailey, J.B., Moffit, J. and Parsley, R.L. 1987. Mandalacystis, a new rhipidocystid eocrinoid from the Whiterockian Stage (Ordovician) in Oklahoma and Nevada. Journal of Paleontology 61: 1222-1235.

Marenco, P.J., Marenco, K.N., Lubitz, R.L. and Niu, D. 2013. Contrasting long-term global and short-term local redox proxies during the Great Ordovician Biodiversification Event: A case study from Fossil Mountain, Utah, USA. Palaeogeography, Palaeoclimatology, Palaeoecology 377: 45-51.

Wilson, M.A., Palmer, T.J., Guensburg, T.E., Finton, C.D. and Kaufman, L.E. 1992. The development of an Early Ordovician hardground community in response to rapid sea-floor calcite precipitation. Lethaia 25: 19-34.

Wooster’s Fossil of the Week: A faulted oyster ball from the Middle Jurassic of Utah

July 25th, 2014

Split oyster ball 062914I’m returning this week to one of my favorite fossil types: the ostreolith, popularly known as the “oyster ball”. These were lovingly described in a previous blog entry, so please click there to see how they were formed and some additional images. They are found almost exclusively in the Carmel Formation (Middle Jurassic) of southwestern Utah.They are circumrotatory (a fancy word for “rolling around while forming”) accumulations of small cup-like oysters along with minor numbers of plicatulid bivalves, disciniscid brachiopods, cyclostome bryozoans (see Taylor & Wilson, 1999), and mytilid bivalves that drilled borings known as Gastrochaenolites. They are nice little hard-substrate communities originally nucleated on bivalve shells (Wilson et al., 1998).

oyster ball close 062914Here is a close view of the oyster valves on the outside of the ostreolith. They are attached to similar valves below them, and it is oysters all the way to the center.

What is special about our specimen here is that it managed to obtain a fault right through its center! The chances of this happening are slim, given that they are relatively rare in the rock matrix. The faulting was probably during the Miocene related to a “left-lateral transfer zone that displaces north-south–trending crustal blocks of the eastern Basin and Range Province to the west” (Petronis et al., 2014, p. 534). This is an interesting tectonic region between the Basin and Range Province and the Colorado Plateau.

Slickenfibers 062914A close view of the fault surface shows it is a striated slickenside. The striations (called slickenlines) are parallel to the direction of movement, not that we have to guess when we look at the ostreolith itself. There are also calcitic deposits here formed during faulting called slickenfibres. These elongated crystals have tiny step-like breaks in them that show the actual direction of movement.

Another nice specimen combining paleontology and structural geology.


Petronis, M.S., Holm, D.K., Geissman, J.W., Hacker, D.B. and Arnold, B.J. 2014. Paleomagnetic results from the eastern Caliente-Enterprise zone, southwestern Utah: Implications for initiation of a major Miocene transfer zone. Geosphere 10: 534-563.

Taylor, P.D. and Wilson, M.A. 1999. Middle Jurassic bryozoans from the Carmel Formation of southwestern Utah. Journal of Paleontology 73: 816-830.

Wilson, M.A., Ozanne, C.R. and Palmer, T.J. 1998. Origin and paleoecology of free-rolling oyster accumulations (ostreoliths) in the Middle Jurassic of southwestern Utah, USA. Palaios 13: 70-78.

Iron Flows and Camera Blows

July 21st, 2014

Guest Bloggers:  Sarah McGrath (’17) and Chloe Wallace (’17), both members of Team Utah 2014


EPHRAIM, UTAH — No longer rookie bloggers Chloe and Sarah here, coming at you from the sweet comfort of our couch in Utah. Before collecting pounds of oncolites and encountering countless kill sites, we were just two inexperienced field geologists spending our long days becoming pros with the Trimble. The Trimble is a survey grade GPS unit. We used it to map the many iron concretions throughout the Six-Mile Canyon Formation. Over the course of a day and a half we were able to map over 200 points on one single rib of the outcrop.

As you will see below it takes a truly skilled and brave geologist to be worthy of the power that is the Trimble. Lesson learned: do not forget to zip the pocket that is holding your camera as you lean over a steep cliff just to collect a single data point. Thankfully, Sarah’s camera survived the fall and still works somehow. Nikons, people! Also as Sarah was retrieving her camera she came upon some lovely iron staining that otherwise would not have been discovered. There’s always an upside!

picture 6 - 585

How to Trimble 101: This isn’t your basic car GPS.

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Seconds before Sarah dropped her camera down the side of the cliff. All in the name of science!

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The iron staining Sarah came upon while retrieving her camera at the bottom of the cliff.

picture 9 - 585

We’ve gotten too used to this view. We’re going to miss Utah! Thanks for an amazing two weeks full of scalding heat, accessibility to more Peace Tea than one human should consume, and unforgettable geology.



Oncolites and Kill Sites

July 21st, 2014

Guest Bloggers:  Sarah McGrath (’17) and Chloe Wallace (’17), both members of Team Utah 2014


EPHRAIM, UTAH —  Rookie bloggers, Sarah and Chloe, coming at you from beautiful Ephraim, Utah! We’ll admit early on that are blogging skills are not the most proficient, but we’re giving it a shot (mostly because we are being “strongly encouraged”). We figure plenty of enticing pictures will make up for what we are lacking.

We began a new project in the field on Thursday. We gathered data and collected oncolites in the North Horn Formation. We measured over 50 oncolites within the rock face and collected about a dozen float samples. The following day we did more oncolite work, collecting at least 150 float samples, in the Flagstaff at “Snake Ridge,” which was cleverly named by Dr. Judge after countless rattlesnake sightings. Luckily for us, we have yet to see a single snake the entire trip. Knock on wood; still one day left in the field.

Although we haven’t seen any rattlesnakes, we’ve encountered enough kill sites to last us a lifetime. At our first sighting we ran away in disgust, but by our most recent kill site we were taking creative photos with them. We suspect our friend Freddy the mountain lion may be at fault.

picture 1 - 585

The view from the North Horn Formation.

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One bag out of many of the collected oncolites at the infamous “Snake Ledge.”  Note the medical tape holding one of the oncolites together!!

picture 3 - killsite

Most recent kill site shot. Maggots don’t scare us.

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More wildlife encountered in the field. This jackrabbit kept us quite entertained for at least thirty minutes.

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Possible homestead of the one and only Freddy the mountain lion.



Hot Springs and I.S. Frenzy

July 17th, 2014

Guest Blogger:  Kelli Baxstrom (’16), member of Team Utah 2014


EPHRAIM, UTAH —  A week into Utah, and feelings are mixed between slight hysteria for those who continue to fall off the couch in the evening due to exhaustion and an ongoing sense of awe of the beautiful world that exists outside Ohio.

Sunday was a day off for us, and so the four of us hopped in a van with some of the OSU field camp students – including recent CoW graduate Tricia Hall – and headed to some hot springs near Spanish Fork. We smelled like sulfur the rest of the day, but the waterfall and pools were worth it!


​Wednesday was very I.S. focused for Michael and myself. For my part, I am a double major in Religious Studies as well as Geology. So in order to meld my I.S., Dr. Judge drove me to Nephi to meet the Chairwoman of the Paiute Indian Tribe of Utah. It was very enlightening to talk to a native and political spokeswoman of the tribe, and I learned so much of political, historical and socioeconomic activity of the Paiutes for the last millennia. Dr. Judge also enjoyed the meeting – possibly more than myself – in learning all the ways that the Paiutes have lived and prospered in the areas where she has worked and researched for several years.

After Dr. Judge and I got back from Nephi, Michael and I spread out on the floor with a multitude of topographic maps of Utah trying to decide what we would like to do for I.S. At the moment, that is a prospect Michael and I irrationally believe is completely​ unattainable. But Dr. Judge has faith in us.

Hey, Team British Columbia, here’s proof that there’s some real wildlife out here in Utah…


Brain-melting Heat in the Sanpete Valley

July 16th, 2014

Guest Blogger:  Michael Williams (’16), member of Team Utah 2014


EPHRAIM, UTAH –Team Utah 2014 is now approaching the one-week mark of being in the field. For the past four days we’ve been working on one of Dr. Judge’s pet projects: deformation bands and fluid flow in the Sixmile Canyon Formation. This Cretaceous sandstone underwent some serious deformation during the building of the Rocky Mountains, and this strain reveals itself in several remarkable features, including jointing, deformation bands, and bizarre outcroppings of iron. Team Utah has been working hard to measure, categorize, date, and record these features, all while enduring non-stop, brain-melting heat.

We agreed early on that work would begin every morning at 8:00am, so naturally we don’t actually make it out in the field until 9:00am or later. It’s a short drive followed by an even shorter hike to our field site, so it’s typically still mid-morning as we begin the day’s work. Each day has had us focusing on different features in our area. Our most productive days involve measuring the orientations of joints. Other days we hike for hours, looking for the perfect outcrop of deformation bands. No matter our mission, the charge is led by Measurement Machine Shelley Judge, Brunton in hand and field notebook at the ready.


Some nice sets of joints in a nearly horizontal wall of sandstone. On our first day alone we managed to measure just over 200 individual joints.  Brunton Compass for scale.


Kelli examines some bizarre iron fins protruding from the rock face. We suspect that these were caused by fluid flow through the porous rock.

reidel ladder

A beautiful example of deformation bands forming Riedel ladders. Unfortunately, this particular rock had fallen off the outcrop, and so it couldn’t be included in our data.

michael below

Michael down below (bottom center), measuring orientations of deformation bands, while Kelli records from above (top right).


Sometimes, when the heat starts getting to us, we decompress by falling off of cliffs.


You can’t help but occasionally stop to admire the postcard-like beauty of the Sanpete Valley.


Even temperatures upward of 100 degrees can’t stop the Scott spirit.

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