Archive for the 'Uncategorized' Category

Bryozoologists on the rocks in South Wales

June 7th, 2018

Cardiff, Wales — There is a tradition at bryozoology meetings that we get out into the field as a group. Caroline Buttler (our organizer) and Lesley Cherns (Cardiff University) took us during the afternoon to two sites. The first (shown above) is the excellent Carboniferous-Triassic-Jurassic section at Ogmore-by-Sea. Tim Palmer took me here on an epic field trip three years ago, and my blog post from then has some of the important geological details. Basically, we have an extensive exposure of the Carboniferous Limestone (High Tor Limestone, Dinantian in age), topped by an unconformity with Triassic wadi deposits in some places and a Jurassic limestone (Sutton Stone, Hettangian). The group above is scampering about on an exposure of the Carboniferous Limestone.

Here the bryozoologists are examining the unconformity between the Carboniferous Limestone (which they’re standing on) and the Jurassic Sutton Stone above.

Andrej Ernst (University of Hamburg) managed to find tiny bryozoans in the Carboniferous Limestone.

Hans Arne Nakrem (University of Oslo; Natural History Museum) and me looking studious with the Carboniferous Limestone.

The Carboniferous Limestone has fantastic sections through large rugose corals.

The trace fossil Zoophycos (“rooster tails”) is also common in the Carboniferous Limestone.

Our second stop was at an Upper Triassic section at The Bendricks along the coast. Here we see desert and flash flood deposits with … wait for it …

… dinosaur footprints! One rather battered example of a print from a three-toed theropod dinosaur is shown above. (Grallator is the ichnogenus.) These were among the earliest dinosaurs, so seeing such a trackway is very cool. You can read here a detailed assessment of the tracks.

Thank you again to Caroline Buttler and Lesley Cherns for arranging this fun trip.

Bryozoologists gather in Wales

June 6th, 2018

Cardiff, Wales, United Kingdom — A dedicated group of bryozoan experts have gathered this week in Cardiff for the 15th Larwood Meeting. It is a diverse group of biologists and paleontologists, and I am proud to be among them. We approach the delightful Phylum Bryozoa from a variety of perspectives and enjoy the challenge of understanding each other’s work and ideas. As you can see above, these Larwood meetings are small, but we cover a lot of bryozoology in our sessions. Thank you to Caroline Buttler for expertly organizing this event and hosting us at Amgueddfa Cymru – National Museum Wales in the Cardiff city center. Today is our first day of the meeting.

This is the front of the main museum building.

My friend Paul Taylor was one of several speakers. His talk was fascinating and inspiring as always.

We had posters as well. This one was designed by Macy Conrad (’18) explaining her Independent Study work (with Paul Taylor and me) in the Campanian of southwestern France. It is officially the first Wooster Geology poster printed on cloth!

I gave a talk on the first day as well, with Caroline and Paul as co-authors. Bryoimmuration: You heard it here first.

The meeting continues through June 8.

Wooster Geologists on Helvellyn

June 4th, 2018

The black mountain icon indicates the location of Helvellyn in the Lake District.

During the last two weeks of May, Dr. Alley and were in the UK.  Part of the experience involved complaining about the inadequate width of UK roads, but there was also some undeniably beautiful geology.  One such location was Helvellyn, in the Lake District of England. This is one of the “top walks” in the UK, but note that the term “walk” has a very loose definition in British English.  Really, this is a hike, with a climb of nearly 3000 ft in about 4 mi.  If you’re a fan of glacially carved, open landscapes, it deserves the hype. 

The exposed rocks of the Helvellyn Range are part of the Borrowdale Volcanic Group. The volcanics here transitioned from primarily intermediate lava flows (andesite) to more silica-rich magma that resulted in pyroclastic flows and ignimbrite deposits.  This all occurred around 450 million years ago (Ordovician) — around the same time as the Taconic Orogeny in North America (most notably in New England).

That’s the raw material for the terrain, but the carving is much more recent.  Glaciers from the last glacial advance have gouged out the sides of these mountains into deep u-shaped troughs with steep sides and wide bottoms. Below Helvellyn sits a deep bowl called a cirque. This is where a large mountain glacier once originated, digging out a hole from which it later advanced.

Look back at Helvellyn Cirque from Birkhouse Moor.

If you go up into the cirque today, that depression has been filled with a small lake called a tarn. Tarns sits at the headwaters of watersheds, and the outlets are often some of the cleaner water you can find (although they may be turbid from lots of sediment).  This tarn, though, had a large number of sheep around it.  So I’d be a little more suspicious.

Red Tarn below Helvellyn.

Actually, the sheep are a more important aspect the the geology than you might think.  Looking down from Helvellyn, you can see the “Striding Edge”.  This is an arête, a sharp ridge that, thousands of years ago, was the boundary between two parallel glaciers.  The glaciers would have been flowing away from you in the image below.

View eastward from Helvellyn overlooking Striding Edge (an arête) and Red Tarn.

Finally, when walking along the northwest side of the mountain, you go by the Greenside Mine. In the 19th century, veins along a normal fault through the mountain were mined for the mineral galena (PbS), which also contains impurities of silver. 

Summer Research in the Tree Ring Lab

May 31st, 2018

This summer, students through the AMRE program with funding from the Sherman Fairchild Foundation are working in the Wooster Tree Ring Lab doing historical dating. Kendra Devereux, Alexis Lanier, and Juwan Shabazz are working with clients to date local barns, cabins and houses, to update pre-existing tree-ring chronologies, and to examine the collected data as a record of past climate. Two additional students are also working in the lab with data collected from Columbia Glacier in Prince William Sound, Alaska. Josh Charlton and Victoria Race, who are funded by NSF (National Science Foundation), will be helping out the AMRE students, but primarily will be developing ice flow models and using tree rings to reconstruct mass balance for Columbia Glacier in Prince William Sound, Alaska.

Summer researchers at Stebbins Gulch in the Holden Arboretum. Pictured left to right: Victoria Race (’19), Kendra Devereux (’21), Alexis Lanier (’20), Josh Charlton (’19), and Juwan Shabazz (’19).

The group has worked on a few different projects thus far. Their first assignment was to update the chronology for the Holden Arboretum in Kirtland, Ohio. The group has gone to the field site twice now to collect core samples from living Chestnut Oak trees in Stebbins Gulch. The AMRE group is currently working on mounting the fresh cores from our second trip and will be gathering and analyzing this data in the coming weeks.

Sampling chestnut oak trees at Stebbins Gulch.

Freshly extracted core at Stebbins Gulch.

Alexis Lanier removing increment borer from a sampled tree.

Kendra and Victoria looking at a giant burl on a sampled chestnut oak.

Chestnut oak tree being sampled at Stebbins Gulch.

The AMRE group has also worked with clients to date two local structures, Stratford Cabin and Gingery Barn. The group was able to date both samples and provide a calendar date for our clients, informing them when the trees used for building these structures were felled. Stratford cabin was dated to 1849 and Gingery Barn was dated at 1883. To provide these dates, the students counted and measured the tree rings. This data was then compared to other developed chronologies, a process called cross-dating, which allows us to assign a calendar date to these rings. 

In the coming weeks, the group will be finishing up the work on Stebbins Gulch, dating some more historical structures from Sonnenberg Village, and compiling Columbia Glacier data. Further information on these projects can be found on the Tree Ring Lab’s website.

Juwan drilling into a beam sample to extract a core from Gingery Barn.

Oak slice ready for sanding from Gingery Barn.

Wooster Geologists in Southwestern Utah (May 2018)

May 25th, 2018

This month, our geological technician Nick Wiesenberg and I had the privilege of taking two Wooster Independent Study students into southwestern Utah to do research on the Carmel Formation (Middle Jurassic). The students were Ethan Killian (’19) on the left and Galen Schwartzberg (’19) on the right. (You’ll get better view of them in the links below where we have blog entries for each day.) I plotted out the localities during a solo expedition last month. We hope we are re-establishing a field area for several more years of work.

This is the local stratigraphic column (modified from that on the Zion National Park website). The area is dominated by the majestic Navajo Sandstone, with our Carmel Formation one of the very few carbonate units.

Our main study areas. 1 = Gunlock region; 2 = Eagle Mountain Ranch; 3 = Dammeron Valley; and 4 = Diamond Valley (“Water Tank”).

Here are links to our daily blog posts —

May 16: Team Jurassic Utah sets to work
May 17: Team Jurassic Utah on the Ranch
May 18: Projects designed, Team Jurassic Utah begins fieldwork
May 19: A day for Jurassic oysters
May 20: Jurassic hardgrounds and Holocene lava flows in southwestern Utah
May 21: Team Jurassic Utah finishes essential data collection
May 22: Zion National Park and life in Santa Clara, Utah
May 23: An oyster ball nursery and Veyo pies on our last field day in SW Utah
May 24: Science and culture on Team Jurassic Utah’s last day

And here are the coordinates of our localities —

N Latitude Longitude Wooster Locality
Location name
37.27875299 -113.78777 C/W-157 C/W157
37.30712598 -113.740137 Eagle MT Road
37.25407499 -113.60516 C/W-751 Water tank
37.308755 -113.73653 C/W-142 Eagle Mtn Ranch cliff
37.27879096 -113.787768 Section base
37.27341698 -113.77961 C/W-752 Double layer DL
37.27298004 -113.778876 C/W-753 Hardground East
37.27855903 -113.787448 C/W-754 Hardground West HW
37.28063799 -113.80023 C/W-755 HFW Hardground
37.27056798 -113.776038 C/W-156 Nursery

Update: Nick heroically drove our samples back to our Wooster paleontology lab. What treasures there are in these three boxes!

Science and culture on Team Jurassic Utah’s last day

May 24th, 2018

Santa Clara, Utah — We spent our last full day in this beautiful state enjoying nature, visiting local historical sites, and ending with a fantastic museum. This morning began with a short journey through Snow Canyon State Park, which is just up the road from Santa Clara. This is a miniature Zion with the same Navajo sandstone, mostly white at the top and red below. The morning light was perfect. Note Nick on the rocks above!

Image by Galen.

Here is an example of the lower red rocks. The foresets on these Jurassic dunes are easy to pick out.

After Snow Canyon we toured the Jacob Hamblin Home in Santa Clara. This house, built in 1862-3, is the oldest surviving structure in Santa Clara. Jacob Hamblin (1819-1886) was a Mormon pioneer with a complicated history but generally known as an honest broker of frontier disputes.

The second floor of the home is a surprisingly large space used as a bedroom for the 11 children and as a community gathering place.

Our final cultural visit was to the St. George Utah Temple of the Latter-day Saints (the Mormons). It is an exquisite structure amidst carefully groomed gardens. We went to the Visitor Center and received a very thorough account of its construction.

Our very last event was suitably paleontological and Jurassic: The Dinosaur Discovery Site at Johnson Farm. This building is constructed over an in situ set of dinosaur trackways in the Moenave Formation (Lower Jurassic).

The tracks are amazingly well preserved and numerous. Above is the dinosaur trace Eubrontes.

Our friend Andrew Milner, Site Paleontologist and Curator, gave us a guided tour, pointing out the extraordinary amount of biological information that can be deduced from trackways.

It is with this wonderful plunge into the world of Early Jurassic terrestrial fauna that our expedition ended. Tomorrow we fly from Las Vegas back to our homes, with Nick driving our precious samples to Wooster. We had a great time. Stay tuned for the laboratory analyses!

An oyster ball nursery and Veyo pies on our last field day in southwestern Utah

May 23rd, 2018

Santa Clara, Utah — When you want to sort out how something grows but can’t actually watch it do it, you look for examples of individuals in various developmental states. You can learn a lot about human growth, for example, by studying a group of people from infants to seniors. We do the same with Jurassic oyster balls: find a diverse population and sort out the relative ages. Today we revisited a site in the Gunlock area which in the 1990s yielded some “baby” oyster balls, thus gaining the name “The Nursery” (C/W-156). On its last day of fieldwork, Team Jurassic Utah (specifically Ethan) found the wonderful array of young oyster balls shown above, from least-developed on the right to most-developed on the left. These will be most useful in our lab analyses this fall.

Here is our last field view of the Gunlock outcrops, mostly the Double Layer (DL) locality. One of our landmarks, Square Top Mountain, rises in the background.

And the last image of Team Jurassic Utah at work. Thanks, Nick.

As we passed through the village of Gunlock, we gave Jay Leavitt two nearly-spherical oyster balls as gifts for him and Judy. They were essential to us for access to private lands, and we had great conversations. The equally generous Hyrum and Gail Smith also received oyster ball presents. I hope they realize what treasures these are. Jay looks a bit dubious!

While in Gunlock we had permission to visit the backyard of a well-known collector, now deceased, who had a pile of oyster balls. Turned out the astounding petrified wood collection dwarfed any we had ever seen!

We had lunch at the famous bakery in tiny Veyo that produces delicious pies.

Beef pot pie followed by strawberry-rhubarb pie. Yum!

Unfortunately we’re going to miss the Utah UFO Festival this weekend in nearby Cedar City! I so would be going.

Our very last fieldwork in the afternoon was anticlimactic. We climbed over this huge exposure of Carmel Formation in Dammeron Valley looking for our holy trinity: oyster balls, hardgrounds, encrusted shells. We found none of these. At least it’s one place to scratch off the paleo list. Lots of potential here for sed/strat projects, though.

Team Jurassic Utah 2018 is done with fieldwork. Tomorrow will be spent visiting local areas of interest, and then we fly out of Las Vegas on Friday.

Zion National Park and life in Santa Clara, Utah

May 22nd, 2018

Santa Clara, Utah — Visiting Zion National Park is an obvious activity for Team Jurassic Utah, considering it is made of beautiful Jurassic rocks. We took the opportunity today. Well, half of the team. Galen and I weren’t feeling well, so Nick took Ethan to the magnificent place. Here they are at The Narrows, with some random people above watching. They had a great time as Galen and I recovered quickly enough back at the base.

Speaking of our base, I should describe it. Our place in Santa Clara is embarrassingly luxurious. I’m forbidden from camping out in southern Utah (an incident with gnat bites and anaphylaxis about 20 years ago!), so I usually stay in motels. Our administrative coordinator Patrice Reeder had a great idea: why not look into Airbnb rentals in the area? She found one on our main route to Gunlock. It is indicated by the red pin above near the southern end of the Santa Clara lava field. Appropriately, this place is called Lava Falls at Entrada. It is significantly cheaper than motel rooms, and much more roomy and private. We’ve also saved on food as Nick, Galen and Ethan are avid (and skilled) cooks.

Here is our own Lava Falls #8 house. The attached garage makes it even more convenient for storing gear and specimens, and for loading and unloading the vehicle.

As you saw from the aerial image, this development is in the lava field, remnants of which surround us. For geologists, this has been a very convenient, comfortable and efficient place to stay. Great idea, Patrice.

Nick brought his mountain bike on the trip, which has been highly useful in the field because he can go off on scouting trips and cover a lot of territory. He also likes to ride the trails at night because of the cool air and lack of other people. Last night he met up with a fox and got this great picture.

 

Team Jurassic Utah finishes essential data collection

May 21st, 2018

Santa Clara, Utah — A dull but direct title. Every Independent Study advisor knows this critical point in the process: when your students have collected the data necessary to actually do their projects. With discovery-based science like ours on this expedition, you never know what incidents or vagaries in the field will occur before minimum data is acquired. We reached that point today for Galen and Ethan. The final three field days now are gravy!

We started at a very familiar site: Eagle Mountain Ranch (EMR), its iconic cliff is shown above. (Thank you again, ranch owners Hyrum and Gail Smith.) We collected here encrusted and bored bivalve shells from the Carmel Formation exposed on the steep slopes. Most shells had to be pounded out of the rock with hammers and chisels, so it was briefly a noisy place. We did very well, finding bryozoans, encrusting bivalves, sabellids, and a variety of borings, from what I could tell with my hand lens. The full glories of the specimens will be known after we wash them up and examine them with our lab microscopes.

You may just be able to make out Galen in this view. I’m used to standing for hours on steep hillsides bending over to pick up fossils, but it is getting harder!

Below our fossiliferous units at the Eagle Mountain Ranch are thick “books” of thin-bedded carbonates with beautiful mudcracks. An effect of the repeated hexagonal cracks is that the unit itself develops columnar joints, analogous to those often seen in basalt flows. This is a sedimentary version.

Our site at Diamond Valley is where a large water tank was erected, so we call it WT. The excavation exposed a very fossiliferous layer of the Carmel Formation, and many of the calcitic shells are encrusted and bored.

Like this bryozoan-rich bivalve I collected here last month. It is spectacular, especially considering how rare bryozoans are in the Jurassic of North America.

Ethan manned the chisel today.

Galen gathered specimens from the fossiliferous talus. The team made several important finds, ensuring the happy Galen he’ll have plenty of sclerobiont fossils to analyze for the next year of research. Ethan finished his ostreolith collecting yesterday. Field success!

Jurassic hardgrounds and Holocene lava flows in southwestern Utah

May 20th, 2018

Santa Clara, Utah — Team Jurassic Utah spent the day on Galen Schwartzberg’s Independent Study project, the sclerobionts of the Carmel Formation. We began with the above carbonate hardground at the appropriately named Hardground West (HW) locality. (Just a few meters south of C/W-157 and Ethan Killian’s oyster balls; 14.9 meters stratigraphically below them.) A carbonate hardground is a synsedimentarily-cemented seafloor. Above the ruler can be seen the top layer of this hardground with many round holes. They are bivalve borings called Gastrochaenolites. They are what tell us that this was a rocky surface exposed to marine life. Below the ruler the top layer has been removed, revealing that the limestone beneath is full of internal molds of aragonite-shelled bivalves. The aragonite likely dissolved early in the diagenetic process. Did this aragonite then provide the calcium carbonate to cement the layer above? Maybe, but we haven’t yet come up with a test of this hypothesis.

Here Galen is inspecting a hardground. Note that he knows how to protect himself from the relentless sunlight!

One of our hardgrounds with truncated borings. There is an interesting cluster pattern here.

Encrusting organisms that require hard substrates are another identifying feature of hardgrounds. Here our friends the oysters Liostrea strigilecula are attached to a hardground. These are left valves with the right valves removed.

At the end of the day we stopped to walk around the remarkably fresh lava flows near where we’re staying in Santa Clara. These are part of the large Santa Clara Lava Field, which extends from the north rim of the Grand Canyon in Arizona northwards to Fillmore in central Utah. The flows in this area are as young as 32,000 years old. Above Nick and Galen are standing on a pressure ridge.

There are numerous large lava tubes in this volcanic field. Nick and Ethan stand near a large one with a collapsed roof.

Nick made this image. The flows are very difficult to navigate, so I gained new respect for lava hoppers.

This Google Earth image shows the black lava flows near the Airbnb we are inhabiting (the red pin). Urban growth of Santa Clara is eating away at the basalt. Our home here is called, in fact, “Lava Falls”.

« Prev - Next »