Last day of fieldwork in England: A working quarry and another great unconformity

June 26th, 2015

1 Doulting quarry sawBRISTOL, ENGLAND (June 26, 2015) — Tim Palmer has a professional interest in building stones, and a passion for sorting out their characteristics and historical uses. He thus has many contacts in the stone industry, from architects to quarry managers. This morning we visited the Doulting Stone Quarry on the outskirts of Doulting near Shepton Mallet in Somerset. Here a distinctive facies of the Jurassic Inferior Oolite is excavated for a variety of purposes. The rock has a lovely color, is relatively easy to work, and is durable. Above is a quarry saw that cuts out huge blocks from the natural exposure.

2 Thalassinoides layer DoultingSuch sawing produces great cross-sections for geologists to examine. We were particularly interested in that light-colored unit above with the irregular top and dark sediment-filled holes. The holes are part of a network of Thalassinoides burrows (tunnels made by Jurassic crustaceans) and reduce the value of the rock as a building stone. There is thus lots of it laying around the quarry yard for study.

3 Pinnid likely Trichites cross section DoultingOne impressive fossil exposed by the sawing is this pinnid bivalve, probably Trichites.

4 Burrow fill sediments DoultingThe Thalassinoides burrows are filled with a poorly-cemented sediment. It is full of little fossils, so we collected a bag of it for microscopic examination. It may give us clues as to what communities lived on the surface of this burrowed unit when it was part of the Jurassic seafloor.

5 shaping saw DoultingWe had a tour of the quarry shops, which included seeing these giant rock saws in action. Many of the saws are controlled by computers, so elaborate cuts can be made.

6 Medieval stone breaking marksThis rock has been quarried since Roman times, so there is over 2000 years of stone working here. The quarry owner set aside this rock face which shows chisel marks made in Medieval times. Wooden wedges were jammed into chiseled channels and then pulled over days to eventually crack the stone free.

7 Tedbury Camp wavecut surface along strikeAfter the quarry visit, Tim Palmer and I tromped through the woods and eventually found (with the help of several locals) an exposure known as Tedbury Camp. It is another Jurassic-on-Carboniferous unconformity like we saw at Ogmore-By-Sea earlier in the week. A century ago quarry workers cleared off this surface of Carboniferous limestone. It is a wave-cut platform on which Jurassic sediments (the Inferior Oolite) were deposited. The surface has many geological delights, including faults, drag folds, differentially-weathered cherts and carbonates, and Jurassic borings and encrusters. Beautiful.

8 wavecut surface foldingIn this view of the surface you may be able to see the odd folding of the dark chert layers in the right middle of the image. These seem to be drag folds along a fault. They clearly predate the Jurassic erosion of the limestone surface. The overlying Jurassic can be seen in the small outcrop on the left near Tim.

9 section view of wavecut surfaceIn this cross-section of the erosional surface you can clearly see we’re working with an angular unconformity.

10 filled borings wavecutTrypanites borings are abundant across this surface, most filled with lighter Jurassic sediment. There are other borings here too that deviate from the straight, cylindrical nature of Trypanites.

11 curved borings wavecutI don’t know yet how to classify these curved borings. They resemble Palaeosabella.

12 Encrusting bivalve wavecutHere is a Jurassic bivalve attached to the Carboniferous limestone at the unconformity. Most of the encrusters have been eroded away.

13 Tim on wavecut platformThere are many possibilities for further study of the Tedbury Camp unconformity. This was a productive site for our last field visit in England this year. Thank you very much to Tim Palmer, seated above, for his expertise, great companionship, and generosity with his time. It was a reminder of how much fun we had together in the field twenty years ago.

My month of geology in the United Kingdom has now come to an end. My next two days will be devoted to packing up and making the long train and then plane flights home. What a wonderful time I had, as did my students on the earlier part of the trip, Mae Kemsley and Meredith Mann. Thank you again to Paul Taylor for his work with us in Scarborough. I am very fortunate with my fine British friends.

For the record, the important locality coordinates from this trip —

GPS 089: Millepore Bed blocks N54.33877°, W00.42339°

GPS 090: Spindle Thorn Member, Hundale Point N54.16167°, W00.23326°

GPS 091: Robin Hood’s Bay N54.41782°, W00.52501°

GPS 092: Northern limit of Speeton Clay N54.16654°, W00.24567°

GPS 093: Northern limit of Red Chalk N54.15887°, W00.22261°

GPS 094: South section Filey Brigg N54.21674°, W00.26922°

GPS 095: North section Filey Brigg N54.21823°, W00.26904°

GPS 096: Filey Brigg N54.21560°, W00.25842°

GPS 097: D6 of Speeton Clay N54.16635°, W00.24520°

GPS 098: C Beds of Speeton Clay N54.16518°, W00.24226°

GPS 099: Lower B Beds of Speeton Clay N54.16167°, W0023326°

GPS 100: Possible A Beds of Speeton Clay N54.16129°, W00.23207°

GPS 101: A/B Beds of Speeton Clay N54.16035°, W00.22910°

GPS 102: C7E layer of Speeton Clay N54.16447°, W00.24043°

GPS 103: Lavernock Point N51.40589°, W03.16947°

GPS 104: Triassic deposits, Ogmore-By-Sea N51.46543°, W03.64094°

GPS 105: Sutton Stone Unconformity N51.45480°, W03.62609°

GPS 106: Sample of lowermost Sutton Stone N51.45455°, W03.62545°

GPS 107: Nash Point N51.40311°, W03.56212°

GPS 108; Devil’s Chimney N51.86402°, W02.07905°

GPS 109: Fiddler’s Elbow N51.82584°, W02.16541°

GPS 110: Doulting Stone Quarry N51.18993°, W02.50245°

GPS 111: Tedbury Camp unconformity N51.23912°, W02.36515°


Wooster Geologist in England (again)

June 25th, 2015

1 old quarry face cotswoldsBRISTOL, ENGLAND (June 25, 2015) — Our little geological exploration of southern Britain now passes into England. Tim Palmer and I crossed the River Severn and drove to the Cotswolds to examine old quarry exposures and Medieval stonework. We are parked above in Salterley Quarry near Leckhampton Hill.

2 devils chimney leckhamptonOur theme again is Jurassic. At Leckhampton Hill we examined exposures of the Middle Jurassic Inferior Oolite. It is not, of course, inferior to anything in the modern sense. The name, originally from William Smith himself, refers to its position below the Great Oolite. This is Devil’s Chimney, a remnant of stone left from quarrying in the 19th Century.

3 fiddlers elbow hdgd and Pea GritWe stopped along a bend in a Cotswold road called Fiddler’s Elbow and found an old carbonate hardground friend in the Inferior Oolite. Borings are evident in this flat, eroded surface. Next to the hammer are pieces of the Pea Grit, a coarser facies. I want to examine the grains for microborings and encrusters.

4 Dogrose leckhamptonThis is the gorgeous dog-rose (Rosa canina, not surprisingly), which is common in the Cotswolds. It is the model for the Tudor Rose in heraldry.

5 Fiddlers elbow orchidsThese tall orchids were also abundant near our outcrops.

6 fiddlers elbow orchids closeA closer view of the orchids. When I learn the name for this plant, I’ll amend this post. [And we have one! Caroline Palmer identified the flowers as Dactylorhiza sp. Thanks, Caroline!]

7 Painswick church and yewsAt the end of the day we stopped by St. Mary’s Church in Painswick, with its distinctive churchyard and variety of building stones. The sculptured trees are English yews.

8 Tim and Painswick gravestonesThe gravestones date back to the early 18th Century, with older ledger stones inside the church.

9 Painswick church pyramid markerThe unique pyramidal tomb of the stonemason John Bryan (1716-1787). He was apparently responsible for most of the 18th Century ornate monuments in this churchyard.

10 copper markers killing lichen PainswickMany of the gravestones have copper plates affixed to their upper faces. The rain washes copper ions out of the metal and over the limestone, killing the lichens and other encrusting organisms. This leaves the lighter patch of bare limestone. Somewhere in this is a study of microbiome ecological gradients!

11 St Marys church Painswick shot divot 1643The Painswick church was the site of a 1643 battle during the English Civil War. There are numerous bullet and shot marks on the exterior stones. Tim commented on the remarkable resilience of this stone to stay coherent after almost 400 years of weathering of these pits.

A great unconformity in South Wales

June 24th, 2015

1 Dinantian Sutton unconformity wide viewBRIDGEND, WALES (June 24, 2015) — Today Tim Palmer and I visited a famous unconformable rock plane in South Wales. I last saw it thirty years ago, when I knew a lot less about eroded, bored and encrusted surfaces. It is an unconformity between a Carboniferous limestone (High Tor Limestone, Dinantian in age) and an overlying Jurassic limestone (Sutton Stone, Hettangian, Lower Jurassic) exposed on the coast near Ogmore-By-Sea. It was most thoroughly described in 2004 by Johnson and McKerrow (Palaeontology 38: 529-541). You can see it as the surface above, with the Jurassic rocks on top of it to the right. (I know, gray rocks on gray rocks. It takes close examination to tell them apart after they both have been subjected to coastal weathering.)

2 Dinantian Sutton close viewHere is a closer view with part of the Lower Jurassic Sutton Stone broken away to show fresh material. (We didn’t do this, despite the guilty-looking hammer. The hammer is Paul Taylor’s, by the way. Thanks, Paul!) Note the pebbles in the Sutton Stone. They are made of the Carboniferous limestone beneath. Classic unconformity.

3 Dinantian Sutton borings wide viewThe Carboniferous limestone is punctured by numerous small borings (Trypanites) drilled by filter-feeding worms of some kind when the Early Jurassic sea covered this surface. They are the clusters of small black dots shown above.

4 Dinantian Sutton borings closeIn this closer view of the borings you can see that they are filled with a lighter Jurassic sediment. The openings have been somewhat enlarged by weathering.

5 Dinantian Sutton reliefThis erosion surface shows some relief, probably formed by cobbles and pebbles washing over it during the Early Jurassic. This matches what we see on modern wave-cut rocky platforms.

6 Triassic Dinantian unconformityOn the same stretch of shoreline there is a small section where Triassic wadi deposits cut down into the Carboniferous limestone — another even more dramatic unconformity, but without marine fossils.

7 Triassic wadi deposits Ogmore by seaComing from a desert myself, I have an affinity for wadi sediments. They are coarse, angular and poorly sorted. These grains are entirely from the underlying Carboniferous limestone. They were likely generated from steep rocky canyons through which intermittent streams flowed.

8 Nash Point viewAt the end of the day Tim and I visited Nash Point, again on the coast of South Wales. Here the Lias is brilliantly (and dangerously!) exposed as a series of alternating limestones and shales.

9 Nash Point CliffWe didn’t get too close to these unstable cliffs. The limestone blocks fall often as the interbedded soft shales holding them in place weather away.

10 Nash PointA view of Nash Point at low tide. Tim always wears that red jacket, so he’s easy to spot. (Classic Redcoat!)

11 Nash Point cobblesWe didn’t find much to paleontologically interest us at this last outcrop, but it was beautiful on another stunning coastal day. These cobbles, all made of Lias limestones, are pretty to look at, but tiresome to walk through. We were ready for a slow dinner after this excellent day.


Wooster Geologist in Wales

June 23rd, 2015

1 Triassic Lavernock Point Penarth GroupBRIDGEND, WALES (June 23, 2015) — My train journey yesterday was successful. It was close, but I made the four tight connections and arrived in Aberystwyth, Wales, from Thurso, Scotland, on schedule. It took 15 hours. My friend Tim Palmer was there to greet me as I stumbled out of my carriage. I went from rainy, cold Scotland to warm and sunny Wales. The top image is of the Triassic/Jurassic transition at Lavernock Point in south Wales (see below).

2 Tim Caroline houseMy first Welsh night was with Tim in his great country home (with is wife Caroline) on the outskirts of Aberystwyth. It is called The Old Laundry because of its function on a previous manorial estate. I had my best sleep here for the entire trip. Quiet and beautiful.

4 Talley Abbey ruinsOne of Tim’s passions is the study of building stones in England and Wales. As we drove to southern Wales for our geological work, we stopped by interesting stone structures, including the ruins of Talley Abbey, a 12th Century monastery.

5 Tim at Talley AbbeyTim is here examining the dressing stones on a corner of this pillar in the Talley Abbey ruins. I learned that these dressings are usually made of stone that can be easily shaped, is attractive, and will hold sharp edges. In many cases these are called “freestones”.

6 Lower Lias Lavernock dinosaur siteOur first geological stop was at Lavernock Point on the southern coast of Wales. We looked here at the boundary section between the Upper Triassic and Lower Jurassic (Lias). In this view we see an alternating sequence of limestones (buff-colored) and shales (dark gray) of the lower Lias. These are marginal marine units with oysters and ammonites. On the left side of the image you can see a broad niche cut back into the cliff. This is the site where the first carnivorous dinosaur in Wales was recently excavated. It is also one of the oldest Jurassic dinosaurs since it was discovered just above the Triassic/Jurassic boundary. More on this dinosaur later.

7 Lower Lias pseudo mudcracksWe wandered across broad intertidal wave-cut platforms at Lavernock Point looking at the limestones and shales of the lower Lias. I was intrigued by these features on some bedding planes. They are not desiccation cracks, but rather some combination of jointing and weathering.

8 Liostrea hisingeri LavernockThe oyster Liostrea hisingeri is very common in this part of the Lias. In the limestones it is sectioned by erosion, resulting in these shelly outlines.

9 Liostrea hisingeri shale LavernockWhen Liostrea hisingeri is present in the shales, it is preserved three dimensionally.

10 Tonypandy street viewAfter our geologizing was done for the day, Tim and I drove up into the Rhondda Valleys just north of our hotel. This was at one time a very busy coal mining and industrial region, but the mines are closed and most of the heavy industry has moved elsewhere. Above is a view down a street in Tonypandy, one of the more famous towns of The Valleys. There were massive riots here in 1910 which eventually a minimum wage for miners in 1912.

A beautiful day for Wooster Geologists in the Silurian of Ohio

April 18th, 2015

aDSC_5072FAIRBORN, OHIO–It’s field trip season at last for the Wooster Geologists. Several geology classes have now been out in Ohio, taking advantage of windows of spectacular weather. Today was one of those days for 25 students in the Sedimentology & Stratigraphy class. We returned to the Oakes Quarry Park exposures in southwestern Ohio (N 39.81472°, W 83.99471°). Three years ago here in April it was 37°F and raining. This year the conditions were perfect. We studied outcrops of the Brassfield Formation (Early Silurian, Llandovery) in the old quarry walls. The students measured stratigraphic columns of these fossiliferous biosparites as part of an exercise, and then explored the glacially-truncated top of the unit.

bDSC_5079The Brassfield is intensely fossiliferous. Large portions of it are virtually made of crinoid fragments. In the random view above you can see columnals, as well as a few calyx plates. This is why this unit is very popular among my echinodermologist friends at Ohio State.

DSC_5056Kevin Komara, Brian Merritt and Dan Misinay (Team Football) are here contemplating the quarry wall, planning how to measure their sections.

DSC_5063One of our Teaching Assistants, Sarah Bender, is here pointing out one of the many thin intercalated clay units in the Brassfield biosparites.

DSC_5065Fellow Californian Michael Williams directed the action. No, actually he’s doing the time-honored technique of following a measured unit with his finger as he finds a place he can safely climb to it and the units above. He is holding one of our measuring tools, a Jacob’s Staff. Why do we call them “Jacob’s Staffs”? Read Genesis 30:25-43. (Yes, today’s students are mystified by Biblical references.)

DSC_5066Here’s Rachel Wetzel, giving me a heart attack. Don’t worry, insurance companies and parents, she’s fine.

DSC_5068Rachel is again on the left. Team Ultimate Frisbee (Meredith Mann and Mae Kemsley) are in the front, and Sharron Ostermann is above. This is the recommended way to get to the top of the exposure!

DSC_5070We carried our lunches in “to go” boxes from the dining hall. Our Teaching Assistants Sarah Bender and Kaitlin Starr enjoyed a sunny picnic on the rocks.

yDSC_5077The top level of the quarry was cleared of soil and brush many years ago to expose a glacially truncated and polished surface of the Brassfield. Looking for glacial grooves and fossils here are (from the left) Tom Dickinson, Jeff Gunderson (another Californian!), Andrew Conaway, and Luke Kosowatz (who seems to also be making a little pile of rocks as a memorial to a great day).

zDSC_5074One of the many corals we found in the top of the Brassfield was this halysitid (“chain coral”), an indicator fossil for the Late Ordovician and Silurian.

Everyone returned safely to Wooster with their completed stratigraphic columns, lithological descriptions, and a few fossils. Thank you to Mark Livengood, our bus driver. Good luck to the other field trip groups later this month!

The karst topography around Guiyang, China

July 5th, 2014

Karstic Guiyang 1GUIYANG, CHINA — I find this karstic landscape enchanting. Photo taken at the airport.

Karstic Guiyang 2

A Nazi hiding hole in Middle Triassic rocks (Będzin, Poland)

June 20th, 2014

Tunnel bunker 062014SOSNOWIEC, POLAND — On my last full day in Poland, Michał Zatoń and his family took me on a tour of the city they live in and where my hotel is located: Będzin. The history of this place is very long, stretching back to the Neolithic, and for us it is dominated by World War II and the horrifying events that took place here from the earliest days of the war in 1939 until its liberation from the Germans in 1945. I thought I’d highlight one part of that history recently excavated and with a geological context.

The above view is looking down a tunnel in a complex bunker constructed by the Germans in 1944. Its purpose was to serve as a refuge from Allied bombing and reconnaissance flights near the end of the war. It had been sealed off and all but forgotten after the Germans retreated in 1945. The city of Będzin is now excavating it to be an underground museum. We were fortunate to have a private tour this morning.

Entrance bunker 062014These are the street level entrances into the bunker complex. You can see the solid rock outcrop behind the doorways.

Unfinished bunker 062014Much of the bunker is unfinished, like this portion. The steel arches are the modern effort to stabilize the roof and walls to make it safe for the public.

Fossilized cement 062014The Germans left in a hurry. This is a pile of unused bags of cement mix. In the decades since they were placed they have essentially fossilized into solid masses of concrete.

Muschelkalk bunker wall 062014This is the leading edge of construction where the concrete was laid against the rock wall. The reddish-yellow limestone is the Muschelkalk (Middle Triassic) unit we visited earlier this week. This is a strong rock suitable for tunneling because it can be easily carved out. This interval is probably equivalent to the crinoid-rich top of the Muschelkalk.

Nazis 062014This is one of the few photos made at the time in 1944 when the bunkers (although unfinished) were opened for use. It is taken from this website (in Polish). The man on the left (Hans Kowohl) was the mayor of the city, and the one in the middle was reportedly hanged as a war criminal in 1946, although I can find no mention of his identity.

Thus ends my Polish experience this summer with great colleagues, wonderful rocks and fossils, and a deep, often disturbing, history. I was challenged on many different levels.

Castles in Poland I expect, but a desert?

June 19th, 2014

Zamek Mirow 061914SOSNOWIEC, POLAND — Today my colleague Michał Zatoń took me and his family (wife Aneta and son Tomasz) on a tour of the Polish Jura, an upland with spectacular exposures of Jurassic rocks and the castles who love them. Above is the castle I consider most dramatic: Zamek Mirów from the 14th Century. Note the large mass of white bedrock at its base. This is a natural outcrop on which the castle was built. This will be a theme.

Mirow Oxfordian bioherms 061914Here we see a series of these white rocks jutting dramatically across the landscape. They are Upper Jurassic (Oxfordian) sponge-rich silicified limestones that grew as bioherms (organic mounds) on portions of seafloor elevated because of igneous intrusions below. The sponges loved being raised off the deep seabed and continued to grow upwards. Since many of them were siliceous sponges, after death their silica was mobilized into the surrounding sediment as a cement. This process produced these outcrops of very hard silicified limestones just waiting to host a castle or two.

Oxfordian limestone 061914Conveniently, the rocks can be quarried to produce the stones used in castle construction. Fossils are quite common in the building stones, like this ammonite external mold.

Zamek Bobolice 061914This is a reconstructed castle built on the outcrops.  (Zamek Bobolice; also 14th Century in origin.)

Zamek Smoleniu 061914Zamek Smoleniu was the smallest castle we visited, but somehow the scariest to climb. Getting to the top of that tower was a challenge.

Zamek Ogrodzieniec view 061914Zamek Ogrodzieniec was the largest and best known castle we visited today. It is haunted, but I ain’t scared.

Zamek Ogrodzieniec 061914The outer fortifications of Zamek Ogrodzieniec have very impressive outcrops of the Oxfordian silicified limestones.

Pustynia Bledowska 061914Now what about that mysterious Polish desert? Well, turns out it isn’t a desert in the official sense (it receives a lot of rain), but it sure looks like a desert. Pustynia Błędowska is its name in Polish. It is definitely an odd patch: 32 square kilometers in the midst of rich Polish pine forests. This place is so deserty that the German Afrika Korps trained here before going to northern Africa, and the Polish military uses it as a proxy for Middle Eastern situations. There is a lesson for humanity here as well: In the 13th and 14th Centuries the forest in this area was completely logged to provide charcoal for smelters producing silver and lead ingots. The removal of the trees exposed highly mobile glacial sands, which blew around enough to create dunes and soil too unstable for the trees to recolonize. This is a medieval ecological catastrophe. The Błędów Desert is now protected from human traffic so it has a chance to be absorbed back into the surrounding forests.

The Triassic limestones at Góra Świętej Anny, Poland

June 18th, 2014

Gora sw. Anny signSOSNOWIEC, POLAND — My friends Michał Zatoń and Tomasz Borszcz took me on a very pleasant day trip to Góra Świętej Anny in southwestern Poland about an hour’s drive northwest from Sosnowiec. This is a place of considerable geological and historical interest. It is an eroded volcanic caldera and the easternmost occurrence of the fine-grained igneous rock basalt in Europe. You would think I’d be able to show you at least a bit of basalt, but we saw only the surrounding Middle Triassic limestone country rock. (Sorry, Dr. Pollock.) We’ll talk about the history later. Now we’ll look at the geology.

Muschelkalk long 061814Here is a great exposure of the Muschelkalk, a Middle Triassic sequence of limestones and dolomites that extends across central and western Europe. This is its best exposure in Poland. The rock appears very massive in this old quarried wall, but it actually has many distinct layers. Michał is standing at the top of stairs that lead down into a massive Nazi amphitheater called a Thingstätte, but more on this later.

Muschelkalk brachs 061814Part of the Muschelkalk unit is dominated by terebratulid brachiopods, many of which are seen on this slab.

Triassic encrinite 061814The topmost Muschelkalk here contains thick beds made primarily of crinoid skeletal debris, a kind of deposit known as an encrinite. We’ve seen encrinites before in this blog.

trace fossil sign 061814You don’t often see informative signs dedicated to the description of a trace fossil type. Rhizocorallium commune is the most common ichnofossil in this part of the Muschelkalk. It is a ropy, loopy tube produced in this case by crustaceans, probably including the decapod shrimp Pemphix.

Rhizocorallium 061814The slabs used to pave the walks and plazas in this area are filled with Rhizocorallium commune traces.

View 061814Finally, this is a view west from Góra Świętej Anny towards the Oder River. It is the highest place around, dominating this fertile valley rich with farms, mines and factories. This will be the reason it is so culturally and historically significant in Silesia.

A paleontology field trip into the Upper Ordovician of Ohio

September 8th, 2013

DSC_2515The 2013 Invertebrate Paleontology class at Wooster had its first field trip today. The weather was absolutely perfect, and the usual boatload of fossils was collected. We traveled this year to Caesar Creek State Park and worked in the emergency spillway created and maintained by the US Army Corps of Engineers for the Caesar Creek Lake dam. Exposed here are the Arnheim, Waynesville, Liberty and Whitewater Formations of the Richmondian Stage in the Cincinnatian Series of the Ordovician System. These units are enormously rich with fossils, especially brachiopods, bryozoans, trilobites, clams, snails, nautiloids, corals and crinoids. There is no better place to get students started on paleontological fieldwork, and to follow up with lab preparation, identification and interpretation throughout the semester.

Spillway090813The Caesar Creek Lake emergency spillway is at N 39.480069°, W 84.056832° along Clarksville Road just south of the dam. The authorities keep it clear of vegetation, and so it is an extensive exposure of bare rock and sediment. The sharp southern boundary is the rock wall shown in the top image (with the intrepid Willy Nelson and Zach Downes). Students quickly fanned out along the entire exposure, so I never did get an image of the whole class of 22 students in one place.

DSC_2505This is the bedding plane of a slab of micritic limestone with numerous worm burrows. Trace fossils are very abundant here. These units, in fact, have some of the first trace fossils to be specifically described in North America.

DSC_2506On some limestone slabs are internal and external molds of straight orthocerid nautiloids. They are often paired like this, with both facing in the same direction. This is an effect of seafloor currents that oriented the shells. The current here was flowing from the left to the right.

DSC_2508Many of the limestones are extremely rich in shelly fossils. Here you can see several types of brachiopods, an isotelid trilobite genal spine, and some molluscan internal molds.

DSC_2511I always check in here with my favorite borings: Petroxestes pera. These are bivalve incisions on a cemented seafloor (a carbonate hardground). This is the type area for this ichnogenus and ichnospecies.

DSC_2512Two of our sophomore paleo students, Michael Williams and Adam Silverstein, are here happily filling their sample bags with fossils. I wanted to get a photo of them in the field because they had such a geologically adventurous summer in both cool and wet Iceland and hot, dry Utah. Not many sophomores have these opportunities!

DSC_2520Here is another pair of nautiloids, this time showing the characteristic internal mold features of curved septal walls. Again they are nestled together and oriented because of seafloor currents.

For the rest of the semester the paleo students will be studying the fossils they collected today, each eventually constructing a paleoecological interpretation based on their identifications and growing knowledge of marine invertebrate life habits and history. Now we’re really doing paleontology!

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