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 Day in Stromness

June 21st, 2015

1 Stromness Museum sceneSTROMNESS, SCOTLAND (June 21, 2015) — I intended to explore the region around Stromness today as I waited for the late afternoon ferry to Thurso, but it rained continuously. Since I can’t afford to get my meager kit wet while traveling, I was confined to indoors activities, including visiting the excellent though small Stromness Museum.

2 Labradorite as ballastThe bulk of the museum displays are devoted to maritime history, naturally, but there is always some geology. This, for example, is a beautiful piece of labradorite (from, naturally, Labrador) used as ship ballast.

3 Hugh Miller fossilI was very pleased to see this small exhibit on the brilliant polymath Hugh Miller (1802-1856) and the fossils he collected from Devonian rocks in the region. This is his most famous specimen: “The Asterolepis of Stromness”. He was the earliest expert on the Old Red Sandstone and its fossils.

This afternoon I take the ferry across these stormy seas back to the Scottish mainland. I’ve very much enjoyed Orkney, cold and wet though it is.

Wooster’s Fossil of the Week: An undescribed cyclostome bryozoan from the Upper Ordovician of Oklahoma

June 19th, 2015

HT_1276 585Paul Taylor and I presented a talk this month at the Larwood Symposium of the International Bryozoology Association in Thurso, Scotland. (Yes, way in the tippy-top of Scotland. Very cool.) Paul found the above wiggly bryozoan encrusting the interior of an orthid brachiopod identified as Multicostella sulcata (thanks, Alycia Stigall!) in the Lower Echinoderm Zone of the Mountain Lake Member of the Bromide Formation (Upper Ordovician, Sandbian) near Fittstown, Oklahoma. This bryozoan is “new to science”, as we grandly say. Paul generously invited me to describe it with him in this presentation and in a future paper. We did a 1994 paper together on Corynotrypa, a similar cyclostome bryozoan. The following are a few slides from our Larwood talk.

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Slide21_052815This last image showing what appear to be an interior wall with a pore is critical. Corynotrypa does not have such walls, so our bryozoan is more like a sagenellid cyclostome.

References:

Carlucci, J.R., Westrop, S.R., Brett, C.E. and Burkhalter, R. 2014. Facies architecture and sequence stratigraphy of the Ordovician Bromide Formation (Oklahoma): a new perspective on a mixed carbonate-siliciclastic ramp. Facies 60: 987-1012.

Taylor, P.D. and Wilson, M.A. 1994. Corynotrypa from the Ordovician of North America: colony growth in a primitive stenolaemate bryozoan. Journal of Paleontology 68: 241-257.

Team Yorkshire finishes its fieldwork

June 15th, 2015

1 Speeton Clay at Reighton Sands 061515SCARBOROUGH, ENGLAND (June 15, 2015) — It is difficult to believe that yesterday was so cold and wet. Today was beautiful on the Yorkshire Coast. Mae Kemsley (’16), Meredith Mann (’16) and I traveled to Reighton Sands for one last look through Mae’s outcrops. The tide was very low and the sunshine abundant, so we took lots of images and collected another bag of fossils. Above is the Speeton Clay (Lower Cretaceous). It rarely looks so good in photographs.

2 Morning commute 061515A scene from our morning commute from Scarborough. We like sitting in the top front of the double-decker bus.

3 SS Laura boilersThe tide was low enough to expose the pair of boilers from the SS Laura. You may recall this Austro-Hungarian cargo ship ran aground here on November 21, 1897. These heavy and resistant boilers have served as coastal landmarks for over a century.

4 Mussels Barnacles on boilersThe SS Laura boilers are also a significant hard substrate for attaching mussels and barnacles.

5 Flamborough Head 061515The white chalk cliffs of northern Flamborough Head were especially beautiful today. I wish there was a way to record the sounds of thousands of circling seabirds.

6 Red Chalk outcrop 061515We visited an outcrop of the Red Chalk (Hunstanton Formation, Lower-Upper Cretaceous) one last tme to collect more belemnites for Mae’s future analytical work.

7 Red Chalk fossils 061515We found quite a few Neohibolites, along with a coiled serpulid or two.

8 Speeton belemnites in placeThen it was back to the gray Speeton Clay. After yesterday’s rain, the belemnites seemed very easy to find. Today we were after belemnites that had borings and/or encrusters.

9 Mae Meredith frisbee SpeetonMae and Meredith took advantage of the beach to toss a frisbee around. They are both members of Wooster’s superb Ultimate Frisbee team.

10 Speeton sand patterns IIWe walked the long arc of Filey Bay to Filey. I was fascinated with the patterns in the sand left by the receding tide.

11 Speeton sand patterns IThose same sand patterns with a stone producing interference.

12 Filey 061515The seaside portion of Filey, viewed from the south.

13 Last view of Filey BriggAnd finally a view of Filey Brigg from Filey. We were very pleased to have our last field day such a pleasant one. We hope we’ve prepared the way for future Wooster Independent Study projects in this beautiful part of the world.

Last day of fieldwork on Filey Brigg in Yorkshire

June 14th, 2015

1 Mae Meredith Passage Beds 061415SCARBOROUGH, ENGLAND (June 14, 2015) — It was a drizzly, breezy, cold day on the outcrops, but Team Yorkshire finished measuring and collecting for Meredith Mann’s project on the Passage Beds Member of the Coralline Oolite Formation (Upper Jurassic, Oxfordian) exposed on the north side of Filey Brigg, a spit of rock between Scarborough and Filey. In the posed but useful image above, Meredith stands at the base of the Passage Beds, and Mae holds a meter stick pointing to the top, with the cross-bar on the Thalassinoides unit at the base of the Hambleton Oolite.

2 Annotated Passage Beds 061415We designated five subsidiary units within the Passage Beds, as shown above. The rocks below belong to the Saintoft Member of the Lower Calcareous Grit Formation; the rocks above are the Hambleton Oolite (Lower Leaf) Member of the Coralline Oolite. Note how more ragged this exposure is because it directly faces the sea. The erosion better exposes the stratigraphy and fossils. It also means when we work here we are more subject to the elements.

3 Low tide access Filey BriggThis location on the north side of Filey Brigg is only accessible at low tide across slick algal-encrusted rocks. The angry sea looms to the right.

4 Bouldery walkWe have to climb over these boulders which are piled against a cliff face.

5 High tide escape ladderSince this area is flooded at high tide, if you wait too long to hike back the only escape from the raging North Sea is up this emergency ladder. I kept my eye on the ocean behind us!

6 Splashy Filey Brigg 061415The remorseless sea pounding away at Filey Brigg during a rising tide. I hate rising tides.

7 Mae Meredith working 061415Meredith and Mae at work collecting rock samples and fossils. We are somewhat protected here from the rain by the overhanging Hambleton Oolite. The wind still blew in plenty of water from sea and sky.

8 Thalassinoides in Unit 1An alcove in Unit 1 of the Passage Beds with galleries of the trace fossil Thalassinoides.

9 Crossbedding Unit 3Unit 3 of the Passage Beds shows cross-bedding, which is consistent with its origin as sediments washed shoreward during storms.

10 Unit 1 fossils 061415A cluster of oysters and pectinid bivalves in Unit 1 of the Passage Beds.

11 Mae Meredith Filey BriggWe celebrated completion of our fieldwork by walking as far out on Filey Brigg as we could! Miserable weather, but a dramatic setting! And no one broke a leg on the boulders or was trapped by the high tide.

Rain delay in Yorkshire. Time for sample management.

June 13th, 2015

Sample management 061315SCARBOROUGH, ENGLAND (June 13, 2015) — Our good fortune with the weather finally ended with a steady downpour this morning. Since it was during an advantageous tide, and I didn’t want us slipping around on wet intertidal boulders at Filey Brigg, we cancelled the day’s fieldwork. As generations of Wooster paleontologists know, this gives us time for Sample Management. We went through all that we collected, washed each fossil in my bathroom sink, and dried the lot on the hotel towels so kindly provided to us. It was the first time I got a good luck at many of the specimens the students collected, so it was rather fun. We then rebagged and labelled everything for the trip back home. Mae and Meredith have put together a nice collection for their studies. We have two more days of fieldwork to finish collecting for Meredith’s project.

Wooster’s Fossils of the Week: Chaetetids from the Upper Carboniferous of Liaoning Province, North China

June 12th, 2015

1 Benxi chaetetid 2a 585Last year I had a short and painful trip to China to meet my new colleague and friend Yongli Zhang (Department of Geology, Northeastern University, Shenyang). The China part was great; the pain was from an unfortunately-timed kidney stone I brought with me. Nevertheless, I got to meet my new colleagues and we continued on a project involving hard substrates in the Upper Carboniferous of north China. Above is one of our most important fossils, a chaetetid demosponge from the Benxi Formation (Moscovian) exposed in the Benxi area of eastern Liaoning Province. We are looking at a polished cross-section through a limestone showing the tubular, encrusting chaetetids.
2 Chaetetid Benxi Formation (Moscovian) Benxi Liaoning China 585This closer view shows two chaetetids. The bottom specimen grew first, was covered by calcareous sediment, and then the system was cemented on the seafloor. After a bit of erosion (marked by the gray surface cutting across the image two-thirds of the way up), another chaetetid grew across what was then a hardground that partially truncated the first chaetetid. This little scenario was repeated numerous times in this limestone, producing a kind of bindstone with the chaetetids as a common framework builder.
3 Chaetetid Benxi cross-section 585Here is the closest view of the chaetetids, showing the tubules running vertically, each with a series of small diaphragms as horizontal floors.

Last week’s fossil was a chaetetid, introducing the group. They are hyper-calcified demosponges, and the classification of the fossil forms is still not clear. Their value for paleoecological studies, though, is clear. This particular chaetetid from the Benxi Formation preferred a shallow, warm, carbonate environment, and it was part of a diverse community of corals, fusulinids, foraminiferans, brachiopods, crinoids, bryozoans, gastropods, and algae. Such hard substrate communities are not well known in the Carboniferous, and this is one of the best.

References:

Gong, E.P, Zhang, Y.L., Guan, C.Q. and Chen, X.H. 2012. The Carboniferous reefs in China. Journal of Palaeogeography 1: 27-42.

West, R.R. 2011a. Part E, Revised, Volume 4, Chapter 2A: Introduction to the fossil hypercalcified chaetetid-type Porifera (Demospongiae). Treatise Online 20: 1–79.

West, R.R. 2011b. Part E, Revised, Volume 4, Chapter 2C: Classification of the fossil and living hypercalcified chaetetid-type Porifera (Demospongiae). Treatise Online 22: 1–24.

Zhang, Y.L., Gong, E.P., Wilson, M.A., Guan, C.Q., Sun, B.L. and Chang, H.L. 2009. Paleoecology of a Pennsylvanian encrusting colonial rugose coral in South Guizhou, China. Palaeogeography, Palaeoclimatology, Palaeoecology 280: 507-516.

Zhang, Y.L., Gong, E.P., Wilson, M.A., Guan, C.Q.. and Sun, B.L. 2010. A large coral reef in the Pennsylvanian of Ziyun County, Guizhou (South China): The substrate and initial colonization environment of reef-building corals. Journal of Asian Earth Sciences 37: 335-349.

Museum work and a castle visit in Scarborough

June 11th, 2015

1 Scarborough museum workSCARBOROUGH, ENGLAND (June 11, 2015) — It is always useful when doing paleontological fieldwork to visit the local museum to see what specimens they’ve curated over the years. Today Team Yorkshire explored the collections at the Scarborough Museums Trust Woodend storage facility, courtesy of Jennifer Dunne, Collections Manager. Above are Mae Kemsley (’16) and Meredith Mann (’16) examining boxes of specimens from the Speeton Clay and Coralline Oolite, the two units they’re working with.

2 Peltoceras williamsoniThis specimen of the ammonite Peltoceras williamsoni is an example of the kind of material we find in museum collections. It comes from the Passage Beds of the Coralline Oolite — Meredith’s unit. We are not likely to come across such a well-preserved fossil in our short interval of fieldwork. This is not the first Peltoceras in this blog.

3 Peltoceras noteThis note that accompanied the above specimen is from J.K. Wright, an expert with these fossils.

4 Scarborough castle keepAfter our museum work, we took an opportunity to visit Scarborough Castle. (We couldn’t do more fieldwork this afternoon because of the high tides.) This is a spectacular place with over 3000 years of history. It was the site of settlements in about 800 BCE and 500 BCE, and then a Roman signalling station around 370 CE. The castle itself dates back to the 12th Century. In 1645 it was the subject of a long Civil War siege, with Parliamentarians on the outside shelling Royalists on the inside. (The cannonades broke the above castle keep in half.) In December 1914, German battleships fired over 500 shells into it.

5 Team Yorkshire castle 061115Mae and Meredith with the castle keep in the background. Note the fantastic weather!

6 St Marys chapel castleThe remains of St. Mary’s Chapel within the castle walls were built on the site of the Roman signals station. Resident of the castle took shelter here during the 1914 German bombardment.

7 Scarborough from castleA view of Scarborough from the castle walls. We could see all of our field areas along the coast from this vantage point.

Another gorgeous day on the Yorkshire coast

June 10th, 2015

Dismantled pillbox Filey BeachSCARBOROUGH, ENGLAND (June 10, 2015) — We certainly can’t complain about the weather for our fieldwork in Yorkshire this year. Today was spectacular with blue skies and cool sea breezes. It made the long beach hikes very pleasant.

1 Mae on Speeton 061015This was our first day without our English colleague (and Yorkshire native) Paul Taylor, so we were on our own for transportation. We figured out the bus system, though, and made it to the Lower Cretaceous Speeton Clay at Reighton Sands in good time. Here is the last view you’ll have of Mae Kemsley (’16) working on her outcrops of this gray, mushy unit. We collected sediment samples this morning, along with a few last fossils.

2 Meredith on Speeton 061015Here is Meredith Mann (’16) doing the same. We finished all of our fieldwork for Mae’s project by 10:30 a.m., so we could make a long beach hike from the Speeton Cliffs northwards to Filey.

3 Meredith waiting on tide

4 Mae waiting on tideWe hiked as far as we could on Filey Brigg, but had to chill because our sites were still cut off by the high tide. Waiting for a tide to drop is tedious, but the students had plenty of patience.

5 Thalassinoides 061015We reached the large slabs of Hambleton Oolite Member (Upper Jurassic, Oxfordian) with Thalassinoides burrows to begin Meredith’s data collection. These are impressive trace fossils, with numerous shelly fossils in the surrounding matrix. We took reference photos and collected what we could. Unfortunately only three slabs met our criteria for measurements, so we moved to a unit exposed just below the Hambleton.

6 Cannonball concretionsOn the north side of Filey Brigg there are these large “cannonball” concretions, which were excellent stratigraphic markers for us. They are in the Saintoft Member of the Lower Calcareous Grit Formation. They told us that the units above were the Passage Beds Member of the Coralline Oolite Formation.

7 Passage Beds 061015Mae and Meredith are here collected fossils from the Passage Beds above the concretions. This unit is interesting to us because it contains shelly debris that was apparently washed onto shore during storms. These shells are often heavily encrusted with oysters and serpulids. Such sclerobionts have been little studied in this part of the section.

8 MMbus 061015On our sunny ride home the students sat in the front of the top section of our double-decker bus. Not a bad commute for a day’s work!

 

Return to the Speeton Clay

June 9th, 2015

1 Mae on Speeton 060915SCARBOROUGH, ENGLAND (June 9, 2015) — Team Yorkshire returned to the Speeton Clay today to begin the fieldwork for Mae Kemsley’s Senior Independent Study project. Mae chose to work on the incredible diversity of belemnites found in this Lower Cretaceous unit. There are two aspects to her study: the paleoecology of the belemnites themselves, and the taphonomy of their distinctive bullet-shaped calcitic rostra (guards). We hope that Mae will be able to do some stable isotope work to help elucidate the paleoenvironments these pelagic creatures lived in. Oxygen isotopes in particular may indicate the seawater temperatures when the belemnites were forming their skeletons. The Speeton Clay has faunas from alternating Boreal (northern, colder) and Tethyan (southern) regions, so this will be interesting.

2 Middle Cliff SpeetonHere is the Speeton Clay forming the Middle Cliff along the shoreline. Virtually every outcrop of this unit is slumped from above, so sorting out the stratigraphy is a challenge.

3 Mae working 060915Here is Mae again working through a small patch of the Speeton Clay. There are four broad intervals of the unit (A, B, C, D) that we must recognize by the fossil content and the position of the outcrop relative to various field markers like abandoned pillboxes, breakwaters, and large rocks.5-SS-Laura-boilers

One of our intertidal landmarks is a set of boilers from the 1897 wreck of the SS Laura, an Austro-Hungarian cargo ship that ran aground near Filey Brigg. The heavy boilers have stayed in essentially the same place for over a century.

4 Speeton work 060915The weather could not have been better today. We got Mae’s project off to a fine start with several sets of samples collected from the four primary units of the Speeton Clay.

Paul Taylor returned to his home in Epsom at the end of the day, leaving the three Americans to their own devices. He was essential in our first week, getting us oriented to the local geology, expertly driving us around to the various sites, and entertaining us with his trademark puns. He trained us well to carry on into week two of the Yorkshire Expedition.

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