Team Yorkshire gets all geochemical

September 20th, 2015

1 MMlab091915BRYN MAWR, PENNSYLVANIA–When we last saw Mae Kemsley (’16) and Meredith Mann (’16) in this blog, they were celebrating the end of their Senior Independent Study summer fieldwork on the coast of North Yorkshire, England. This weekend the three of us traveled to Bryn Mawr College and the geochemistry lab of Professor Pedro Marenco to start the geochemical analysis phase of our research. We learned a lot under Pedro’s kind and generous direction.

2 CW715 090315 belemnitesBoth Mae and Meredith have belemnite fossils in their field collections. Meredith has just a few from the Passage Beds Member of the Coralline Oolite Formation (Upper Jurassic, Oxfordian); Mae has dozens from the Speeton Clay (Lower Cretaceous). A belemnite was a marine squid-like cephalopod that had a hard, bullet-shaped internal structure called a guard (shown above). These guards are made of almost pure calcite which took in trace elements from the seawater as they grew. The carbon and oxygen isotopes in their calcite crystals also reflect the isotopic composition of the seawater. These fossils are thus geochemical repositories from ancient seas. We are interested in what our belemnites tell us about the ambient chemical conditions in their environments, which in turn are proxies we can use to interpret paleotemperatures and other factors.

3 Belemnite cut sampleIn our Wooster geology labs we cut small disks from a series of belemnites, then polished the surfaces and cleaned them thoroughly. We brought these prepared disks to Pedro’s lab in Bryn Mawr.

4 Drilling 091915Mae is here in the Bryn Mawr petrography lab using a small drill to excavate fine calcite powder from the belemnite disks. This powder, measured in fractions of a gram, was then collected into sheets of weighing paper, folded like origami and taped to keep it in place.

5 Weighing091915Mae and Meredith are here weighing the powder samples with Pedro’s fancy balances. Each plastic sample vial had to be paced through an ion generator to reduce static charge and improve measurements to the microgram. A lot of chemwipes, weighing sheets, and gloves are used in the process to reduce contamination.

6 Mae tubes 091915After dissolving the powder samples in acid, and then diluting the liquids in carefully-measured ways, we finally ended up with these precious tubes filled with essence de belemnite. We learned how much work goes into preparation of geochemistry samples — a lot!

7 ICP MS 0091915The liquid samples are now ready for analysis in a device called an ICP-MS, which stands for Inductively Coupled Plasma Mass Spectrometer. This is the process and equipment Wooster geologists Mary Reinthal (’16) and Chloe Wallace (’17) described in their recent geochemistry blogpost. We’re doing the same thing: assessing the trace elements in our samples. Pedro will later run our samples through this magic machine and give us the results. We have a duplicate set of drilled belemnite powders to send to another lab for carbon and oxygen isotope analysis.

8 Katherine Pedro 091915Thank you very much to our Bryn Mawr hosts Dr. Katherine Nicholson Marenco (’03) and Dr. Pedro Marenco. We are very much looking forward to our continuing collaboration. Thanks as well to Dr. Paul Taylor of the Natural History Museum in London who was our Essential Companion in the field.

Wooster’s Fossil of the Week: An encrusted and bored oyster from the Upper Jurassic of northern England

August 28th, 2015

1 Passage Beds Oyster shell bored 585This week’s fossil is a celebration of classes beginning again at Wooster, and a memory of excellent summer fieldwork. It isn’t especially attractive, but it has paleontological significance. We are looking at a broken surface through a thick oyster from the Passage Beds Member of the Coralline Oolite Formation (Upper Jurassic, Oxfordian) exposed on the north side of Filey Brigg, North Yorkshire, England. It was collected by Meredith Mann (’16) as part of her Senior Independent Study research in June. One of her project goals is to assess the sclerobionts (encrusters and borers) that lived on and within hard substrates in this interval. This thick shell is a start.
2 Passage Beds borings 585In this closer view we can see three rounded objects penetrating the oyster shell. These are bivalve borings called Gastrochaenolites. They were open holes excavated by drilling bivalves that were later filled with sediment and cement.
3 Passage oyster encrusters 585The outer surface of the oyster shell is covered with encrusting oysters and serpulid worm tubes. These will be more visible later after Meredith prepares the specimens. The first thing she is likely to do is use some bleach to remove the modern marine algae. Our specimens were all collected near the high-water tide level on the rocky north coast of Filey Brigg (N54.21823°, W00.26904°).
4 Meredith Passage Beds  072415Meredith is here standing against the Passage Beds Member on June 14, 2015. Her feet are on the top of the underlying Saintoft Member of the Lower Calcareous Grit Formation. About a meter and a half above her head is the base of the overlying Hambleton Oolite Member (Lower Leaf) of the Coralline Oolite Formation. As we took this photo the sea was pounding behind us on a rising tide.
5 Passage Unit 1 fossils 072415Here is a cluster of oysters preserved in the lowest unit of the Passage Beds. It is a sandstone distinct from the overlying limestones. There is much evidence of high-energy transportation of shelly material.
6 Meredith collection 072315Here are Meredith’s specimens from this site, all cleaned and in stratigraphic order. A critical part of her work will be a petrographic analysis of the Passage Beds Member. We hope to show you these thin-sections next month.
7 Meredith Filey Brigg point 072415Meredith celebrating the end of her fieldwork as she confronts the rising sea on the tip of Filey Brigg (N54.21560°, W00.25842°).

Wooster’s Fossil of the Week: A small lobster from the Lower Cretaceous of North Yorkshire, England

July 10th, 2015

Meyeria ornata fullMae Kemsley (’16) found this little beauty during her Independent Study fieldwork last month on the Speeton Cliffs of North Yorkshire. It is Meyeria ornata (Phillips, 1829), a decapod of the lobster variety, from the Speeton Clay. It is relatively common in Bed C4, so much so that it is referred to as “the shrimp bed”. Mae is the only one of our team of four who found one, though, so it is special to us. The above is a lateral view, with the head to the left and abdomen on the top of this small concretion.
Dorsal Meyeria ornataHere is a dorsal view looking down on the abdominal segments.
Screen Shot 2015-07-01 at 9.14.03 PMSimpson and Middleton (1985, fig. 1b) have this excellent diagram of Meyeria ornata in life position. The scale bar is one centimeter. “Details of pleopods, third maxillipeds and first antennae of M. ornata unknown. Dashed line represents length of extended abdomen. Symbols: a branchiocardiac groove; c postcervical groove; e cervical groove; m3 third maxilliped; p pereiopod; pi pleopod; t telson; u uropods; x ‘x’ area; r rostrum; al first antennae; a2 second antennae; ar antennal ridge; sr suborbital ridge; 1,2,3. branchial ridges.”

According to Simpson and Middleton (1985), Meyeria ornata actively crawled about on the muddy substrate like modern lobsters. They did not have true chelae (large claws), so they were likely scavengers in the top layers of the sediment rather than predators.

3 Mae working 060915Mae at work.

References:

Charbonnier, S., Audo, D., Barriel, V., Garassino, A., Schweigert, G. and Simpson, M. 2015. Phylogeny of fossil and extant glypheid and litogastrid lobsters (Crustacea, Decapoda) as revealed by morphological characters. Cladistics 31: 231-249.

M’Coy F. 1849. On the classification of some British fossil Crustacea with notices of new forms in the University Collection at Cambridge. Annals and Magazine of Natural History, series 2, 4, 161-179.

Phillips, J. 1829. Illustrations of the geology of Yorkshire, Part 1. The Yorkshire coast: John Murray, London, 184 p.

Simpson, M.I. and Middleton, R. 1985. Gross morphology and the mode of life of two species of lobster from the Lower Cretaceous of England: Meyeria ornata (Phillips) and Meyerella magna (M’Coy). Transactions of the Royal Society of Edinburgh: Earth Sciences 76: 203-215.

Link to posts from Wooster Geologists in the United Kingdom in June 2015

June 29th, 2015

11 Mae Meredith Filey BriggI spent 25 days in England, Scotland and Wales this month, 12 of them with these two happy Senior Independent Study students, Mae Kemsley (’16) and Meredith Mann (’16) — dubbed “Team Yorkshire”. We had to delay our blog posts until today. You can see all of them by clicking the UK2015 tag. It was a spectacular expedition. Thanks again to Paul Taylor, Jen Loxton, Joanne Porter, Tim Palmer, Patrice Reeder and Suzanne Easterling for the parts they played in this adventure. Thank you as well to Mae and Meredith who were not only sharp field paleontologists, they were great companions as well. They are shown above on the tip of Filey Brigg in North Yorkshire. (N54.21560°, W00.25842°; Google Earth image below. Cool study site!)

Screen Shot 2015-06-29 at 11.47.54 AM

On the rails heading north. Way north.

June 17th, 2015

Scarborough station 061715SCARBOROUGH, ENGLAND (June 17) — It is my turn to leave Scarborough. Mae and Meredith went south to London and then on to Paris yesterday. I’m heading north today into Scotland for a Larwood Symposium (run by the International Bryozoology Association) in Thurso and later Stromness.

Screen Shot 2015-06-24 at 8.36.16 PMThe trip is nearly 12 hours long by train, with connections in York, Edinburgh, and Inverness. I’m getting good use out of my BritRail Pass. I hope to see much through my windows as we cross through Lowland Scotland into the Highlands and eventually the north coast. Thurso is the most northerly station in the British rail system.

Scarborough benchDid you know the world’s longest bench is in the Scarborough Rail Station?

Travel days

June 16th, 2015

1 Mae Meredith waiting 061615SCARBOROUGH, ENGLAND (June 16, 2015) — Team Yorkshire split up this morning. Mae Kemsley (’16) and Meredith Mann (’16) packed up very efficiently and took a train to London via York. There plan is to see some London sights and then take a night train to Paris, where they will spend a few days.

2 Mae Meredith on train 061615It is always a sweet time to see healthy and happy students at the end of the fieldwork heading off on their own adventures. Bittersweet, though, because we had such a great time and I have one more day in Scarborough.

3 Scarborough station 061615This is the small Scarborough train station. A set of tracks ends here, so there is only one way in and out.

4 Train to York 061615The train that took Mae and Meredith out of Scarborough. I will be on the same train tomorrow as I start a 14-hour journey to Thurso, Scotland, via York, Edinburgh and Inverness.

5 Scarborough Westborough StreetFor the rest of my lonely day, I explored Scarborough. This is Westborough Street with its modern shops and restaurants. Team Yorkshire ate a lot of fish and chips in this neighborhood.

6 Scarborough view 061615Merchants Street is an older part of Scarborough. You can see the walls of Scarborough Castle on the skyline.

7 Grand Hotel 585 061615Finally, one last view of the Grand Hotel, a Victorian building that has a long history, including being shelled by the Germans in 1914. Our hotel was across the street and far less fancy. This afternoon I sat in its lobby and read a book to escape the cold and clammy weather that descended on the city.

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.

Battle of Flamborough Head (September 23, 1779)

June 13th, 2015

Flamborough HeadMost of our work as Team Yorkshire this month has been in Filey Bay on the northeastern coast of England. When we look south, as above, we see the northern extent of the famous Cretaceous chalk cliffs that extend far into the south of the country along the Channel coast. This point of chalk that we see jutting into the North Sea is Flamborough Head. If we were here on September 23, 1779, we would have seen here a dramatic naval battle between the Royal Navy and the earliest ships of the Revolutionary United States.

Flamborough Google MapFor orientation, you see Scarborough at the top of this Google map, and then Filey down the coast (with Filey Brigg visible as a thin finger of rock diving into the sea). The top image was taken on the coast at Reighton Gap looking south.

Gilkerson 1In these waters on that September day, Commodore John Paul Jones in the USS Bonhomme Richard (on the right) met Captain Richard Pearson of the HMS Serapis. The painting is by William Gilkerson and is displayed in the US Naval Academy Museum. The battle was a complicated bit of seamanship on both sides, and both sides could claim victory. Overall, though, it was an astounding feat of American arms to have engaged the world’s largest and effective navy in its home waters. The story of the battle is best told by J. Scott Harmon on this website.

Battle map FlamboroughThe initial engagement of the HMS Serapis and USS Bonhomme Richard north of Flamborough Head. (From the US Naval Academy. Go there for a nice set of map animations.)

Richard Willis paintingThis part of the world has seen much dramatic military history, from the Romans to the Germans. We find this battle particularly moving because of the role of the new United States asserting its independence. (Painting by Richard Willis.)

Next »