Wooster Geologists in Bristol, England

June 11th, 2016

1 Bristol Museum and UniversityBristol, England — Cassidy Jester (’17) and I are spending the weekend in Bristol after finishing our fieldwork in Dorset this week. Our travel and lodging arrangements required a couple of days here before we go to London on Monday and then our separate ways. We’ll continue to sort out our specimens, work on a GSA abstract, and explore the city. This afternoon, while waiting for our hotel rooms to open, we walked through the central part of the city to the Bristol City Museum and Art Gallery. It is the building with the pillars on the left. The magnificent tall building on the right is part of the University of Bristol — the part that houses the Earth Sciences Department.

2 Bristol City Museum and Art GalleryThis museum is a wonderful combination of art, history and science, with considerable space devoted to geology and paleontology.

3 Bristol pregnant ichthyosaurAmong the many exhibits, I picked one to share: a pregnant ichthyosaur from the local Jurassic. Note the tiny arrow in the lower left of the skeleton.

4 Bristol ichthyosaur fetusAt the arrow, among the bones of this female ichthyosaur is this hand-sized skeleton of a fetus, direct evidence that ichthyosaurs, though reptiles, gave live birth. Paleontology is so cool.

Team Dorset finishes its fieldwork

June 10th, 2016

1 Snuffbox serpulidssSherborne, England — Cassidy Jester (’17), Tim Palmer and I today finished our fieldwork. Cassidy is now set for her Senior Independent Study project with plenty of specimens, observations, photographs and ideas to last the next 10 months. This morning we visited the Burton Bradstock beach exposure of the snuffboxes, meeting our great colleague Caroline Buttler (Department of Natural Sciences, Amgueddfa Cymru – National Museum Wales, Cardiff) and her husband Simon for lunch on the outcrop. It was great fun, and Caroline had additional discoveries for us, including the exfoliated snuffbox layer shown above with serpulid worm tubes.

2 Ammonite gastropod snuffboxesWe had time to look for more fossils associated with the snuffboxes. Above you see a gastropod on the left and an ammonite on the right, with snuffbox bits scattered about.

3 Burton Bradstock pendentWe also found many examples of burrow systems with cryptic pendent iron-rich layers, including those shown above. (I rotated the image 180° because the block we studied on the beach is upside-down.)

4 Maiden Castle rampartsOn the way back to our lodgings near Sherborne we stopped by the Iron Age hill fort Maiden Castle, a portion of the massive earthen ramparts of which are shown above.

Our collecting, measuring and describing is done. Most of the work for this project, of course, will be in the Wooster geology labs. We will have delightful memories of our sunny days in Dorset, and the invaluable assistance of our colleagues Bob Chandler and John Whicher. I am personally most grateful for the geological and navigational skills of Tim Palmer, our wonderful companion and astute advisor. Without him none of this could be done.

Crew in Whicher MuseumThe Dorset crew in the Whicher Museum. From the left, Bob Chandler, Mark Wilson, Tim Palmer, John Whicher, and Cassidy Jester (’17).

Team Dorset makes a cryptic discovery

June 9th, 2016

1 Cassidy Mapperton 060916Sherborne, England — It was a good day for Team Dorset. Cassidy Jester (’17) is shown above in Coombe Quarry near Mapperton, Dorset. She is standing on an erosion surface between the Comptocostosum Bed (Aalenian) below and Horn Park Ironshot (Bajocian) above. These are beds 2d and 3a in the local stratigraphic system, and ammonite zones Scissum and Discites. There is a considerable disconformity here, meaning a significant hiatus of unrecorded time, several ammonite zones worth. The snuffboxes we’re interested in are found jut above this boundary.

2 Pendent layers 060916Tim Palmer picked up the above rock as we started our measurements and descriptions. He deduced right away that he was looking at a cross-section of a burrow now filled with light brown sediment. The darker layers above are ferruginous (iron-rich), serpulid-bearing laminae like those that make up the snuffbox cortices, and they are hanging pendently from the roof of this burrow into the original cavity beneath. At one time this burrow was an open tunnel with cemented walls and the iron-rich layers grew from the ceiling like stalactites. Tim demonstrated with this single specimen that the iron-rich layers grew in dark, cryptic spaces, strongly supporting the hypothesis of Palmer and Wilson (1990) that the equivalent snuffbox layers accumulated on the undersides in gloomy darkness

3 Infilled Thalassinoides MappertonCassidy and I then recognized that the iron-rich “stromatolites” we had seen on our earlier visit to the quarry were actually these iron-rich layers filling Thalassinoides burrow systems that are truncated by the erosion surface. In the above image you are looking down on the erosion surface at a branching burrow filled with iron-rich layers. These are not stromatolites but cryptic burrow fills.

5 Sherborne Thalassinoides 2 585Later in the afternoon we returned to the Sherborne Stone quarry yard and looked at Thalassinoides burrow systems in the Sherborne Building Stone cut by giant saws. We see here a view parallel to bedding showing a box work of tunnels filled with a darker sediment. This matches the pattern seen in the Coombe Quarry erosion surface.

6 Sherborne Thalassinoides section 585This is a cross-section of the same kind of Thalassinoides burrow in the Sherborne Building Stone. We see the vertical connections to the surface and the lateral tubes. These burrows formed the cryptic spaces for iron-rich layer deposition as seen at Coombe Quarry. Or at least that is our hypothesis! Tomorrow we will test it by examining the burrow systems associated with the snuffboxes at Burton Bradstock.

7 Sherborne Castle 585As usual, we ended our day with more historical architecture and stonework, this time at nearby Sherborne Castle, a 16th century Tudor mansion sitting on magnificent estate grounds. Much of our work is on land owned by this estate.

The format below is a bit messy, but here is a download of our GPS data for the localities on this expedition:

GPS# Latitude Longitude Location
138 50.96268903 -2.503268039 Frogden Quarry
139 50.96319797 -2.501848983 Frogden Quarry older
140 50.93710503 -2.601833018 Babylon Hill
141 50.94292902 -2.556813983 Louse Hill
142 50.79496597 -2.71623401 Coombe Quarry, Mapperton
143 50.70015801 -2.734380998 Hive Beach, Burton Bradstock
145 50.81626003 -2.771674013 Horn Park
146 50.70154396 -2.737065973 Burton Bradstock snuffboxes

Snuffboxes! Team Dorset has a project

June 8th, 2016

1 Snuffbox colection BBSherborne, England — Cassidy Jester (’17) now has a Senior Independent Study project: Origin and paleoecology of ferruginous oncoids (“snuffboxes”) from the Middle Jurassic (Bajocian) of southern England and northern France. (We’re not going to France; I have specimens I collected 20 years ago there.) Pictured above is a nice collection of these snuffboxes on the Dorset coast near Burton Bradstock. More on them below. Today Tim Palmer, Cassidy and I had a great time starting our data collection.

2 Whicher museumThe first thing we did this morning, though, was visit the astounding fossil collection of John Whicher, one of our new citizen scientist friends. He has a spectacular collection of exquisite fossils, most from the Inferior Oolite and all meticulously curated. His preparations are amazing, especially when you know what a fossil looks like when first collected.

3 Tim Cassidy Whicher museumTim and Cassidy are here admiring some of the Inferior Oolite ammonites in John’s display cases. Each specimen is numbered and has full locality and stratigraphic context.

4 Whicher workshopJohn has a workshop that would be the envy of any university, along with storage for those specimens awaiting his patient preservation. Here we see our other new friend Bob Chandler cutting a rock for us. Bob has his own equal collection. These indefatigable amateurs are making extraordinary contributions to science.

5 Burton cliff fallAt noon we started our own work along the coast at Burton Bradstock, Dorset. We depended upon cliff falls like this one where the rocks of the Inferior Oolite at the top of the cliff crashed to the beach below.

6 Burton Bradstock large block 060816This gorgeous block is an example of the snuffbox bed fallen into our hands on the Burton Bradstock beach. The long part of the measuring stick is one meter. We are looking at the base of the snuffbox-bearing unit, so the block is upside-down.

7 Cassidy working 060816Cassidy is here studying that above block, with the English Channel in the background and brilliant sunlight.

8 Snuffbox bored shell nucleusThis is one of the snuffboxes with a shell fragment as a nucleus. The shell has many borings that were excavated before it started accumulating the layers of iron oxides.

9 snuffboxes horns ooidsThe snuffboxes have all sorts of details, from the compositions of the nuclei, the structure of the cortices, the fossils found encrusting them, and their overall shapes. Many have “horns” in cross-section like the two above. Note also the iron ooids (rusty red dots) between the snuffboxes. Their origin is another mystery.

10 Cerne Abbey 585We ended the day with a visit to the ruins of Cerne Abbey in Cerne Abbas, which was founded in 987. The remaining buildings are considerably later but still incorporate remnants of the old. This is now a romantic ruin on a small estate.

11 Cerne Abbey signTomorrow we continue to study the snuffboxes in other localities. We hope again to avoid the rains that have affected much of the country this week.

Reference:

Palmer, T.J. & Wilson, M.A. 1990. Growth of ferruginous oncoliths in the Bajocian (Middle Jurassic) of Europe. Terra Nova 2: 142-147.

 

 

Team Dorset closes in on a project

June 7th, 2016

1 Burton Radstock cliffSherborne, England — Another gorgeous day of exploring in the Middle Jurassic of southern England. The weather and the companions could not be better. Today was our last day of reconnaissance and tomorrow Cassidy Jester (’17) begins her Independent Study project fieldwork. Exactly what that project will be will be decided in the morning. So many possibilities. No doubt Tim Palmer and Cassidy are thinking about them as they walk the beach at Burton Bradstock (above).

2 Cassidy on Maperton surfaceWe began the day at Coombe Quarry near Maperton, Dorset. There we saw an interesting combination of snuffboxes (essentially iron-rich, fossiliferous oncoids), a carbonate hardground, and microbially-generated layers of iron oxides. Cassidy is standing above on the top of the most interesting unit.

3 Maperton surfaceAbove is a close view of the Maperton carbonate hardground surface (light-colored) perforated by Gastrochaenolites borings with the microbial iron oxides (darker and brownish) filling in the low spaces. The snuffboxes are just below. These are complex units that are highly condensed, so a few centimeters of section represents multiple depositional events.

4 Hive Beach snuffboxesWe next traveled to Hive Beach at Burton Bradstock along the English Channel (see the topmost image). Here we found blocks of the Inferior Oolite that had fallen down to the beach, enabling us to see the stratigraphy in separate bits. In this limestone cross-section, Cassidy’s hand is at the snuffbox level. The snuffboxes are the elliptical, layered brown objects.

7 Snuffbox in dikeThe layered object above is a snuffbox in cross-section. The center is a bit of limestone that served as the nucleus on which the brown microbial layers grew. The snuffbox occasionally was overturned by currents, allowing the layers to grow completely around the nucleus. These have been called snuffboxes since the 19th century because the inner limestone bit often weathered out, leaving the iron-rich parts looking a bit like a flat box to carry snuff.

5 Cassidy on neptunian dikeAt Burton Bradstock we also saw this very unusual rock along the beach. It has a limestone matrix and very diverse clasts in seemingly random orientations. The clasts include large red blocks (Cassidy has her hand on one), ammonites, and snuffboxes (including the one shown earlier).

6 Dike rubble 060716In this closer view of what is thought to be a neptunian dike rock, Cassidy’s finger is on an ammonite in cross-section. There are many iron-rich layers and calcite-filled veins. This rock appears to have been formed from sediment collecting in a large fissure that cut across rock layers.

8 Stromatactis debrisThese odd flat-bottomed clasts were quite mysterious to us until Tim nailed them as fragments of a stromatactis layer. Still a mystery, though, where these clasts came from.

9 Horn Park surfaceOur last stop of the day was at Horn Park Quarry, a gated natural reserve, reputed to be the smallest in the United Kingdom. The whole of the Inferior Oolite is exposed here, including this remarkable flat surface that we’re told extends for miles.

10 Horn Park ammonite 1The surface is almost perfectly flat, and it truncates thousands of fossils, including this ammonite.

11 Horn Park belemnitesAnd these belemnites with no preferred orientation.

12 caged ammonitesThe site was at one time heavily exploited for its ammonites, some of which are now preserved under this locked cage.

13 Tim Puzzled 060716Tim seems despondent because we have no strong explanation for the origin of this remarkable surface. We think it was likely formed by abrasion processes, but how is unclear. There are numerous such surfaces in this small section, compounding the mystery.

Now Cassidy decides what to do!

 

 

Jurassic cephalopod heaven in southwestern England

June 6th, 2016

1 Trail to old FrogdenSherborne, England — Cassidy Jester (’17) and I are now at our main base in a bed and breakfast in northern Dorset. Our lodgings are a converted milking house on an estate with a beautiful view of the surrounding rolling hills and fields around Sherborne. We met our first partner Tim Palmer yesterday in Bristol, and today we met our guide to the local stratigraphy and fossils, Bob Chandler. We were also joined by retired physician John Whicher for part of the day. Bob and John are amateur paleontologists, but that hardly seems the right label considering how long they’ve been studying the fossils in the region, and the number of papers they’ve published. They are “citizen scientists” of the highest order. We are grateful for their enthusiasm and essential assistance.

2 Sherborne Stone signOur first stop of the day was to a quarry yard on the estate of Sherborne Castle. As always, the local quarry offices are fantastic places to start exploring the rocks of a region. The quarry operators are always keen on fossils, and usually save the best ones they find to share with visiting geologists. This particular quarry specializes in Sherborne Building Stone, part of the Middle Jurassic Inferior Oolite we are studying.

3 Sherborne Stone yardThe quarry yard has many cut and polished blocks and slabs of the Sherborne stone, providing useful views of the rock interiors and cross-sections of the fossils.

5 Cut nautiloid FrogdenThe Sherborne Building Stone and associated rocks above and below also have huge nautiloids. They make fine polished sections showing interior chambers filled with combinations of sediment and calcite cement. We found the range of infillings to be surprisingly diverse, even within a single conch.

4 Sherborne Stone ammonites yardHere is a collection of ammonites the workers saved from the saws and splitters.

6 Macro micro conchs FrogdenAmmonites are very common in the Sherborne quarries. On the left is the macroconch Stephanoceras with its long body chamber (the lighter-colored part) and on the right is its microconch Normannites. (Thanks to Bob Chandler for all the names.) The macroconch is most likely the female of the species, and the microconch the male, despite the different names. The ammonites are so numerous in this unit that whole breeding populations appear to be preserved.

7 Frogden nautiloid yardThis is a polished section through one of the large nautiloids we saw in the quarry yard. Not the complex infillings of the chambers, including geopetal structures indicating the orientation of the conch when filled.

8 Frogden QuarryThis is Frogden Quarry itself, which we visited this morning. The lower parts here contain the Sherborne Building Stone.

9 Frogden woodThere are many other fossils in the Sherborne units, including wood that is apparently from gingko trees.

10 Babylon Hill Road LiasIn the afternoon we visited other exposures of the Inferior Oolite and associated units, including this odd exposure on Babylon Hill. This excavation in the soft rocks of the lower Inferior Oolite and upper Lias was made by horses and carriages when this was a main road in the 19th century and earlier. A lesson in the erosion of unpaved roads without even gravel as a cover.

11 Cassidy Lias Babylon HillCassidy Jester (’17) in the Babylon Hill road exposure. A poorly-cemented sand of the Upper Lias is behind her.

12 Louse Hill quarryOur last stop of the day was an old abandoned quarry on Louse Hill. (It is pronounced “lows” and apparently has nothing to do with the parasite!). Bob Chandler is on the left, with Tim Palmer in the middle, and Cassidy on the right searching through the many fossils in the top of the Inferior Oolite. Not the best exposure, but a historically-important one.

We ended our day of exploration with a fine meal in downtown Sherborne, followed by a walk around the local medieval abbey with its rich history and, of course, diverse building stones!

Sherborne Stone crewThank you to the staff at Sherborne Stone for such fine hospitality and excellent geological observations!

Team Dorset arrives in England

June 5th, 2016

1 Temple Meads StationIlminster, Somerset, England — Little Team Dorset, consisting of Cassidy Jester (’17) and me, arrived today in England after a long journey of cars, planes and trains. As you can see from the above image of the Bristol Temple Meads train station, we have brilliant weather. Cassidy and I are here to do the fieldwork for her Independent Study project in the Inferior Oolite (Jurassic, Bajocian) of inland Dorset. We met Tim Palmer at the train station and then drove into Somerset for the afternoon and evening. Tim Palmer and I explored the Inferior Oolite and other units in this region last year to prepare for this expedition.

2 Hinton Blewett St MargaretIf you know anything about Tim Palmer, you know we’re going to examine building stones every chance we get. This is an ideal introduction to our project because of its combination of geology and history. Tim is a master of this topic, especially Jurassic stones. We first stopped in the little parish of Hinton Blewett to examine a Medieval baptismal font in the 13th century Church of St. Margaret (above).

3 Hinton Blewett font and TimHere is Tim examining the baptismal font, looking closely at the stonework.

4 Hinton Blewett font 585The font is made of Dundry Stone, from the top of the Inferior Oolite, with the exception of a later addition of an oolitic limestone cylinder in the stem, apparently to raise it a bit higher. The basin is lined with hammered lead.

5 St Margaret stone Hinton BlewettThe oldest stone in the structure of the church itself is also a Jurassic limestone. It shows these distinctive patterns of iron-rich layers.

6 Wells Cathedral frontWe next visited Wells and its magnificent cathedral. This is the first time I’ve been here. It is spectacular, especially in the brilliant sunlight. It is made mostly of Doulting Stone, a local limestone Tim and I studied last year.

7 Wells top detail 585The front of Wells Cathedral has dozens of Medieval statues, most still well preserved. Christ and the apostles make up the first two rows, followed by English bishops.

8 Wells detailMost of the statues are protected within stone niches.

9 Wells ClockUnusual for English cathedrals, there is a large clock with animated figures that ring bells. This is a feature more common in continental Europe.

10 Purbeck Carboniferous DoultingThis beautiful detail shows a pillar of Purbeck Marble, topped with a disk of dark Carboniferous limestone, and then the Doulting stone.

11 Vicars' Close 585We then visited the famous Vicar’s Close near Wells Cathedral, which is the oldest preserved residential street in Europe. The houses were built in the 14th and earl 15th century.

Tim, Cassidy and I then drove to Ilminster for a night in a Travelodge before fieldwork begins tomorrow. We had an excellent day.

 

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 very large Upper Jurassic ammonite from southern England

August 14th, 2015

1 Titanites fragment Bowers QuarryThe shard above doesn’t look like much. It comes from a specimen far too large for us to excavate, let alone pack onto a plane for the trip home.
2 TitanitesinrockHere’s a view of one of the full specimens still in bedrock.
3 KN&Titanites 2002And here we see a liberated specimen with Katherine Nicholson Marenco (’03) for scale 12 years ago. This is the ammonite Titanites anguiformis Wimbledon and Cope, 1978, from the Portland Freestone (anguiformis Zone, Portlandian, Upper Jurassic) exposed on the Isle of Portland in Dorset, southern England. Katherine and I, with help from Rich Poole (’03), Clive Griffiths, Tim Palmer and Paul Taylor, worked there in the summer of 2002 looking at encrusting faunas on shells for her Independent Study project. We could only take bits home, hence the fragment above. It was a wonderful field season in a spectacular place.

Titanites anguiformis is one of the largest ammonites, with specimens up to a meter in diameter. Our specimens above are all molds made of limestone; the aragonitic shells dissolved away. These lumbering beasts were swimming predators like all ammonoids, feasting on a variety of invertebrates in a shallow Jurassic sea.
4 CoombefieldBlocks2Our team spent most of its time in active building stone quarries like this one (Coombefield) looking at excavated blocks of Portland Freestone. This rock is one of the most comon building stones in England.
5 KNChiselling2The many surfaces of the blocks exposed fossils in a variety of orientations. Here is Katherine doing what she did for three weeks: chiseling bits of shell from the limestone.
6 Titanitesclose-up1Our goal was to collect surfaces like this. We have here an internal mold of Titanites anguiformis. The inner surface of the shell (a cryptic space) was encrusted by bryozoans, serpulid worms and oysters. When the aragonitic shell dissolved, the undersides of the encrusters were exposed like we see here. We then studied the attachment surfaces of the encrusters, looking at their growth patterns and successional overgrowths. Katherine’s work resulted in this GSA presentation.

[#Beginning of Shooting Data Section] Nikon CoolPix2500 2002/06/18 10:24:09 JPEG (8-bit) Normal Image Size:  1600 x 1200 Color ConverterLens: None Focal Length: 5.6mm Exposure Mode: Programmed Auto Metering Mode: Multi-Pattern 1/900.9 sec - f/4.5 Exposure Comp.: 0 EV Sensitivity: Auto White Balance: Auto AF Mode: AF-S Tone Comp: Auto Flash Sync Mode: Not Attached Electric Zoom Ratio: 1.00 Saturation comp: 0 Sharpening: Auto Noise Reduction: OFF [#End of Shooting Data Section]This fossil bit is thus a reminder of a great field season on the coast of southern England many years ago.

References:

Falcon‐Lang, H. 2011. The Isle of Portland, Dorset, England. Geology Today 27: 34-38.

Wimbledon, W.A. and Cope, J.C.W. 1978. The ammonite faunas of the English Portland Beds and the zones of the Portlandian Stage. Journal of the Geological Society of London 135: 183-190.

Wooster’s Fossil of the Week: A calcareous sponge from the Lower Cretaceous of England

July 24th, 2015

Raphidonema faringdonense 070715a 585One of my favorite fossil localities is a gravel pit in Oxfordshire, England. Gravel pits are not usually good for fossil collecting given their coarse nature and high-energy deposition, but the Lower Cretaceous (Aptian) Faringdon Sponge Gravels are special. They are tidal gravels sitting unconformably over Jurassic rocks that have an extraordinary diversity and abundance of marine fossils, both from the Cretaceous and reworked from the Jurassic below. I have previously described in this blog bored cobbles, bryozoans, ammonites and a plesiosaur vertebra from this unit. Above is one of the most characteristic fossils from Faringdon, the calcareous sponge Raphidonema faringdonense (Sharpe, 1854).
Raphidonema faringdonense 070715b 585This is a view of the upper surface of this sponge. Like most sponges it was a filter-feeder sitting stationary on the seafloor. This one was probably attached to a cobble in the gravel. It is in the Class Calcarea because it has a fused network of calcitic spicules making up its skeleton. This is why it has remained a very resistant, rigid object long after death. It probably spent some time rolling around in those gravels with the tidal currents.
Sophie Faringdon 2007The Faringdon Sponge Gravels are a member of the Faringdon Sand Formation. They are cross-bedded gravels that have been mined for construction purposes since Roman times. Above is Wooster Geologist Sophie Lehmann (as a student) when she and I visited one of the gravel pits in 2007. For the record, this sponge comes from the Red Gravel, 5.5-8.5 meters above the disconformity with Oxfordian limestones, in the Wicklesham gravel pit on the southeast edge of Faringdon, Oxfordshire (51.647112° N, 1.585094° W).

after Maull & Polyblank, photogravure, circa 1856

Daniel Sharpe FRS (1806-1856) named Raphidonema faringdonense in 1854. He was born in Marylebone, Middlesex, England. His mother died shortly after his birth and he was raised by his uncle Samuel Rogers, a literary figure of some merit. He entered the mercantile business as an apprentice when he was 16, and he stayed connected with trading the rest of his life. His first research as a geologist (and this was very early in the discipline of geology) was examining geological structures around Lisbon, Portugal. He then studied the strata of north Wales and the Lake District of England. Sharpe was an early opponent of Adam Sedgwick in a dispute over the Cambrian, which brought him some notoriety among English geologists. His most prominent geological work was sorting out what rock cleavage meant in regard to stress and strain, using distorted fossils as part of his evidence. He died as the result of a riding accident in 1856, shortly after he had been elected president of the Geological Society of London.

Sorting out the taxonomic history of Raphidonema faringdonense is more complex than I would have expected for such a simple fossil. I’m using the most common version of the name, but we also see “farringdonense“, “faringdonensis” and farringdonensis“. (I know. Who worries about such things?)
Manon farringdonense Sharpe figuresManon farringdonense description 1854Above are Sharpe’s original figures of Raphidonema faringdonense, along with his description (and the nice bryozoan Reptoclausa hagenowi below). We can see that he spelled the species name with a double r in keeping with a common spelling of the village’s name then. I don’t know when we lost one of those letters.

Just to add to the complexity, Raphidonema is also the genus name of a filamentous green alga. Since it is not an animal, though, there is no legal problem with having the name also refer to a sponge. (There should be a rule against such homonymy, but there’s not.)

References:

Austen, R.A.C. 1850. On the age and position of the fossiliferous sands and gravels of Faringdon. Quarterly Journal of the Geological Society of London 6: 454-478.

Lhwyd, E. 1699. Lithophylacii Britannici Ichnographia. 139 pp. London.

Pitt, L.J. and Taylor, P.D. 1990. Cretaceous Bryozoa from the Faringdon Sponge Gravel (Aptian) of Oxfordshire. Bulletin of the British Museum, Natural History. Geology 46: 61-152.

Sharpe, D. 1854. On the age of the fossiliferous sands and gravels of Farringdon and its neighbourhood. Quarterly Journal of the Geological Society of London 10: 176-198.

Wilson, M. A. (1986). Coelobites and spatial refuges in a Lower Cretaceous cobble-dwelling hardground fauna. Palaeontology, 29(4), 691-703.

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