Final day at The Natural History Museum … and one more Jurassic snuff-box

June 17th, 2016

1 Chandler snuff-box cutLondon, England — My last day in London was spent working on GSA abstracts and examining one last ferruginous oncoid (“snuff-box”) from the Jurassic (Bajocian) of southern England. Bob Chandler donated to the cause a large discoidal snuff-box. We cut it (cross-section through the center shown above) and revealed its intricate internal structure.

2 Chandler snuff-box nucleusThe typical limestone nucleus is smaller than I expected, but it still shows typical features such as bioerosion.

3 Snuff-box horn 061716This specimen has beautifully-developed “horns” around the periphery. They are made of laminae not connected to the central cortex. Paul Taylor suggested that they form when the snuff-box is no long being moved about. Nice specimen. Cassidy Jester (’17) will have much to figure out in her Independent Study focused on these objects.

I’ve had a great and productive time on this expedition to England. Thank you again to my amigos Tim Palmer and Paul Taylor, as well as John Whicher, Bob Chandler and Consuelo Sendino. Science marches on.

Addendum: This is the way I like my Tube stations — empty! Take me home, District Line to Paddington. Saturday, June 18, 5:08 a.m.

Fulham Broadway tube station at 0508

Research in a paleontological paradise

June 16th, 2016

1 NHM front 061616London, England — If any center of scientific research can be sacred, the Natural History Museum of London is a holy of holies for paleontology. Its deep history, highly skilled researchers and staff, and magnificent architecture makes it a very special place. As I wrote before, it is a secular cathedral of science, particularly life science.

2 NHM cathedral of scienceIt is no accident the design of this building reflects a place of worship. Who do you think the white figure on the raised platform in the center is? He might as well be sitting on the altar.

3 Darwin presidingOf course! A portrait on Darwin’s upper left, not visible here and probably rarely noticed, is of his colleague Alfred Russel Wallace.

4 Darwin's NHM viewThis is Darwin’s view of the main hall and entrance of the museum. Six million visitors per year pass under his gaze.

5 Paul and SEM 061616This morning Paul and I worked with a scanning electron microscope to study particular fossils we had set aside for closer examination. Paul is the best scanning electron microscopist I have met.

6 SEM stageThis is the open stage and chamber of the SEM, with a brachiopod fixed in place by Paul for scanning. It is a complicated apparatus that can move the specimen in almost all directions in a vacuum under the electron beam.

7 Cortex pdt19574The first specimen we worked with was one of the Jurassic snuff-boxes. This is part of Cassidy Jester’s Independent Study project and her continuing research with Tim Palmer and me. Paul and I are mystified by the pattern we see here in the cortex of the snuff-box.

8 Ooid pdt19575These are two ferruginous ooids embedded in the cortex of the snuff-box. They show exactly the same mysterious irregular platy objects. Tim Palmer suggests they may be limonite, which is amorphous (without crystals). We’ll test that idea later with mineralogical and elemental analysis.

9 Jeffrey Thompson at NHM 061616I was delighted to see my friend Jeffrey Thompson in the palaeontology section doing research for his dissertation at the University of Southern California. He made an earlier appearance in this blog when he was just a kid.

10 Oscar Mmari and Jubilate Lema in LondonFor lunch I met my former student and veteran of an Independent Study field trip to Israel Oscar Mmari (on the left) and fellow Wooster graduate Jubilate Lema on the right. Both of these young Tanzanians are now making their way in the world. Oscar starts this fall at Imperial College, and Jubilate is an economist working with an investment firm in Johannesburg, South Africa. We had a delightful meal and walk around the museum neighborhood.

11 Dinner view 061616My long day ended with an excellent dinner with Paul and Patricia Taylor at the Swan Restaurant along the Thames River. This was our view from the table. This will all seem a dream in just two days time.

 

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, nd 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: A terebratulid brachiopod from the Middle Jurassic of northwestern France

April 29th, 2016

1 Cererithyris arkelli Almeras 1970 dorsal 585We have another beautiful brachiopod this week from our friend Mr. Clive Champion in England. He sent me a surprise package of fossils earlier this year. They are very much appreciated by me and my students!

The specimen above is Cererithyris arkelli Almeras, 1970, from the Bathonian (Middle Jurassic) of Ranville, Calvados, France. (Ranville, by the way, was the first village liberated in France on D-Day.) It is a terebratulid brachiopod, which we have seen before on this blog from the Miocene of Spain and the Triassic of Israel. They have the classic brachiopod form. The image above shows the dorsal valve with the posterior of the ventral valve housing the round hole for the fleshy stalk (pedicle) it had in life.
2 Cererithyris arkelli Almeras 1970 sideThis is a side view of C. arkelli. The dorsal valve is on the top; the ventral valve on the bottom. It is from this perspective that brachiopods were called “lamp shells” because they resemble Roman oil lamps.
3 Cererithyris arkelli Almeras 1970 ventralThis is the ventral view of the specimen. These brachiopods are remarkably smooth.
4 William_Joscelyn_ArkellCererithyris arkelli was named by Almeras (1970) in honor of William Joscelyn Arkell (1904–1958). Arkell was an English geologist who essentially became Dr. Jurassic during the middle part of the 20th Century. I’m shocked to see that with all his publications, awards and accomplishments, he died when he was only 54 years old.

W.J. Arkell grew up in Wiltshire, the seventh child of a wealthy father (a partner in the family-owned Arkell’s Brewery) and artist mother (Laura Jane Arkell). He enjoyed nature as a child, winning essay contests on his observations of natural history in his native county and south on the Dorset coast. Arkell was unusually tall for his age (6 feet 4.5 inches by age 17.5 years in an unusually detailed note) and was considered to have “outgrown his strength”. Nature and writing were escapes from athletic events. He also published poems.

Arkell attended New College, Oxford University, intending to become an entomologist, but Julian Huxley was his tutor and he quickly adopted geology and paleontology. Eventually he earned a PhD at Oxford in 1928, concentrating his research on Corallian (Upper Jurassic) bivalves of England. As a side project, he published work on Paleolithic human skeletons from northern Egypt.

Oxford suited Arkell, so he stayed there as a research fellow, expanding his research to the entire Jurassic System of Great Britain, then Europe, and then the world. His work became the standard for understanding Jurassic geology and paleontology for decades.

After World War II (in which he served in the Ministry of Transport), Arkell took a senior research position at Trinity College and the Sedgwick Museum, Cambridge University, continuing his work on the Jurassic. He travelled often, including long stints in the Middle East. His health was never good, though, and he had a stroke in 1956, and died after a second stroke in 1958.

During his career Arkell received the Mary Clark Thompson Medal from the National Academy of Sciences in the USA, a Fellowship in the Royal Society, the Lyell Medal from the Geological Society of London, and the Leopold von Buch medal from the German Geological Society.

References:

Almeras, Y. 1970. Les Terebratulidae du Dogger dans le Mâconnais, le Mont dʼOr lyonnais et le Jura méridional. Étude systématique et biostratigraphique. Rapports avec la paléoécologie. Documents des Laboratoires de Géologie Lyon, 39, 3 vol.: 1-690.

Arkell, W.J. 1956. Jurassic Geology of the World. New York; Edinburgh: Hafner Publishing Co; Oliver & Boyd; 806 pp.

Cox, L.R. 1958. William Joscelyn Arkell 1904-1958. Biographical Memoirs of Fellows of the Royal Society 4: 1.

Rousselle, L. and Chavanon, S. 1981. Le genre Cererithyris (Brachiopodes, Terebratulidae) dans le Bajocien supérieur et le Bathonien des Hauts-Plateaux du Maroc oriental. CR somm. Soc. Géol France, 1981: 89-92.

Last day of fieldwork in Israel: More Jurassic enjoyment

March 20th, 2016

1 SU66 at Meredith 032016MITZPE RAMON, ISRAEL — For my last day of fieldwork during this short Spring Break trip to Israel, I returned to Makhtesh Gadol to collect a bit more data from subunits 65 and 66 of the Matmor Formation (Middle Jurassic, Callovian). The above image shows part of my field site in the Meredith section north of the “British Road” across the top of the makhtesh. The yellowish marls are subunit 66, with the white limestone of subunit 65 peeking out at their base. The Matmor Formation is distinguished by this alternation of carbonates and marls, and the faunas in each sediment type are very different.

2 SU65 bivalve at Meredith 032016I did not do any collecting today. Most of my work was tracing rock units, photographing fossils, and taking lots of notes. Above is a nice bivalve in the limestone of subunit 65.

3 SU65 bivalve and bullet 032016Here’s another bivalve with a spent bullet for scale. (Dramatic effect. There is far less ordnance in Makhtesh Gadol than other places I’ve worked in the Negev.) Note that the bivalve is articulated (both valves are locked together), meaning it likely was buried alive. Almost all the bivalves in subunit 65 are articulated.

4 SU65 branching coral 032016There is one horizon in subunit 65 with a surprising number of branching corals. These look very much like the modern Acropora, but they’re not.

5 SU65 SU66 boundary at Meredith 032016This is again the boundary between the white and resistant subunit 65 and the yellowish and nonresistant subunit 66. I have no images of fossils to show you from subunit 66 because they weren’t very photogenic. They are relatively rare and consist mostly of small solitary and colonial corals and occasional oysters.

Thus ends my 2016 fieldwork in Israel! I learned a lot in these eight days of exploration and study, and I worked with excellent colleagues. I have some ideas now for a project that will place these Middle Jurassic rocks and fossils in a global paleobiogeographic and evolutionary context. Many future Independent Study projects are possible!

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