At some point you must start collecting data

March 18th, 2016

1 Acacia at Meredith SectionMITZPE RAMON, ISRAEL — Today my friend Yoav Avni (Geological Survey of Israel) and I returned to Makhtesh Gadol to pursue a project with Subunit 65 of the Matmor Formation (Callovian, Middle Jurassic). You may recall this limestone contains an extraordinary bedding plane of fossils preserved in near-life positions (as seen in a recent Fossil of the Week entry). Yoav’s job was to find additional exposures of this subunit in the area; mine was to map the distribution of fossils on the bedding plane. This area of the makhtesh, by the way, is called “Meredith’s Section” after IS student Meredith Sharpe, who did splendid work here. The acacia tree above is our traditional lunch spot (when the camels aren’t using it).

2 SU65 bedding plane 031816This is the bedding plane of Subunit 65. I went over every square centimeter of it photographically mapping and detailing it with a square-meter quadrat. It was hot work, and a bit of drudgery compared to the previous days of exploring new exposures.

3 SU65 quadrat 031816This is a typical quadrat, complete with my boot toes. I took 41 quadrat photos like this, and then detailed the fossils within and their positions. In the meantime, Yoav wandered the hills and found many excellent exposures of the same unit, although none with a bedding plane like this. We will be able to compare the fossils in the “traditional” exposures with what we see here.

That’s pretty much it for my day in the desert!

Wooster’s Fossils of the Week: A Jurassic seafloor assemblage

March 18th, 2016

1 DSC_0184 copyImages from fieldwork this week. These are all fossils exposed on a single bedding plane in the Matmor Formation (Middle Jurassic, Callovian) exposed in Makhtesh Gadol. I found them many years ago while working through the stratigraphy near the top of the formation. They present a vignette of life in a shallow carbonate Jurassic sea. They are so well preserved you can almost feel the gentle waves and hear the squawks of the pterosaurs wheeling above. In the top image we have my favorite of the set: A gastropod shell in the middle surrounded by mytilid bivalves. The bivalves were no doubt attached to the gastropod by their thin byssal threads, holding them in place in the choppy waters. The preservation is remarkable. All these shells are calcitized, but retain their ornamentation. They are exposed on a bank of a wadi, and so they have been lightly etched from the matrix by sandy water during floods.

2 DSC_0180 copyJust to show the gastropod-bivalve association is not a fluke of preservation, here’s another set. On this bedding plane are four such assemblages.

3 DSC_0178 copyHere’s another gastropod, this one with heavy spines.

4 DSC_0179 copyA high-spired gastropod is on the left, with a mytilid in side-view on the right.

5 DSC_0181 copyAnother gastropod to end the set. These are just a few of the many such fossils exposed on this bedding plane of the Matmor Formation.

Paleontological heaven in the northern part of Makhtesh Gadol

March 17th, 2016

0 Makhtesh Gadol satellite viewMITZPE RAMON, ISRAEL — Today I spent quality time with two Israeli students and some of the most interesting fossils in the world. Yael Leshno and Or Eliasson, students at Hebrew University, joined me for a walking journey through the Zohar and Matmor Formations (Middle Jurassic) in the northeastern part of Makhtesh Gadol. I’ve included a Google map above showing the makhtesh (an erosional crater in a breached anticline, to make it simple). The structure is about 10 km long, walled by Cretaceous sandstones with a soft, delightful core of Jurassic sediments. We worked today in a portion south of the main road through the makhtesh.

1 SU51 view 031716Or is standing here on the top of the basal unit of the Matmor Formation. We used this surface as a walkway to the brown hills in the background. Our first goal was to visit several outcrops of “Subunit 51”.

2 SU51 at 004This unremarkable scene is actually the location of important and very well preserved Jurassic invertebrate fossils. The brown marls are the easternmost exposure of Subunit 51 of the Matmor Formation. They are loaded with corals, echinoids, crinoids, brachiopods, bryozoans (yes!), and other treasures. The soft marl helped preserve the fossils from most of the ravages of diagenesis, and makes them easy to free from the matrix. Some of the fossils we found here will be future Fossils of the Week on this blog. I particularly enjoyed our work in this interval today because Yael and Or are such excellent field paleontologists. They put their young eyes to good use.

3 Yael ZoharAfter lunch on the Matmor Formation, we walked south to find the lowest exposures of the Zohar Formation, which underlies the Matmor and “Kidod”. Here is the first outcrop we found, located in a wadi. Yael is doing here lithological and paleontological descriptions so that she can plan her next expedition to these rocks for her dissertation work.

4 Zohar long viewThe lowest Zohar Formation in the makhtesh is exposed along a central wadi. Yael is on the skyline scouting it out. The upper beds where she is walking are very rich in mollusks, brachiopods, and echinoderms.

5 Zohar view 031716The Zohar Formation contains alternating limestones and marls, much like the Matmor.

6 Zohar ThalassinoidesThis is the underside of a thick layer of Zohar Formation limestone. It has convex hyporeliefs of Thalassinoides burrows about 5-10 cm in diameter. These were produced by burrowing crustaceans in shallow waters. The early geologists in this area did not recognize these features as trace fossils, referring to them as “negative mudcracks”.

7 Zohar and ballonIn this perspective on the Zohar limestones, you can just make out a white balloon in the far distant sky. This tethered balloon is operated by the Israel Defense Forces to watch over the border with Jordan with all kinds of fancy detection equipment (I imagine).

8 Gecko 031716This little gecko watched us work at the Zohar outcrop.

9 Mousterian workshop floorOn our walk back to the car, sharp-eyed Or pointed out numerous flint flakes in a patch of desert pavement several meters square. These are the remains of a tool-making workshop. These are Mousterian and, astonishingly, about 150,000 years old. They were worked by Neanderthals!

10 Lithic Core Negev 585This is a lithic core, from which flakes were chipped by our busy cousins. I’ve seen this flint material all over the Negev, but hadn’t realized how old it is and who was responsible. I am very much in the Old World here.

 

Exploring the top of the Matmor Formation (Middle Jurassic) in Makhtesh Gadol

March 16th, 2016

1 SU65 south view 031616MITZPE RAMON, ISRAEL — Today I joined four Israeli colleagues to study in detail the top of the Matmor Formation (Callovian, Middle Jurassic) in Makhtesh Gadol, Negev Highlands, southern Israel. The view above is looking south in the Matmor Hills along this upper section. You can see why this kind of exposure is popular with geologists. I love to be able to walk along a single rock unit for kilometers, noting its changes and the distribution of its fossils.

2 Field start 031616Our party consisted of the two Yaels (Edelman-Furstenberg and Leshno), Rivka Rabinovich from Hebrew University and the National Natural History Collections, and her undergraduate student Or Eliasson. We started along the Goldberg section and worked our way up the formation.

3 Quadrat group 031616We concentrated on getting Yael Leshno’s PhD dissertation data collection methods established. Here she sits (in the green scarf) with her advisors Rivka Rabinovich on the left and Yael Edelman-Furstenberg on the right. They are gathering data from a quadrat in Subunit 65 of the Matmor.

4 SU65 view 031616This particular subunit (a term and designation from Goldberg, 1963) is of particular importance to us because it is exposed in the north of the makhtesh as a spectacularly fossiliferous bedding plane. Here we see the same fossils, but they are fully embedded in the calcareous matrix. Or is the young man above searching for fossils, a task he is very good at.

5 Field end of day 031616That was basically our day! The weather was better, with less wind (although still plenty) and far less dust.

A day in the Zohar and Matmor Formations of the Negev

March 15th, 2016

1 Zohar outcrop 031516MITZPE RAMON, ISRAEL — It was another very windy day in southern Israel, but still just fine for fieldwork. Yael Edelman-Furstenburg, Yael Leshno and I returned to Makhtesh Gadol to work on Yael Leshno’s data collection procedures for her PhD project in the Middle Jurassic sequence here. Our first task was figuring out the detailed stratigraphy, which is not especially easy considering all the faulting and somewhat dated lithological descriptions for orientation. The above image is of the Zohar Formation just below its contact with the Kidod Formation (depending on what stratigraphic scheme you follow!).

2 Zohar disconformityThe top few meters of the Zohar Formation are a series of argillaceous limestones with numerous trace fossils (Planolites and Thalassinoides, mainly) and this gorgeous erosion surface (disconformity). The white limestone beneath was lithified when it was exposed and downcut by sand-bearing currents. On the left you can see pieces of the limestone incorporated into the overlying calcareous sandstone. Classic.

3 Goldberg trench 031516We then moved up section into the Kidod Formation (or upper Zohar!) to the site of the first stratigraphic column constructed through these rocks. Right of center you can see a trench dug into the marls by Moshe Goldberg in 1962. This was part of his project to describe the entire Jurassic section in Makhtesh Gadol. We still use his iconic work today as “Goldberg, 1963”.

4 Quadrat start 031516Here are the Yaels starting the very first quadrat measurements within the Matmor Formation. Within a half-meter square they are counting and identifying all the fossils — every little bit over a few millimeters. Student Yael has many of these quadrats in her future!

5 Makhtesh view 031516Here is a view of the Makhtesh with the Yaels at work. You can see our white field vehicle from the Geological Survey in the middle distance.

6 Matmor bedding plane 031516We ended the day at this bedding plane in the upper Matmor Formation I remembered finding many years ago. It has spectacular clam and gastropod fossils across its surface, many in apparent life positions. I’d show you images of the critters, but I’m saving them for a Fossil of the Week post!

 

Return to Makhtesh Gadol … and introducing the Yaels

March 14th, 2016

1 Yaels Makhtesh view 031416MITZPE RAMON, ISRAEL–Today I went to one of my favorite geological places: Makhtesh Gadol in the northern Negev highlands of Israel. It was a special day as well because I worked there with two excellent geologists: Yael Edelman-Furstenberg of the Geological Survey of Israel, and Yael Leshno, a graduate student at Hebrew University beginning a project comparing the Middle Jurassic communities in the south of Israel with their temporal equivalents in the north. Yael E-F is one of Student Yael’s advisors; I am on her dissertation committee. The two Yaels are shown above in the Matmor Hills of Makhtesh Gadol sorting out the complicated stratigraphy.

2 Yaels at 055 031416Yael Edelman-Furstenberg is on the left and Yael Leshno is on the right (along with my intruding shadow). We are standing at GPS location 055, where fossils from Subunit 51 of the Matmor Formation are abundant. Student Yael is presently surveying the Middle Jurassic sections in Makhtesh Gadol to find suitable places to do stratigraphic fossil collecting and quadrat measurements.

3 Oolite unit bedding planeWe spent some time studying “the oolite unit” (Subunit 63) at the top of the original Goldberg (1963) stratigraphic section. It is, as Goldberg wrote on his column, a “characteristic guide horizon”. It’s curious because there are no other oolitic units in the Matmor Formation, and because it loses its oolitic nature a few hundred meters south and north of the section. I will make a thin-section of this rock and see what’s up with these ooids.

4 Oolite unit weatheringText

5 Jeffs PerchThe top of the triangular cliff has an exposure of a fossiliferous marl of the Matmor Formation. In 2005, Jeff Bowen (’06) perched up there for hours and collected tiny specimens.

6 Jeffs viewThis would have been Jeff’s view of the makhtesh as the sun began to set. I hope he appreciated it!

7 Sponge embedment MatmorFinally, here is a bathroom counter (the best light in my hotel room) image of a calcareous sponge I found in Subunit 60 (just below Jeff’s location above) with embedment structures (bioclaustrations). Some worm-like organisms lived within the sponge body, and the sponge grew skeleton around them. I’ve not seen these before in sponges.

Wooster’s Fossils of the Week: Zig-zag oysters from the Middle Jurassic of southern Israel

December 4th, 2015

Actinostreon Matmor Jurassic 171 173 585These pretty little oysters are from the Matmor Formation (Middle Jurassic, Callovian) of Makhtesh Gadol in southern Israel. Because I regrettably missed going to Israel for fieldwork this summer, I thought I’d choose these exquisite fossils to be celebrated this week. The genus is Actinostreon Bayle, 1878. There may be more than one species here, so we’ll just leave the identification at the genus level.
Actinostreon single 585Actinostreon is very common in some units of the Matmor Formation. Hundreds can be found scattered through a single unit. They were epifaunal filter-feeders as all oysters, and like most attached to hard substrates. The Actinostreon in the Matmor Formation commonly settled on small shell fragments in marl, giving them the appearance of dwelling in mud. Their zig-zag commissures (their shells are formally called plicate) strengthened their shells with ribs and helped them maintain high water inflow for filter-feeding with a relatively small opening (gape).
bayle 300The French paleontologist and mineralogist Claude Émile Bayle (1819-1895) named the genus Actinostreon in 1878. Bayle was raised in the beautiful French coastal city of La Rochelle. His family was related to Alcide Dessalines d’Orbigny (1802-1857), one of the greatest French naturalists, so collecting and analyzing fossils and modern shells was encouraged. Bayle studied at the Ecole Polytechnique and then the Ecole des Mines. After his schooling he was employed as the Chief Engineer of the Corps des Mines. He assembled a large collection of fossils (about 185,000 of which were cataloged). In 1848 he began teaching paleontology and mineralogy at the Ecole des Mines, retiring in 1881. His paleontological specialties were mollusks (especially Jurassic and Cretaceous bivalves) and Cenozoic mammals. He had a fairly modest publication record until he produced his magnum opus, an 1878 fossil atlas to accompany a new geological map of France. It is here that he described Actinostreon, and many other new taxa.

References:

Alberti, M., Fürsich, F.T. and Pandey, D.K. 2013. Seasonality in low latitudes during the Oxfordian (Late Jurassic) reconstructed via high-resolution stable isotope analysis of the oyster Actinostreon marshi (J. Sowerby, 1814) from the Kachchh Basin, western India. International Journal of Earth Sciences 102: 1321-1336.

Bayle, E. 1878. Fossiles principaux des terrains: Explication carte geologique France. France Service Carte Geologique, vol. 4, pt. 1, pl. 132.

Hirsch, F. 1980. Jurassic bivalves and gastropods from northern Sinai and southern Israel. Israel Journal of Earth Sciences 28: 128-163.

Machalski, M. 1998. Oyster life positions and shell beds from the Upper Jurassic of Poland. Acta Palaeontologica Polonica 43: 609-634.

Wooster’s Fossil of the Week: “Lapis Judaicus” from the Middle Jurassic of southern Israel

September 25th, 2015

Pseudocidaris spine 371Paul Taylor (Natural History Museum, London) is, along with his other talents, an expert on the folklore of fossils. His accounts of how fossils have been used and imagined in the past are fascinating, especially to paleontologists who work with them every day. (We had an example this summer at Whitby, England, with Saint Hilda and the ammonites.) So I was primed when Tim Palmer told me about an article on “Lapis Judaicus” or “Jews’ Stone” by Christopher Duffin (2006). Tim thought the medicinal value of these things was particularly appropriate for me.

At the top of this post is a clavate (club-shaped) spine from the echinoid Pseudocidaris. I collected it years ago from the Matmor Formation (Middle Jurassic, Callovian) exposed in Makhtesh Gadol, southern Israel. In classical and medieval times this would have been a Jews’ stone (or jewstone). Its shape is critical, of course, but also its provenance in the Middle East.
Gesner 1565 figureThis is an illustration from Gesner (1565) showing a set of Jews’ stones (taken from Duffin, 2006, fig. 2). The image on the right (“.3”) is very close to our Pseudocidaris spine. The range of shapes for Jews’ stones was broad; all simply had to have this general clavate appearance and be from the Holy Lands.

Jews’ stones are examples of a kind of sympathetic magic attached to natural objects. It was thought that the globular shape of these spines resembled a bladder, and so these stones could be used to treat urinary disorders of various kinds. Sometimes the ancient prescriptions called for them to be sucked, but more often the stones were ground into a powder and combined with other exotic ingredients for consumption either orally … or other ways. The Jews’ stones were thought to have both preventative value as well as curative.

And that is why Tim recommended them to me. One of their primary uses was for the cursed kidney stones.

Nice to know I could have a potential treatment available right there on the outcrop!

References:

Duffin, C.J. 2006. Lapis Judaicus or the Jews’ stone: the folklore of fossil echinoid spines. Proceedings of the Geologists’ Association 117: 265-275.

Gesner, C. 1565. De Rerum Fossilium. Lapidum et Gemmarum maxime, figures et similitudinibus Libel’: non solum Medicis, sed omnibus rerum Naturae ac Philologiae studiosis, utilis et jucundus futurus. Publisher unknown, Zürich.

Gould, S.J. 2000. The Jew and the Jew Stone. Natural History 6: 26-39.

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 Fossils of the Week: calcareous sponges from the Middle Jurassic of southern Israel

September 18th, 2015

1 Four Matmor SpongesThis post is in honor of Yael Leshno, a graduate student at The Hebrew University of Jerusalem who is beginning her dissertation on the Middle Jurassic marine fossils of Israel. I’m proud to be on her committee. She will have some fascinating material to work with, and she has great ideas to test. This will be a fun and productive project.

Among the Jurassic groups Yael will concentrate on are the calcareous sponges. This is ambitious because they are poorly known and the literature is replete with outdated names and concepts. Her work will be of great value, though, because sponges can tell us a lot about the environments in which they flourished. They may also give us much needed information on the biogeographical context of the Jurassic faunas of the Middle East.

Above are four sponges from the Matmor Formation (Callovian, Middle Jurassic) of Makhtesh Gadol, southern Israel. These types of sponge are fun because they actually look like sponges with their porous exteriors and central osculum (excurrent hole). They are the least complicated type of fossil sponge. (Yael will see plenty of the challenging ones!)
2 Matmor calcisponge Peronidella 585In this closer view of one of the Matmor sponges you can see the complex spicular network of the exterior (the structure that held the living cells). You will also note near the base the coiled tube of a sabellid worm named Glomerula gordialis (Schlotheim, 1820).
3 Matmor Peronidella osculum 585Here is a top view looking into the osculum of the largest specimen. Sponges are filter-feeders, sucking in water through their exterior pores, filtering the organic material out, and then sending the used water out an osculum like this.

This sponge type is traditionally named Peronidella Hinde, 1893; it would be then placed within the Family Peronidellidae WU, 1991. I’m suspicious of this name because it used for sponges from the Devonian through the Cretaceous, so it is likely a form-genus (meaning a named form that may not have particular systematic value). Yael will no doubt section these common Matmor sponges and find enough internal detail to come up with a more useful name.
4 GJ Hinde imageGeorge Jennings Hinde (1839-1918; image from Woodward, 1918) named the fossil sponge genus Peronidella in 1893. Hinde grew up in a farming family in Norwich, England. He was clearly a self-starter, studying classical languages and science on his own as a boy. When he was about 16 he listened to a lecture given by a clergyman on the Scottish geological polymath Hugh Miller (1802-1856), who had recently died tragically. Hinde was intrigued and began to explore geology. In 1862, after beginning his own farming, Hinde visited the geological collection at the British Museum in London. He began an acquaintance there with a family relative, the famous geologist and paleontologist Henry Woodward (1832-1921). In that same year Hinde sold his farm and moved to Argentina to raise sheep. A few years later he traveled to North America and began an epic seven years studying geology, traveling across the eastern half of the continent. (He must have had a considerable source of income for this!) He enrolled as a student in Toronto University under the paleontologist H.A. Nicholson (1844–1899) and began to produce his first geological papers. When he returned to England in 1874 he was elected a Fellow of the Geological Society of London. He continued to travel, this time over much of Europe and the Middle East. In 1880 he finished his PhD under Professor Karl Alfred Ritter von Zittel (1839-1904). He had a long career after that with numerous papers and scientific awards. Long et al. (2003) adds to this biography that Hinde very much wanted women to be allowed membership in the Geological Society of London, a point neglected in the obituary by Henry Woodward (1918). Hinde did not, alas, live to see the success of his progressive quest. The first woman was elected a Fellow of the GSL on May 21, 1919, a little more than a year after his death.

References:

Hinde, G.J. 1893. A monograph of the British fossil sponges, Part III. Sponges of the Jurassic strata, p. 189-254. The Palaeontographical Society, London.

Hurcewicz, H. 1975. Calcispongea from the Jurassic of Poland. Acta Palaeontologica Polonica 20: 223-291.

Long, S.L., Taylor, P.D., Baker, S. and Cooper, J. 2003. Some early collectors and collections of fossil sponges represented in The Natural History Museum, London. The Geological Curator 7: 353-362.

Vinn, O. and Wilson, M.A. 2010. Sabellid-dominated shallow water calcareous polychaete tubeworm association from the equatorial Tethys Ocean (Matmor Formation, Middle Jurassic, Israel). Neues Jahrbuch für Geologie und Paläontologie 258: 31-38.

Woodward, H. 1918. Obituary: George Jennings Hinde, Ph.D.(Munich), FRS, FGS, VP Pal. Soc. Geological Magazine (Decade VI) 5: 233-240.

Zittel, K.A. 1879. Studien über fossile Spongien, Teil 3. — Bayer. Akad. d. Wiss., math. naturwiss Cl. Abb. 13: 91-138.

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