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!

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.

 

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 Geologist Returns to Israel: A visit to the Cretaceous Ora Formation

March 13th, 2016

1 Ora at GerofitMITZPE RAMON, ISRAEL — This is my 14th visit to Israel. I’ll be spending ten days here doing fieldwork in places I’ve come to love: Makhtesh Ramon, Makhtesh Gadol, and the Aravah Valley. I’ve returned to complete some Jurassic studies, explore a bit of the Cretaceous, and collect specimens for future Independent Study projects by Wooster geology majors. I’ve also come to work with an excellent Israeli graduate student, Yael Leshno. I’ll introduce her and her project later in this blog.

The top image is of my first field site of the trip: an exposure of the Ora Formation (Upper Cretaceous, Turonian) at Gerofit Junction at the edge of the Aravah Valley in southern Israel. It is a fun location because you can eat lunch while gazing at mountains and valleys in nearby Jordan. Of course, since it is the junction of routes 40 and 90, it’s a noisy place. The Ora Formation is well exposed north of the road junction.

2 Ora Gerofit faultThis outcrop is significantly faulted, so you must pay close attention to the stratigraphy to work your way through it. This is a low-angle normal fault. Note that it does not cut the topmost units. All sorts of tectonic situations are possible here next to the Dead Sea Transform system. Dr. Judge would love these structures! Me, not so much.

3 Ora limestone 031316Parts of the Ora Formation are very fossiliferous. This is a platy limestone rich in small oysters. Other beds have zillions of tiny gastropods, still others with plant and terrestrial arthropod remains. I came here ot find bryozoans, but found only a single specimen encrusting an oyster.

4 Mishhash view 031316On the way back to Mitzpe Ramon, I stopped at another exposure of the Ora Formation just south of Makhtesh Ramon. It is a place very familiar to several Wooster students, especially Andrew Retzler and Micah Risacher who did much of their I.S. field research on those steep slopes ahead. We often stopped to look at the Ora exposed in the wadis. The view is a bit hazy because of the typical Saharan dust that moves into the Negev in the spring.

5 Ora hardground MRThere is a fantastic bivalve-bored carbonate hardground in the Ora Formation at this second locality. It is especially well exposed now, probably because of winter floods washing away the soft sediment covering it.

6 Ora oysters 031316One amazing bed, about a half-meter thick, is packed with thin-shelled oysters. Every time I visit I look for encrusting bryozoans here, but none have appeared. They’ve got to be there!

It was a good start for these few days of fieldwork. I’m now acclimated, my geological eyes are tuned, and I’m ready for tomorrow’s fieldwork in the Matmor Formation of Makhtesh Gadol — the main event!

Wooster’s Fossil of the Week: A mystery from the Middle Devonian of Ontario, Canada

March 11th, 2016

Hungry Hollow 1This week’s fossil is a strange one. Mr. Darrell Ellis collected the above tiny specimen from the Hungry Hollow Member (Middle Devonian) at the famous Hungry Hollow location near Arkona, Ontario. (He also took this excellent photograph.) In the classic way exploratory paleontology works, he contacted an expert, my friend Olev Vinn at the University of Tartu in Estonia. Olev was puzzled, having never seen anything like it, so he sent the image to me. I was baffled. Darrell next sent me the actual specimen, which I examined an photographed. I could see that it is a calcitic spiral, flattened tube extending from a discoidal holdfast at its proximal end. I then passed images on to another buddy and expert, Paul Taylor at the Natural History Museum in London. The form is new to Paul as well, and he suggested it might be an odd microconchid, a twisty tube-dweller now extinct. That made sense, even if no microconchid like this has ever been described. We know that some microconchids did grow tubes extended upwards (such as Helicoconchus from the Permian of Texas, described earlier in this blog). Since we need to see the microstructure of the calcitic tube to support the hypothesis that this is a microconchid, I then sent the specimen to yet another friend, Michał Zatoń at the University of Silesia in Poland. He will examine the specimen with a scanning electron microscope (SEM). This is citizen science at work. Thank you, Darrell, for donating this specimen to science. It is also a reflection of how small scientific networks exchange ideas, information and specimens — Olev, Paul and Michał have been featured in this blog many times; we are old friends and colleagues with similar interests and diverse skill sets (and equipment!).

Hungry Hollow 2This is a closer view of the top of the spiral. We hope that Michał will be able to see the microstructure of the calcite on these broken surfaces.

Hungry Hollow 3This is the simple holdfast of this specimen. The tube began to grow  upwards very early in its ontogeny.

If you have ever seen a specimen like this before, whole or partial, please let me know in the comments or by email. We have only this one specimen that is clearly “new to science”. Other collectors and paleontologists may have bits of this they did not recognize before.

Again, thank you to Darrell Ellis for his sharp eyes, eagerness to contact experts, and generosity!

References:

Wilson, M.A., Vinn, O. & Yancey, T.E. 2011. A new microconchid tubeworm from the Artinskian (Lower Permian) of central Texas, USA. Acta Palaeontologica Polonica 56: 785-791.

Zatoń, M. & Vinn, O. 2011. Microconchids and the rise of modern encrusting communities. Lethaia 44:5-7.

Zatoń, M., Wilson, M.A. and Vinn, O. 2012. Redescription and neotype designation of the Middle Devonian microconchid (Tentaculita) species ‘Spirorbis’ angulatus Hall, 1861. Journal of Paleontology 86:417-424.

 

Wooster’s Fossil of the Week: A low-spired, battle-worn trochid gastropod from the Pliocene of Cyprus

February 26th, 2016

1 Gibbula Risso, 1826 apexThis shell looks like a cinnamon roll. It is another product of the 1996 Wooster-Keck expedition to Cyprus with Steve Dornbos (’97) and me. Like the rest of the Cypriot specimens on this blog, it is from the Nicosia Formation (Pliocene) exposed on the Mesaoria Plain in the center of the island. This specimen comes from the Coral Reef locality described in Dornbos and Wilson (1999). We are looking at a well-preserved specimen of the herbivorous gastropod Gibbula Risso, 1826. (I can’t fit it into any known species within the genus.)
2 Gibbula Risso, 1826 sideIn this side view the growth lines are evident (they are parallel to the aperture; the thin ribs following the whorls are ornamentation), as are a couple of shallow, circular pits drilled by some unsuccessful predator. That predator could have been another gastropod or even an octopus. The pits are known by the trace fossil name Oichnus.

Those growth lines are interesting in  this genus. Schöne et al. (2007) studied a species of modern Gibbula and determined that they formed “microgrowth lines” in association with tidal cycles, forming “distinct fortnight bundles of microgrowth increments and lines”. We would need to section this shell and examine it microscopically to see such patterns.

3 Gibbula Risso, 1826 baseHere is the basal view of our Gibbula specimen.

4 RissoThe genus Gibbula was named and described by Giuseppe Antonio Risso (1777-1845), called Antoine Risso, was a productive Italian (more or less; he later can be considered French) naturalist. He was born in the city of Nice, then in the Duchy of Savoy. In 1792, soon after the French Army occupied Nice, Risso became a pharmacist’s apprentice, which encouraged his interest in medicinal botany. Risso was also a pioneering mountaineer in the Alps and other European ranges. He published several books on invertebrates, fish and plants. The work most relevant to us is his 1826 tome entitled: Histoire naturelle des principales productions de l’Europe Méridionale et particulièrement de celles des environs de Nice et des Alpes Maritimes. Risso’s Dolphin is named after him.

References:

Donnarumma, L., Bruno, R., Terlizzi, A. and Russo, G.F. 2015. Population ecology of Gibbula umbilicaris and Gibbula ardens (Gastropoda: Trochidae) in a Posidonia oceanica seagrass bed. Italian Journal of Zoology, DOI: 10.1080/11250003.2015.1073377

Dornbos, S.Q. and Wilson, M.A. 1999. Paleoecology of a Pliocene coral reef in Cyprus: Recovery of a marine community from the Messinian Salinity Crisis. Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen 213: 103-118.

Risso, A. 1826. Histoire naturelle des principales productions de l’Europe Méridionale et particulièrement de celles des environs de Nice et des Alpes Maritimes. Paris: F.G. Levrault. Vol. 4: IV, 1-439, 12 pls.

Schöne, B.R., Rodland, D.L., Wehrmann, A., Heidel, B., Oschmann, W., Zhang, Z., Fiebig, J. and Beck, L. 2007. Combined sclerochronologic and oxygen isotope analysis of gastropod shells (Gibbula cineraria, North Sea): life-history traits and utility as a high-resolution environmental archive for kelp forests. Marine Biology 150: 1237-1252.

Williams, E.E. 1964. The growth and distribution of Gibbula umbilicalis (da Costa) on a rocky shore in Wales. The Journal of Animal Ecology 33: 433-442.

Wooster’s Fossil of the Week: A conid gastropod from the Pliocene of Cyprus

February 19th, 2016

Conus pelagicus Epsilos 585Cyprus again for this week’s fossil. This is a nearly complete shell of the predatory snail Conus pelagicus Brocchi 1814 found at the Epsilos exposure of the Nicosia Formation (Pliocene) on the Mesaoria Plain of central Cyprus by Steve Dornbos (’97) and me in 1996. In life this species no doubt had an intricate shell color pattern, as their cousins do today.

The taxonomic intricacies of the genus Conus are far beyond the scope of a mere blog entry, so I’ll simply link to a list of associated genera, subgenera and synonymies. Conus as an organism is fantastic. These are venomous predators famous for shooting radular teeth loaded with very effective toxins. Some species can kill a human in less than five minutes. No worries, though — the venom contains analgesic compounds so there is little pain. The best way to demonstrate the extraordinary killing process used by Conus is to look at a video. You’ll never look at snails the same way again.
BrocchiImageConus pelagicus was originally described by Giovanni Battista Brocchi in 1814. We met him in a previous blog entry, so much of this information is repeated. Brocchi (1772-1826) was an Italian natural historian who made significant contributions to botany, paleontology, mineralogy and general geology. He was born in Bassano del Grappa, Italy, and studied law at the University of Padova. He liked mineralogy and plants much better than lawyering, though, and became a professor in Brescia. His work resulted in an appointment as Inspector of Mines in the new kingdom of Italy. He famously said, “The science of fossil shells is the first step towards the study of the earth.”

Brocchi wrote the first thorough geological assessment of the Apennine Mountains, and he included in it a remarkable systematic study of Neogene fossils. He compared these fossils to modern animals in the Mediterranean — a very progressive thing to do at the time.
Brocchi plate 122915Above are drawings made by Brocchi of the conid (and a couple cypraeid) fossils he found in the Apennines during his extensive study published in 1814. Note that in the Continental fashion still followed today, the shells are figured aperture-up. Americans and the rest of the English-speaking world orient them in the proper way. Figures 11a, b and c, though, are oriented in the opposite direction, maybe to fill the space efficiently.

Brocchi was an adventurous traveler, but it eventually did him in. He died in Khartoum in 1826, a “victim of the climate” and a martyr for field science.

References:

Brocchi, G.B. 1814. Conchiologia fossile subapennina con osservazioni geologiche sugli Apennini e sul suolo adiacente. Milano Vol. I: pp. LXXX + 56 + 240; Vol. II, p. 241-712, pl. 1-16.

Cowper Reed, F.R. 1935. Notes on the Neogene faunas of Cyprus, III: the Pliocene faunas. Annual Magazine of Natural History 10 (95): 489-524.

Cowper Reed, F.R. 1940. Some additional Pliocene fossils from Cyprus. Annual Magazine of Natural History 11 (6): 293-297.

Dornbos, S.Q. and Wilson, M.A. 1999. Paleoecology of a Pliocene coral reef in Cyprus: Recovery of a marine community from the Messinian Salinity Crisis. Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen 213: 103-118.

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