Archive for March, 2016

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 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!


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 Pseudofossils of the Week: Shatter cones from southern Ohio

March 4th, 2016

Real shatter cones 585This brief post is a correction of a previous entry. Last year I showed what I thought were shatter cones collected many years ago in Adams County, Ohio, by the late Professor Frank L. Koucky of The College of Wooster. James Chesire commented on the post and said it was more likely the specimens were cone-in-cone structures produced by burial diagenesis not bolide impacts. When he sent me the photo above of real shatter cones from the Serpent Mound impact region in southern Ohio, I knew he was correct. Shatter cones have distinctive radiating, longitudinal fractures not seen in similar conical structures in limestones. The above shatter cones are in an unknown Ordovician limestone.

Both shatter cones and cone-in-cone structures are nevertheless pseudofossils in that they are both sometimes confused with organic structures like corals and chaetetids. I shall never mix them up again! Thanks for the correction, James.


Carlton, R.W., Koeberl, C., Baranoski, M.T. and Schumacher, G.A. 1998. Discovery of microscopic evidence for shock metamorphism at the Serpent Mound structure, south-central Ohio: confirmation of an origin by impact. Earth and Planetary Science Letters 162: 177-185.

Dietz, R.S. 1959. Shatter cones in cryptoexplosion structures (meteorite impact?). The Journal of Geology 67: 496-505.

Sagy, A., Fineberg, J. and Reches, Z. 2004. Shatter cones: Branched, rapid fractures formed by shock impact. Journal of Geophysical Research 109: B10209.

Shaub, B.M. 1937. The origin of cone-in-cone and its bearing on the origin of concretions and septaria. American Journal of Science 203: 331-344.

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