A 10K run into the Eocene of the Negev

April 20th, 2014

Horsha view 042014MITZPE RAMON, ISRAEL–Yoav and I had a long hike today into the Eocene succession of rock units in the northern Negev. We wanted to look especially at the Horsha Formation (Eocene, Lutetian) because it has some cool trace fossils and massively large oysters. Along the way there are also interesting features like submarine debris flows, thick chalk deposits, unconformities and faulting.

rainstorm 042014Despite the sunshine in the top image, we started the day with a thunderstorm at our back. It was the first time I’d heard thunder in Israel, and for awhile we contemplated in which rocky crevice we should take cover. (It’s not like we carry raingear with us here.) We did get rained upon, but not seriously.

Yoav and layer 042014Yoav is here looking at a thin limestone unit near the base of the Horsha Formation (at GPS 072; N 30.32537°, E 35.00653°). Note the sharp base and yellowish mineralization of the chalk.

Horsha traces 042014There are fantastic trace fossils in convex hyporelief on the base of this limestone layer.

Trace nummulitids 042014The small disks near this trace are nummulitid foraminifera. They are a major component of this limestone.

Horsha algae 042014There are also many broken bits of calcareous algae.

Giant oysters 042014These giant oysters are common in this unit. Some are bored, which you might be able to see in the specimen on the far left. We will return to this area tomorrow for continued exploration.

Negev Berry shrub large 042014On the long way back to the car we encountered this shrub. I wish I knew the name. Yoav said it was called “Bread of the Monks”, but that has led me nowhere. It may be Ochradenus baccatus, also known as sweet mignonette.

Negev Berry shrub close 042014I’m not one to eat wild plants I don’t know, but Yoav assured me the berries on this shrub were tasty. Indeed. Sweet like blueberries. Worth the risk!

Wooster’s Fossils of the Week: A scleractinian coral and its tube-dwelling symbionts (Middle Jurassic of Israel)

April 20th, 2014

MatmorCoral010114aI have a weakness for the beautiful scleractinian corals of the Matmor Formation (Middle Jurassic, Callovian-Oxfordian) of southern Israel. This particular specimen is Microsolena aff. M. sadeki from locality C/W-367 in Hamakhtesh Hagadol, southern Israel. (The “aff.” in the name means “affinities with”. It is a way of saying this looks like a particular species, but we’re not quite sure.) This is a place we’ve now had ten Wooster Team Israel expeditions, the latest of which was last summer. The corals are a prominent part of the very diverse fossil fauna there. Note in the above side view of the specimen the star-shaped corallites (which held individual polyps) each with radiating septa. In the middle of the view you can see a narrow tube covered by coral skeleton. (More on this below.)
MatmorCoral010114bThis is a top view of the coral. It has a generally flat base and an upper surface with extended knobs. Usually this particular species is flat across the top as well as the base, giving it a platter shape as in this previous Fossil of the Week.
MatmorCoral010114cFlip the coral over and we see how it is preserved. The skeleton was originally made of the mineral aragonite, which dissolved after the death and burial of the colony. The resulting void was filled with stable calcite, preserving even fine details of the septa (see below). This delicate preservation, though, is only of the exterior of the skeleton. The interior is coarsely crystalline calcite with no trace of internal coral structures. This preservation, then, is properly called a cast, not true replacement.
MatmorCoral010114tubeThese scleractinian corals had many symbionts (organisms that lived with them). Among them were tube-dwelling worms, probably polychaetes, that spread across the surface. We know this happened while the coral was alive because, as seen above, the septa sometimes grew over the tubes. The tubes themselves are here preserved in three dimensions because they are originally calcitic and did not dissolve after death and burial.

We have much to learn about these gorgeous Jurassic fossil corals of Israel. They are virtually unstudied and offer a great opportunity for comparing them to the global Jurassic coral world.

References:

Martin-Garin, B., Lathuilière, B. and Geister, J. 2012. The shifting biogeography of reef corals during the Oxfordian (Late Jurassic). A climatic control?. Palaeogeography, Palaeoclimatology, Palaeoecology 366: 136-153.

Pandey, D.K., Ahmad, F. and Fürsich, F.T. 2000. Middle Jurassic scleractinian corals from northwestern Jordan. Beringeria 27: 3-29.

Reolid, M., Molina, J.M., Löser, H., Navarro, V. and Ruiz-Ortiz, P.A. 2009. Coral biostromes of the Middle Jurassic from the Subbetic (Betic Cordillera, southern Spain): Facies, coral taxonomy, taphonomy, and palaeoecology. Facies 55: 575-593.

Wilson, M.A., Feldman, H.R., Bowen, J.C., and Avni, Y. 2008. A new equatorial, very shallow marine sclerozoan fauna from the Middle Jurassic (late Callovian) of southern Israel. Palaeogeography, Palaeoclimatology, Palaeoecology 263: 24-29.

Wilson, M.A., Feldman, H.R. and Krivicich, E.B. 2010. Bioerosion in an equatorial Middle Jurassic coral-sponge reef community (Callovian, Matmor Formation, southern Israel). Palaeogeography, Palaeoclimatology, Palaeoecology 289: 93-101.

Stratigraphy day at Makhtesh Ramon

April 19th, 2014

Labled cliff 041914MITZPE RAMON, ISRAEL–Usually on Saturdays Yoav Avni and I do something “touristic”, like visit an archaeological site or museum. Since it is the Passover holiday, though, and we are both averse to crowds, we decided to do a little stratigraphy outside Mitzpe Ramon instead. Our challenge from Amihai Sneh was to sort out the lower boundary of the En Yorqe’am Formation (Upper Cretaceous, Cenomanian), so we added another section to our argument.

The above image is taken from N 30.62947°, E 34.82085°, about three kilometers northeast of town along the rim of Makhtesh Ramon. (Check those coordinates out on Google Maps. Very cool, especially if you tilt the Earth image to show the cliff edge.) The three critical formations are labelled above with our new concept. The top boundary of the En Yorqe’am with the Zafit Formation is not controversial; it’s the base of the En Yorqe’am that is at issue. Presently it is defined as the top of the cemented carbonates shown just above the “Y” of En Yorqe’am. With this definition the unit is about 20 meters thick — less than half its thickness elsewhere. This has led to some tectonic arguments about uplifts, erosion and unconformities that are not supported by the record in the rocks, other than this anomalously thin section. From our studies of the boundary to the south, we believe we have good evidence to put it here between the massive and bedded limestones as shown. The fossils support this (especially oysters) and the thickness of the En Yorqe’am goes back to an expected 50 meters or so. That’s the argument we’re going to make to Amihai, at least. I will see more of this unit with Amihai further north next week.

H-E contact 041914Here Yoav is standing on what we consider the top of the Hevyon Formation, with the En Yorqe’am behind him.

Yoav cliff 041914Let me emphasize to Gloria and my Mother: that is not me on that precipice! Yoav is here checking the lithology and paleontology of the top Hevyon. It all ended well.

storm 041914We got back just as a massive wind and dust storm swept into town. A front is moving through from north Africa. They say it could rain, but I don’t believe it.

Our camel friends in the Negev

April 18th, 2014

camel head 041814MITZPE RAMON, ISRAEL–It is a problematic relationship between camels and me. My first experience with a camel out here was watching one eat my lunch, bag and all, when I foolishly left it in the shade of the vehicle while I measured a section. My students and I have been dissuaded more than once from visiting a particular outcrop by aggressive, bellowing camels standing their ground and looked very, very big and toothy. I was thus a bit hesitant when Yoav just walked up to this beauty on our way to the center of Makhtesh Gadol. I followed and did just fine within touching distance. This is a female (hence the lack of attitude) and a pregnant one at that. She is part of a small herd owned by a Bedouin family that may or may not have an arrangement to graze animals in this nature reserve. She eased my camel anxieties.

camel bed fossils 041814After our encounter I realized that camels actually play a role in our work. This is one of our most productive fossils sites (“GPS 055″). It is an exposure of a marl in subunit 51 in the Matmor Formation. This is also a camel resting spot. They love the soft sediment, probably as a break from the rocky soil elsewhere. We thus find such dry camel wallows often in our explorations of the Matmor. By stirring up the marl, the camels unearth fossils that would otherwise lay hidden.

Random Echinoderm bits 041814Here is a random assortment of crinoid and echinoid bits found in this camel haven. If we ignore the poop and flies, and avoid the angry males, these camels have done us a scientific favor!

“I know a tree”

April 17th, 2014

Acacia distant 041714MITZPE RAMON, ISRAEL–I met this particular tree in 2003 when searching for a good place to have lunch. Yoav said, “I know a tree”, and then we drove a half-hour to get to it. As you can tell, trees are not particularly common in Makhtesh Gadol. Now this acacia has served as a resting place for a dozen Wooster geology students over the years. Its patchy shade is welcome indeed. Today I had a lonely little lunch of nuts and fruit underneath it, with the magnificent makhtesh walls surrounding me.

Acacia close 041714Acacia trees are critical for wildlife and domesticated animals in this region because they maintain an African metabolic timing, being greenest during the hot, dry Negev summer as a genetic memory of the contemporary wet season in Africa. Animals depend on this bounty, despite the thorns and stinging ants. Acacia is known as “shittim wood” in the Bible, where it is mentioned several times.

Makhtesh Gadol 041714I had the beautiful Makhtesh Gadol to myself today. The Passover holiday is a sort of Spring Break for Israelis, so the roads are miserably crowded, even through the Negev. Once I get here, though, I’m in a closed nature reserve that no one can enter without a permit. I have the only permit now, so this is a place of complete solitude for me until I must return to the highway and civilization.

The Negev wildflower post

April 16th, 2014

A DSC_3602 copyMITZPE RAMON, ISRAEL–Today I worked in the Jurassic of Makhtesh Gadol and the Triassic of Makhtesh Ramon. A highlight was that I was joined by Yael Leshno, an Israeli master’s student on her way to a paleontology career. She was very good at finding crinoid parts in the Matmor Formation. Otherwise it was a dusty, windy, non-photogenic day. Time to post wildflower images!

DSC_3555 copyOf course, I don’t know what most of these flowers are, just that they’re pretty. The Negev had good winter and spring rains, so the wildflowers are abundant. [Update: Lyn Loveless, a biologist at The College of Wooster, tells us, “The first two photos are plants in the Brassicaceae (mustard family), and look a lot like Raphanus, wild radish. The one [below] – well, maybe a mint? Bifid stigma, four anthers.” Thank you very much, Lyn!]

DSC_3600 copyThere must be an interesting pollinator for this plant. James in the comments identified this flower as Echium judaeum. Thanks!

DSC_3595 copyI know I’ve identified this plant before, but the name now escapes me. It tends to be in moister parts of wadis. It might be Broomrape (Cistanche tubulosa), a parasitic plant that taps the roots of other plants.

Erodium cicutariumThis I learned is the Stork’s Bill (Erodium cicutarium). It is native to the Mediterranean and was introduced to North America over 200 years ago (and is now an invasive pest in some places). It has a very impressive way of distributing its seeds, one of which is shown in the center of this image.

DSC_3756 copyThe seeds of the Stork’s Bill are so common this spring that they blow around the desert landscape like snow. Each has a feathery shaft to catch the wind, and then a screw-like device that enables the seed to bury itself in the soil with changing humidity and the action of the wind on the shaft. This Wikipedia page on the plant has images of the seeds. Very r-selected!

DSC_3760 copyWhich brings me to this odd creature. You see here a collection of Stork’s Bill seeds bound together like a sheaf of wheat. In the lower right is the head of a caterpillar-like arthropod seeming to carry it along. When I touched it the head retreated into the seed mass.

DSC_3764 copyWhen I turned it over I observed that it is an agglutinated tube of some kind with sticks on the base and the feathery seeds on the top. It looks like a terrestrial equivalent of a caddisfly tube that is pulled along by the little beast. I’d love to hear if anyone recognizes this animal and its habit! [Update: Laura Sirot, a biologist at Wooster, has identified this as a Bagworm Moth. Todah raba, Laura!}

Return to the Jurassic Paradise of Makhtesh Gadol

April 15th, 2014

Makhtesh Gadol 041514MITZPE RAMON, ISRAEL–This week I’m back in Makhtesh Gadol, that great bowl of Jurassic delights. This is the most extensive exposure of marine Jurassic rocks in southern Israel, and it is highly fossiliferous. This is just a brief report. I’ll summarize the latest finds and ideas later.

Greened 608 041514Today I spent most my time sitting on these low outcrops at a place we affectionately call “GPS 004 C/W-608″. It is the most productive site for crinoids and their associated sclerobionts (organisms that lived on or in their skeletons, before or after death). There was something about the original distribution of these organisms, and then the preservation and landscape erosion, that makes this site so good. Today I was not disappointed.

MatmorCollectView070513Compare this view of the site in July last year with Oscar Mmari, Steph Bosch and Lizzie Reinthal (all Wooster seniors now). The winter and spring rains were a bit higher than normal in this part of the country, so the outcrop today looks positively overgrown! This picture makes me miss having my students along on this trip, but such are research leaves.

Holiday in Mitzpe Ramon

April 14th, 2014

Mitzpe Ramon edge 041414MITZPE RAMON, ISRAEL–Pesach (Passover) begins this evening at sundown, but essentially the holiday has started today as people prepare for this evening’s family seders. The town has gone very quiet as stores have closed and traffic dropped to almost no vehicles moving. I spent the day walking around the periphery of Mitzpe Ramon enjoying the beautiful weather and occasionally making some accidental geological observations. As you can see from above, it doesn’t take long to leave the city and enter The Wilderness.

Mitzpe Ramon archaeology 041414This is a small archaeological site on the western end of town. I don’t know much about it, other than it is likely Iron Age. Israeli archaeology students often map it for practice.

Western Makhtesh Ramon 041414A view of the western end of Makhtesh Ramon because … why not?

Mitzpe Ramon Camel 041414This feature is called The Camel for obvious reasons. It perches on the edge of the makhtesh and has long served as a beacon for a route in and out of the makhtesh. An observation platform has been built on it as a “saddle”. The units here are the En Yorqe’am at the base and the camel itself made of the dolomitic Zafit Formation.

Mitzpe Ramon En Yorqe'am 041414I took advantage of the quiet to visit a housing development and check out the problematic muddy dolomitic unit near the base of the En Yorqe’am.

Ibex 041414Finally, I met this young, friendly Nubian ibex (Capra nubiana), one of hundreds that calmly wander the streets here. He was happily eating bread slices that had been thrown out in preparation for Pesach.

 

In the Valley of Elah

April 13th, 2014

Valley of Elah from Tel Azeka 041314MITZPE RAMON, ISRAEL–Simon Schama begins his magnificent series The Story of the Jews at an archaeological site near the Valley of Elah called Khirbet Qeiyafa. He said that the first physical evidence for the existence of the Jewish people was not the Exodus from Egypt (for which there is not a trace) but the structures on a hill visible across the valley above. I mentioned to Yoav Avni that I’d love to see the place on our return from a set of Jerusalem meetings we had this morning. He not only said it would work, he arranged for his brother Gideon Avni, a well-known archaeologist and Head of the Archaeological Division of the Israel Antiquities Authority, to meet us there for a guided tour. How very cool is that?

You may have heard of the Valley of Elah before. It’s the Biblical location where David met and slew Goliath. (It’s always “slew”, isn’t it?) Historically the valley is a route from the coastal plains into the Judean Mountains, and thus a place of conflict between plains dwellers and mountain tribes.

Khirbet Qeiyafa city wall 041314This is a view of the exterior city wall near the first gate of Khirbet Qeiyafa. Most of this wall was underground until excavation began in 2007 by the archaeologists Yosef Garfinkel of Hebrew University and Saar Ganor of the Israel Antiquities Authority. This is remarkably late for such an important site to be discovered. The location is N 31.69658°, E 34.95667°.

Khirbet Qeiyafa first gate 041314The first gate into the city. It has a three-part structure characteristic of Iron Age structures.

Khirbet Qeiyafa double wall 041314The walls of the city are double, with narrow rooms inside for the non-claustrophobic. To the left are remaining walls of dwelling and cooking spaces.

Khirbet Qeiyafa view of Tel  Azeka 041314At the top of this view you see Tel Azeka across the valley, a wall in the middle view, and the Iron Age structures below. The main wall here was built later on top of the ancient city walls, probably as a sheep pen of some kind. Note the plastered walls in the room below.

Khirbet Qeiyafa second gate 041314The second gate on the opposite side of the city from the first.

Khirbet Qeiyafa cave 041314There is a cave near the middle of the city, so of course we had to go in.

Khirbet Qeiyafa cave interior 041314Yoav in the cave interior, lit by the camera flash. This cave is not completely excavated, so it is unclear how much was natural and how much dug by people and for what purpose.

Khirbet Qeiyafa Gideon Yoav 041314Gideon Avni on the left and his brother Yoav. World-class discussions between them on archaeological interpretations and the geological context of this settlement. Thank you very much to both of them for this experience. If you want to learn much more about Khirbet Qeiyafa, please visit the official archaeological website.

Yoav and I also visited Tel Azeka across the valley at N 31.69982°, E 34.93578° (see below). It has a much longer history than Khirbet Qeiyafa, with several Biblical references.

Tel Azeka 041314The tell is about 20 meters or so above the natural top of the hill.

Tel Azeka excavation 041314It has excavations in several places exposing its complex stratigraphy. This appears to be an Iron Age dwelling place.

Tel Azeka cave 041314Tel Azeka, or more properly the rocks below it, have a famous series of caves and tunnels dug through the soft chalk. Here Yoav is in a cavern he likely played in as a boy. Most of the tunnels are very narrow, the kind you can imagine a young Yoav wriggling through.

Tel Azeka caveern 041314The caves themselves have a long history of occupation, most famously by fugitives from the Romans during the Bar Kokhba Revolt.

What a great day we had in the valley of David and Goliath!

Wooster’s Fossil of the Week: An unusual scleractinian coral from the Upper Cretaceous of Israel

April 13th, 2014

Aspidiscus 041114aOriginally this was going to be a mystery fossil for a crowd-sourced identification while I’m here in Israel doing fieldwork, but through the wonders of the internet I finally found a match for the strange fossil above: it is the scleractinian coral Aspidiscus König, 1825 (Family Latomeandridae) Yoav Avni and I found several specimens in the lower third of the En Yorqe’am Formation (Upper Cretaceous, Cenomanian) in the Negev of southern Israel. I had never seen anything like it before.

The view above is of the upper surface of this discoidal fossil. There are several short and seemingly random ridges, which I learned later are called monticules in this genus. Each monticule has a series of septa, or thin vertical partitions. This was a compound coral, meaning it had multiple polyps on its surface, presumably each sitting on a monticule.
Aspidiscus 041114bThis is a reverse view of the En Yorqe’am variety of Aspidiscus. The pits appear to be molds of a gastropod on which the young coral must have recruited. It then grew centripetally, making a fine series of growth lines across a soft sediment.
Aspidiscus cristatus diagramThis diagram from Pandey et al. (2011) is a diagram of Aspidiscus cristatus found in the Cenomanian of Sinai, not too far from here. (This species is also found in Algeria, Tunisia, Spain, Greece, and Afghanistan — all in the Cenomanian.) Note that the center of A. cristatus has two large crossing monticules and the Israeli specimen does not. This is why I’m keeping it in open nomenclature — it doesn’t appear to be the same species. A. cristatus is found in the middle to early late Cenomanian; the En Yorqe’am specimen seems so far to be only in the early Cenomanian. This may mean the Israeli version is an older species. Both clearly liked living in marly shallow marine sediments.
Aspidiscus symbiontsHere’s the bonus: look at the round holes in the upper surfaces of these two specimens. These are caused by symbionts of some kind that lived within the growing coral. You can see best in the specimen on the right how the coral grew around the symbionts, producing a kind of tube. Nice.

Sorry for the lower quality of images this week. I’m photographing the fossils as best I can with a bedside lamp, a tiny tripod, and a shirt for background.

References:

Avnimelech, M. 1947. A new species of Aspidiscus from the Middle Cretaceous of Sinai and remarks on this genus in general. Eclogae geologicae Helvetiae 40: 294-298.

Gill, G.A. and Lafuste, J.G. 1987. Structure, repartition et signification paleogeographique d’Aspidiscus, hexacoralliaire cenomanien de la Tethys. Bulletin de la Societe Geologique de France 3: 921-934.

Pandey, D.K., Fürsich, F.T., Gameil, M. and Ayoub-Hannaa, W.S. 2011. Aspidiscus cristatus (Lamarck) from the Cenomanian sediments of Wadi Quseib, east Sinai, Egypt. Journal of the Paleontological Society of India 56: 29-37.

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