Mark Wilson March 12th, 2012
MITZPE RAMON, ISRAEL–Melissa Torma, our friend Yoav Avni (Geological Survey of Israel), and I just ended a productive first day in the field. The two of them are shown above in classic paleontological poses. They are collecting fossils from Subunit 51 of the Matmor Formation (Middle Jurassic) in Hamakhtesh Hagadol in the northern Negev. We found excellent crinoid stems and calyx plates, brachiopods, corals, sponges, echinoid spines, serpulid worms, clams, and oysters.The day was very windy but seasonably cool.
You might be wondering why the sky in the above photograph is not the usual bright blue for this region? It is because the air is filled with dust blown off the Sahara Desert to the eastern Mediterranean countries (see NASA image below from 2011). This is a common occurrence here in the spring when a storm system is on its way. In the course of a year, every square kilometer in Israel receives 30-60 tons of this dust. The storm will bring rain to northern Israel tomorrow and Wednesday, but it is very unlikely to break the drought here in the southern dessert.
Shown below is a curious fossil Yoav found at our new site in the Matmor Formation we’ve called (creatively) “halfway”. It is a crinoid stem with a pair of skeletal galls, each with several holes. It appears some organisms infected the living crinoid, which then responded by growing skeletal tissue around the offending critters. Eventually the walled-in organisms drilled their way out, leaving the holes. This is what it looks like, anyway. Feel free to speculate!
I’ve placed a slightly different view of the fossil below to show that these are not encrusters but rather echinoderm skeletal material.
We had a great day despite the pervasive dust and wind gusts. It feels so good to get back to a desert again.
Mark Wilson May 31st, 2011
MITZPE RAMON, ISRAEL–What is Will examining so intently? There was drama on the outcrop this afternoon. We are used to seeing cute little geckos clinging to the rocks we study. As we skirted the edge of a limestone cliff, Will saw a very long and narrow snake dash after a lizard. We all watched as the lizard dived down the rocks of the cliff, scrambling to the bottom. The snake followed its every move, catching it in a talus pile. The circle of life.
You can see the snake’s coils here and a motionless lizard. Why is he holding so still in such a dangerous place?
Because on closer view we see that the snake has him by the head and has started to slowly swallow him.
This encounter reminds me of the lizard-scorpion battle witnessed by the 2010 Wooster Geologists team in Utah.
This was our last field day in Israel. Tomorrow morning, very early (4:00 a.m.!), we start the long drive north to Tel Aviv and Ben Gurion airport. Then the long flight to Newark and then Cleveland. It has been another wonderful adventure of geology, biology and history.
Mark Wilson May 29th, 2011
MITZPE RAMON, ISRAEL–Today Will and I drove south, east and north to meet Dr. Yael Edelmen-Furstenburg of the Geological Survey of Israel. She gave us a most excellent tour of the Mishash (pronounced ME-shawsh) Formation (Campanian, Upper Cretaceous) in the Wadi Ashosh region (shown above) near Zuqim and Tsofar in the Negev Desert. We talked much about the fossil fauna, particularly the trace fossils in soft and hard substrates. There could be many future Wooster Independent Study projects in this formation, especially here where it is so diverse.
As seen above, much of the Mishash Formation consists of bands of chert. The folds are syndepositional (formed at the time of deposition) as part of the Syrian Arc deformation. This makes for some very interesting local stratigraphy and depositonal patterns.
The Mishash Formation has exquisite fossil shell beds, often silicified (replaced with silica). Above you can see gastropods and bivalves.
An old Cretaceous friend, the ammonite Baculites, is used to sort out the biostratigraphy of the Mishash. They are identified by the style of ribs they have on the outside of the conch.
Like everywhere else in the Negev Desert, shade is a bonus. We always appreciate the acacia trees, even if their shade is not so complete. Will is standing here next to the Geological Survey of Israel vehicle. Shlomo, an old friend and the driver, gave us quite the off-road adventure. Many people pay for such tours!
Mark Wilson May 29th, 2011
Flat tire at N30.54352°, E35.14007°.
Near miss (if we had been eating lunch here, say, 15 years ago).
Mark Wilson May 28th, 2011
MITZPE RAMON, ISRAEL–On our way back from Eilat this afternoon, Will and I took a short hike to see the “Ammonite Wall” on the southern outside beds of Makhtesh Ramon. It is an impressive tilted array of large ammonites in the Tamar Formation (Cenomanian). Current thoughts are that this represents a massive death assemblage. The ammonite conchs, which all seem to be of the same species, washed into an embayment and were buried. This is not uncommon as ammonite conchs probably filled with gases after death and floated great distances. They are all preserved as internal molds, with a few, such as the one below, showing their suture patterns.
Mark Wilson May 28th, 2011
MITZPE RAMON, ISRAEL–The only other time I’ve seen rain in southern Israel was with Elyssa Krivicich on our March 2008 trip. By May the rains are done in this part of the world. Nevertheless, it rained last night and then sprinkled on us as we drove south to Eilat this morning. The temperature has also dropped a good 6°C, which suits us just fine.
This is the 400th post on the Wooster Geologists blog! It is also near our two-year anniversary. It appears from our statistics (which I do not fully understand) that we have had 21,793 visitors and 163,072 pageviews. I’m not sure if those are unique visitors or what a “pageview” is, but I know we’ve had enough feedback to make this project much fun.
Mark Wilson May 27th, 2011
MITZPE RAMON, ISRAEL–This morning Will and I finished our work with the Zihor/Menuha boundary cobbles. We drove to the southern side of Makhtesh Ramon (pictured above) to see the same units we examined 25 kilometers to the north in Wadi Aqrav yesterday. The scenery was spectacular — and the day so hot that the wind felt like a hair-dryer in the face.
Will standing on the very top of the Zihor Formation where it is overlain by the Menuha chalks. This picture was deliberately posed to give his parents a bit of a thrill.
The Zihor/Menuha cobbles in the southern sections. They look very much like those we studied in Wadi Aqrav. They certainly are more numerous here and easy to measure. Some have borings by bivalves (Gastrochaenolites) and worms (Trypanites). We found no encrusters here, but we did find oyster shell fragments.
A difference between these southern exposures and those to the north is that the Zihor Formation top surface here is very well exposed. We can see that it was probably lithified during the erosion that created the disconformity and the cobble lag. It is undulating and well polished. Note that it is also on the edge of oblivion.
The Zihor/Menuha boundary is very distinctive because of the erosional differences, so faults through it show up well. What kind of fault is this? (It is not a trick of perspective because the fault plane has eroded back a bit.)
This is the kind of shade we had in the field today — when we were lucky! It was 40°C by 1:00 p.m. Will is pressed up against an outcrop of the Menuha Formation, by the way, showing a sequence of carbonate nodules that may help explain the origin of the boundary cobbles.
Mark Wilson May 26th, 2011
Yoav Avni and Will Cary hiking down the wadi that exits Makhtesh Gadol. In the background is the wall of the makhtesh. It is made of diverse Cretaceous units.
MITZPE RAMON–Our colleague Yoav Avni of the Geological Survey of Israel is part of a movement to declare the Negev Desert around the three major makhteshim a Geopark cataloged by the United Nations Educational, Scientific and Cultural Organization (UNESCO). A Geopark is defined by UNESCO as “A territory encompassing one or more sites of scientific importance, not only for geological reasons but also by virtue of its archaeological, ecological or cultural value.” Yoav’s dream is that scientists and the general public from around the world will someday visit the makhteshim to tour the unique geological features with an infrastructure in place much like that of a US National Park. The ecological and cultural heritage of this region will be as important as the geology.
Modified from Google Maps.
I played a small role in this process when I wrote a letter to the Israeli government in 2005 (at Yoav’s request) explaining the geological value of Makhtesh Gadol and opposing further expansion of a sand quarry in the northern part of the makhtesh. This added a seed of international scientific interest to the discussion that continues to grow.
Now when we describe geological phenomena and fossils in the makhteshim, we are thinking about the ways we can explain these things to the public through nature trails, museum exhibits and popular press articles. It is exciting to be on the ground floor of such an endeavor.
There is plenty of opposition to this Geopark, of course. On one side are industries and government officials who want to squeeze every bit of economic usefulness from the land; on the other are extreme preservationists who wish to close off large tracts to all human entry. Somehow Yoav and his colleagues will have to find a way to make the future Geopark economically viable and yet with all the protections necessary to preserve its natural assets. This will be a slow process but maybe I will someday be posting blogs from the Makhteshim Country Geopark.
Mark Wilson May 26th, 2011
MITZPE RAMON, ISRAEL–It wouldn’t be the Middle East without a camel encounter or two. One year a camel literally ate my lunch when I left it in the shade of the car during a long morning’s work. (He even ate the plastic around the sandwiches.) The local Bedouin care for small camel herds that range throughout the Negev. If you’re near a wadi with a source of vegetation and water, camels are nearby. The version here is the one-humped variety: the dromedary (Camelus dromedarius).
Will and I were walking up a long dirt road around noon when we met the large male camel pictured above. He stared us down, standing almost completely still. We immediately saw why he was so intense: a group of females and young camels was behind it and we were about to walk between him and them. Of course, we had no interest in dying under the hooves of a camel (or whatever they do when they attack), so we moved carefully off the road. After a few minutes he slowly strolled down a wadi and the rest of the group caught up with him, a female at the end keeping her eyes on us until they were out of sight.
Females and young following the male down a wadi.
Mark Wilson May 25th, 2011
Will Cary collecting crinoid pieces at a site we creatively call "GPS 055". In the upper left you can see a triangular exposure of marl where Jeff Bowen did his Independent Study work in 2005.
MITZPE RAMON, ISRAEL–One of our missions on this expedition to Israel is to find more and better examples of a distinctive crinoid in the Middle Jurassic Matmor Formation. Crinoids are stemmed echinoderms with a very long geological history, dating back to the Ordovician (or Cambrian, depending on who you believe). They are still alive today so we know much about their biology. They usually have long stems with a holdfast on one end (attaching it to the substrate) and a calyx on the other containing most of the body. The calyx has feathery arms attached at the top that filter the water to catch fine-grained organic particles and pass them down to a central mouth.
Parts of the Matmor Formation have abundant crinoid fragments, all belonging to at least two types of Apiocrinites (a crinoid genus). Two years ago I collected some beautiful specimens, but still lacked some critical pieces. Today Will and I revisited my earlier localities (thank you, GPS technology) and found beautiful specimens.
Our prize is the holdfast pictured above. This is a mass of skeletal calcite the crinoid used to glue itself to the bottom of a coral. The shallow pits apparently represent additional “roots” it used to brace itself in a cavity under the coral. The stem then horizontally protrudes to the right so that the calyx and feeding arms could eventually reach the open seawater. I’ve never seen a holdfast this elaborate in the Jurassic.
Above are typical other parts of this Jurassic crinoid (imaged with all my hotel room photographic skills). At the top are two calyx side pieces showing the interior (left) and exterior (right). The star-shaped object in the middle is the calyx base, seen from the inside. It is flanked by stem fragments, the one on the far right encrusted by an oyster. At the bottom is a crinoid stem with a branching holdfast of another crinoid attached to it.
Mission accomplished as far as the crinoids go!