Archive for March, 2012

Wooster Geologists as guests in a Bedouin village

March 17th, 2012

MITZPE RAMON, ISRAEL–Melissa and I had a fantastic day, much of which will stretch over at least another couple of blog entries. We traveled to the Dead Sea region with our Israeli geologist colleague and friend Yoav Avni and his wife Noa (an education specialist and botanist). We saw extraordinary things at the Dead Sea itself, and then on the way back we visited with some Bedouin friends of the Avnis in a tiny village of three families a few kilometers north of Mitzpe Ramon. In the image above we see the family patriarch Ali, one of his sons, and two visiting neighbor boys. We are gathered around glowing coals in their tent — welcome warmth in the cold. Note that we have just been served sweet Bedouin tea in glasses. (Empty your glass and it is immediately refilled.)  Ali, Yoav and Noa conversed in Hebrew and occasionally translated for us the stories Ali was telling in a very animated way. Melissa and I later commented to each other how interesting it was to watch a conversation we could not understand. So many moving hands!

We were served this Bedouin goat cheese. It is very hard so you nibble off small bits. It is also very salty, so the tea was quite welcome!

This is the inside of the tent. It is made of diverse materials, including cotton sheets and canvas. The rugs are laid on packed soil.

Ali wanted to demonstrate for us the traditional Bedouin way of grinding wheat grains between two carefully-fashioned limestone disks. Here he is adding grain to the hole in the top block.

Ali is rotating the top stone across the surface of the bottom stone with an inserted stick. The limestone must be coarse enough to grind the grain and hard enough not to add rock to your meal!

Here is the product — whole-grain flour! They often mix this with warm water to make a simple porridge.

This is a view of the small village from Ali’s tent. The buildings are made from diverse materials. In the foreground is a donkey pen.

We enjoyed this brief cultural moment very much. The Bedouin are in transition from their original nomadic state to settlement. Ali and his family wish to preserve some of the old ways to educate others (like us) and pass down traditions to succeeding Bedouin generations who will not know life in a tent.

A tribute to our Garmin Montana 600 GPS

March 17th, 2012

MITZPE RAMON, ISRAEL–This isn’t a product review — it’s a love note. We’ve mentioned our field equipment on this blog before, most notably while using iPads in Estonia and Iceland. I just want to express a little gratitude for the technology and national effort that brought the Garmin Montana 600 GPS into my needy hands. (And to thank the Luce Fund at The College of Wooster for buying it!)

You can find many formal reviews of the Garmin Montana online, and some excellent instructive videos on YouTube. As usual with my electronic gear and fancy software, I use less than 10% of their actual capacities. I need a GPS to record sample locations, remember where I parked the vehicle, and figure out how to get from here to there before sunset. The Garmin Montana has made all of this so much easier and intuitive than with my many past GPS devices.

The Garmin Montana is touchscreen-operated, which makes a huge difference when you need quick measurements and want to record waypoints. The screen is also plenty large and in color. I can now record a waypoint and then edit its name (015 becomes “camels be here”, for example). I can also add a long note to each waypoint, all done with a qwerty typepad in landscape mode. So easy. The map and go-to functions are also easily accessed and used. There is a real magnetic compass inside to supplement the one based on the GPS system. There are many other extras, from waypoint averaging (increasing the accuracy of a waypoint) to sunrise/sunset local times, a calculator, alarm clock, stopwatch, calendar … you get the idea. You can even use the device to pace out a polygon and measure its area.

I use a free app called “Garmin BaseCamp” on my MacBook Pro laptop to download and upload waypoints and other data through a USB cable supplied with the GPS. This can include photos for reference in the field. There is also a free software program to connect your device to the Garmin website to receive updates and new free gizmos. (My previous GPS systems did not like the Mac — this one uses the interface quickly and easily.)

Melissa is currently using my old Garmin because of all its stored waypoints from Israel, so we’ve been able to see the two devices in action together. The Garmin Montana receives data from the satellites much faster, and I suspect it is more accurate. My test is to stand at an easily recognized point and take a measurement, then look at it on Google Maps. Above you see a Google Map view of an acacia tree along a wadi in Makhtesh Gadol. I stood beside it and took the measurement shown by the green arrow. At most there is a meter or so difference between where I was standing and what is indicated, so Google Maps has a little correcting to do!

Glorious blue skies emerge in southern Israel

March 17th, 2012

The first photo below was taken from my hotel room yesterday afternoon as the cold wind raged and rain approached. The second was taken this morning. Springtime in Israel!

We are now leaving on a trip to the Dead Sea with Yoav. It is always a privilege to travel with him, but this is extra special because he is one of Israel’s top experts on the Dead Sea and surrounding region.

Iron Age water management in the northern Negev

March 16th, 2012

MITZPE RAMON, ISRAEL–This region has a very deep human history, and some of it is evident in subtle changes to the landscape itself. Throughout the northern Negev are simple stone structures that are sometimes called “Davidic forts” after King David of Israel. They are, though, a lot more mysterious and difficult to date. They are usually associated with cisterns and water systems, and so they may have indeed been guardposts of some kind. Who exactly made these buildings and the water infrastructure is unclear. All we can say is that they are Iron Age and show an early agricultural people who had skills in collecting and managing the scarce water resources of this area. We saw evidence of them today in the field north of Mitzpe Ramon. Above you see Yoav and Melissa walking by one of these open cisterns cut into Upper Cretaceous limestone (the Vroman Bank of the Ora Formation) and then dug below in shale and claystone.

The hillsides to the sides and above these cisterns have long ditches lined with slabs of limestone on their downward sides. These were designed to catch runoff water from the slopes above and direct it to the open cistern below. Some of these ditch-and-rock channels stretch for kilometers.

Here a ditch heads to a large cistern, recognizable immediately by the sediment tailings dug out of the hole. This system takes advantage of the heavy and infrequent rains in the northern Negev. Sheetflow and water in small natural channels is captured and sent along the gentle gradient to the cistern below. By keeping the water from flowing too fast these early engineers minimized erosion of their channels.

This is the second cistern we saw today. It is many meters deep and could have held a great deal of water year-round. Bedouin herders today still use some of these cisterns for their flocks.

The later Nabateans elaborated upon these innovations and made roofed cisterns to reduce evaporation (which is 2.5 meters of water per year in Mitzpe Ramon). Sometimes they dug their cisterns into solid limestone rather than shale so they could have a small top opening and large covered container below.

As I write this the wind howls and rare rain is falling on the Negev. These rock systems are still channeling water after 3000 years!

Desert Tulips!

March 16th, 2012

MITZPE RAMON, ISRAEL–These were a delightful surprise this morning. Scattered across the rough Cretaceous limestones were these astoundingly red desert tulips (Tulipa systola). They looked like drops of blood across the landscape. (An unfortunate metaphor in this part of the world, but true nonetheless!) They are so red they even overwhelm the red distinctions in my digital images, making them just glow like light bulbs.

These tulips are very sensitive to soil moisture. Because of the drought, Yoav was impressed we saw any, let alone dozens. All appear to be nestled between rocks which might have preserved just a tad of moisture for their growth. Many other tulip plants can be seen in the area, but only a minority are flowering.

Hard to believe with these warm, bright colors that we were freezing in the wind as we admired them!

A windy, windy day in the Cretaceous

March 16th, 2012

MITZPE RAMON, ISRAEL–Melissa and I finished our work in the Jurassic of Makhtesh Gadol yesterday, so today we went out with Yoav to explore the Upper Cretaceous and Eocene exposures just a few kilometers north of Mitzpe Ramon. This is what we do near the end of each expedition so that we have more ideas for the next. It was cold and very windy on the barren hillsides this morning, but we still saw and learned a great deal.

We examined outcrops of four units: The Ora Formation (Upper Cretaceous) is primarily shales and claystones and below the stratigraphic column shown above. It has an interesting limestone unit composed mostly of rudistid bivalves and their shelly debris shown later below. The Gerofit Formation, also Upper Cretaceous, is a mix of limestones and marls unconformably above the Ora Formation. The Mishash Formation (Upper Cretaceous again) is a chert-rich unit unconformably above the Gerofit here. Andrew Retzler and Micah Risacher, who worked in the region two years ago, will immediately ask, where are the Zichor and Menuhah Formations that are supposed to be between the Gerofit and Mishash? They are absent due to a deep unconformity. On top of the Mishash, above another significant unconformity, are nummulitic limestones of the Avedat Group (Eocene). These three unconformities are all structurally and paleoenvironmentally significant — and they no doubt will be future projects for Wooster Geologists.

Some items of interest in this long section. Just below the Vroman Bank in the Ora Formation is the above cemented horizon with well-distinguished Thalassinoides burrows. These were produced by crustaceans burrowing into stiff mud in shallow waters. This unit is usually not very well exposed, but Yoav and I dropped down into an ancient cistern to see this outcrop.

This is a polished surface at the top of the Vroman Bank in the Ora Formation. Erosion in a small wadi over the centuries smoothed it off. We can see here borings known as Gastrochaenolites, some with outlines of bivalve shells still inside them. This is thus a carbonate hardground.

Some of the units in the Gerofit Formation are lithographic limestones, meaning they are very fine-grained and of uniform composition. You can see in the above photo that the stress pattern around my hammer blow is preserved as a nearly perfect sphere. This rock has been the premier building stone in Israel for millenia. It is known as “Jerusalem Stone” because so many buildings in that city are made of it and its equivalents.

Melissa is standing in what appears to be an ancient quarry for the lithographic limestone. There is a small Iron Age fort made of the stone nearby. Note how bundled up Melissa is. Not the usual image of Israel in this blog!

Finally, all our localities today were on ground that has been part of an IDF training base for decades. There is much discarded military gear around. I thought I would add this old British tin-hat to our blog’s collection of shot-up helmets! (We have German examples already, and somewhere in there is a Russian set.) I neglected to take a photo of a well-worn Egyptian helmet we found this morning.

The Dancing Flowers of Makhtesh Gadol

March 15th, 2012

MITZPE RAMON, ISRAEL–It was difficult to coax them into standing still long enough for their portraits. The wind kept everything moving, so for some of these shots I held the camera in one hand and used the other as a windbreak for the blossoms. It was not easy to do this and not block the weak sunlight gamely penetrating through the dust above. Most of these flowers were in wadis where enough moisture persists to give them a chance for life. The Negev is in a severe drought, so every one of these flowers is a gift.

I do not know their names. Maybe an Israeli friend or two will post them in the comments and I will amend the text? I’m also not using my usual composite photograph technique for these images. Since space is cheap on this blog, why not use the whole frame for such little splendors?

[Please see the comments below by Wooster's intrepid botanist and plant ecologist, Lyn Loveless. Very helpful!]

This tall yellow flowering plant is found near water holes in wadis. It is not especially common — I’ve only seen three. It might be Broomrape (Cistanche tubulosa), a parasitic plant that taps the roots of other plants.

The plant above has flowers that appear to mature first at the base of the plant, with the youngest at the top.

These flowers (and the little insect) are found on a bush with very thin, almost leafless branches. It looks a bit to me like a pant we call “Mormon Tea” in the Mojave Desert. It may be White Weeping Broom (Retama raetam), which is an invading pest in North America. This is supposedly the bush under which the prophet Elijah sat.

A beautiful little blue flower emerging out of dried mud on the bank of Wadi Hatira. Lyn identifies it as Anagalis arvensis (Scarlet Pimpernel), a cosmopolitan species. I can add that it is probably Forma azurea because of the blue color and Mediterranean location.

A small purple flower common on the windswept higher regions between wadis. Lyn thinks it might be Erodium telavivense.

Another small purple flower common along the wadi banks throughout the makhtesh.

Surely this is a white daisy!

And this must be a yellow one!

Finally, my favorite Negev flower of all. This beauty was rare on our hiking routes. I found only three, all in Wadi Hatira along the edge of a dried-up waterhole. With Lyn’s help identifying this as not an orchid but an iris, we now know it is Gynandriris monophylla. Thanks, Lyn!

What a privilege it is to be a natural scientist and have a chance to experience such wildlife as part of my profession.

A field day cut short by angry camels and a threat of rain … but at least the dust is gone!

March 15th, 2012

MITZPE RAMON, ISRAEL–Compare the image above to the one taken in the same place two days ago. Much better! Our only dust today was a local product from the unending winds. The Saharan dust is gone. We paid for this clarity, however, with a dramatic drop in temperature. It was 8°C (46°F) when we started work this morning. This is typical for spring fieldwork in the northern Negev. The weather is less predictable, and the temperatures can swing wildly from day to day. The summers are very predictable: sunny, hot, dry, and not a breeze. I don’t take my hat’s chinstrap in the summers, but in the spring it is tied firmly all day.

Our goal today was to travel as far south as we could along the strike of the Matmor Formation, sampling “subunit 51″ when we could. Melissa and I walked into the makhtesh about five kilometers. This was not a long distance, but in the summer we just couldn’t carry enough water to pull it off without a four-wheel drive vehicle.

We walked south from the Negev Minerals mine, where we park, along an old pipeline road until we reached Wadi Hatira (shown above). This is the wadi that drains the makhtesh through its single opening in the northeast. It is the greenest zone in the structure because it has the most soil moisture. There were some beautiful flowers along its banks, photos of which I’ll post later. From the wadi we climb up to the old British road and continue south into the Matmor Hills.

Melissa is standing above at the base of Subunit 51 of the Matmor Formation (Middle Jurassic). This is typical of its exposure in the central part of the makhtesh where there is higher relief in the Matmor Hills. The unit is difficult to follow because of an abundance of small faults cutting perpendicular to strike. Its marly nature means it is often covered with debris from the units above. The northern outcrops have lower relief, which in our case means we have more gentle slopes to search for fossils.

Around noon we ran into a camel herd wandering around our outcrops. (The most active of the beasts is shown above.) They had calves with them and were immediately disturbed by our appearance. They started to make angry camel noises. We did not want a run in with riled-up camels, nor did we want to give their Bedouin herdsmen any reason to think we were harassing them. Since the camels weren’t going anywhere, we reluctantly turned around and headed back.

To aid our decision to retreat, the skies looked very threatening (see above). Rain? Who would have thought? We could smell rain and see what looked like rain to the northeast. We did not want to be in a big rock bowl if it really did pour, so we hastened back to the car. It didn’t actually rain on us, but it may have in the makhtesh after we left.

We got a minimum amount of work done today, though, so it was not a loss. Now we’re back in our warm rooms listening to the wind continue to howl outside.

Wooster Geologists in the Wilderness of Zin

March 14th, 2012

MITZPE RAMON–Three times we cross Nahal Zin (or Wadi Zin) on our way to Makhtesh Gadol from Mitzpe Ramon. Nahal Zin is an intermittent stream, meaning it is dry most of the time, but during the rainy season can have a considerable flow, even to the point of flooding. I’ve always seen it bone dry. Nahal Zin is 120 kilometers long with impressive canyons in its upper region and meandering channels in its lower parts. It is the largest wadi that begins in the Negev.
The significance of Nahal Zin is that it is the defining feature of the “Wilderness of Zin” from biblical times. There is still some dispute about its location among biblical enthusiasts, but experts agree that it is essentially the northern portion of the Negev. The passions among the amateurs have much to do with the historicity of the Exodus events. This region was explored by T.E. Lawrence just before he became Lawrence of Arabia.
Google map image of Wadi Zin near Avdat. The red asterisks mark where it crosses Highway 40.

The Wilderness of Zin was on the southern border of Judah and is mentioned several times in the Hebrew Bible. Here are three:

“So they went up, and spied out the land from the wilderness of Zin to Rehob, to the entrance of Hamath.” (Numbers 13:21)

“The children of Israel, even the whole congregation, came into the wilderness of Zin in the first month: and the people abode in Kadesh; and Miriam died there, and was buried there.” (Numbers 20:1)

“The lot for the tribe of the children of Judah according to their families was to the border of Edom, even to the wilderness of Zin southward, at the uttermost part of the south.” (Joshua 15:1)

(Courtesy of Biblos.com)

During our work in the Negev we do not usually see much of biblical relevance, so living and working in the Wilderness of Zin reminds us of just how deep the human history here runs.

A silent desert friend on the outcrops

March 14th, 2012

MITZPE RAMON, ISRAEL–This exquisite snail is not a fossil, although students in the field often mistake it for one. (Melissa did not, I quickly add.) It is a terrestrial, air-breathing pulmonate snail called Sphincterochila boissieri. It is abundant in parts of the Negev and the Sinai Peninsula. Its shell is relatively thick for a land-dwelling mollusk, so it becomes a common constituent of the desert soil in certain habitats.
Sphincterochila boissieri is well adapted to its desert environment. It has a predator-resistant shell with a small aperture to reduce moisture loss. With its white color it reflects significant amounts of solar energy, staying relatively cool. (Compare this to the black ground beetle in the last post. It is most active in the winter and stays in shady areas during the summer.) They are active for only a few days during the winter rainy season, doing all their feeding (on algae, moss and lichens), mating and egg-laying. For the rest of the year they stay dormant, often in the soil or attached to rocks and woody plants. While dormant, they pull all the way back into the second and third whorls of their shell to stay as moist as possible. They can survive droughts, and thus do no feeding, for at least six years.

So, S. boissieri may not be one of our fossil targets, but it is a silent (and completely unmoving) companion during our fieldwork. It has our respect!

References:

Yom-Tov Y. 1971. The biology of two desert snails Trochoidea (Xerocrassa) seetzeni and Sphincterochila boissieri. Israel Journal of Zoology 20: 231-248.

Shachak M., Chapman E.A. and Orr Y. 1976. Some aspects of the ecology of the desert snail Sphincterochila boissieri in relation to water and energy flow. Israel Journal of Medical Science 12: 887-891.

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