Mark Wilson April 11th, 2014
MITZPE RAMON, ISRAEL–Today Yoav and I worked on the outskirts of his hometown. This was a field trip that began in his garden and then we wandered into the hills behind his house, eventually circling this little city to return to his house. About half the journey was along the cliff of Makhtesh Ramon, so the top image is a view from north to south. It is geologically inspiring to see this site every day.
After looking at the Avnon Formation for a bit (with its newly-found corals) and the Zafit Formation (with silicified tree trunks), we settled into our special mission to sort out stratigraphic issues of the En Yorqe’am Formation (Upper Cretaceous, Cenomanian). It was a lesson for me in how much a formation can differ in a few kilometers. I would not have recognized it from our explorations earlier this week. The above is a view of a new housing development and an excavation exposing the top part of the En Yorqe’am.
This is a closer view of a mysterious silty dolomitic layer in the En Yorqe’am at the housing development. We’ve seen nothing quite like it in the other exposures of the unit. There is also below this what looks like a recrystallized biosparite showing the bedding associated with submarine dunes.
A key feature of that strange layer is the presence of these calcite-filled cavities. They appear to be formed from original anhydrite nodules, which were produced under hypersaline conditions. This is something we saw in the unit at Hamakhtesh Hagadol.
The solution to the stratigraphic dilemma of the En Yorqe’am is the position of what we call the “grey layer”. This means we have to examine it wherever it is, including on the edge of the makhtesh. “Like a sidewalk, but in the sky.” I wasn’t happy about our hike to that little point of rock, but it really was perfectly safe. And it was worth the effort because we found characteristic features to add to our analysis. It certainly was a fantastic view from there!
Mark Wilson April 11th, 2014
MITZPE RAMON, ISRAEL–Early Wednesday morning Yoav had a special mission to perform before we began our fieldwork. He had been asked by a botanist to get a sample of a new species of plant endemic to Makhtesh Ramon. The botanist needed it for a DNA study to confirm the species designation and link it to other related plants. This plant is a member of the Capparis genus, the most common species of which (Capparis spinosa) is a common site in our Negev field areas. C. spinosa is shown above growing in cracks of a limestone outcrop in Wadi Neqarot. (Remember that lifestyle!) The common names for the plant are the Thorny Caperbush or just Caperbush. This is where capers grow. Who knew? Here are Yoav and Yacov looking at a specimen of the new species of Capparis. It grows only on the thin soil developed from gypsum exposures in the Triassic section of Makhtesh Ramon. This sulfate-rich sediment is very difficult for other plants to take root, so this species has some valuable adaptations to the geochemistry. Note there are very few other plants around it. The plant shows mostly dead growth from previous years, with the spring sprouting visible in the lower left. Yoav is cutting some sprigs for the sample. There are several other plants in the vicinity, so we’re not endangering the species! All for science.
The cuttings of the Capparis plant. Note the recurved spines beneath the branching points for the leaves. For some reason the botanist wanted these samples wrapped in newspaper, not placed in a plastic bag.
Here is Capparis spinosa in one of our wadis. It is a mostly upright bush with beautiful white flowers.
A Capparis spinosa flower. Delicate and sweet-smelling. The fruit of these flowers are the capers that are harvested both in the wild and from cultivated varieties.
Now where have we seen these caper bushes before? Why in the Western Wall in Jerusalem. I’ve wondered what these are and where they come from. Turns out they are natives of the Middle East and particularly like growing in the cracks of limestone walls, either natural or artificial. Cool.