Triassic-Mesozoic Field Trip, Saudi Arabia

I know, I know, it's been two weeks since I last posted something! I've got good excuses, really I do.

Last week I went on a field trip to look at Triassic and Jurassic rocks in central Saudi Arabia. More than 70% of the world's booked hydrocarbon reserves are in carbonates...and most of that is in Jurassic shallow marine platform carbonates in Saudi Arabia.

Geologic map of the Arabian Plate. The colors correspond to the age of the rocks exposed at the surface.

Because the Arabian Plate tilted a bit to the east when the Red Sea opened between it and Africa around 40 million years ago, give or take 5 million years, nearly the entire succession of rocks from Neoproterozoic basement to Paleocene is exposed in a series of bathtub rings that get younger and younger as you go east.

This particular field trip is designed around exposures of the very proximal (more landward) parts of the Triassic and Jurassic reservoirs that contain so much oil and gas here in Saudi Arabia.

We stayed in the Sheraton in Riyadh and drove out to the various outcrops and road cuts in a series of very long day trips (we were often out for 10 to 12 hours, which are unusually long days for a show and tell sort of trip like this).

This was my first trip to Riyadh, the capital city of Saudi Arabia (the administrative capital that is, since Mekkah is the religious capital). I'm sure glad I traveled there on Aramco's dime. It was just as dirty and half-constructed as Khobar, only much, much larger. So there's no need to go back!

I learned some really amazing things on this trip. For example, there is "local Saudi beef" sold in the markets but you never see cows grazing. What would they graze on that the sheep and camels hadn't already eaten? So where does this "local beef" come from? It turns out that cows are indeed raised in Saudi Arabia...in underground farms, stacked level upon level. They never go outside. They only see artificial light. They shit and piss on the next level down. Basically all of the "local beef" is veal since the cows never really move. Thank god I only bought imported beef from Brazil but this story has turned me off beef in a big way.

Then we learned that there is a small "high quality" cement plant outside Riyadh. Nearby is a significantly larger "low quality" cement plant. It seems the demand for "high quality" cement just isn't there. This explains a lot...every building that you see under construction is made of cinder blocks that look like they have been stacked together by children: blocks pointed every which way (hole side in, out, to the side), irregular spacing, gaps plugged by rags, newspaper, rubble. Low quality cement will do just fine when that is the general standard of construction.

The lunches were provided each day and for the most part were reasonable. However, the logistics coordinator decided to do a Saudi lunch one day. He showed up with bags of canned tuna, canned olives, peanut butter, honey...and canned cream, canned cheese, and white bread. The Saudis apparently love them some canned cheese. Grab a piece of it with a hunk of white bread, dip it in the canned cream and then honey...yikes! The four westerners on the trip (including me) were pretty appalled by this discovery--the amount of chemicals required to stabilize "cream" and "cheese" in cans is appalling. We stuck to peanut butter. At least we weren't going to starve.

There were three women on this trip, two westerners (me and a Brit) and a fairly westernized Saudi woman. So you might be wondering about bathroom facilities. There are truck stops in Saudi Arabia and they usually have a women's facility. And the mosque in small towns often has a small female prayer room and toilet (except in Mekkah, women are either discouraged or actively prevented from going into mosques in Saudi Arabia). Most of these places were not very clean (the one on the first day was downright appalling) so I tried to pee at our field stops as often as I could. Thank god for hand sanitizer and personal packets of Kleenex.

The fact that women were permitted on this trip is a bit unusual. Government Affairs turned down female applicants for this trip for all of 2010 and 2011, then suddenly relented (actually, our logistics team probably found the right guy to bribe). I knew that I had to go because the opportunity could be pulled away with no warning or explanation.

I'm still working on captions for a Picasa album of my field trip photos. But I'll stick in a few here to give you the basic idea.

Looking at the Triassic Jilh Formation (the dark brown stuff in the hill to the left and the stuff we are standing on). Here in central Saudi Arabia, it is composed of fluvial (river) clastics. In the subsurface, the Jilh is a restricted, hypersaline, lagoonal carbonate.

This is some middle Jurassic carbonate that I can't identify from the photo. Field notes are not at hand.

There is a sword on the Saudi flag, and swords figure heavily in religious and civil government iconography. Islam, the religion of peace. I took this from a moving car and that's all I'm going to say about it.

Some crappy middle Jurassic carbonate that has absolutely no resemblance to its reservoir equivalent to the east. The faint trails are made by camels. Saudi Arabia is lousy with camels, which are free range for the most part. Oddly, I have no photos of them although we saw plenty of them every day.

A suspension bridge over a very large wadi to the east of Riyadh. One of my few attempts at "art."

Dalh Hith. The only known exposure of the Hith anhydrite, an extremely important regional seal for the Jurassic hydrocarbons. Anhydrite is an evaporitic mineral and quickly dissolves when exposed to water. Even though it doesn't rain much here, it rains enough to dissolve most of the Hith exposures. Most of what you see in this photo is the earliest Cretaceous Sudair carbonate; the Hith anhydrite is that darkish material at the base of the cliff.

We were looking at Late Cretaceous Aruma braided fluvial clastics in this quarry exposure when suddenly this Bedouin showed up with his two donkeys (the dark one was the offspring of the white one), his flock of sheep, and three dogs which appeared to be just hanging out with the group. They had absolutely no function in moving the sheep. The Bedouin moved the sheep by throwing rocks at them and waving a staff around.