Stuck in the Sabkha Mud EarthCache

This cache has been archived.

Carbon Hunter: The Winds of Change are a blowing - and that was not Aeolian action that covered the area in Sweihan sand (ideal for building!!!!).

Progress continues and more areas are built up as Abu dhabi expands.

A good day to end this cache as the Mayan Calendar closes out (now you know what was really going to end - the life of this Earthcache) :)

More
Hidden : 3/10/2009
Difficulty:
3 out of 5
Terrain:
2 out of 5

Size: Size: not chosen (not chosen)

Join now to view geocache location details. It's free!

Watch

How Geocaching Works
Looking for a different adventure?

Please note Use of geocaching.com services is subject to the terms and conditions in our disclaimer.

Geocache Description:

A flat area of sabkha at the end of the Mussafah channel. Best accessed from the Officers City side – although it is possible to gain access from the Mussafah side.

Sabkha is an Arabic name for a salt-flat that has come into general use in sedimentology following classic research in the United Arab Emirates of the Arabian Gulf in the 1960s and later. The flatness is controlled by the content of capillary moisture from the water-table, which is only about half a metre (one and a half feet) down, keeping the sand damp and firm and preventing it from being blown away. Any higher dryer sand can be moved away by deflation.
They often appear to be ideal for driving over being wide and flat but their appearance is deceptive. They are composed of areas of saline sand or silt, lying just above the water table and generally deposited over a long period of time by the action of wind-blown sand falling into areas of low sea. Their flatness is controlled by the humidity associated with the presence of the relatively high water table which, commonly, is about half a metre below the surface. During the rainy season it is advised to proceed with EXTREME CAUTION. The location is easily reached with a saloon car but caution should be exercised at all times. I suggest parking on the tar road and walking – I purposefully made the cache location very close to a tar road for this reason. A gentle sunset stroll is recommended.
Our sabkhas may look dull, but they’re the salt of the earth by Peter Hellyer
It is, I suppose, an aspiration of every country to have something about it that is unique and that is of real international significance. These features may be man-made, such as the Pyramids, or Big Ben, or the Statue of Liberty; they may be natural, such as the River Amazon, or Mount Vesuvius in Italy, or Uluru (Ayers Rock) in Australia. We have them too in the Emirates and I would like to draw attention to an aspect of the UAE’s natural environment that is both unique and of international importance: the sabkhas (salt flats) that stretch along the coastline of Abu Dhabi from the northeast to the far west.
They’re boring to look at, at least for the casual passer-by: an apparently featureless, flat landscape stretching back from the shoreline, sometimes for 20 or more kilometres inland. And they are indeed flat: it has been suggested that they are actually 10 times flatter than a pancake. No trees grow here naturally (though some have been planted along the highway) and they lack plant life. After rainfall they are highly treacherous: many a vehicle and many a camel has become bogged down in them. They look, to be honest, of very little importance.
Abu Dhabi’s sabkhas are, in geological terms, “carbonate-evaporite depositional environments” formed by the interaction between the highly saline water table just beneath the surface and the grains of sand. They appear to have begun to form around 6,000 years ago as a result of a gradual decline in sea level from a high point about two metres higher than at present, and have gradually extended outwards, linking up with offshore islands such as those that form the outer core of the Dabb’iya peninsula. They have extended inland, too, as the surface sand is blown away down to the wet zone just above the water table. It is a complex and a fascinating process (to geologists anyway).
Geologists who have been studying our sabkhas tell me that they are one of the few places in the world where the interplay between two different processes of sedimentation – carbonate and evaporate sedimentation – can be studied. Indeed, our sabkhas are actually the best place in the world to study this geological process. They are, quite simply, unique.

As a result, geologists from all over the world come to Abu Dhabi, many on trips organised by leading oil companies, since our sabkhas also provide important insights into how oil and gas reservoirs were formed millions of years ago.
Two particular areas are of enormous scientific interest. One is west of Abu Dhabi, opposite the island of Al Qanatir, just beyond the Dabb’iya peninsula. Here geologists can study the gradual transformation of the surface for over a kilometre stretching inland from the shoreline, and if they dig down they can look at the processes by which crystals of gypsum and layers of a white, sticky mineral known as anhydrite are formed.
The other area of special importance is at the inner end of the Musaffah Channel, cut from the sea into the sabkha 20 or so years ago. Here a vertical sequence is displayed that shows the structure of the sabkha sediments deposited during the last major sea level rise and the subsequent fall, around 6,000 to 5,000 years ago. Studies by geologists from ADNOC, ADCO and ZADCO have provided clearly defined evidence of how they were created.
In this sabkha exposure in the Musaffah Channel there is something else of importance: a complete whale skeleton, around 16 metres long. The animal was washed up around 5,000 years ago and its skeleton is the only known one dating from that period anywhere in the Gulf. It was discovered by geologists from ADNOC and an excavation was undertaken early this year by the Environment Agency – Abu Dhabi (EAD), with sponsorship from ADNOC and support from the Abu Dhabi Authority for Culture and Heritage.
These two sites are a perfect training ground for young UAE geo-scientists and petroleum engineers, helping them to understand and analyse the much older sediments deep beneath the surface in which the giant oil and gas fields of Abu Dhabi are found. Their unique importance to scientists all over the world and their educational value locally make the sabkhas a national treasure. Petroleum geologists have long argued for a long time that they should be afforded some kind of long-term protection – a proposal which I wholeheartedly endorse.
But the wheels of the decision-making process appear to be grinding rather slowly, and although the Al Qanatir sabkhas are safe for the moment, since they lie within an oilfield area, the inner end of the Musaffah Channel is at risk from development activity: rubble has already been dumped on top of part of the exposed vertical section, although not yet, fortunately, on top of the whale skeleton, which has not been fully excavated.
I hope that EAD, the Urban Planning Council and other relevant bodies will move quickly to give the site the protection it deserves. We have here something that is of international scientific importance and which, at the same time, provides insights into the way in which the coastline of Abu Dhabi was formed and has been affected by sea-level change, something we need to understand for the years ahead.
They may not be much to look at, but the importance of these two bits of sabkha is real. In terms of the country’s natural heritage, it would be almost criminal to let them be lost.

Peter Hellyer is a writer and consultant specialising in the UAE’s heritage and environment. He has also written extensively on the country’s social, political and economic development
(Ref: (visit link)

In order to substantiate your visit and be able to claim this Earthcache, a number of questions need to be answered and submitted to the cache developer, via e-mail.

You must also post a photograph on the site with your log of you or your team and GPSr standing on the sabkha.

1. Describe in your own words what the crust of the sabkha looks like to the naked eye. The crust is also the “anhydrite” layer.

2. Describe in your own words what the crust of the sabkha feels like when you rub it between your fingers.

3. Look around and describe the gypsum crystals that are visible. BTW: there are much larger examples (probably due to the slower crystal growth rates) further from the sea – especially around Khalifa City in amongst the unbuilt areas where crystals larger than a hand are quite common.

4. Why would it be more dangerous to drive over the sabkha in the rainy season?

5. Give your impressions of the area and some observations that you and your team made about this location (not necessarily related to the sabkha) – and also – did you find the whale? Actually the whale is closer to Mussafah - and has now been "protected" and can not be accessed. Sorry :(

NOTE: You may log your visit prior to approval, but e-mail submissions that do not meet the above criteria will be deleted.

Additional Hints (Decrypt)

Erzrzore gb fraq lbhe rznvy naq ybt n cubgb va lbhe cbfg naq orjner jvgu n iruvpyr jura jrg!.

Decryption Key

A|B|C|D|E|F|G|H|I|J|K|L|M
-------------------------
N|O|P|Q|R|S|T|U|V|W|X|Y|Z

(letter above equals below, and vice versa)


Advertising with Us