View from bottom of the wadi I called ‘Grand Canyon’ in Oman, near Juwaif.
This was one of my favorite places to visit . . . the drive down the steep track into the wadi bed was always fun, as was the equally steep track on the opposite side.
For those interested in the geology of the area, Grand Canyon offered an ideal site to see the different layers of conglomerate and the relatively loose material deposited on top over thousands of years.
In the wadi bed, there were often small pools with wadi fish and toads; was always a mystery where on earth these critters came from between wet seasons.
The view down the wadi towards the ‘white triangle’ that marks the spot where the wadi crosses the Juwaif road the first time; it crosses back and forth a few times before merging with Wadi Sha’arm.
Like wadis everywhere in the Hajar Mountains, one side was featured the conglomerate, the other the solid bedrock. The water always found the line of least resistance: the interface of the bedrock and the conglomerate.
Each geological period featured a different recipe of conglomerate, and so various layers of cemented material.
Within the bedrock material, any crack was filled with material that had been extruded ages ago; often the material was magnetite but in other instances softer material had filled the cracks. The pressure exerted to fill the cracks must have been enormous.
The view from slightly above the floor of the wadi, showing the various layers of conglomerate (right) above the bedrock. Feral date palms and assorted bushes and trees survived as there was usually water just a short below the wadi bed.
Some years the small pools lasted almost all summer, though more often than not they were gone by June. If the wildlife was fortunate, they lasted long enough for the frog eggs to hatch and the tadpoles mature though, some years, there was a mat of dried carcasses at the bottom of the pools.
In side channels, one often found pools that survived later into the season as they were not exposed to direct sunlight. In late winter, these were ideal for a quick swim; later, because there was no fresh water, they were unsafe for swimming.
Detail of one layer of conglomerate, the wadi stones cemented in place. It is likely that ancient occupants noticed the natural cementing of the material and began experimenting, leading to the production of ‘Omani cement’, sarooj, which was manufactured in great quantities for falaj systems, houses, and other structures. At least two sarooj factories, using traditional production means, were in operation during my time in Oman.
The wadi beds were the natural highways for some travelers and explorers as the wadi bed was flat and consisted of gravel. However, the footing would have been too difficult for camels, though donkeys could have managed. Getting in and out of a massive wadi was sometimes tricky but trails in the mountains included sets of marker stones to show where it was safe to drop down into a wadi.
Sections of Grand Canyon were well used. Some used short sections of Grand Canyon when crossing from one side to the other, using steep access roads. Beyond Grand Canyon there were a number of farms. Though there were alternative access routes, for some farms crossing Grand Canyon offered the shortest route. When the swimming hole was large and fresh, there would be considerable traffic after Friday prayers.
The dark gabbro was common throughout the Hajar Mountains. The other common rock was ophiolite. The geology of Oman attracted geologists from around the world as such deposits are relatively rare. The limestone cap that made ‘The Swiss Mountains’ so recognizable was another feature of the geological history of the region.
My trusty Nissan parked at the pool, the furthest one can drive upstream from Wadi Sha’arm. The pool is as close to a permanent feature as you can find in that section of Grand Canyon as the location is a choke point with hard gabbro on both sides of the wadi, creating a relatively narrow channel.
This year (2010) the pool was relatively deep and clean; a few seasons later the debris washed downstream had filled it almost completely.
The natural barrier at the pools.
The choke point where the pool is located. The exposed gabbro below the pool is smooth from thousands of years of wadi flows containing sand, gravel, and stones.
A small, secondary pool, just below the larger swimming pool. The dark gabbro ‘dam’ below the pool is visible.
A farmer using the wadi to cross to one of the farms in the foothills.
At the bottom of the vertical (right), a small depression where, in winter, water would have collected and, perhaps, a new generation of frogs were born.
View from the edge of the wadi looking north towards Juwaif.
The oasis of Juwaif visible (left) with ‘Grand Canyon’ on the right.
View upstream from ridge; over the years I enjoyed many of the wadis that fed ‘Grand Canyon’, always full of fresh water.
View from ridge; fails to portray the depth and majesty of the wadi.