Wadi Hajir

October 2009

 

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Wadi Hajir cuts deep into the heart of Oman's Al Hajar Mountains. It joins the bigger wadi Bani Kharus near the village of Awabi, some 31 km from Nakhl.. Old villages, deep gorges and great views.

Also known as Wadi Hijir


Wadi Hajir is geologically famous for its age-old rocks exposing what is known as "snowball earth", some 600-700 million years old. The lower parts of the wadi consist of Precambrian rocks, starting with the "snowball earth" glacial rocks, overlain by an about 100m thick and massive limestone package (the Hajir Formation, equivalent to the Khufai Formation). Wherever exposed in the Oman Mountains, this massive limestone is characerised by narrow and deep gorges, with the most famous being "Snake Gorge" at the end of wadi Bani Awf. Wadi Hajir also features spectacular gorges cutting almost vertical through this limestone package. Above these hard rocks, dominating the wider valley in wadi Hajir is a much softer package of shales (Mu'yadin or Shuram Formation). These rocks split easily, sometimes along one single flat surface, but more often along several surfaces, resulting in pencil-shaped slivers of shale. High above the wadi tower massive carbonates again (Saif or Khuff Formation), with vertical steep cliffs rising to 1500-2000 metres altitude. These rocks are some 300 million years old. A good observer will see that the shale beds below have a different angle than the massive carbonates above. The contact between these units represents a whapping gap of some 200 million years in time. The same contact is a spring line, where water contained in the porous carbonates above meets the impermeable shales below and slowly seeps out. Most of the villages in the mountains get their water from these springs flowing along ingneous age-old stone channels (falaj) into the gardens below. Nowadays one sees more and more thick plastic pipes as these are easier to construct and maintain than the stone falaj channels.
The main goal of our visit was a huge cave in the Hajir limestones that my accompanying friends had spotted before. They had tried to get to the cave by climbing and swimming through the gorge below, but met steep rock faces that would require climbing gear. The plan this time was to climb-up to the end of the gorge and from there try to get down along the canyon to the cave. A great excuse to explore the area. The old path up is relatively easy to follow (see 'how to get there' below) for the first kilometer or so, but beyond that it comes and goes while winding steadily upwards. It is a reasonable strenuous walk, but the views are great. We found the springs hidden in the bushes below the steep cliffs, with several plastic water pipes cemented into the rocks. From there it is easy to get down into the gorge, but again halfway there are several steep drops that require climbing gear. Mission aborted, except for some nice pictures of the cave from above.  

Snowball Earth

The latest Precambrian or Neoproterozoic seems to have been a period in the history of the earth with widespread glaciations, even found at low latitudes and therefore possibly global. The origin of such widespread glaciations has been widely debated and gave rise to the ‘snowball earth’ hypothesis with synchronous, long-lasting (>10 million years), global glaciations, followed by a rapid warming (hothouse) and widespread carbonate deposition. The glaciations observed in the rocks exposed in the core of the Oman Mountains suggest repeated glacial cycles and the verdict is still out whether these corroborate the long lasting global glaciations of the Snowball Earth theory. Polar reconstructions for Oman indicate that the Fiq glaciation in Oman occurred at a low latitude low-latitude (13° calculated for a location at Muscat, Oman) and supports extensive late Neoproterozoic cooling. Deposition of both the glacials and the overlying Hadash cap carbonate took place at the same latitude in the tropics. Other evidence suggests that these tropical latitudes were not continuously covered by ice during the Marinoan snowball episode, indicating less extreme climate models.
Snowball Earth and the early evolution of life.
The Neoproterozoic world, snowball or not, witnessed extraordinary changes from widespread glaciations reaching as far as the tropics followed by rapid warming as recorded by the paradoxical cap carbonates. Earth may have changed from icehouse to hothouse a number of times, stressing the development of early life and possibly jump-starting the evolution of life, ultimately leading to what we know as the Cambrian explosion of life on earth.

To read more about snowball earth and the rocks in the Oman Mountains check-out the references below. Wadi Hajir features very good outcrops of the snowball earth rocks, but further into the main wadi beyond the village of Hajir.

Awabi to wadi Hajir
Google Earth Image
How to get there: Follow road from Nakhl to Rustaq until the village of Awabi ( 23°19'2.64"N,  57°32'22.98"E), some 31km from Nakhl. Follow road signposted to Awabi Fort ( 23°17'58.43"N,  57°31'50.13"E), which is situated at a dominant position at the mouth of wadi Bani Kharus. Turn right into wadi Hajir, signposted some 8km from the fort (23°14'55.66"N, 57°31'35.37"E). Turn left to the village of As Suwayh some 5.5 km from the turnoff (23°12'18.04"N,  57°30'32.26"E) and park your car under one of the big trees near the falaj that crosses the wadi (23°12'14.53"N,  57°30'45.77"E). The start of the path is just beyond the ruins of the old village, passing underneath the falaj and at the left side of the gorge, unless you want to have a bit of adventure getting through the gorge.  Follow the footpath (donkey path) upwards, first staying left of the first gorge, subsequently through the wadi and when you meet an steep drop in front up to the right and subsequently up again. Some 700m from the falaj crossing look for a path sharp-up to the right. This path will take you up and around the ridge to an old path leading to the fortified village some 200 m at the other side of the ridge. You can also follow the path further up, either following the main gorge to the springs below the limestone ridge on top or turning up to a well maintained garden that used to be the home of the "blind honey man, Mohamed Ali". We met a nice old man who called himself Salim bin Ali on his way back home. Family?

Both of these walks are reasonably strenuous and you will need to take sufficient drinks.
Google Earth kmz file for Wadi Hajir

 Please note: all coordinates and tracks are with reference to WGS84, UTM zone 40.
Wadi Hajir detail map 2

At the start of the walk at the village of As Suwayh, parking the car under one of the big trees. Note the concrete falaj crossing the wadi. The gorge and the path up are at the other side of the falaj.

Plenty of rock carvings, many faded with time, some clearly rather new. The smooth limestone surface invites to leave marks and that's what many have done over the years. Mostly camels and people
 

On the way up looking back across wadi Hajir with the village in the middle right and a massive gorge dissecting the rocks. On one of the blocks carved by the gorge is a beautiful old fortified village.  More on that village below

The reason why we climbed up: to get into the gorge, without risky climbing, and explore the big cave below. Coming from below in the gorge requires climbing gear and we concluded that coming from above you will face the same problems.

Cave close-up. Part of the ceiling has collapsed and it does not look like people have used this cave after the rock fall. Whether they did before can not be seen from the distance

The Hajir gorge seen from above with a steady flow of water and some pools. 

The springs at the end of the gorge. Water is seeping out of the rocks, depositing lime that encases the plants as well, creating a porous brownish rock known as travertine or tufa.

Relaxing in the shade of trees and overhanging cliffs with a million dollar view. The track further up is unclear, with huge boulders blocking the way.
On the way down we took a small detour to visit the beautiful fortified village that seems to be litterally sculpted from the rocks. I don't know its name, nor its age, but it must have been built in a time that safety took priority. Getting water must have been a real problem though, unless they would have used a pulley and ropes to lift water from the canyon deep below. The village-fortress would not provide any defense from gunfire from the other sides. Together with the rather eroded access path this suggests that it could be ancient. On the geological map of Oman the back of the area is labeled "Rais Alinah". 'Rais' means 'leader' or 'chief' in Arabic, whereas 'Alinah' could mean 'noble'. This may be tied to the fortified village, which could well be the base of an important leader with the organisational power to build this fortress village.

From above one hardly notices the deep gorge cutting its way down

The gorge has cut a pinnacle of rock deep down at three sides and partly down at one side. This massive block features a fortified abandoned village on the top. The vertical rock faces would have made this a natural fortress, but getting water may have needed a daily climb down or perhaps pulleys and ropes.
Above: close-up view of the fortified village. Notice the defensive wall facing the one side that is still partly connected to the adjacent hill. A narrow path can be seen from lower left up to the middle of the picture where a gate must have been.

Right: frontal view of the fortified village, almost blending with the surrounding rocks. The vertical rock face and the wall on top must have been a formidable defense.
 
 
Man made hole (about 15 cm across) in the rock more or less in the most prominent position in the village. Similar holes I have seen in other Omani fortified villages such as on top of Ghul and Hawra Burgha. Its function is unclear.
 
Most of the walls of the houses in the village still stand to man-height. The rock slabs are very suitable for drystone walls, with larger blocks used as linters for doors and the rather small window openings
 
Impressive and well-built walls, but no sign of pottery, nor of water cisterns.
 
The top of this slab is concave, worn down. Probably by using it as a base for grinding. Some hand-size round pebbles can be found scattered in the houses and may have been used as grinding tools.
 
The main building at the highest point, with the "hole in the rock" more or less in front of the main entrance.
The village has a defensive wall at the side that allows access. It does not have any surrounding walls at the other sides. Obviously the steep canyon would provide the best possible defense. But this may also imply that it was built before guns made their way into Arabia as it would be easy to shoot into the village from across the canyon. Despite its relatively fresh look, the village may be rather old. The solid walls will stand the test of time, safe above any floods. This is not the case for the access path to the village, which clearly suffered from floods, washed away and buried below big boulders.

In the canyon beyond As Suwayh  village one can see the concrete modern falaj but carved in the rocks below is a much older falaj channel. This is partly used as a base for the supporting wall of a yet higher falaj. An impressive feat, getting this falaj fixed on the vertical canyon walls. The same falaj crosses the wadi on an old and fragile looking bridge. The path through the wadi passes below and subsequently along the right side following a narrow ledge, smoothly polished by hundreds of years of use.
   
  Above and left.
Time to leave the wadi as dark clouds accumulated, accompanied by the sound of thunder. Minutes later it started to rain. We just made it back to the safety of Awabi fort when streams and waterfalls started to run down the wadi.
With thanks to Flora, Paul and Alasdair for introducing me to this rather nice corner of wadi Hajir.

References (Geology)

  • Hoffman, Paul.F. and Daniel P. Schrag, 2002, The snowball Earth hypothesis: testing the limits of global change. Terra Nova, 14, 129-155.
  • Knoll, Andrew H, 2003, Life on a Young Planet, the first three billion years of evolution on earth. Princeton University Press. ISBN  0-691-00978-3
  • Walker, Gabrielle, 2003, Snowball Earth, the story of the Great Global Catastrope that spawned life as we know it. Crown Publishers New York. ISBN 0-609-60973-4
  • Leather, Jonathan, J, 2001, Sedimentology, chemostratigraphy and geochronology of the Lower Huqf Supergroup, Oman. PhD Thesis, University of Dublin.
  • Le Guerroué E., P. Allen and A. Cozzi, 2005, Two distinct glacial successions in the Neoproterozoic of Oman, GeoArabia, Vol. 10, No. 2, 2005.
  • Leather, J., Phillip A. Allen, Martin D. Brasier and Andrea Cozzi, 2002. Neoproterozoic snowball Earth under scrutiny: Evidence from the Fiq glaciation of Oman. Geology, v 30; no. 10; p. 891-894.

References (Visitor)

  • Grist, M.,  2006. Oman Offroad  Explorer. www.Explorer-Publishing.com  
  • Hatim Al Taie, John Pickersgill & Nasser Al Taie, 1999 ‘A Comprehensive Guide to the Sultanate of Oman

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@ J. Schreurs November 2009