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The first complete album in the newsBriefsOman gallery has been put together following a request by Bowser, who felt that it would be a public tribute to Don Davison. Don, a hydrogeologist, worked in Oman from 1980 to 1994. Don took all the photos displayed in this album of the coast between Al Hajir and Wadi Misoweyah, on boat trips between January to May 1992, with the exception of the view of W. Khaban Nakhl from the cliff-top, which he obtained from Peter Gibbs. Peter Gibbs carried out field trigonometric surveying on behalf of the Ministry of Water Resouces in the first half of the 1990s.

Don has left no notes other than the cryptic comments on the photos themselves. Or rather, I have only these photos and no notes.

The area under study was the coastline of Oman south of the small settlement of Al Hajir, at the southwestern-most point of Al Daghmar plain, starting at the Big Rubbly Cave extending southwards to Wadi Misoweyah. At distance, looking north from the hills flanking Al Hajir, the Daghmar plain resembles a delta formed at the outlet of Wadi Dayqah (Dhaiqa). The length of coastline that Don was interested in lies due east of the course of Wadi Dayqah, which pursues a generally northeastward flowing course through Tertiary limestone. The wadi course does change direction markedly in places.

Massive bedding of the limestone at the coast, with some incompetent layers, appears from the photos to dip gently north-northeast. Inland, the geological map of the area (BRGM 1992) shows the Tertiary abutting directly against the older Hajar Group, the boundary being demarcated by a major, linear fault. Traced northwestwards, the fault transmutes into a low-level thrust.

I'm told that there is some question about the impact of faulting as opposed to major landslides, as if a regional block of Tertiary rocks had simply slid over the underlying, and older geology, whether directly due to earth movements or because of the effects of gravity and lubrication at the base of the rocks, I simply do not know. I'm not aware that this idea has ever been published, and so you must be aware that it is entirely speculative.

I've mentioned some of the ideas about the hydrogeology of the Wadi Dayqah area in previous posts : Don's Springs, and The dam at Wadi Dayqah. The gallery shows springs emerging from fissures at the base of the cliffs and bubbling up through sands on the shore. A density stratified pool, with a brine of tds 43,000 mg/l at a temperature of 21 centigrade, underlies a somewhat fresher brine with tds 15,600 mg/l at a temperature of 27 centigrade. This suggests mixing of waters from different sources.

Don was generally interested in caves. These photos reveal a series of caves along the coastline above a feature he describes as a 'disrupted zone', marked as D.Z. on several of the photos. The springs emerge from this zone. Perhaps the formation of the caves was due to solution along pre-existing weaknesses in the limestone. Don has left no notes to confirm that this was his hypothesis.

The first two photos in the gallery show the stretch of coast from Al Hajir to Misoweyah. You can put the two photos together at the match line. Five other photos form a panorama from the Big Rubbly Cave extending northwards. There are also a couple of shots of a wavecut terrace and emergent platform, presumably dating from the Alpine deformation during the Tertiary period.

I hope the sketchmap helps, which I have modified from the BRGM memoir to give an idea of locations.



Don't forget that I have added other features at newsBriefsOman, such as a listing of officials, businessmen and businesses in Oman as I come across them in the press, a list of Royal Decrees as I spot them being published, and a list of what I consider to be headlines or interesting articles.