Site visit to United Arab Emirates island
IGS senior specialist geoscientist Dr. Christoph J. Dobmeier took part in a pre-tender site visit on one of the islands of the United Arab Emirates in the Persian Gulf from December 11 to 13. 2024.
The round to elliptical shape of many of the islands gives a direct indication of their geology, as they expose parts of salt-piercement structures. All associated rocks of these structures form the Ediacaran to early Cambrian Hormuz Complex. A characteristic feature is the presence of megaclasts which can reach several 100 m in edge length. Current U-Pb ages indicate that the megaclasts (volcanic, subvolcanic, volcanogenic and detrital sedimentary lithologies) were not detached from younger units as the salt moved toward the surface. Since the ages match that of the salt, they must have been located directly underneath, above, next to or in between it.
The megaclasts are embedded in the so-called Hormuz breccia, a commonly poorly sorted breccia with a very fine-grained maroon matrix composed of gypsum (and/or anhydrite), quartz, and haematite. A slight salty taste indicates the presence of some halite. The almost complete absence of salt, however, was not expected and therefore a very big surprise. It is best explained by salt dissolution during arid weathering. The widespread occurrence of gypcrete (or gypcrust) supports this assumption. Sedimentary rocks of the Holocene Jebal Dhanna Formation rim the salt structure. While the salt structures were emplaced in Miocene time, the displacement of the Holocene rocks suggests that the salt is still or again moving.
IGS would like to thank the UAE Ministry of Energy and Infrastructure (MOEI) and Sharjah Environment and Protected Areas Authority (EPAA) for the invitation and their hospitality during the visit.
Participants of the site visit including IGS senior specialist geoscientist Dr Christoph J Dobmeier (standing, 3rd from right)
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IGS Team at FMF25 in Riyadh and Dr Feargal Murphy Speaking at Knowledge Exchange Program in the conference
Dr Feargal Murphy, Principal Geophysicist at IGS, was one of the Knowledge Exchange Program Speakers at a workshop on the first day of FMF25 in Riyadh.
His presentation was on an overview of the SGS (Saudi Geological Survey) RGP airborne Geophysics project in Saudi Arabia and he presented preliminary data examples to demonstrate the hugely increased resolution of the data compared with legacy data. Some of this data is available for free on the National Geoscience Database portal.
IGS Ltd also turned out in strength for FMF2025 in Riyadh Saudi Arabia. It was great to meet so many clients at the IGS booth. The exhibition continues to grow in size and quality every year and this was reflected in the volume and focused nature of many visitors who visited our booth.
Dr Feargal Murphy speaking at Knowledge Exchange Program workshop during FMF25 in Riyadh
From left Dr. Rowan Vernon, Dr. Ashley Johnson, Dr. Feargal Murphy, Dr. Peter Zawada
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