Geology of the Dubai, Sharjah and Sir Bu N’Air 1:100 000 map sheet, 100-5, United Arab Emirates

This Sheet Description describes the Quaternary and solid geology of the Dubai 1:100 000 scale geological map. It includes parts of the major urban conurbation of Dubai and also includes urban coastal areas to the north of Dubai including Sharjah and Ajman and the offshore island of Sir Bu N’Air. The majority of sheet 100-5 is urbanised so that much of the onshore landscape and the coast has been strongly influenced by anthropogenic activity. Dubai’s urban development has been rapid. The growth of the city since the 1970s, has taken place through landscaping of the desert and reclamation of shallow marine, offshore areas through large, offshore island reclamation projects including the Palm islands of Jebal Ali, Deira, Jumeira, and The World. Major residential, commercial and industrial developments exist to the south and southeast of the old towns of Bur Dubai and Deira. Major development zones include Dubailand [330856 2775258], Dubai Sports City [319567 2770083], Tiger Woods Golf [337757 2764545], Dubai International Media City [316500 2769550], Dubai Marina [311853 2774383], Bawadi Residential [328151 2766057] and Dubai Motor City [321979 2771127]. Many of these large scale developments cover areas in excess of 20 km2. Many of the excavations in the development sites around Dubai and Jebal Ali provided excellent exposures of the underlying geology. The best exposures were usually associated with pipeline excavations, especially those related to the extensive irrigation development for the Tiger Woods Golf development. Details of some of these sections are provided in this report. Access to sites concentrated within sheet 100-5 was along major tarmac roads and constructed or partially constructed highways around Dubai. Access was obtained into approximately 80% of all major development and construction sites in Dubai with the exception of the Falcon Residential Development (part of Dubai World), [333116 2777292], and the Lagoons Development [335347 2787940] adjacent to Dubai creek. Some areas, to the south of the major urban conurbations were reached using hard packed ‘gatch’ tracks or generally well used sand tracks. The area was part of the detailed geological survey zone where field observation points were collected at a spacing of 2 and 4 km where exposures and urban development allowed. In some major development sites, the spacing was less than 4 km to reflect the density of abundant geological exposures. Superficial deposits in the major urban areas in the emirates of Dubai, Sharjah and Ajman comprise Quaternary fluvio-aeolian, aeolian and shallow marine deposits. Over much of the area, anthropogenic activity has resulted in the widespread deposition of Made Ground, including engineered fill. Quaternary superficial deposits are underlain by variably calcareous and dolomitised sandstone, siltstone and conglomerate of the Barzaman Formation and weak, mudstone, siltstone and gypsum of the Gachsaran Formation. In heavily urbanised areas, the extent of Made Ground, the lack of exposures and the confidential nature of many of the site investigation reports means that the geological line-work is based on air photographs and satellite imagery taken prior to development