Geology of the Sweihan and Remah 1:100 000 map sheet, 100-7, United Arab Emirates

This Sheet Description describes the geology of the Sweihan and Remah 1:100 000 scale geological map. The Sweihan and Remah district covers 2780 km2 east of Abu Dhabi. Over 700 observation points were made throughout the district. Pre-Quaternary bedrock comprises Miocene conglomerate of the Barzaman Formation which probably underlies the entire area. It is poorly exposed in roughly east-west trending inter-dune areas and in a number of excavations in the northwest and eastern parts of the area. Over almost the entire area, the Barzaman Formation is overlain by deposits of the Quaternary (Pleistocene) Hili Formation, which is up to at least 20 m thick in places. Three facies of the Hili Formation were mapped; coarse fluvial channel gravels, fluvial sands, and siltstones (overbank deposits). They represent a complex fluvial outwash system draining from the Hajar Mountains in the east. As such, they tend to fine distally to the southwest, where the majority of the fluvial sands and siltstone/mudstones occur. They locally contain intercalated aeolian sand beds which were blown in from the north-west. Quaternary carbonate-cemented aeolianites of the Ghayathi Formation are well-developed in the north western corner of the district. These represent fossil seif dune systems which locally form the cores to fields of modern pale carbonate-dominated low dunes. The Quaternary deposits are overlain by various modern dune sands (Rub al Khali Formation) with various morphologies, mapped as dune ridges, locally culminating in star dunes, and barchanoid low dune fields. Interdune areas, floored either by Miocene or Quaternary rocks typically have continental sabkha veneers and, adjacent to the dune fields, thin sand veneers

Geology of the Al Lisaili 1:100 000 map sheet, 100-6, United Arab Emirates

This Sheet Description describes the Quaternary and solid geology of the Al Lisaili 1:100 000 scale geological map. It includes the southern outskirts of Dubai, including part of Jebal Ali and the development around the new Al Maktoum International Airport. Apart from these urban areas, the region is largely undeveloped desert. Much of the map area is covered by dune forms, mostly either low dunes or dune ridges, with large interdunes underlain either by variably dolomitised sandstone, siltstone and conglomerate of the Miocene Barzaman Formation or the Quaternary fluvial sandstones, conglomerates and calcretes of the Hili Formation. The Barzaman Formation forms the rock-head across most of the district and is locally well exposed in interdunes. Quaternary carbonate-dominated aeolianites (Ghayathi Formation) form distinctive palaeodune ridges that trend southwest-northeast-across the district, particularly to the west and northwest of the district. Marine deposits of the Abu Dhabi Formation are present around Jebal Ali, mostly forming areas of coastal sabkha. Although the majority of sheet 100-6 is desert, significant parts of the onshore landscape and the short stretch of coast has been strongly influenced by anthropogenic activity. The rapid growth of Dubai since the 1970s has led to extensive areas being landscaped or reclaimed for development or forestry. Major residential, commercial and industrial developments exist or are proposed around Jebal Ali, and around the Al Maktoum International Airport, whilst forestry and farming projects occur in the south and west. Many of the excavations in the development sites around Dubai and Jebal Ali, such as for example, the trial excavations for the proposed Arabian Canal scheme, provided excellent exposures of the underlying geology. Details of some of these sections are provided in this report. Over much of the area, ‘Made Ground’ that includes engineered fill is widespread