Geology

Biography

Biography: Asma Al-Farraj AlKetbi

Abstract

With the small area size (83,600 km2) of the United Arab Emirates (UAE), it is blessed with a number of significant and rare geologic features and environments that are both well exposed and easily accessible, zones such as the Dibba zone (where 3 rock types outcrop adjacent to each other). This presentation will go through overall geological history of the UAE. Then, it will appraise in more detail the Quaternary geology, from the oldest Quaternary sediments (The Hurmuz salts) to the youngest (the modern coastal sabkhas). North UAE is an area of young tectonic activity, and continuous uplift and dissection, creating a desert mountain environment. They are formed of rocks of late Palaeozoic to late Mesozoic age, deposited on the margin of the Tethys Ocean. The main rocks groups are; the Ruus Al-Jibal group, the Elphinstone group and the Musandam group. During the late Cretaceous these groups have been overthrust as a unit onto the rocks of the Hawasina series of approximately the same age (Glennie et al., 1974). Over the past 1.8 million years, the Quaternary history of the UAE–as with many other parts of the world has been greatly influenced by Quaternary climatic sequence, affecting both erosion rates and sea-level change. Sea-level change primarily reflects global climatic changes, but is locally modified by tectonics. In the UAE, these factors plus salt tectonics are well exposed in the present landscape. Much of the evidence for the Early Quaternary is missing. It has been either eroded away or covered by sea or by sand. The most well established Early Quaternary feature is the marine terrace at the mountain front in Northern UAE. This is followed by tufa from the relict spring water along the fault line through Wadi Idan. At Wadi Taweeyen and Kudaa, they are relict fragments of old relatively high wadi terraces. The late Quaternary features are more obvious; wadi terraces and alluvial fans as well as the complex sand dunes and sabkhas of the modern desert areas.