Illustrated Guide to the Holocene carbonate/evaporites of Western Abu Dhabi, U.A.E. and their Jurassic Analogs
Click on red location or numbered box to view detailed scenes of areas of interest to you.
Figure: The six major geomorphic units of the coastal complex of Abu Dhabi above are differentiated on the basis of their relationship to sea level and geographical position. These are: (A) Open marine shelf; (B) Offshore bank - shoal, channel and barrier islands [1, 3, 6, 7, 13, 16, & 17]; (C) Lagoons [2, 4, 5, 8, 9, 11, 12, and 15]; (D) Coastal terrace [2, 4, 5, 8, 9, 11, 12, 14, 15, 18, 19 23, 21, and 22], and (E) Mainland Coastal Plain [landward of coastal terrace].
These pages whose titles are listed here provide a guide to the Holocene shallow water Carbonate and supratidal evaporite tract that lines the United Arab Emirates (U.A.E.) coastal embayment consists of seaward reefs, barrier islands and tidal flats. The text provided here often paraphrases papers and guidebooks written by Christopher Kendall, Abdulrahman Al Sharhan and Gregory Whittle.
- Introduction
- Reefs
- Ooid shoals
- Grapestone shoals
- Intertidal Travertines
- Mangroves
- Sabhka Evaporite Flats
- Cores from Abu Dhabi Sabkha
- Coastal and interior Dunes
- Jurassic Sedimentary Record
- Conclusions
- UAE Gallery of Holocene Photos and Images
- References
- PDFs of literature
The work of many others is listed in the references. The core photographs from the Abu Dhabi sabkha are of push cores collected by Godfrey Butler for his PhD. Most of the illustrations are field photographs taken by Christopher Kendall, Greg Whittle and Nassir Alnajii, while Abdulrahman Al Sharhan supplied many of the remote views and others come from the public domain service that NASA generously provides. Christopher Kendall drafted the maps and diagrams.
As with similar sedimentary sequences from the geological section in the subsurface of the Arabian Gulf, and elsewhere in the geological record, the sediments of this coastal region pass landward into a continental facies and seaward into a basinal facies.
Link to images of general marine facies of the coast of Abu Dhabi, U.A.E.
In eastern Abu Dhabi the Holocene coast trends northeast southwest and the barrier/lagoon complex narrows. To the west, the protecting barrier islands are more widely spaced than those to the east. These latter islands occur on extensive sandy shoals and coral banks cut by tidal channels. Here, south of the barrier, is a continuous open body of water, the Khor al Bazam lagoon. It has less restricted circulation than the lagoons to the northeast and its western end is connected to the Arabian Gulf.
The distribution of the sediments in the U.A.E. coastal embayment reflects the physiographic differences listed above. To the east, Oolites form on the inter island tidal deltas and coral reefs are restricted to small patches along channels and just seaward of the center of the islands. To the west, coral reefs grow along the northern edges of most of the offshore banks north of the Khor al Bazam. Eastward, in the protected lagoons, Carbonate muds and Pellets are accumulating, whereas to the west of Al Dhabaiya Island, Carbonate muds only accumulate in a narrow belt south of the offshore bank. Grapestones and skeletal debris are the dominant components. The entire province is evolving. The offshore bank is accreting seaward through a combination of coral reef growth and tidal delta progradation. South of this bank, supratidal flats are encroaching on the lagoons through the development of beach ridges and cyanobacterial flats.
The similar relationship of these sedimentary facies to some of the Upper Jurrassic found in the subsurface of the Central Arabian Gulf, suggests that Abu Dhabi coastal area can be used as a comparative model for understanding some ancient carbonate/evaporite depositional and diagenetic processes. The facies relationships at the pinch out between the Hith Anhydrite and the Asab Oolite suggest that these sediments accumulated in a nearshore to sabkha setting. Eastward of this margin the Hith changes its character and appears to have accumulated in a standing body of water.