ABU DHABI, Mar. 17th, 2008: A new type of soil rich in Anhydrite (Calcium Sulphate - CaSO4), a mineral known for its value for construction purposes, was discovered only 70 cm deep in the coastal sabkha (salt flat) of the emirate of Abu Dhabi, announced to the Environment Agency- Abu Dhabi (EAD).
According to EAD secreatary general Majid Al-Mansouri, high salinity and high temperatures preserve this mineral and prevent its conversion to gypsum which is a white or colorless mineral consisting of hydrated calcium sulfate used in cement, plaster and fertilizers. A relatively common sedimentary mineral that forms massive rock layers, Anhydrite does not form directly, but is the result of the dewatering of the rock forming mineral Gypsum (CaSO4-2H2O). This loss of water produces a reduction in volume of the rock layer and can cause the formation of caverns as the rock shrinks. Good mineral specimens of Anhydrite were extremely rare despite its common occurrence. However, fine specimens of Anhydrite have been found in Mexico and Peru that show good crystal habit, a nice blue color and even a play of light internally in the crystal. The discovery which was made by made by EAD Scientists, Dr. Mahmoud Abdelfattah and Dr. Shabbir Shahid is significant because it is rare for this type of soil to occur in such an environment. The discovery was made during a study conducted by the Environment Agency- Abu Dhabi (EAD), of the coastline of the emirate that stretches over approximately 400 km. This coastal area, he explained, has very high salinity due to sea water intrusion, therefore anhydrite forms in this marine environment and remains stable under an environment where the water table reaches 70 cm and the site experiences seasonal water flooding. The types of soils, 13 in total, that compose the coastline of Abu Dhabi Emirate have already been mapped in detail. The map is available to the public at EAD's in-house Library. The discovery has already been recognized by the Soil Science Society of America which published an Article about "A Unique Anhydrite Soils in the coastline of Abu Dhabi Emirate" in the Soil Survey Horizons distributed internationally. Recently a formal proposal jointly prepared by EAD and a USDA staff has been submitted to US Department of Agriculture for a change in US Soil Taxonomy. The changes are recommended for new additions of Anhydrite rich materials at the level of subgroup, a new mineralogy class as well as a new addition of Anhydritic subsurface accumulation.Copyright Emirates News Agency (WAM) 2008.
