“The Architecture of Oman varies and depends on the location. The most important building materials used in Oman consist of stones, baked bricks, mud bricks, palm trees, mangrove poles and lime which is mainly used for plaster and mortar.”
Source of quote: This website has photos of some old buildings in Oman.
http://www.visualgeography.com/categories/oman/houses.html

So what is happening here is that a new tradition may have been begun. We shall see if the earthbag construction technique is adopted by the people in that location, and if they come up with a local visual language of their own.
I will also argue that the high-quality work shown in the finish on these domes is strong evidence the local workers are familiar with working with a clay/lime materials, and have take pride in their work.