Al Khayran in OMAN
Al Khayran is an area of great geological and biological diversity. It features drowned river valleys creating islands and fjord like coastline, several types of rock formations, extensive mangrove woodland, intertidal mudflats, saltmarsh and sabkha (salt flats).
Here three types of sedimentary rocks can be seen. The islands and coast to the north east are mainly tertiary limestones around 50 million years old. South of these are 250 million year old late Permian mudstone and silty limestones bedded with black limestone. In the west the Permian limestones are covered by 240 million year old Triassic dolomite.
The rocks originally formed during different periods as part of the ocean floor. Since then the rocks have been buried by the sea either from movement of the landmass itself over millions of years or by rise and fall of sea levels over the last few hundred thousand years. Additional layers of light-brown limestone have been deposited during each period of inundation by the sea.