The Huqf Uplift
Oman's Geologic History from A - Z
Contribution by Alan Heward
The Huqf area is a special one for geologists because there are rocks to look at from almost all of Oman’s geological history. This is possible because of the Huqf’s location near the eastern edge of the Arabian Plate which has kept it up-lifted through long periods of geological time.
The oldest rocks in the area are dated using mineral isotopes at about 730 million years. These are basement rocks, a type of granite, which formed deep within the earth’s crust from molten rock. Granite is a type of igneous rock. As the years went by, the basement rocks became covered in layers and layers of rocks, each layer being younger than the one before. These rocks that are made up of lots of fragments of weathered rock or shell fragments, are sedimentary rocks. Often they have fossils or features which give clues about how they formed.
The Huqf area has not always been a desert. At one time, about 300 million years ago, the rocks show evidence that ice sheets covered the area. At other times, it was under a shallow tropical sea. The layers left behind by these seas often contain fossils, but the fossils vary a great deal over time. The oldest fossils are mound structures made by mats of algae, which are called stromatolites. Younger fossils include wonderful tropical shells, such as the rudists bivalve. At yet another time, the area was fairly arid, but with big rivers flowing through. Fossil soils and trees occur in these layers. Each type of climate left behind its own particular pattern of layers of rocks which geologists interpret by looking at what goes on today in places with a similar environment.
In the 1950s, geologists began to study and map the region. They used their understanding of the fossils and rock layers present in the Huqf to help them drill for oil at Fahud, Ghaba and Haima. They found that the rock layers which produce oil from deep below the ground, are the same as those that can be seen at the surface in the Huqf area. So when oil company geologists want to understand the characteristics of the layers of rocks that make up an oil or gas reservoir, they often visit the rocks in the Huqf. Other geologists and students from Sultan Qaboos University and other universities around the world also visit this area with its fascinating geology.
Much of the Huqf area off lies within the Arabian Oryx Sanctuary. If you want to leave the blacktop roads to look at the spectacular scenery, geology and wildlife, then you need to obtain permission from the Ministry of Municipalities, Environment and Water Resources. The Ministry is working to conserve the rich natural heritage of the area.