By Dr Siva Kumar
Travelling across Oman has always been enjoyable thanks to the surrounding mountains, consisting of rocks in different colours, textures, foliation (layers) and faults. What we observe on the sides while casually passing by is a story of 800 million years. During this time there were at least three periods when the whole region was covered completely by ice, producing unique geological and cave structures.
Oman is referred to as a geologist’s paradise across the world and remains one of the most sought after places in international geo-tourism. As we already live here, it is important for us to know what is so special about Oman’s geological features. We can understand and appreciate this when we know some of the basics of geology.
Geology is one of the Earth science subjects and is concerned with the study of rock; its composition and the processes that change it over time. Geology explains the formation of rocks, fossils, structures, caves and meteorites. We can find examples of each of them in Oman and, therefore, it is no wonder geologists across the globe come to visit.
The mountains contain rocks that have formed due to physical changes such as deforming, compacting, eroding, melting and cooling. Sedimentary rock is a type of rock formed from existing pieces of rocks or other materials. Limestone and sandstone fit into this category. When the traces of plants or animals are preserved in sedimentary rocks, they are called as fossils.
When immense heat or pressure is applied, rocks change their appearance and are described as metamorphic rocks. These rocks often contain foliation perpendicular to the direction of pressure.
Slate and marble are examples of this type. Igneous rocks are those formed when hot material cools and solidifies. They can be formed both inside the Earth and on its surface. Basalt and Pumice are examples of igneous rocks.
Situated near the Gulf of Oman on the edge of the Arabian plate, Oman’s mountains contain several arrangements that illustrate the effect of continental collisions and oceanic movements. The 700 km-long Al Hajar Mountain range contains peaks and drowned valleys that tell us about the north-eastern tectonic movement of the Arabian plate at the rate of 2 cm per year.
Gigantic movements of the outer layer of the Earth, known as the Earth’s crust, cause mountain formation. There are several types of mountains such as folded, block, dome, volcanic and plateau mountains. When a section of oceanic crust is exposed, it is called an ophiolite. The world’s best-exposed and largest ophiolite, the Semail Ophiolite, is found in the Hajar Mountains. The Wadi Mayh area, located in North-eastern Oman, also contains the world’ largest and best-exposed mega-sheath fold ever discovered.
The Mountain of Sun (Jabal Shams), Mountain of Green (Al Jabal Al Akhdar), Mountain of Water (Natif-Hasik ) and Mountain of Moon (Jabal Al Qamar) are some of the popular destinations finding their way into the itineraries of international geo-tourists.
Jabal Shams is the highest mountain in the Al-Hajar mountain range and all of Oman, with a peak height of 3004 m. Jabal Akdhar is 2980 m high, and Samhan Mountain measures 2,100 m. These mountains contain stunning canyons, spectacular viewpoints, beautiful creeks and tremendous caves.
Next time a child shows you a stone and asks curiously about it, you can try explaining a bit more about geology. Or you can be even smarter and install a mobile app such as Rock Identifier or
Fossil Recognition and surprise them by saying, “it is a Cenozoic gastropod fossil formed 65 million years ago”, while smiling like a rock star.