Sahara Desert Rocks and Mineral Oddities

Sahara Desert Rocks...It’s not surprising that some very unique rocks and minerals are found in the Sahara Desert. The Sahara is the world’s largest hot desert and one of the harshest environments on the planet. It is the third largest desert after Antarctica and the Arctic, which are cold deserts.

The name “Sahara” is Arabic for "The Great Desert". The Sahara Desert landmass is 3.6 million square miles covering most of North Africa. The desert includes areas in Algeria, Chad, Egypt, Libya, Mali, Mauritania, Morocco, Niger, Western Sahara, Sudan and Tunisia. The Sahara is bordered by the Atlantic Ocean on the west, the Atlas Mountains and the Mediterranean Sea on the north, the Red Sea on the east, and the Sudan and the valley of the Niger River on the south. The Sahara is divided into Western Sahara, the central Hoggar Mountains, the Tibesti Mountains, the Air Mountains, an area of desert mountains and high plateaus, Ténéré desert and the Libyan desert, which is the most arid region.

The Sahara is located in the trade winds belt and is subject to constant and strong winds from the northeast. The drying and dust-laden winds are often felt north and south of the desert, where they are known as Sirocco, Khamsin, Simoom, and Harmattan. The northern slopes of the Atlas Mountains absorb most of the moisture from winds blowing inshore from the Mediterranean Sea. The Sahara Desert dust storm is a constantly reoccurring event where strong and violent winds will move fine particles of silt, clay, silicon dust and other materials for long distances. These fine particles moved around in the air during the storm can spread over hundreds of miles and rise up to over 10,000 feet.

Are the oddly shaped stones in the deserts the result of wind erosions? These stones are typically formed by erosion caused by water. Wind erosions are not powerful enough to break down stone in this way. The central part of the Sahara, known as the Libyan Desert, is the driest, receiving an average of less than 1 inch of rain per year. Other parts of the Sahara receive an average of up to 4 inches of annual rainfall. Occasionally the Sahara Desert gets flooded by heavy downpours. These sudden and extreme rains can be accompanied by strong sandstorms as well.

The world’s most famous desert was not always as dry as it is now. An international research team recently suggested the presence of massive river systems in the Sahara existed between 130,000 and 100,000 years ago. These rivers would have created narrow stretches of nutrient-rich soil, producing “green corridors” that would have allowed animals and plants to thrive in the otherwise hostile desert much like the Nile River did in Egypt. It is thought that an estimated 27,000 square miles in northeastern Libya was also covered by massive lagoons and wetlands.

At nearly 30 miles in diameter, the Sahara Desert‘s sprawling Richat Structure (named the Sahara Eye) is one of the most mysterious geological features on Earth. The Richat Structure is situated in Oudane, Mauritania, is a huge circular formation (50 km in diameter), that resembles an eye when looked upon from space. Why the structure is nearly circular, however, remains a mystery. Originally thought to be a crater, this volcanic dome is most likely a product of erosion, an ancient geological artifact in the middle of featureless Maur Adrar desert, in Africa’s Western Sahara. The earliest space missions used it as a landmark.