- Temperature Fluctuation: Extreme temperatures in the desert undergo diurnal and seasonal variations, causing rocks to expand and contract. This causes the creation of cracks and fissures, weakening the rock structure.
- Insolation Weathering: The Sahara desert receives intense solar radiation, causing thermal stress on rocks. This heating and cooling cycle leads to flaking and scaling of rock surfaces.
- Wind Abrasion: Strong and persistent desert winds carry sand and dust particles acting like natural sandblasters. The continuous bombardment of sand erodes and polishes rock surfaces, producing smooth and rounded shapes known as "ventifacts".
- Hydrolysis: Moisture from the infrequent desert rainfall reacts with minerals within the rocks. This hydration process causes mineral expansion and alteration, leading to the breakdown of rock structures.
- Salt Weathering: Underground water rich in dissolved salts seeps up through the rocks and evaporates, leaving behind salt crystals. These crystals exert enormous pressure on the rock, causing it to fragment into smaller pieces.
- Frost Shattering: In colder desert regions, freezing and thawing cycles can further break down rocks. Water trapped in cracks expands when it freezes, causing fracturing and chipping.
- Biological Weathering: Limited vegetation and the presence of bacteria and microorganisms release organic acids and enzymes that react with rocks. This biochemical activity contributes to the gradual degradation of rock surfaces.
The combined effect of these weathering processes over long periods shapes the Sahara's distinct rock formations, including sand dunes, inselbergs, and weathered rock outcrops that add to the desert's captivating landscapes.
