The iliac crest is the curved superior border of the ilium, the largest of the three bones that merge to form the os coxa, or hip bone. It is located on the superior and lateral edge of the ilium very close to the surface of the skin in the hip region. When a person places their hands on their hips, it is the skin above the iliac crest that they rest their hands on.
1. Weathering is a term which describes the general process by which rocks are broken down at the Earthâs surface into such things as sediments, clays, soils and substances that are dissolved in water. 2. The process of weathering typically begins when the earthâs crust is uplifted by tectonic forces. After the physical breakup and chemical decay of exposed rocks by weathering, the loosened rock fragments and alterations products are carried away through the process of erosion.
How does chemical weathering form a cave? Weak acids seep into the ground until they reach a zone soaked with water. As the ground water become more acidic, it dissolves calcite and other minerals in the rock.