Iliac crest pain is not that common in the general population, but it is frequent in older individuals, runners (and athletes in general), lower back pain sufferersâ¦ But that doesn`t mean âregularâ people like you and me can`t experience it from time to time!
The mantle is composed of iron-magnesium silicates, and the crust is composed of roughly 5 percent iron. All together, iron makes up an estimated 35 percent of the Earth's mass. Oxygen. Oxygen, the second most abundant element on Earth, is found mainly in the crust.
This layer that maintains life on earth is called the lithosphere. The Lithosphere is composed of the crust and upper most solid mantle. While the Asthenosphere, which lies beneath the lithosphere, is composed of the upper most weaker part of the mantle. As we move from the lithosphere to the asthenosphere the temperature increases. This increase in temperature as well as extreme pressure causes rocks to become plastic.