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.
Quick Answer. Earth's lower mantle is made up of mantle-crust that consists of aluminum, silicon, magnesium, calcium, oxygen and iron. These elements in the lower mantle account for 72.9 percent of the entire mass of the Earth's mantle and about 50 percent of the planets entire mass. The lower mantle is directly underneath Earth's upper mantle and stretches from 416.319 to 1809.976 miles below the surface.