The deepest rocks known from within Earth are fragments of normal mantle ( approximately 400 km) and metamorphosed sediments ( approximately 350 km), both found exhumed in continental collision terranes. Here, we report fragments of a highly reduced deep mantle environment from at least 300 km, perhaps very much more, extracted from chromite of a Tibetan ophiolite. The sample consists, in part,...

What is fly ash? Fly ash consists of the lighter particles that travel up from the coal furnaces during combustion. Bottom ash is the heavier particles that cling to the sides of the furnace and do not escape during the burning of coal. Fly ash particles range in size from 1 to 100 micrometers in diameter (EPRI, 2009) and are comprised of silica, alumina, calcium oxides and iron oxides (EPRI, 2...