Igneous rocks are formed from the cooling of molten ... the weight of the layers on top compacts the layers below. 5 Cementation In the final process of sedimentary rock formation, some of the ...
One of the most common types is an igneous rock high in silica content called ... which was over 2.5 billion years ago. Experts have proposed that changes in Earth's oxygen may have led to the ...
The Journal of Geology, Vol. 23, No. 8, Supplement: The Later Stages of the Evolution of the Igneous Rocks (Nov. - Dec., 1915), pp. 1-91 (91 pages) ...