A new variation diagram has been devised in which the ratio $\frac{Total O not combined in OH^{-}}{Si^{+4}+ (A1^{+3} in 4-co-ordination)}X10$ is plotted as abscissa. This ratio, here called the ...

Oceanic crust covers two-thirds of Earth's solid surface, but scientists still don't entirely understand the process by which it is made. Analysis of more than 600 samples of oceanic crust reveals a ...

This is a preview. Log in through your library . Abstract Boisa Island is the tip of a Quaternary island-arc volcano. It consists of an older cone made up of porphyritic, amphibole-free, mafic rocks, ...