The Age of the Earth |
Common terms and phrases
a-particles a-rays accumulation actinium actinium series actino-uranium alteration amount Analyst Arendal atomic weight average basaltic biotite Boltwood bröggerite calculated Cambrian carnotite Cenozoic cent Ceylon Chem Cleveite common lead correlation Cretaceous Crystallization Dana denudation deposits determined Devonian disintegration Earth estimate Euxenite evidence feet fergusonite formation Geol geological age gram granites helium helium ratios Holmes Hydrous igneous rocks ionization isotopes Joachimsthal Joly Joly's Katanga Kirsch Langesundfjord later lead ratios limestone Lower mass material Mesozoic metamict meteorites method Middle Pre-Cambrian million Mineralogy monazite Moss Norway number of atoms Occurs ocean Ontario Paleozoic pegmatites period Phil pitchblende pleochroic halos Pre-Cambrian present probably Proc radioactive minerals radium range rare-earth ring samarskite sandstone sediments shale sodium specimen Strutt Table Tertiary thickness ThO₂ Thorianite thorite thorium thorium-lead tion Upper Pre-Cambrian uraninite uranium uranium and thorium uranium minerals weight of lead Ytterby zircon