Keywords: Uranium distribution in crust.PNG Distribution of Uranium in the Earth's crust<br> On the y axis is the amount of uranium in metric tons<br> On the x axis is the ore grade in ppm<br> The line approximates a lognormal distribution<br> Typical ores are as follows <br> Vein deposits 10 000+ ppm <br> Pegmatites unconformity deposits 2 000-10 000<br> fossil placers sand stones 1 000-2 000<br> lower grade fossil placers sandstones 200-1 000<br> volcanic deposits 100-200<br> black shales 20-100<br> shales phosphates 10-20<br> granites 3-10<br> average crust 1-3<br> evaporites siliceous ooze chert 0 2-1<br> oceanic igneous crust 0 1-0 2<br> ocean water 0 0002-0 001<br> fresh water 0 0001-0 001<br> Distribution of Uranium in the Earth's crust self-made source of data Deffeyes MacGregor World Uranium resources Scientific American Vol 242 No 1 January 1980 pp 66-76 5/11/2007 Tungsten Uranium Geochemical diagrams |