Heat productivities of various rocks

rock type abundances

U

ppm Th

ppm Rb

ppm K

%

granite 3.4 50 220 4.45

andesite 1.9 6.4 67 2.35

oceanic basalt 0.5 0.9 9 0.43

peridotite 0.005 0.01 0.063 0.001

average upper-continental crust 2.5 10.5 110 2.7

average continental crust 1.0 2.5 50 1.25

rock type heat production total A

(in 10⁻⁶ calories per gram per year)

from U from Th from K

granite 2.52 9.95 1.16 13.63

andesite 1.41 1.27 0.61 3.29

oceanic basalt 0.37 0.18 0.11 0.66

peridotite 0.0037 0.002 0.0003 0.006

average upper-continental crust 1.85 2.09 0.7 4.64

average continental crust 0.74 0.5 0.33 1.56

Source: Modified from compilation by William Van Schmus in Robert S. Carmichael, ed., Handbook of Physical Properties of Rocks, vol. III, CRC Press, Inc. (1984).