Table 2 The assumed average content of heat-producing elements (HPEs) in today’s bulk silicate Moon
From: Effects of magma-generation and migration on the expansion and contraction history of the Moon
HPEs | heating rate (pW kg−1) | Concentration (kg kg−1) | Decay constant (Gyr−1) |
|---|---|---|---|
\({ }{}_{ }^{238} {\text{U}}\) | \(9.46 \times 10^{7}\) | \(21.3 \times 10^{ - 9}\) | 0.16 |
\({ }{}_{ }^{235} {\text{U}}\) | \(5.69 \times 10^{8}\) | \(0.15 \times 10^{ - 9}\) | 0.98 |
\({ }{}_{ }^{232} {\text{Th}}\) | \(2.64 \times 10^{7}\) | \(79.5 \times 10^{ - 9}\) | 0.05 |
\({ }{}_{ }^{40} {\text{K}}\) | \(2.92 \times 10^{7}\) | \(4.39 \times 10^{ - 9}\) | 0.55 |