Geoscience Reference
In-Depth Information
Table 13.1 Radioactive decay series most usually used for geological
dating.
Uranium
!
lead [
238
U decays to
206
Pb with a half-life of 4,470
million years]
[
235
U decays to
207
Pb with a half-life of 704
million years]
Thorium
!
lead [
232
Th decays to
208
Pb with a half-life of 14,000
million years]
Potassium
!
argon [
40
K decays to
40
Awith a half-life of 1,250million
years]
Rubidium
!
strontium [
87
Rb decays to
87
Sr with a half-life of 48,800
million years]
[
147
Sm decays to
143
Nd with a half-life of 106,000
million years]
Rhenium
!
osmium [
187
Re decays to
187
Os with a half-life of 43,000
million years]
Lutetium
!
hafnium [
176
Lu decays to
176
Hf with a half-life of 35,900
million years]
Samarium
!
neodymium
Source: half-lives after G. Brent Dalrymple, The Age of the Earth
(1991), p. 80.
Gateshead where his father ran an ironmongery and later was engaged
in the insurance business. The young Arthur shone at school, and in
his final year first encountered the works of Lord Kelvin and also read
parts of The Face of the Earth by the German geologist Eduard Suess
(1831-1914). The year 1907 saw him take up a scholarship at the Royal
College of Science in South Kensington in London where he studied
physics, but also took some courses in geology - a training that
moulded his future work. He applied for a position as a petrologist,
someone who specialises in the study of rocks, in the British Museum
(Natural History) but was unsuccessful, losing out to William
Campbell Smith (1887-1988) who proved to be a very able mineralo-
gist and petrologist. Sensibly Holmes had more than one iron in the
