. The Earth beneath the sea : History . Ag/. Fig. 2. Age determination with the aid of the ratio of two radioactive elements from the same series where the decay constant of the daughter product is large compared with the decay constant of the parent element. The ordinate gives the ratio of activities of the two radio-elements. The abscissa gives the time scale in non-dimensional units as multiples of mean lifetime. The produced nuchdes with half life large enough to be used for the purposes of marine geology are, in that case, ionium (230Th), protactinium (23iPa) a
. The Earth beneath the sea : History . Ag/. Fig. 2. Age determination with the aid of the ratio of two radioactive elements from the same series where the decay constant of the daughter product is large compared with the decay constant of the parent element. The ordinate gives the ratio of activities of the two radio-elements. The abscissa gives the time scale in non-dimensional units as multiples of mean lifetime. The produced nuchdes with half life large enough to be used for the purposes of marine geology are, in that case, ionium (230Th), protactinium (23iPa) and radium (228R,a, 226^^). (b) In the case where Ai is much larger than A2 the equilibrium equation is approximately N'^ NoHl -^,f ), but as No'^^Nh^i', we obtain as a formula for the age iV2\ t i-i 1 + NK (6) (7) where the same notation is used as above. This equation is used when a radio-nuchde produces a stable isotope, such as potassium-40 giving argon-40, and rubidium-87 producing strontium-87. The
Size: 3090px × 1618px
Photo credit: © The Bookworm Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookcollectionbiodivers, booksubjectoceanbottom
