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CH3041
LIFETIMES
• The major ions
have long lifetimes (x 106 y) in the
ocean due to their high solubility.
• Assuming steady state & complete
mixing.
Lifetime= Inventory (ocean) / Input (from
rivers)
eg. Lifetime
(Na+) = 78 x 106 y (Fluxin = A / t)
Inventory: = (1.37 x 1021 l) x (470
x 10-3 mol/l)
Input: = (3.6 x 1016 l/y) x (0.23 x 10-3 mol/l)
• The composition
of evaporite deposits has remained quite constant over the last
900 million years Þ the ionic composition of the sea has been quite constant.
900 million years Þ the ionic composition of the sea has been quite constant.
