-20-
390 p tn diameter (mostly 100-400 p).
Identification of
the chemical form was made by electron and X-ray dif-
fraction techniques.
Calculations of Miyoshi (18) indicate
that particles of calcite 4090 p in diameter would settle —
from the surface to 200 meters in 26 minutes and those 100 p
in diameter in 7 hours.
Thus the mechanism for rapid
scavenging of sr39-30 in fallout introduced into the sea
would be provided by calcite settling through the thermocline.
Co-precipitation would provide another scavenging mechanism for radiostrontium in the fallout area.
When calcium
carbonate is precipitated in sea water strontium is co-precipitated and carried down with the calcium.
This technique
is commonly used in radiochemical separations on sea water.
The amount of strontium removed from solution in the sea by
the precipitation of calcium derived from oxidized and hydrolyzed coral is not known but probably is not low.
Strontium,
co-precipitated with calcium carbonate into
the particulate form,
feeding organisms.
then would become available to filter
However, a limited fraction of the parti-
cles would settle out of reach of the biosphere into deep
water.
A rapid turnover of strontium has been observed in
all marine
Thus,
invertebrates and fishes studied ub to now (1,
3).
ingested radioactive strontium in the particulate form
would be continually recycled to the sea in solution so that
in time it would come to equilibrium with the naturally occurring non-radioactive form.