<p> Wet chemical neutron activation analysis procedures for Au.,
Pd and Ir together with a non-destructive gamma-counting procedure
for Mn are described and applied to the determination of these metals
in three Antarctic (E21 -17, E13-3 and E 17-10) and one Caribbean
(P63 04-9) deep-sea cores.
A total of 49 samples were analyzed. The average values of
Au, Pd, Ir in ppb and Mn in Wt.% (together with standard deviations of
the mean are: (see table in theses) No large differences exist between Au, Pd and Ir concentrations
in different types of deep-sea sediments nor in cores from different
areas and their values are within the general concentration range found in
most crustal rocks.
A general discussion of the sources of precious metals in deep-sea
sediments is given. The most important precious metal source in the
cores studied in this work is detrital material from land. The contribution
of extraterrestrial material to the Au and Pd content of deep-sea sediments
is not important but in cores with depositional rates as low as a
few tenths of a mm per thousand years, extraterrestrial material may
account for more than half of the total Ir content.
From the non-detrital Ir content of deep-sea manganese nodules
the accretion rate of extraterrestrial material over the. entire surface
of the earth is calculated to be about 200 tons per day with an upper limit
of 310 tons per day. The constancy of Ir content in deep-sea cores as a
function of depth suggests that the influx of extraterrestrial material
during the past 3 to 4 million years was probably fairly constant. </p> / Thesis / Master of Science (MSc)
| Identifer | oai:union.ndltd.org:mcmaster.ca/oai:macsphere.mcmaster.ca:11375/18547 |
| Date | 05 1900 |
| Creators | Kuo, Hsiao-Yu |
| Contributors | Crocket, James, Geology |
| Source Sets | McMaster University |
| Language | English |
| Detected Language | English |
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