96 NATIONAL OCEANOGRAPHIC PROGRAM—1965 
All the participants used either gridded ionization chambers or solid-state 
detectors for determining the alpha spectra of their samples. Equally good 
results were obtained with both detectors provided that infinitely thin and 
homogenous samples were available. The method of choice for the preparation 
of thin samples is usually electrodeposition. Stephen Kim (Oak Ridge Institute 
of Nuclear Studies) discussed how he used dilute hydrochloric acid and ethanol 
as an electroplating solution. He varied temperature, pH, current, and time 
of electrodeposition and found that under the best conditions very thin samples 
ean be prepared with a yield of 80 to 100 percent for uranium, thorium, and 
protactinium. 
It is apparent that dating of marine sediments by the ratio of Th” to Pa*™ 
cannot be extended beyond a few hundred thousand years. Peter Deines (Penn- 
sylvania State University) outlined a program in which Be” is used. It is 
formed in the atmosphere by cosmic rays and has been detected in deepsea sedi- 
ments through its 6 activity. It has an approximate half life of 2.7 by 10° years. 
The change in concentration of this isotope in profiles of cores whose age fell 
beyond the limit of Th” measurement can be used to date sediments with ages 
ranging to millions of years. The concentration of Be’ in the sediments is very 
low, and it is obvious that methods of ultrahigh sensitivity have to be used. 
Deines described a mass spectrograph now under construction that is designed 
to reach this sensitivity. With this instrument determination of Be” will be 10 
to 1000 times as great as is possible by measurement of its radioactivity and dating 
sediments of ages up to 20 million years may be possible. 
The conference was stimulating, ideas were exchanged, and information 
shared. Some of the controversial issues—the use of whole sample versus leach- 
ing techniques, correction for allogenic thorium and protactinium, and the need 
for determinations of isotope fractionation in dating the samples—were clarified. 
Among the problems that still remain unsolved are the varying results obtained 
in Similar samples and sample preparation by different methods and measure- 
ment. It was generally agreed that it may be possible to clarify controversial 
issues by the preparation and interlaboratory distribution of samples, such as 
red clay marine carbonates and marine limestones. These samples will be dis- 
tributed among laboratories which are active or interested in dating marine sedi- 
ments. Results of these investigations should be presented at a later date, 
possibly at a conference to be convened as a follow-up of this meeting. 
ELIZABETH RONA, 
Oak Ridge Institute of Nuclear Studies, Oak Ridge, Tenn. 
Mr. Lennon. Our next witness will be Comdr. H. Nygren, Chair- 
man of the Surveys Panel program. 
We are delighted to have you. Do you have a prepared statement? 
STATEMENT OF COMDR. HARLEY D. NYGREN, U.S.C. & GS., ACTING 
CHAIRMAN, OCEAN SURVEYS ADVISORY PANEL, INTERAGENCY 
COMMITTEE ON OCEANOGRAPHY 
Commander Nyeren. It is nine pages. I would be happy to con- 
dense it. 
Mr. Lennon. We will put the full text of your statement in the 
record immediately following your testimony. 
Commander Nyeren. With your permission I will emphasize the 
areas of the statement that describe the accomplishments of the Panel, 
the operations of the Panel, and avoid the other. 
T think it is well to note that I am only the Acting Chairman of the 
Surveys Panel in the absence of Dr. Stewart, the permanent Chair- 
man. I am here because he is unable to be here. The statement lists 
the members of the Panel. It gives a little background information 
in its formation. I will not repeat that. 
One of the specific accomplishments of the Panel since the hearings 
of 1962 is represented by ICO Pamphlet No. 7, the national plan for 
ocean surveys, which was issued in May of 1963. This plan was pre- 
