THORIUM ISOTOPES METHOD FOR DATING MARINE SEDIMENTS (thesis)
A radiochemical modification of the ionium (Th/sup 230/) method of dating marine sediments, based on measurements of four isotopes of Th (Th/sup 230/ , Th/sup 232/, Th/sup 234/, and Th/sup 228/), was develoeod. A sample of chemically and radiochemically pure Th is isolated from the sediment sample. The (Th/sup 230/ Th/sup 232/) activity ratio is determined from the time dependence of the total beth activity of the sample. The latter ratio is equal to the (U/ sup 238/Th/sup 232/ activity ratio. The difference is = (Th/sup 230//Th/sup 232/ ) -- (Th/sup 234//Th/sup 228/) is the ioniu m excess on a Th-normalized basis. It is related to the age T of the sample by I= I/sub 0/e/sup - lambda T/, where I/ sub 0/ is the effective value of I at the time of deposition and lambda is the disintegration constant of ionium. (auth)
- Research Organization:
- Carnegie Inst. of Tech., Pittsburgh
- NSA Number:
- NSA-14-021773
- OSTI ID:
- 4162275
- Report Number(s):
- NYO-8919
- Country of Publication:
- United States
- Language:
- English
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