U-Th isotopic measurements using secondary ion mass spectrometry
- Lamont-Doherty Geologic Observatory, Palisades, NY (United States)
A technique for Th isotopic analyses by SIMS (secondary ion mass spectrometry) has been developed using the Lamont Isolab 54. The high ionization efficiency afforded by SIMS, compared to thermal ionization (TIMS) permit analyses of [sup 230]Th/[sup 232]Th ratios at the 5% 2[sigma] level with 5 to 10 ng of total Th. Relative to TIMS and [alpha]-spectrometry, sample preparation times are markedly reduced, and contamination problems are minimized. The technique is being used to investigate the temporal evolution of young volcanoes, by obtaining U-Th mineral isochrons on individual lava flows, and U-Th fractionations in the sub-ridge mantle via the study of MORBs and young, near-ridge seamount basalts. Results of these topics will be presented and discussed at the meeting.
- OSTI ID:
- 6077099
- Report Number(s):
- CONF-9304188-; CODEN: GAAPBC
- Journal Information:
- Geological Society of America, Abstracts with Programs; (United States), Vol. 25:4; Conference: 42. annual Geological Society of America (GSA) Southeastern Section meeting, Tallahassee, FL (United States), 1-2 Apr 1993; ISSN 0016-7592
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
THORIUM
MASS SPECTROSCOPY
VOLCANIC ROCKS
AGE ESTIMATION
ION MICROPROBE ANALYSIS
ISOTOPE RATIO
SAMPLE PREPARATION
THORIUM 230
THORIUM 232
ACTINIDE ISOTOPES
ACTINIDE NUCLEI
ACTINIDES
ALPHA DECAY RADIOISOTOPES
CHEMICAL ANALYSIS
ELEMENTS
EVEN-EVEN NUCLEI
HEAVY ION DECAY RADIOISOTOPES
HEAVY NUCLEI
IGNEOUS ROCKS
ISOTOPES
METALS
MICROANALYSIS
NEON 24 DECAY RADIOISOTOPES
NONDESTRUCTIVE ANALYSIS
NUCLEI
RADIOISOTOPES
ROCKS
SPECTROSCOPY
SPONTANEOUS FISSION RADIOISOTOPES
THORIUM ISOTOPES
YEARS LIVING RADIOISOTOPES
580000* - Geosciences
400102 - Chemical & Spectral Procedures