Abstract
The application of /sup 230/Th and /sup 231/Pa growth methods to the hard tissues of living things, which are effective for the radiometric age measurement for latter Quaternary period, has been limited to certain corals, therefore it has been scarcely utilized in other areas than coral reefs. Reef coral fossils (Porites) were obtained from terrace deposits of Magdalena Island in Southern Baja California, and the methods were applied to them. At the time, the isotope compositions of Th, Pa and U in the shells of echinoderm Encope Grandis and of the living samples were examined. The estimated ages were in agreement with those of coral. It suggests that the reliable /sup 230/Th and /sup 231/Pa ages of sea-urchin fossils were presented for the first time and that the method is applicable to such fossils only if the conditions can be met. The results are highly significant, since the method may be used in other areas than coral reefs. (J.P.N.).
Citation Formats
Omura, A, and Ku, T.
Th, Pa and U isotopes in an echinoderm, Encope grandis. An application to dating of some fossil samples from Southern Baja California.
Japan: N. p.,
1979.
Web.
Omura, A, & Ku, T.
Th, Pa and U isotopes in an echinoderm, Encope grandis. An application to dating of some fossil samples from Southern Baja California.
Japan.
Omura, A, and Ku, T.
1979.
"Th, Pa and U isotopes in an echinoderm, Encope grandis. An application to dating of some fossil samples from Southern Baja California."
Japan.
@misc{etde_7096764,
title = {Th, Pa and U isotopes in an echinoderm, Encope grandis. An application to dating of some fossil samples from Southern Baja California}
author = {Omura, A, and Ku, T}
abstractNote = {The application of /sup 230/Th and /sup 231/Pa growth methods to the hard tissues of living things, which are effective for the radiometric age measurement for latter Quaternary period, has been limited to certain corals, therefore it has been scarcely utilized in other areas than coral reefs. Reef coral fossils (Porites) were obtained from terrace deposits of Magdalena Island in Southern Baja California, and the methods were applied to them. At the time, the isotope compositions of Th, Pa and U in the shells of echinoderm Encope Grandis and of the living samples were examined. The estimated ages were in agreement with those of coral. It suggests that the reliable /sup 230/Th and /sup 231/Pa ages of sea-urchin fossils were presented for the first time and that the method is applicable to such fossils only if the conditions can be met. The results are highly significant, since the method may be used in other areas than coral reefs. (J.P.N.).}
journal = []
volume = {85:3}
journal type = {AC}
place = {Japan}
year = {1979}
month = {Mar}
}
title = {Th, Pa and U isotopes in an echinoderm, Encope grandis. An application to dating of some fossil samples from Southern Baja California}
author = {Omura, A, and Ku, T}
abstractNote = {The application of /sup 230/Th and /sup 231/Pa growth methods to the hard tissues of living things, which are effective for the radiometric age measurement for latter Quaternary period, has been limited to certain corals, therefore it has been scarcely utilized in other areas than coral reefs. Reef coral fossils (Porites) were obtained from terrace deposits of Magdalena Island in Southern Baja California, and the methods were applied to them. At the time, the isotope compositions of Th, Pa and U in the shells of echinoderm Encope Grandis and of the living samples were examined. The estimated ages were in agreement with those of coral. It suggests that the reliable /sup 230/Th and /sup 231/Pa ages of sea-urchin fossils were presented for the first time and that the method is applicable to such fossils only if the conditions can be met. The results are highly significant, since the method may be used in other areas than coral reefs. (J.P.N.).}
journal = []
volume = {85:3}
journal type = {AC}
place = {Japan}
year = {1979}
month = {Mar}
}