1989 Fiscal Year Final Research Report Summary
Study on ESR and TL dating for late Pleistocene rocks
| Project/Area Number |
63460050
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
地質学一般
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| Research Institution | Kyushu University |
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Principal Investigator |
HAYASHI M. Kyushu Univ. Fac. Eng. Assoc. Prof., 工学部地熱開発センター, 助教授 (40038592)
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| Co-Investigator(Kenkyū-buntansha) |
WATANABE K. Kyushu Univ. Fac. Eng. Assistant, 工学部, 助手 (10182916)
SHINNO I. Kyushu Univ. Gen. Education Prof., 教養部, 教授 (00038465)
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| Project Period (FY) |
1988 – 1989
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| Keywords | ESR / TL / fission track / zircon / morphology |
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| Research Abstract |
(1) Ill-crystallized quartz, which is not suitable for TL dating can be dated by ESR method. The age range of quarts samples for ESR dating will be from 1000 years to 2 million years.
(2) There are several ESR signals of zircon in a range from g=2.000 to 2.009, none of them being caused by impurity ions. The signal g=2.008 was first generated by ^<4O>Ca(n,alpha)^<37> Ar reaction in Ca-doped zircon, suggesting that it is due to the disintegration of alpha -particles from radioactive elements U and Th in natural zircon.
(3) Zircon has very strong thermoluminescence intensities, and therefore is one of the most suitable mineral for dating young rocks. The intensity was confirmed to increase proportionally to the artificial gamma -rays irradiation doses.
(4) The annual dose of zircon can be easily estimated from the TL measurement of dosimeters which are mixed with zircon powder for one month or longer.
(5) A new method of describing zircon crystal morphology quantitatively: it is applicable to various fields of earth science, including the distinction of essential zircon crystals from older accidental ones.
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