Thermal stabilities of paramagnetic defect and impurity centers in quartz: Basis for ESR dating of thermal history.

Toyoda, Shin; Ikeya, Motoji

doi:10.2343/geochemj.25.437

Cited by 152 publications

(85 citation statements)

References 20 publications

(22 reference statements)

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“…Firstly, pretreated samples were irradiated with -radiation (total dose of 2.5 kGy) using a 60 Co source at the Inter-University Laboratory for the Joint Use of Japan Atomic Energy Agency Facilities. Consequently, pretreated samples were heated at 300 °C for 15 minutes to convert the oxygen vacancies to E'1 centers (Toyoda and Ikeya, 1991). ESR signal intensity measurements were conducted at room temperature with an X-band ESR spectrometer JEOL JES-FA100 at University of Tokyo under 0.01 mW of microwave power, and 0.1 mT magnetic field modulation (100 kHz), 5 mT scan range, two minutes scan time, and 0.03 seconds time constant.…”

Section: Electron Spin Resonance Signal Intensity Content and Crystmentioning

confidence: 99%

Millennial-scale East Asian Summer Monsoon variability recorded in grain size and provenance of mud belt sediments on the inner shelf of the East China Sea during mid-to late Holocene

Wang

Zheng

Tada

et al. 2014

Quaternary International

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The response of the monsoon climate on the inner shelf of the East China Sea (ECS) to abrupt climate changes events within the monsoonal Yangtze River drainage is contentious. Repositioning of the monsoon front is thought to have been responsible for the changes in hydroclimate over the Yangtze River drainage, which has exerted great impact on the sedimentation of the inner shelf of the ECS during the Holocene. Here, we present high-resolution analyses of grain size and provenance of the sediments from core MD06-3040 recovered from the inner shelf of the ECS during MD155-Marco Polo II-IMAGES XIV cruise. Significant variability occurred in the core MD06-3040 with notable decrease in East Asian Summer Monsoon precipitation (presumably drought events) at 6000 BP, 5300 BP, 4500 BP, 3700-3300 BP, 2200 BP, 1400-1300 BP, and 800-600 BP, which coincide with the 18 O w record in the northern ECS and stalagmite 18 O sp records from southern China. Similar patterns of these temporal variations suggest that the Yangtze River discharge associated with EASM precipitation has been a dominant control on the sedimentation on the inner shelf of ECS.

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Section: Electron Spin Resonance Signal Intensity Content and Crystmentioning

confidence: 99%

Millennial-scale East Asian Summer Monsoon variability recorded in grain size and provenance of mud belt sediments on the inner shelf of the East China Sea during mid-to late Holocene

Wang

Zheng

Tada

et al. 2014

Quaternary International

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“…As the second and the third g factors are so close to each other, their powder spectrum is similar with that of axial symmetry as shown in Fig. 2a under normally used conditions of ESR measurements of a microwave power of 0.01 mW and the modulation amplitude of 0.1 mT (e. g., Toyoda and Ikeya, 1991). It is also well known that the signal saturates at a low microwave powers of < 0.01 mW (e.g., Ikeya and Ishii, 1989).…”

Section: The E 1 ' Center For Dating Of Quartzmentioning

confidence: 73%

The E1’ center in natural quartz: Its formation and applications to dating and provenance researches

Toyoda

2011

Geochronometria

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Quartz is one of the minerals useful for electron spin resonance (ESR) dating. The E 1 ' center is one of well-known paramagnetic defects in crystalline quartz. This center has a unique feature; its intensity increases on heating. An electronic process to explain this increase was found to be controlled not only by the number of oxygen vacancies, which are the precursors, but also by the number of Al hole centers, which depend on the previous radiation dose and on the Al concentration. The maximum intensity on heating is called the heat treated E 1 ' center, which has been posited to correspond to the number of oxygen vacancies in quartz and was found to be correlated with the ages of the host granites (Toyoda and Hattori, 2000). The experimental results on spin-spin relaxation times of the E 1 ' center indicate that external beta and gamma rays create oxygen vacancies in natural quartz rather than alpha or alpha recoil particles (Toyoda et al., 2005). The correlation between the numbers of the oxygen vacancies in quartz and the ages of the host granite made it possible to distinguish the quartz of a sedimentary reservoir from another with different age of crystallization (Toyoda and Naruse, 2002). Quartz fractions extracted from leoss and atmospheric deposition in Japan and from sediments in Japan sea were analyzed by ESR. The temporal change of the contributions from two dust sources in China were discussed in the context of climate change.

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“…The number of oxygen vacancies was measured as the intensity of the E 1 ' centre after gamma ray irradiation to 1 Gy and heating at 300ºC for 15 min (Toyoda and Ikeya, 1991). The following measurement conditions of the ESR were used: the microwave power of 0.01 mW, the magnetic field modulation frequency of 100 kHz, its amplitude of 0.1 mT, the centre field of 336.0 mT, the sweep range of 5 mT.…”

Section: Methodsmentioning

confidence: 99%

“…As a result the vacancies become paramagnetic (with one electron). Using this feature, an experimental procedure was proposed to estimate the relative number of oxygen vacancies (Toyoda and Ikeya, 1991;Toyoda and Hattori, 2000). This procedure consists of a gamma ray irradiation to more than 200 Gy followed by heating at 300ºC for 15 minutes.…”

Section: The E 1 ' Centre and The Oxygen Va-cancy In Quartzmentioning

confidence: 99%

The Grain Size Influence on the E1' Centre Observed in Quartz of Atmospheric Deposition at Two Japanese Cities: A Preliminary Study

et al. 2010

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Abstract:The grain size influence on the number of oxygen vacancies in quartz was investigated by ESR in atmospheric deposition collected at two Japanese cities, Fukuoka and Akita, in 1969 and 1971. The finer grain size fraction shows the highest value of concentration of oxygen vacancies, most closely resembling dust originating in the Taklamakan desert. Month to month and year to year variation of the dependence was also observed which could possibly be attributed to the variation of the mixture ratio of at least two dust sources in China, A conclusive statement can not be made at this stage.

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Thermal stabilities of paramagnetic defect and impurity centers in quartz: Basis for ESR dating of thermal history.

Cited by 152 publications

References 20 publications

Millennial-scale East Asian Summer Monsoon variability recorded in grain size and provenance of mud belt sediments on the inner shelf of the East China Sea during mid-to late Holocene

Millennial-scale East Asian Summer Monsoon variability recorded in grain size and provenance of mud belt sediments on the inner shelf of the East China Sea during mid-to late Holocene

The E1’ center in natural quartz: Its formation and applications to dating and provenance researches

The Grain Size Influence on the E1' Centre Observed in Quartz of Atmospheric Deposition at Two Japanese Cities: A Preliminary Study

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