Дисертації: "Quartz; Thermoluminescence dating; Thermoluminescence"

1

韓志勇 and Zhiyong Han. "Thermoluminescence dating of granitic quartz." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1999. http://hub.hku.hk/bib/B31238555.

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2

Han, Zhiyong. "Thermoluminescence dating of granitic quartz /." Hong Kong : University of Hong Kong, 1999. http://sunzi.lib.hku.hk/hkuto/record.jsp?B21583766.

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3

Chen, Yongye. "Study of luminescence signals from quartz and their applications in geothermometry." Click to view the E-thesis via HKUTO, 2008. http://sunzi.lib.hku.hk/hkuto/record/b40203955.

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4

Chen, Geng, and 陳耿. "Studies of quartz luminescence sensitivity relevant to dating and dosimetry." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2000. http://hub.hku.hk/bib/B42576143.

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5

Chen, Geng. "Studies of quartz luminescence sensitivity relevant to dating and dosimetry." Click to view the E-thesis via HKUTO, 2000. http://sunzi.lib.hku.hk/hkuto/record/B42576143.

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6

Chen, Yongye, and 陳永曄. "Study of luminescence signals from quartz and their applications in geothermometry." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2008. http://hub.hku.hk/bib/B40203955.

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7

Zhao, Hui, and 趙暉. "Studies of isochron luminescence dating with sand-sized grains." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2002. http://hub.hku.hk/bib/B42577329.

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8

Zhao, Hui. "Studies of isochron luminescence dating with sand-sized grains." Click to view the E-thesis via HKUTO, 2002. http://sunzi.lib.hku.hk/hkuto/record/B42577329.

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9

McFee, Christopher James. "The use of an imaging photon detector for luminescence dating." Thesis, University of Oxford, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.296940.

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10

Salmazo, Giovana Oliveira [UNESP]. "Caracterização das propriedades termoluminescentes de sedimentos da formação geológica Rio Claro." Universidade Estadual Paulista (UNESP), 2009. http://hdl.handle.net/11449/91988.

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Made available in DSpace on 2014-06-11T19:25:33Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-10-21Bitstream added on 2014-06-13T20:53:36Z : No. of bitstreams: 1 salmazo_go_me_ilha.pdf: 1435780 bytes, checksum: 267d629a52fdf58b7156f4c83fc33587 (MD5)
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
A formação geológica Rio Claro constitui um dos mais importantes registros sedimentares cenozóicos da Depressão Periférica Paulista. Apesar de essa formação geológica ser muito estudada, sua idade ainda encontra-se indeterminada. De modo a contribuir aos conhecimentos sobre a formação geológica Rio Claro, o trabalho objetivou um estudo geocronológico de seus sedimentos. Para isso, foram estudas cinco amostras sedimentares coletadas de pontos arbitrários da formação geológica, as quais foram denominadas de DSRC- 09, DSRC-10, DSRC-21, DSRC-22 e DSRC-23, e caracterizadas pela técnica da termoluminescência (TL). Grãos de quartzo de diâmetros entre 75 a 180 μm foram utilizados na caracterização. As amostras apresentaram sinal de termoluminescência natural entre 200 e 450 °C. Com exceção da amostra DSRC 22, todas as amostras apresentaram região de Plateau, que indica a região da curva de emissão que se manteve estável durante o período geológico a temperatura ambiente. A região de Plateau de DSRC-09, DSRC-10, DSRC 21 e DSRC-23 compreendeu o intervalo de temperatura de 320 a 380 °C. Pelo método Tm-Tstop se observou a presença de três picos constituindo a curva de emissão termoluminescente nessa região de temperatura. O nível residual da TL foi obtido após 80 horas de exposição dos grãos de quartzo à luz solar. Os sedimentos apresentaram não estar saturados, pois a intensidade do sinal TL aumentou em função de dose adicional artificial. Para a avaliação da idade dos sedimentos, o pico de 325 °C foi isolado e a energia de ativação foi calculada pelo método de crescimento inicial. As idades de deposição obtidas para as amostras DSRC-09, DSRC-10 e DSRC-21 foram respectivamente de 188.000 anos, 210.000 anos e 166.000 anos.
The geological formation Rio Claro constitutes one the most important sedimentary records of São Paulo Peripheral Depression. Although this geological formation is too much studied, its age yet is not determinate. To contribute to knowledge about Rio Claro geological formation, the work aimed a geocronological study of its sediments. For this, five sedimentary samples collected from arbitrary points were studied, which were called DSRC-09, DSRC-10, DSRC- 21, DSRC-22 and DSCR 23, and characterized by thermoluminescence technique. Grains of quartz with diameter between 75 and 180 μm were utilized to characterize it. The samples showed natural thermoluminescence signal between 200 and 450 °C. Except for the sample DSRC 22, all samples showed Plateau region, indicating that the region of glow curve remained stable during the geological time at environment temperature. Plateau region of DSRC-09, DSCR-10, DSRC-21 and DSRC-23 was defined by temperature range of 320 °C to 380°C. The method Tm-Tstop showed that the glow curves are composed by tree peaks in this temperature range. The residual TL was obtained after 80 hours of sunlight exposure. The sediments had not been saturated, because the TL signal intensity increased according to the artificial additional dose. For evaluation of the age sediments, the 325 °C peak was isolated and the activation energy was calculated by the method initial rise. The deposition ages for the samples DSRC-09, DSRC-10 and DSRC-21were respectively 188.000, 210.000 and 166.000 years.

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11

Salmazo, Giovana Oliveira. "Caracterização das propriedades termoluminescentes de sedimentos da formação geológica Rio Claro /." Ilha Solteira : [s.n.], 2009. http://hdl.handle.net/11449/91988.

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Orientador: Keizo Yukimitu
Banca: Ana Maria Osório Araya Balan
Banca: Sonia Hatsue Tatumi
Resumo: A formação geológica Rio Claro constitui um dos mais importantes registros sedimentares cenozóicos da Depressão Periférica Paulista. Apesar de essa formação geológica ser muito estudada, sua idade ainda encontra-se indeterminada. De modo a contribuir aos conhecimentos sobre a formação geológica Rio Claro, o trabalho objetivou um estudo geocronológico de seus sedimentos. Para isso, foram estudas cinco amostras sedimentares coletadas de pontos arbitrários da formação geológica, as quais foram denominadas de DSRC- 09, DSRC-10, DSRC-21, DSRC-22 e DSRC-23, e caracterizadas pela técnica da termoluminescência (TL). Grãos de quartzo de diâmetros entre 75 a 180 μm foram utilizados na caracterização. As amostras apresentaram sinal de termoluminescência natural entre 200 e 450 °C. Com exceção da amostra DSRC 22, todas as amostras apresentaram região de Plateau, que indica a região da curva de emissão que se manteve estável durante o período geológico a temperatura ambiente. A região de Plateau de DSRC-09, DSRC-10, DSRC 21 e DSRC-23 compreendeu o intervalo de temperatura de 320 a 380 °C. Pelo método Tm-Tstop se observou a presença de três picos constituindo a curva de emissão termoluminescente nessa região de temperatura. O nível residual da TL foi obtido após 80 horas de exposição dos grãos de quartzo à luz solar. Os sedimentos apresentaram não estar saturados, pois a intensidade do sinal TL aumentou em função de dose adicional artificial. Para a avaliação da idade dos sedimentos, o pico de 325 °C foi isolado e a energia de ativação foi calculada pelo método de crescimento inicial. As idades de deposição obtidas para as amostras DSRC-09, DSRC-10 e DSRC-21 foram respectivamente de 188.000 anos, 210.000 anos e 166.000 anos.
Abstract: The geological formation Rio Claro constitutes one the most important sedimentary records of São Paulo Peripheral Depression. Although this geological formation is too much studied, its age yet is not determinate. To contribute to knowledge about Rio Claro geological formation, the work aimed a geocronological study of its sediments. For this, five sedimentary samples collected from arbitrary points were studied, which were called DSRC-09, DSRC-10, DSRC- 21, DSRC-22 and DSCR 23, and characterized by thermoluminescence technique. Grains of quartz with diameter between 75 and 180 μm were utilized to characterize it. The samples showed natural thermoluminescence signal between 200 and 450 °C. Except for the sample DSRC 22, all samples showed Plateau region, indicating that the region of glow curve remained stable during the geological time at environment temperature. Plateau region of DSRC-09, DSCR-10, DSRC-21 and DSRC-23 was defined by temperature range of 320 °C to 380°C. The method Tm-Tstop showed that the glow curves are composed by tree peaks in this temperature range. The residual TL was obtained after 80 hours of sunlight exposure. The sediments had not been saturated, because the TL signal intensity increased according to the artificial additional dose. For evaluation of the age sediments, the 325 °C peak was isolated and the activation energy was calculated by the method initial rise. The deposition ages for the samples DSRC-09, DSRC-10 and DSRC-21were respectively 188.000, 210.000 and 166.000 years.
Mestre

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12

Lontsi, Sob Aaron Joel. "Thermoluminescence of natural quartz." Thesis, Rhodes University, 2014. http://hdl.handle.net/10962/d1013358.

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The kinetic and dosimetric features of the main thermoluminescence peak of quartz have been investigated in unannealed as well in quartz annealed at 500˚C for 10 minutes. The main peak is found at 92 and 86˚C respectively for aliquots of unannealed and annealed samples irradiated to 10 Gy and heated at 5.0˚C/s. For each sample, the intensity of the main peak is enhanced with repetitive measurement whereas its maximum temperature is unaffected. The peak position of the main peak in each sample is independent of the irradiation dose and this, together with its fading characteristics are consistent with first-order kinetics. For low doses, typically between 2 and 10 Gy, the dose response of the main peak in each sample is linear. In the intermediate dose range from 10 to 60 Gy, the growth of the main peak in each sample is sub-linear and for greater doses, in the range from 60 Gy to 151 Gy, it is linear again. The half-life of the main peak of the unannealed sample is about 1.3 h whereas that of the annealed sample is about 1.2 h. The main peak in each sample can be approximated to a first-order glow peak. As the heating rate increases, the intensity of the main peak in each sample decreases. This is evidence of thermal quenching. The main peak in each sample is the only peak regenerated by phototransfer. The resulting phototransferred peak occurs at the same temperature as the original peak and has similar kinetic and dosimetric features. For a preheat temperature of 120˚C, the intensity of the phototransferred peak in each sample increases with illumination time up to a maximum and decreases afterwards. At longer illumination times (such as 30 min up to 1 h), no further decrease in the intensity of the phototransferred peak is observed. The traps associated with the 325˚C peak are the main source of the electrons responsible for the regenerated peak. Radioluminescence emission spectra were also measured for quartz annealed at various temperatures. Emission bands in quartz are affected by annealing and irradiation. A strong enhancement of the 3.4 eV (~366 nm) emission band is observed in quartz annealed at 500˚C. A new emission band which grows with annealing up to 1000˚C is observed at 3.7 eV (~330 nm) for quartz annealed at 600˚C. An attempt has been made to correlate the changes in radioluminescence emission spectra due to annealing with the influence of annealing on luminescence lifetimes in quartz.

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13

Niyonzima, Pontien. "Thermoluminescence characteristics of synthetic quartz." Thesis, Rhodes University, 2014. http://hdl.handle.net/10962/d1013190.

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Quartz is one of the most abundant natural minerals in the crust of the earth. Due to its dosimetric luminescence properties, it is employed in retrospective dosimetry, archaeological and geological dating. The intensity and the structure of the TL glow curves of quartz are strongly dependent upon the origin, impurity content, formation condition and pre-irradiation heat treatment. The aim of this project is to study the mechanisms of thermoluminescence (TL), Phototranssferred thermoluminescence (PTTL) and radioluminescence (RL) in synthetic quartz and to discuss the results in terms of physical characteristics of point defects involved. Thermoluminescence measurements were made on a sample of synthetic quartz in its as-received state (unannealed) synthetic quartz annealed at 500˚C for 10 minutes. The unannealed sample shows six TL glow peaks located at 94, 116, 176, 212, 280 and 348˚C at a heating rate of 5˚Cs⁻¹. The annealed sample shows seven TL peaks at 115, 148, 214, 246, 300, 348 and 412˚C at a heating rate of 5˚Cs⁻¹. The intensity of peak I, at 94 and 115˚C for the unannealed and annealed samples respectively, increases with irradiation. Peak I has an activation energy of approximately 0.90 eV and a frequency factor of the order of 10¹¹ s⁻¹. The order of kinetics is between 0.9 and 1.2. The unannealed synthetic quartz shows phototransferred thermoluminescence (PTTL) at the position of peak I after removal of the first three peaks followed by illumination. The PTTL intensities show peak shaped behaviour when plotted against illumination time. The PTTL showed a quadratic increase with dose. The material exhibits fading of PTTL intensity with delay time. Radioluminescence was measured on synthetic quartz unannealed and annealed annealed at 500, 600, 700, 800, 900 and 1000˚C for 10 to 60 min. The emission spectra of synthetic quartz show seven emission bands. The effect of irradiation on the RL spectra is to increase the intensity of all emission bands for samples annealed at temperatures less than or equal to 700˚C. The effect of annealing time is to increase the RL amplitude for the samples annealed at temperatures greater than 700˚C. The annealing temperature increases the RL amplitude of all emission bands of the spectrum for all samples.

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14

Atang, Elizabeth Fende Midiki. "Thermoluminescence of annealed synthetic quartz." Thesis, Rhodes University, 2016. http://hdl.handle.net/10962/420.

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The kinetic and dosimetric features of the main thermoluminescent peak of synthetic quartz have been investigated in quartz ordinarily annealed at 500_C as well as quartz annealed at 500_C for 10 minutes. The main peak is found at 78 _C for the samples annealed at 500_C for 10 minutes irradiated to 10 Gy and heated at 1.0 _C/s. For the samples ordinarily annealed at 500_C the main peak is found at 106 _C after the sample has been irradiated to 30 Gy and heated at 5.0 _C/s. In these samples, the intensity of the main peak is enhanced with repetitive measurement whereas its maximum temperature is unaffected. The peak position of the main peak in the sample is independent of the irradiation dose and this, together with its fading characteristics, are consistent with first-order kinetics. For doses between 5 and 25 Gy, the dose response of the main peak of the annealed sample is superlinear. The half-life of the main TL peak of the annealed sample is about 1 h. The activation energy E of the main peak is around 0.90 eV. For a heating rate of 0.4 _C/s, its order of kinetics b derived from the whole curve method of analysis is 1.0. Following irradiation, preheating and illumination with 470 nm blue light, the main peak in the annealed sample is regenerated during heating. The resulting phototransferred peak occurs at the same temperature as the original peak and has similar kinetic and dosimetric features, with a half-life of about 1 h. For a preheat temperature of 200 _C, the intensity of the phototransferred peak in the sample increases with illumination time up to a maximum and decreases thereafter. At longer illumination times, no further decrease in the intensity of the phototransferred peak is observed. The traps associated with the 325 _C peak are the main source of the electrons responsible for the regenerated peak.

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15

Templer, R. H. "Thermoluminescence techniques for dating zircon inclusions." Thesis, University of Oxford, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.376953.

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16

Es, Hendrickje Jacoba van. "Thermoluminescence dating of sediments using mineral zircon." [S.l. : [Groningen : s.n.] ; University Library Groningen] [Host], 2008. http://irs.ub.rug.nl/ppn/308380185.

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17

Spooner, Nigel Antony. "The effect of light on the thermoluminescence of quartz /." Title page, contents and summary only, 1987. http://web4.library.adelaide.edu.au/theses/09SM/09sms764.pdf.

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18

Fox, Phillip James. "Optical studies of thermoluminescent materials /." Title page, contents and summary only, 1990. http://web4.library.adelaide.edu.au/theses/09PH/09phf793.pdf.

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19

Zhou, Li-Ping. "Thermoluminescence dating and environmental magnetism of loess from China." Thesis, University of Cambridge, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.239183.

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20

Fattahi, Morteza. "Studies on red thermoluminescence and infrared stimulated red luminescence." Thesis, University of Oxford, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.246618.

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21

Wheeler, G. C. W. S. "Luminescence studies relevant to archaeological dating." Thesis, University of Oxford, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.670305.

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22

Hochman, Mark Brett McEwen. "The application of artificial thermoluminescence to uranium exploration and uranium ore genesis studies." Title page, abstract and contents only, 1989. http://web4.library.adelaide.edu.au/theses/09PH/09phh6825.pdf.

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23

Spooner, Nigel A. "The validity of optical dating based on feldspar." Thesis, University of Oxford, 1993. http://ora.ox.ac.uk/objects/uuid:79041fc9-be84-4330-8142-b3766cb932c7.

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The potential for valid dating using feldspar minerals has recently been increasingly questioned with the recognition of a range of effects capable of giving rise to age shortfalls. The intention here was to investigate the more serious of these, and to simultaneously extend the surprisingly meagre body of knowledge on the luminescence of the feldspar minerals. A suite of feldspars representative of all major mineral species of the feldspar ternary system was assembled and mineralogically classified by XRD and SEM techniques. Characterization of some luminescence properties relevant to dating (radiation dose-sensitivities, emission spectra, thermal sensitization and bleaching by IR and green light) was conducted to enable comparison of these properties with the anomalous fading behaviour in each feldspar (IRSL and OSL intensities being subsequently measured as a function of storage duration at 10°C and 100°C). Examples of feldspars representative of each major compositional regime of the ternary system were found to fade, and similarly some were stable; no luminescence characteristics or storage duration at these temperatures permitted reliable separation of stable signals. A new method for analysis of localised transition-type anomalous fading was successfully tested on zircon; however the fading mechanism operant in feldspars was found to be tunnelling-type fading. Such fading cannot be circumvented by any feasible laboratory procedure and it was concluded that monitoring of samples for the presence of fading is essential: discovery of fading is a rejection criteria. The long-term trapping stability of the IRSL source traps was investigated by "conventional" kinetic means, and also by a combined optical and thermal approach in which the bleaching response curves of five selected feldspars were measured along with their low temperature (= 100-400 K) response. It was concluded that the IRSL signal originates from one trap type only in all feldspars, which possesses a constant ground state-to-excited state transition energy of 1.44 ± 0.01 eV. However, the excited state-to-conduction band energy varies depending on the major element composition of the feldspar. Lifetimes of microcline TL from glow curve temperatures > 300°C greatly exceed the minimum required for dating and this work and complementary experiments showed no physical basis for the existence of an age limit for coarse grain feldspars, other than dose saturation. Supplementary work supported the existence of an upper age limit of = 100 ka for fine grain materials.

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24

Jungner, Högne. "Thermoluminescence dating in archaeology and geology in Finland comparison with results from radiocarbon dating /." Hki : Societas scientiarum Fennica : Academic Bookstore [distr.], 1987. http://catalog.hathitrust.org/api/volumes/oclc/57779283.html.

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25

Mthwesi, Zuko. "Thermoluminescence of synthetic quartz annealed beyond its second phase inversion temperature." Thesis, Rhodes University, 2017. http://hdl.handle.net/10962/46077.

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Thermoluminescence of synthetic quartz annealed at 1000 ºC for 10 minutes has been studied. The aim was to study mechanisms of thermoluminescence in annealed synthetic quartz and to discuss the results in terms of the physics of point defects. The sample was irradiated with a beta dose of 10 Gy of beta radiation and then heated at a linear heating rate of 1 ºC.s-1 up to 500 ºC. The thermoluminescence (TL) glow curve consists of three glow peaks. Peak I at 74 0C (main peak) with high intensity as compared to the other two peaks. Peak II at 144 ºC is more intense than peak III at 180 ºC. This study was on the main peak (MP) at 74 ºC and peak III at 180 ºC. Kinetic analysis was carried out to determine the trap depth E, frequency factor s and the order of kinetics b of both peaks using the initial rise, peak shape, variable heating rate, glow curve deconvolution and isothermal TL methods. The values of kinetic parameters obtained were around 0.7 to 1.0 eV for trap depth and in the interval of 108 to 1015 s-¹ for frequency factor for both peaks. The effect of heating rate from 0.5 to 5 ºC.s-¹ on the TL peak intensity and peak temperature was observed. Also the effect of thermal quenching was observed at high heating rates. Since the TL glow curve has overlapping TL peaks, the Tm-Tstop method from 54 ºC up to 64 ºC and E -Tstop methods were introduced where a first order single peak was observed. Phototransfered thermoluminescence (PTTL) was investigated and characterized by three peaks. First PTTL peak I at 72 ºC, peak II at 134 ºC and peak III at 176 ºC. Analysis was carried out on peaks I and III for the effect of dose dependence from 20-200 Gy. Thermal fading was observed on PTTL peaks I and III, after storage time of 30 minutes.

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26

Luiz, Juliet C. "Comparative thermoluminescence dating of Quaternary North American obsidians and crystalline lavas." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape17/PQDD_0008/MQ36368.pdf.

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27

Sanderson, D. C. W. "Thermoluminescence dating of Scottish vitrified forts : development, evaluation and demonstration of the potential of thermoluminescence dating techniques to resolve outstanding chronological problems associated with Scottish vitrified forts." Thesis, University of the West of Scotland, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.376105.

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The Scottish vitrified forts form a unique assemblage of archaeological monuments exhibiting the common feature of partly melted masonry generally found in the vicinity of a ruined wall. Although they have received considerable attention from scholars since their discovery in the late eighteenth century many questions relating to origins, purpose and chronology remain unanswered. This work represents the first coherent attempt to develop and apply direct dating to vitrified rocks _ using thermoluminescence (TL) techniques to establish the time elapsed since the last heating of the sample. The technique is based on equating the thermoluminescence acquired by minerals within vitrified rocks, during the period following vitrification, to the levels of natural ionising radiation within and around the samples. Study sites were selected on the basis of a mineralogical, analytical and dosimetric survey of material from museum collections, and sampled from secure contexts using a portable diamond coring tool. Radiation dose rates to the samples were determined using a combination of thermoluminescence and low level counting methods coupled to standard microdosimetric models for specific mineral phases. A promising new method of rapid beta dose rate measurement was developed during this work. Thermoluminescence measurements of separated mineral extracts were performed using computerised eqUipment to determine the total radiation dose experienced since firing. Particular attention was paid to the form of the radiation dose dependence of samples from different Sites, and to the stability and reproducibility of TL signals. Coherent thermoluminescence ages were obtained from the sites of Finavon,Craig Phadrig, Dun Lagaidh, Langwell, Knockfarrel and Tap 0 Noth, using feldspar fractions extracted from the samples, and indicate a long time span for the monuments stretching from the 2nd millenium Be to the first millenium AD. This evidence considerably extends the timespan attributable to the monuments and paves the way for further work to establish the relationship between the morphology and chronology of a wider range of sites.

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28

Wong, Wai-leung Nelson. "Thermal stability of luminescence signals relevant to dating /." Hong Kong : University of Hong Kong, 1997. http://sunzi.lib.hku.hk/hkuto/record.jsp?B19471129.

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29

Parks, D. A. "TL dating and geochemistry of brickearths in S.E. England." Thesis, University of Sussex, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.282705.

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30

Wong, Wai-leung Nelson, and 王韋良. "Thermal stability of luminescence signals relevant to dating." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1997. http://hub.hku.hk/bib/B31220137.

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31

Zhang, Jiafu. "Development and application of luminescence dating to quaternary sediments from China." Hong Kong : University of Hong Kong, 2000. http://sunzi.lib.hku.hk/hkuto/record.jsp?B22266628.

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32

Ivaldi, Jean-Pierre. "Thermoluminescence et orogenèse. Les Alpes occidentales au Paléogène." Phd thesis, Université de Nice Sophia-Antipolis, 1989. http://tel.archives-ouvertes.fr/tel-00690610.

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Le sujet de ce travail est l'étude du Paléogène marin de la zone alpine externe. Son objet : rechercher par l'analyse détaillée des unités lithostratigraphiques externe. Son objet : rechercher par l'analyse détaillée des unités lithostratigraphiques formelles, des données et des schémas paléogéographiques cohérents qui permettent de préciser l'évolution tectono-sédimentaire de la marge interne de la plaque européenne au cours de la période paléogène. La principale méthode d'investigation utilisée est la thermoluminescence (TL), en association avec des méthodes d'étude plus classiques empruntant à la biostratigraphie, à la pétrographie et à l'analyse structurale. Quatre parties constituent le présent mémoire. La première partie est d'ordre méthodologique. Successivement , sont précisés: la phénoménologie de la thermoluminescence, les modalités d application de la méthode d'analyse dans le domaine des Sciences de la Terre, les différentes techniques expérimentales utilisées, le choix des paramètres TL et leur traitement statistique. La seconde partie traite des relations entre la thermoluminescence et le métamorphisme mésoalpin. Ce métamorphisme, qui affecte irrégulièrement les matériaux paléogènes et leur substratum, est générateur d'une thermoluminescence de néogenèse dont les caractères spécifiques sont appréhendés grâce à l'analyse des filons de quartz syn- à tardimétamorphes post-priaboniens. Les effets de ce métamorphIsme sont variables et sélectifs à l'échelle des Alpes occidentales,limités dans la zone alpine externe, plus importants dans le domaine interne - notamment dans le Briançonnais - où ils peuvent entraîner l'effacement partiel ou total des caractères thermoluminescents originels du quartz et introduire une part d'incertitude non négligeable dans le raisonnement et les conclusions d'ordre paléogéographique. La troisième partie est consacrée à l'étude régionale des formations détritiques paléogènes de la zone alpine externe affleurant dans les Alpes maritimes s .l., dans le Champsaur et dans le Dévoluy, dans le Pays des Arves et en Haute-Savoie. L'emploi de diagrammes bidimensionnels et de cartes isofactes prenant en compte les paramètres de thermoluminescence les plus performants permet de défInir les principales provinces distributives de matériaux terrigènes, de faire la part des apports d'origine externe et interne lors des différents stades de remplissage des bassins et sous-bassins paléogènes dont l'évolution paléogéographique et structurale est également précisée par l'établissement de cartes de paléofaciès et par l'analyse de la déformation des matériaux à toutes les échelles. Le modèle géodynamique proposé en conclusion, dans la dernière partie du mémoire, lie intimement la sédimentation et la déformation progressive des flyschs crétacés allochtones et des flyschs paléogènes d'avant-pays dans les Alpes occidentales. Il considère l'ensemble de ces flyschs comme un continuum de formations synorogéniques déposées dans des bassins convergents installés par subsidence "forcée' à l'avant de chevauchements crustaux actifs engendrés par la collision Europe-Afrique à partir de l'Albien terminal, le remplissage des bassins sédimentaires étant d'abord assuré par des reliefs bordiers externes rajeunis par le développement de bombements lithosphériques, puis par les parties internes de l'orogène intégrant progressivement ces mêmes flyschs dans leurs superstructures.

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張家富 and Jiafu Zhang. "Development and application of luminescence dating to quaternary sediments from China." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2000. http://hub.hku.hk/bib/B31242662.

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Pucillo, Kevin. "Quaternary palaeochannel evolution and groundwater movement in the Coleambally Irrigation District of New South Wales." School of Earth and Environmental Sciences - Faculty of Science, 2005. http://ro.uow.edu.au/theses/406.

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The Quaternary alluvial and aeolian sediments underlying the eastern portion of the Riverine Plain have been examined to assess their impact on groundwater access and movement in the Coleambally district. Over 9800 borehole logs from the Coleambally Irrigation Area (CIA) and surrounding districts were digitized using GIS and database software and supplemented with 632 borehole logs from the Department of Land and Water Conservation (Leeton) to form the platform for stratigraphic and groundwater investigations conducted in this study. The borehole data were summarised into two sediment classification schemes, the first to delineate the distribution of palaeochannel sediments and the second to assess to spatial distribution of aquitards and aquifers. A series of detailed cross-sections differentiated between at least four distinct palaeochannel sequences identified within the Upper Shepparton Formation overlying the clay-dominated Lower Shepparton Formation. The two deepest sequences, the new Gumblebogie and Ugobit members, comprise thick (3-10 m), laterally extensive (up to 25 km wide) sheets of coarse sandy alluvium that occur to the north of the CIA at depths between 12 to 35 metres below the surface. These deposits are evidence of highly active alluvial phases on the plain, more vigorous than any since. Slightly higher in the sequence (typically 10-20 m depth) is a thick (2-15 m), laterally extensive (up to 10 km wide) mixed-load sequence (the new Duderbang member), which is stratigraphically disconnected from the deeper sanddominated units. Near-surface palaeochannel deposits, which consist of less extensive (up to 3 km wide) coarse sandy alluvium at depth and a combination of mixed- and bedload sequences closer to the surface, make up the youngest palaeochannel deposits in the area. The size and extent of reserved palaeochannel sequences beneath the study area have decreased markedly since what is interpreted as the mid Quaternary and is probably symptomatic of declining fluvial activity on the Riverine Plain through to the present. The development of source-bordering dunes associated with belts of palaeochannel material in the area was examined using shallow geophysics (GPR), topographic surveys, laser particle size analysis and thermoluminescence dating. Dune building in Contents the area occurred in conjunction with channel activity during the Kerarbury (55-35 ka) and Coleambally (105-80 ka) palaeochannel phases (Page et al., 1996) when sediment supply conditions were favourable, probably due to strongly seasonal discharges draining the southeastern highlands. The presence of stabilising vegetation on the channel margins is believed to have played a key role in the development of dunes in the area, which show poorly developed internal structure. The increased precipitation that enhanced channel discharges must also have sustained dune vegetation. Increased aridity and reduced vegetation approaching and during the LGM appears to have caused the widespread remobilization of dune crests. The complex alluvial and aeolian stratigraphy of the Shepparton Formation strongly influences groundwater movement in the Coleambally district. Piezometric levels show that deeper, highly permeable units (e.g. Ugobit member) in the northern part of the study area act as conduits for the discharge of groundwater, helping to maintain much lower watertables in the north as well as induce groundwater flow from the CIA. ‘Sediment vs depth’ analysis demonstrates that there is limited vertical connection through the thick, clay-dominated sequence of the Lower Shepparton Formation to the highly transmissive sands and gravels of the underlying Calivil Formation. The tendency of the Lower Shepparton Formation to restrict downward leakage is likely to both contribute to the problem of shallow irrigation-induced watertables in the CIA as well as impede efforts to lower watertables by pumping from deeper aquifers. The upper 3 metres of the Shepparton Formation are clay-dominated with a low water storage capacity, causing near-surface watertables to be highly responsive to recharge by surface water. The available data indicate that when piezometric levels fall below this clay-rich zone they are able to absorb short-term increases in recharge due to the higher proportion permeable alluvium in the unsaturated zone.

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Nyirenda, Angel Newton. "Mechanisms of luminescence in α-Al₂O₃:C : investigations using time-resolved optical stimulation and thermoluminescence techniques". Thesis, Rhodes University, 2013. http://hdl.handle.net/10962/d1002961.

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Carbon-doped aluminium oxide, α-Al₂O₃:C, is a ultra-sensitive dosimeter of topical research interest. The aim of this project was to investigate the dynamics of luminesce in this material. The methods of investigation consisted of thermoluminescence and time-resolved optical stimulation. Thermoluminescence measurements provide information on trap distribution and kinetic parameters of the traps involved in luminescence whereas time-resolved optical stimulation is a handy technique in investigation of luminescence lifetimes and provides an insight into the charge transitions between traps and recombination centres. Measurements were made on samples annealed at a nominal temperature of 900⁰C for 15 minutes. The material shows the presence of five thermoluminescence peaks at 37⁰C, 160⁰C, 300⁰C 410⁰C, and 480⁰C at a heating rate of 0.03k/s when irradiated to 6.0 Gy of beta. The main peak at 160⁰C, shows a linear dose response for doses between 0.1 Gy and 10 Gy and then goes sublinear above 10 Gy, the peak at 37⁰C shows a sublinear dose response for doses between 0.1 Gy and 10 Gy and appears to saturate thereafter, whereas the dose response of the peak at 300⁰C goes from linear to supralinear then apparently quadratic behaviour in the dose range of 0.1 Gy to 16.0 Gy. The trap depth of the main peak, that is, its activation energy as determined below the conduction band, has been approximated at 1.3 eV with a kinetic order of approximately 1.2. Time-resolved optical stimulation has been used to investigate luminescence lifetimes. The mean luminescence lifetime obtained for the sample at ambient temperatures is 35.0±1.0 ms. The investigations of the dependence of luminescence lifetimes on measurement temperature show that the material suffers from thermal quenching effects at measurement temperatures above 140⁰C with the activation energy of thermal quenching estimated at 1.045±0.002 eV. Shallow traps i.e. traps lying close to the conduction band, seem to elongate the lifetimes of optically stimulated luminescence in the material at temperatures between 30⁰C - 80⁰C due to charge retrapping. The material exhibits both fading and recuperation of the optically stimulated luminescence signal with storage time.

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Farias, Thiago Michel de Brito. "Estudo das propriedades termoluminescentes e de absorção óptica de oito variedades de quartzo." Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/43/43134/tde-15042009-165630/.

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No presente trabalho, foram investigadas propriedades de absorção óptica e termoluminescência para sete variedades de quartzo natural brasileiro (Azul, com enxofre, leitoso, rosa, verde, vermelho e preto). Para efeitos comparativos, empregou-se o quartzo hialino e o sintético, ambos na fase alfa. Ametista e citrino não foram estudados devido ao número grande de relatos na literatura destes materiais. A difração de raios-X mostrou que todas as variedades de quartzo estudadas possuem a mesma estrutura padrão de quartzo. A composição das amostras obtidas por Fluorescência de Raios-X e Espectroscopia de Massas com Plasma (ICP-MS), revelam a presença de Al2O3 e Na2O em todas as variedades além de concentrações de Ca, Zn, Zr e Ba. Os picos TL nas curvas de emissão são discrepantes das curvas usualmente encontradas na literatura, com picos em 1100C, 2200C e 3250C. Apenas o pico em 1100C é comum a todas as amostras. Em relação à forma das curvas de emissão também existe discrepância. O comportamento da intensidade TL em função da dose, para picos em 2200C e 3250C é singular para cada amostra, de forma que o comportamento linear-supralinear-sublinear é observado apenas nos picos em 2200C para amostras de quartzo azul e hialino. O pico em 3250C, apresenta em praticamente todas as amostras, um terceiro estágio de crescimento com a dose. Admiti-se que o segundo estágio, que é da supralinearidade, é causado pela criação de novas vacâncias de oxigênio pela radiação, o segundo estágio é seguido de outro não-linear. Aqui se propõe um modelo em que a radiação cria novas vacâncias, dentro do grupo de tetraedros SiO4, do qual se formou a vacância de oxigênio. O germânio, no presente trabalho, possui concentrações baixíssimas em amostras como o quartzo leitoso e quartzo com enxofre, de maneira que não apresenta correlação com o pico de 110°C, conforme descrito na literatura, pois ambas amostras apresentam intensos picos nesta região de temperatura. Estudos de absorção óptica revelam a existência de bandas de absorção em 620, 450 e 350nm. Conforme a literatura, estas bandas são causadas pela presença do alumínio, pois crescem rapidamente com a radiação, causando a transição do quartzo hialino para quartzo fumê. Ao se comparar com amostra de quartzo artificial, com concentrações de alumínio, próximas as do hialino, a amostra não apresentou as três bandas mencionadas anteriormente, de maneira que se pode concluir que o alumínio não é o responsável por elas. Conclui-se que, as sete variedades de quartzo do presente trabalho, apresentam propriedades TL e de AO muito singulares para cada variedade, ao contrário do que se espera ao analisar os difratogramas das amostras.
Thermoluminescence and optical absorption properties of seven varieties of natural Brazilian quartz, namely, blue, sulphurous, milky, pink, green, red and black quartzs, have been investigated. For comparasion measurements were carried out also on natural alpha and synthetic quartz. Since gemological amethyst and citrine have been studied by several authors, they were not included in this work. The X Ray diffraction analysis has shown that all seven varieties of quartz have a same crystal structure of a standard sample. X Ray fluorescence and Plasma Mass Spectrometry (ICP-MS) analysis reveal Al2O3 and Na2O in all the quartz in fairly large amount, wich are essential in TL emission. Ca, Zn, Ba and Zr are also found in all the quartz samples, however several previous studies of silicate minerals indicated that they do not participate in the physical properties investigated. It is commonly known that a natural alpha quartz presents in its glow curve, 110, 220 and 325°C (sometimes replaced by 375°C) peaks. Except for 110°C peak, the two others are found is some variety but not in others. No explanation was found yet. The shape of glow curves also vary considerably from one variety to others. A striking result was obtained concerning TL response as function of radiation dose of 220°C (245°C in black quartz) and 325°C peaks. The linearsupralinear- sublinear, commonly observed in alkali halides, oxides, sulphates, etc. crystals are not observed in quartz samples except for 220°C peak in blue quartz and hyaline quartz. If linear and supralinear behavior are called first and second stage, the third stage in many of them is not sublinear, rather it keeps growing. In some cases, the first and second stages are strongly supralinear, sulphurous such as in quartz and pink quartz . In alkali halide crystal, for instance, the second stage is due to anion vacancy generated by radiation. In quartz it is due to generation of oxygen vacancy. For the third stage it is proposed that the radiation creates new oxygen vacancy in the group of SiO4 tetrahedron generating oxygen vacancy for the second stage. In the literature, one finds Ge being responsible for production of 110°C peak. The ICP-MS measurements has shown that Ge is found in all the varieties seven quartz, except in sulphurous one, but in less that 2 ppm concentration. Furthermore it was found that the 110°C peak intensity, in these quartz, has no correlation to Ge concentration, the 110°C peak has a huge intensity. Therefore, it is proposed that the oxygen removed from its normal site ends up in an intersticial position as neutral oxygen. The irradiation liberating e-h pairs enable intersticial oxygen to capture electron and became O- centre. This is the source of 110°C peak. The optical absorption spectra of alpha quartz, particularly of heavily irradiated one, show bands at 620, 450 and 350nm. They were attributed to aluminum. Similar result was found in alpha quartz, but the synthetic one with a comparable concentration of aluminum as in the natural alpha quartz did not present such bands, even after irradiation to 20 to 25kGy gamma rays. It was concluded that 620, 450 and 350nm bands are not due to aluminum. It was not found the impurities responsible for there bands. In conclusion, the seven varieties investigated, present quite different behaviour. Compared to that of the usual nature alpha quartz.

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Yukimitu, Keizo. "Eletrodifusão, absorção óptica e termoluminescência no quartzo e berilo." Universidade de São Paulo, 1993. http://www.teses.usp.br/teses/disponiveis/43/43131/tde-13092013-112622/.

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No presente trabalho, foi montado um sistema de eletrodifusão para o estudo dos efeitos da substituição de íons alcalinos, presentes no canal estrutural, por íons de hidrogênio (H POT. +), nas propriedades termoluminescentes e ópticas do quartzo. A corrente elétrica de eletrólise apresenta, na parte inicial de aquecimento, um ombro ou pico de corrente. Através da análise do comportamento deste pico e informações obtidas de dados de absorção óptica na região espectral do infravermelho, concluiu-se que o pico presente na curva inicial de eletrólise se deve ao complexo [AL POT. 3+/M POT. +]. As medidas de termoluminescência e absorção óptica na região espectral do visível e ultra-violeta foram feitas em amostras de quartzo eletrodifundidos e não eletrodifundidos e chegou-se à proposição de uma reação envolvendo os alcalinos presentes no canal. Nesta reação, os íons alcalinos fazem o papel de centros armadilhadores de íons de oxigênio O POT. produzidos pela radiação ionizante, e estabilizadores de vacâncias de oxigênio. O aquecimento, em tomo de 300 GRAUS C, provoca a desestabilização desses centros armadilhadores, liberando os íons alcalinos que reagem com os defeitos [ALO IND. 4] POT. 0 emitindo luz TL. Aproveitando a existência de canais estruturais, semelhantes ao quartzo, tentou-se eletrodifundir H POT + no berilo. Através de medidas de termoluminescência e corrente inicial de eletrólise, discute-se a possibilidade da existência do defeito [FE POT. 3+/M POT. +] no berilo.
A system of electrodiffusion was made in the laboratory to investigate effects of exchanging alkali ions, usually present in the structural channels by protons, in the optical and thermoluminescent properties of quartz. In the initial part of heating, the sweeping current presents a peak at about 350 GRAUS C. The analysis of the behaviour of this peak with additional data of optical absorption in the region of infrared, it was concluded that the peak at 350 GRAUS C of the current is due to [AL POT. 3+/M POT. +] system. Thermoluminescence and optical absorption spectra in the visible and ultraviolet light region for swept and unswept quartz were compared. Based on this comparison it was shown that, once irradiated to gama- or X-rays, alkali ions are removed from [AL POT. 3+/ M POT. +] and either couple to o ions or capture electron and become interstitial alkali atom, leaving, further, [ALO IND. 4] POT. 0 hole center. Heating at about 300 GRAUS C electrons from M POT 0 or M POT +O POT recombine with holes in [ALO IND. 4] POT. 0, emitting TL light, besides regrouping Al POT. 3+ and M POT. + to reform [Al POT. 3+/M POT. +] system by coulomb attraction. The electrodiffusion experiment was extended to beryl crystal, because beryl has also structural channels. To explain initial sweeping current behaviour as well as thermoluminescent property a mechanism involving [FE POT. 3+/M POT. +] system is proposed.

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LOYER, STEPHANE. "Thermoluminescence du quartz naturel : apports methodologiques a la datation des sediments eoliens et contribution a celles des argiles cuites archeologiques." Rennes 1, 1993. http://www.theses.fr/1993REN10077.

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Le quartz est tres abondant dans les argiles et dans les sediments eoliens. Pendant leur fabrication ou leur utilisation, les ceramiques archeologiques sont chauffees a haute temperature. Les charges piegees dans les niveaux permis de la bande interdite des grains de quartz inclus sont thermo-videes. Lors du transport eolien d'un sediment, les quartz subissent un vidage similaire mais stimule optiquement. Les instants de ces deux vidages sont datables par la methode de la thermoluminescence. Les recherches ont porte sur deux methodes absolues de datation, l'une applicable au quartz extrait des ceramiques archeologiques et l'autre au quartz de sediments eoliens quaternaires. Un mode de preparation du quartz de ceramique a ete propose. Des ages tl obtenus par la methode de la pre-dose ont ete confrontes avec les donnees d'une datation archeomagnetique sur les memes echantillons. Le quartz est peu utilise pour dater les sediments eoliens du nord-ouest de l'europe car on lui attribue un mauvais photo-vidage et sa forte dose annuelle lui confere une faible dose a saturation. Un pic caracteristique de thermoluminescence a ete observe sur cinq types de sediments a 370 degres avec une emission maximale a 470-480 manometres. Son photo-vidage est rapide et les pieges associes ne conservent qu'une faible proportion de charges. Les courbes de croissance de ce pic avec la dose radioactive ajoutee sont complexes. Cependant, la dose accumulee (ou paleodose) a ete determinee par les methodes du photo-vidage (ou blanchiment) total et de la regeneration normalisee. Cette seconde methode, developpee specialement pour les quartz eoliens au cours de cette etude, utilise la proportionnalite des courbes primaires et tertiaires. Deux lss vrais du nord de la bretagne ont ainsi ete dates avec une bonne precision

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Martin, Loïc. "Caractérisation et modélisation d'objets archéologiques en vue de leur datation par des méthodes paléo-dosimétriques : simulation des paramètres dosimétriques sous Geant4." Thesis, Bordeaux 3, 2015. http://www.theses.fr/2015BOR30055/document.

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Les méthodes paléodosimétriques permettent d’obtenir l’âge de certains matériaux de nature minérale qui se comportent comme des dosimètres naturels, l’âge étant alors donné par le rapport de la dose accumulée depuis l’événement à dater, au débit de dose naturel auquel l'échantillon a été soumis. La détermination du débit de dose repose le plus souvent sur des modèles simples, qui seuls permettent des calculs explicites, mais ces modèles ne reproduisent que très imparfaitement la diversité des situations rencontrées. La modélisation informatique permet d’envisager des modèles plus complexes et plus réalistes, qui conduisent à simuler numériquement le débit de dose. Dans ce travail, la boite à outils Geant4, qui permet de simuler les interactions particule-matière selon la méthode de Monte-Carlo, a été utilisée pour créer des modèles complexes, ainsi que des outils de modélisation accessibles et adaptables aux différents types d'échantillons et situations dosimétriques. Des simulations ont tout d'abord été faites à partir de modèles basiques afin d'étudier l’origine des variations du débit de dose dans des sédiments, mettant en évidence les limites des modèles simples utilisés couramment. Ces informations ont permis d'orienter le développement d'outils de modélisation basés sur les codes de Geant4, et aussi de préciser les protocoles d'analyse des échantillons permettant de réunir les données nécessaires aux simulations numériques. Le programme DosiVox permet de modéliser simplement une grande variété d'échantillons grâce à une représentation voxélisée de l’objet et de son environnement, et de simuler la radioactivité pour calculer la distribution spatiale du débit de dose. Il a été développé dans une optique d'accessibilité et d'usage courant. Des comparaisons avec des situations dosimétriques préalablement étudiées, ou mesurées, ont montré la pertinence des modélisations, et les possibilités de cet outil informatique sont exposées au travers d’une série d'exemples et d'applications. La caractérisation de la distribution des débits de dose bêta dans les sédiments hétérogènes constitue l'une des problématiques les plus complexes à traiter. En plus d'une étude destinée à évaluer le potentiel de DosiVox à considérer ces situations, le programme DosiSed a été développé pour modéliser spécifiquement des ensembles polyminéraux de grains. Cet outil a permis d'étudier l'hétérogénéité du débit de dose dans des échantillons réels, ainsi que d'inclure certains résultats dans une problématique de datation
The paleodosimetric dating methods allow to obtain the age of some mineral materials which behave as natural dosimeters, the age being derived as the ratio of the dose accumulated from the dated event and the natural dose rate to which the sample was subjected.. The determination of the dose rate is usually based on simple models which only allow explicit calculations, but these models reproduce very imperfectly the diversity of situations encountered. Computer modeling allows to represent more complex and more realistic models, which lead to numerically simulate the dose rate. In this work, the toolbox Geant4, allowing to simulate particle-matter interactions by the Monte-Carlo method, was used to create complex models , as well as modeling tools accessible and adaptable to different types of samples and dosimetric situations. Simulations were first made with basic models in order to study the origin of dose rate variations in sediments, highlighting the limits of the simple models commonly used. This information was used to guide the development of modeling tools based on the Geant4 codes, and also to specify the protocols of samples analysis for gathering the data needed for numerical simulations. The DosiVox software allows to easily model a wide variety of samples through a voxelised representation of the object and its environment, and to simulate the radioactivity for calculating the spatial distribution of the dose rate. It was developed with a view of accessibility and current use. Comparisons with dosimetric situations previously studied or measured showed the relevance of the modelings, and the possibilities of this computer tool are exposed through a series of examples and applications. The characterization of the beta dose rate distribution in heterogeneous sediment is one of the most complex problems to be treated. In addition to a study aims at assessing the potential of DosiVox to consider these situations, the DosiSed software was developed specifically for modeling poly-mineral sets of grains. This tool was used to study the heterogeneity of the dose rate in real samples and allowed to include some of the results in a dating problematic

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Oliveira, Luiz Carlos de. "Estudos dosimétricos da hidroxiapatita por ressonância paramagnética eletrônica e termoluminescência." Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/59/59135/tde-21052010-104010/.

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Estudos dosimétricos em hidroxiapatita (HAp) podem ser utilizados para a determinação da dose absorvida em tecidos duros em diversas situações, tais como acidentes radiológicos, controle de processos de esterilização e datação arqueológica. Essa tese apresenta estudos da resposta à dose de radiação tanto do sinal de Ressonância Paramagnética Eletrônica (RPE) quanto de termoluminescência (TL) para HAp. A fauna de mamíferos fósseis encontrada na Planície Costeira do Rio Grande do Sul é conhecida desde o final do século XIX, porém ainda pouco se sabe sobre seu contexto bio e cronoestratigráfico. Neste trabalho foram datadas, por RPE, onze amostras de dentes de mamíferos extintos, coletados no Arroio Chuí e ao longo da praia, proveniente do sul da costa do Rio Grande do Sul. As idades obtidas para essas amostras contribuem para um melhor entendimento da origem dos depósitos fossilíferos. Em um segundo momento do trabalho, é proposto um novo procedimento de decomposição de espectros complexos de RPE, voltados para a dosimetria e datação. O método consiste na utilização de funções do pacote de funções do software \"Easyspin\", que é gratuito, associadas a métodos de minimização de funções. Após a validação, o método foi aplicado na decomposição de espectro de duas amostras de dentes de Stego-mastodon waringi, provenientes do nordeste do Brasil. A decomposição visa verificar o efeito que tem as componentes sobrepostas ao sinal dosimétrico sobre o cálculo da dose acumulada e mostrou-se útil para melhorar a precisão na determinação da dose. Por fim, hidroxiapatita sintética carbonatada do tipo-A e hidroxiapatita natural extraída de dentes fósseis foram caracterizadas por TL. Os resultados obtidos por essa técnica mostrou que esses dois tipos de amostra são capazes de responder a radiação ionizante. Contudo, esses mesmos resultados também revelaram a impossibilidade de se fazer dosimetria por termoluminescência com fins à datação, para esse tipo de amostra.
Dosimetric studies on hydroxyapatite (HAp) can be used to determine the absorbed dose in hard tissues in several situation, such as radiologic accidents, control of sterilization process and archaeological dating. This PhD thesis presents studies about radiation dose response assessed by electron paramagnetic resonance (EPR) as well as thermoluminescence in HAp. The fossil mammalian fauna from the Coastal Plain of Rio Grande do Sul State has been known since the late XIX century; however, its biostratigraphic and chronostratigraphic context is still poorly known. The present works describes the results of electron spin resonance (ESR) dating on teeth of extinct mammals collected along the Chuí Creek and coastline. The ages obtained for these samples contribute to a better knowledge about the origin of these fossil. In a second stage of this work, we propose a new EPR spectrum deconvolution (or decomposition) procedure aimed to dosimetry and dating. The method uses the EasySpin (a freeware software) set of functions associated with minimization procedures. After validation, the method was applied in spectrum deconvolution of two Stegomastodon waringi enamel samples, originated from northeast of Brazil. The spectrum econvolution is aimed to verify the superposed components effects on the dosimetric signal over the accumulated dose calculation. The results have shown to be helpful in improving the dose calculation accuracy. In the last stage of this work, synthetic carbonated A-typ hydroxyapatite and natural one were investigated by Thermoluminescence. The obtained results shown that the two samples respond linearly to the ionizing radiation dose. However, the short thermoluminescent glow-peak lifetime suggest that it\'s inadequate for dating purpose.

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奥野, 充., Mitsuru Okuno, Ma Hanah T. Mirabueno, 俊夫中村, Toshio Nakamura, 勲. 高島, Isao Takashima та ін. "フィリピン共和国,ルソン島の火山活動に関する熱ルミネッセンス法と放射性炭素法による年代学的研究(第19回名古屋大学年代測定総合研究センターシンポジウム平成18(2006)年度報告,第2部)". 名古屋大学年代測定資料研究センター, 2007. http://hdl.handle.net/2237/13705.

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第19回名古屋大学年代測定総合研究センターシンポジウム平成18(2006)年度報告<第2部> Proceedings of the 19th symposiumon on Chronological Studies at the Nagoya University Center for Chronological Research in 2006 日時:平成19 (2007)年1月15日(月)～17日(水) 会場:名古屋大学シンポジオン Date:January15th-17th, 2007 Venue:Nagoya Uhiversity Symposion Hall

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Tudela, Diego Renan Giglioti. "Estudo da luminescência de cristais de quartzo naturais e artificiais crescidos pelo método sol-gel." Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/3/3140/tde-08032019-090623/.

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Este trabalho foi dividido em duas grandes partes principais, a primeira relacionada ao estudo da luminescência de quatro espécimes de quartzo naturais brasileiros (verde, hialino, rosa e azul) e a segunda trata da confecção e caracterização de amostras sintéticas, baseadas na estrutura do SiO2, obtidas pelo método de sol-gel para fins de dosimetria das radiações ionizantes ambientais. Através da Análise por Ativação com Nêutrons Instrumental (AANI) e Fluorescência de Raios X por Reflexão Total (TXRF), foram determinadas as principais impurezas em concentrações maiores, menores e traços de forma quantitativa e qualitativa, respectivamente. Os espécimes verde e azul foram os que apresentaram as maiores quantidades de impurezas, incluindo metais e elementos terras raras, enquanto que o hialino e rosa são praticamente puros. Suas emissões de TL foram distintas, em termos de intensidade e posição dos picos. Testes de recuperação de dose por luminescência opticamente estimulada (LOE), através dos protocolos de alíquotas múltiplas (MAR) e única (SAR) com doses regenerativas, foram realizados e o espécime verde foi o único que apresentou resultados satisfatórios nesses testes, seguido do azul. Os cristais hialino e rosa apresentaram saturação e curva de crescimento fora da linearidade, onde o primeiro mostrou o efeito da fototransferência para a maioria das análises de SAR. Como os cristais verde e hialino apresentaram resultados opostos, em termos de quantidades de impurezas e emissões luminescentes, foi realizado um tratamento térmico em alta temperatura (1600 °C) para observar o efeito da mudança de fase (cristobalita) nas suas emissões luminescente. Ajustes teóricos das curvas de emissão de LOE contínua, linearmente modulada e TL mostraram que elas seguem o modelo teórico de cinéticas de ordens gerais. Na segunda parte deste trabalho, 32 amostras artificiais, do polimorfo de alta temperatura do quartzo, a cristobalita, foram sintetizadas com diferentes quantidades e tipos de dopantes, baseado nas impurezas determinadas no quartzo verde, utilizando duas rampas de aquecimento nas calcinações (3 e 15 °C/min). Essa parte do trabalho teve como finalidade o estudo do efeito do Fe na emissão luminescente das amostras sintéticas, a reprodução de uma das amostras naturais e produção e caracterização de dosímetros para radiações ionizantes ambientais. A utilização das duas rampas de aquecimento na emissão de TL, de forma geral, não desempenhou papel determinante na intensidade dos picos de altas temperaturas. Já na LOE foi observado que as amostras calcinadas com a rampa de maior temperatura apresentaram resposta à dose mais elevadas. O Fe como dopante em maior quantidade atuou como um inibidor de luminescência tanto na TL quanto na LOE. Uma amostra com características qualitativas semelhante ao quartzo verde, na fase da cristobalita, foi obtida com relativo sucesso utilizando como dopante todas as doze principais impurezas adquiridas para realização deste projeto. Quatro amostras foram sintetizadas com diferentes tipos e quantidades de dopantes para aplicação em dosimetria das radiações. Somente uma destas apresentou resposta linear às doses de radiação utilizando estimulação térmica (TL), cuja mínima dose de detecção (MDD) foi de 172 µGy. Utilizando estimulação óptica (LOE), duas amostras apresentaram comportamento linear com as doses de radiação, em que valores de MDD de ~440 µGy e 405 µGy foram obtidos.
This work was divided into two major parts, the first one related to the study of the luminescence of four Brazilian natural quartz specimens (green, hyaline, pink and blue) and the second one deals with the confection and characterization of synthetic samples, based on SiO2 structure, obtained by means of sol-gel method to environmental ionizing radiation dosimetry. Through Instrumental Neutron Activation Analysis (INAA) and Total Reflection X-ray Fluorescence (TXRF), the main impurities in major, minor and trace concentrations were determined quantitative and qualitatively respectively. The green and blue specimens presented the highest amounts of impurities, including metals and rare earth elements, whereas hyaline and pink are practically pure. Their TL emissions were distinct, in terms of intensity and peak position. OSL dose recovery tests, using multiple (MAR) and single aliquots regeneration (SAR) dose protocols were performed and the green specimen was the only one which presented satisfactory results in these tests, followed by blue. The hyaline and pink crystals showed saturation and growth curve out of linearity, where the first one showed the effect of phototransference for most SAR analysis. As green and hyaline crystals presented opposite results, in terms of impurities quantities and luminescent emissions, a high temperature (1600 °C) heat treatment was performed to observe the effect of the phase change (cristobalite) on its luminescent emissions. Theoretical adjustments of the CW-OSL, LM-OSL and TL emission curves showed that they follow the theoretical model of general order kinetics. In the second part of this work, 32 artificial samples of the high temperature polymorph of the quartz, cristobalite, were synthesized with different amounts and types of dopants, based on impurities determined in green quartz, making use of two heating rates in the calcinations (3 and 15 °C/min). This part of the work had as purpose the study of the effect of Fe in the luminescent emission of the synthetic samples, the reproduction of one of the natural samples and production and characterization of dosimeters for environmental ionizing radiation. The use of the two heating rates in TL emission, in general, did not play a determining role in the intensity of the high temperature peaks. In the OSL, it was observed that samples calcined with higher heating rate temperature showed higher response to dose. The Fe as a dopant in greater quantities acted as a quencher of luminescence both in TL and OSL. A sample with qualitative characteristics similar to the green quartz, in the cristobalite phase, was obtained with relative success using as dopants all the twelve main impurities acquired for this project. Four samples were synthesized with different types and amounts of dopants for application in ionizing radiation dosimetry. Only one of these showed a linear response to radiation doses using thermal stimulation (TL), with a minimum detectable dose (MDD) of 172 µGy. Using optical stimulation (OSL), two samples showed linear behavior with radiation doses, in which MDD values of ~440 µGy and 405 µGy were obtained.

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Bassinet, C. "Datation par luminescence : recherches méthodologiques et applications au volcanisme dans l'environnement de Laschamp." Phd thesis, Université Blaise Pascal - Clermont-Ferrand II, 2007. http://tel.archives-ouvertes.fr/tel-00171318.

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L'objectif de ce travail était de dater des coulées volcaniques de la Chaîne des Puys (Massif Central, France) situées chronologiquement dans la période de l'événement paléomagnétique de Laschamp (30-50 ka). Les méthodes utilisées étaient la thermoluminescence et la luminescence stimulée optiquement appliquées à des grains de quartz et à des galets quartzeux extraits de sédiments cuits par ces coulées. Ces minéraux émettent des signaux de luminescence dont le comportement est souvent irrégulier. Leur paléodose a donc été déterminée par différentes méthodes pour choisir celles qui seraient les plus appropriées à l'obtention de résultats fiables. Ces intercomparaisons ont mis en évidence une dispersion des résultats supérieure à ce qui pouvait être attendu au regard des incertitudes habituellement associées à chacune d'entre elles. Dans la plupart des cas, ces observations ont conduit à proposer un intervalle assez large dans lequel est compris l'âge probable de l'échantillon.

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SANTOS, JOSE O. dos. "Estudos arqueométricos de sitios arqueológicos do baixo São Francisco." reponame:Repositório Institucional do IPEN, 2007. http://repositorio.ipen.br:8080/xmlui/handle/123456789/11536.

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Made available in DSpace on 2014-10-09T12:52:59Z (GMT). No. of bitstreams: 0
Made available in DSpace on 2014-10-09T13:58:11Z (GMT). No. of bitstreams: 0
Tese (Doutoramento)
IPEN/T
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

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45

Hickel, Pierre-Emmanuel. "Croissance hydrothermale du quartz-A : solubilité, caractérisations physico-chimiques et applications des monocristaux." Bordeaux 1, 2000. http://www.theses.fr/2000BOR10517.

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Le quartz est un matériau piézoélectrique utilise pour des dispositifs électroniques hautes fréquences. L’amélioration de leurs performances requiert une diminution de la densité des défauts physico-chimiques induits au cours de la croissance hydrothermale des cristaux. Dans cet objectif immédiat, le présent travail a mis en œuvre deux axes de recherche : la recherche de nouveaux solvants dans lesquels la solubilité du quartz est compatible avec le procédé, une croissance de cristaux dans des conditions thermodynamiques différentes des conditions utilisées industriellement. Ces axes de recherches ont nécessité des développements technologiques afin d'assurer une augmentation de la fiabilité des cycles (étanchéité, suivi et contrôle des paramètres thermodynamiques). Par ailleurs, une recherche à plus long terme a porté sur une meilleure connaissance de la nature des défauts. Cela par une création volontaire des défauts et l'interprétation de leur signature par corrélation des informations recueillies par les différentes techniques de caractérisations utilisées (spectrométrie infrarouge, icpms, microsonde de Castaing, thermoluminescence, cathodoluminescence, topographie de rayons x)
Quartz-a is a piezoelectric component of high frequency electronic devices. Improving its performance requires a reduction in the physical and chemical defects induced during the hydrothermal growth of the crystals. With this objective in mind this study has concentrated on two main areas of research; the search of new solvents in which the solubility of quartz is suitable for the hydrothermal growth process and the ability to grow crystals with thermodynamic parameters that are more demanding than those currently in use in industrial processes. These two areas of research have required further development of the existing technology so as to improve the reliability of the production processes. In particular by improving the seal for the autoclave and adopting an accurate real time control system. In the long term this research will help bring about better knowledge of ways to analyse the defects in the growth of synthetic crystals. As a first step towards thi crystal defects have been purposely introduced and the signal obtained interpreted using a number of investigative techniques. Infra-red spectrometry, ICPMS, Castaing microprobe, cathodoluminescence, thermoluminescence, X-ray topography)

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46

Bassinet, Céline. "Datation par luminescence : recherches méthodologiques et applications au volcanisme dans l'environnement de Laschamp." Clermont-Ferrand 2, 2007. https://tel.archives-ouvertes.fr/tel-00171318.

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Анотація:

L'objectif de ce travail était de dater des coulées volcaniques de la Chaîne des Puys (Massif Central, France) situées chronologiquement dans la période de l'événement paléomagnétique de Laschamp (30-50 ka). Les méthodes utilisées étaient la thermoluminescence et la luminescence stimulée optiquement appliquées à des grains de quartz et à des galets quartzeux extraits de sédiments cuits par ces coulées. Ces minéraux émettent des signaux de luminescence dont le comportement est souvent irrégulier. Leur paléodose a donc été déterminée par différentes méthodes pour choisir celles qui seraient les plus appropriées à l'obtention de résultats fiables. Ces intercomparaisons ont mis en évidence une dispersion des résultats supérieure à ce qui pouvait être attendu au regard des incertitudes habituellement associées à chacune d'entre elles. Dans la plupart des cas, ces observations ont conduit à proposer un intervalle assez large dans lequel est compris l'âge probable de l'échantillon

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Santos, José Osman dos. "Estudos arqueométricos de sítios arqueológicos do baixo São Francisco." Universidade de São Paulo, 2007. http://www.teses.usp.br/teses/disponiveis/85/85131/tde-18052012-134947/.

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O estudo minucioso das características físicas e químicas dos artefatos cerâmicos, associado com as pesquisas históricas e arqueológicas tem pennitido a reconstituição dos costumes culturais e modos de vida das comunidades antigas. O presente estudo objetivou estudar composição química elementar e mineralógica de cerâmicas arqueológicas coletadas nos sítios .lustino, São José, Curítuba, Saco da Onça, Porto Belo e Vitória Régia, localizados na região do Baixo São Francisco, Sergipe, Brasil. Por meio da análise por ativação com nêutrons instrumental (AANl) e difratometria de raios - X (DRX), pennitiuse definir grupos composicionais de cerâmicas conforme a similaridade química da pastas cerâmica, a qual reflete a composição da matéria-prima utilizada em sua manufatura pelo homem pré-histórico, e inferir a atmosfera e temperatura de queima da cerâmica. As amostras abeiTantes foram identificadas por meio das distâncias Mahalanobis clássica e robusta. O efeito do tempero na pasta cerâmica foi estudado por meio do filtro de Mahalanobis modificado. Os resultados foram interpretados por meio da análise de agioipamento, análise das componentes principais e análise discriminante. O horizonte temporal das cerâmicas foi verificado por meio de técnicas de datação tennoluminescência (TL). Os resultados obtidos neste trabalho, em associação com infonnações oriundas da Arqueologia, pennitiram a identificação dos gi-upos cerâmicos correspondentes às ocupações ceramistas no sítio Justino e a definição de gi\'upos cerâmicos de referência confonne o comportamento químico. A tecnologia de queima foi estabelecida para alguns vasos cerâmicos, bem como a contemporaneidade dos grupos composicionais segundo as datações determinadas por TL. Dessa forma, o trabalho contribui para a reconstituição da pré-história das comunidades que habitaram a região do Baixo Rio São Francisco e para remontagem do quadro geral das populações ceramistas do Nordeste brasileiro.
The study of the physical and chemical characteristics of the ceramics crafts, in association with historical and archaeological research, has allowed for the reconstruction of the cultural habits from ancient communities. The goal of this work was to study the chemical and mineralogical compositions of archaeological potteries collected from Justino, São José, Curituba, Saco da Onça, Porto Belo and Vitória Régia sites, located in Baixo São Francisco region, Sergipe state, Brazil. The use of the instrumental neutron activation analysis (INAA) and X-ray diffractometry (XRD), allowed the definition of compositional groups of potteries according to the chemical similarities of the ceramic paste, which reveals the composition of the raw materials utilized in the manufacturing process by prehistoric man, and the inference of the atmosphere and temperatures in which the potteries were burned. The outliers were identified by means of classic and robust Mahalanobis distance. The temper effect in the ceramic paste was studied by means of modified Mahalanobis filter. The results were interpreted by means of cluster analysis, principal components analysis and discriminant analysis. The ages of some potteries were determined by means of the thermoluminescence techniques. The results obtained in this work, in association with archaeological information, allowed for the identification of the ceramic groups relative to ceramist occupations at Justino Site and for the definition of the reference groups according to the chemical composition. The burning technology was established for some potteries and the relative ages among the compositional groups were determined by means of TL. Thus, this work provides contributions to the reconstmction of the prehistory of the communities which lived in the Baixo São Francisco region, and to the reconstitution of the general frame of the ceramist population from Brazilian Northeast.

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Júnior, Valdomiro Severino de Souza. "Mineralogia de solos e ambientes de sedimentação em manguezais do Estado de São Paulo." Universidade de São Paulo, 2006. http://www.teses.usp.br/teses/disponiveis/11/11140/tde-05042006-142238/.

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Manguezais são formados por grupos de árvores e arbustos que se desenvolvem na zona de intermarés de regiões tropicais. Este ecossistema ao se estabelecer na interface do ambiente marinho e continental, apresenta sua formação relacionada com as flutuações relativas do nível do mar quaternário, através do preenchimento dos vales dos rios, margens de lagunas e baías com sedimentos tanto de origem continental como marinha. O conhecimento da distribuição de partículas e dos minerais constituintes da assembléia mineralógica dos solos em ambiente de planícies estuarinas, auxilia na compreensão de processos de sedimentação e geoquímica dentro dos estuários. O trabalho foi realizado nos manguezais distribuídos ao longo do litoral do Estado de São Paulo, e objetivou-se caracterizar os ambientes de sedimentação de acordo com a granulometria e o processo de evolução quaternária, determinar qualitativamente e semiquantitativamente a assembléia mineralógica e estudar em detalhe os tipos de esmectitas presentes nesses solos. Para tanto foram coletadas amostras de solos de 14 manguezais nas camadas de 0-20 e 60-80cm e de sedimento em suspensão do Rio Ribeira de Iguape, além de amostras de diferentes profundidades para datações. Determinaram-se as frações, argila, silte, areia total e 5 frações da areia, foram realizadas datações 14C por cintilação líquida e AMS na fração humina da matéria orgânica e por termoluminescência em grãos de quartzo. As análises mineralógicas foram realizadas na fração silte e argila e no sedimento em suspensão através de DRX, IV, MET, MEV com microanálise, ATD e ATG, realizou-se também o teste de Greene- Kelly para identificar o tipo de esmectitas presentes nesses solos. De acordo com os resultados obtidos, concluiu-se que os solos dos manguezais do Estado de São Paulo podem apresentar diferentes texturas desde arenosa até muito argilosa, freqüentemente contêm altos teores de silte e todos têm idade holocênica, oscilando entre 410 anos A.P. e 3.700 anos; a distribuição de partículas está relacionada à morfologia atual do estuário e à natureza dos sedimentos costeiros adjacentes; a assembléia mineralógica da fração fina dos solos é constituída de pirita, nontronita, caulinita, illita, gibbsita, quartzo, feldspato, e localmente ocorrem goethita, vermiculita, biotita, halloysita e anatásio; os minerais alóctones são de origem continental e marinha; a distinção entre os cenários geomorfológicos ao longo do litoral condiciona a distribuição de minerais, e ainda foi inferido que ocorre neoformação de esmectita e de caulinita, e que o processo de oxidação de matéria orgânica nesses solos pode estar utilizando o Fe3+ da nontronita como receptor de elétrons.
Mangroves are formed by groups of trees and shrubs that develop in the intertidal zone of tropical regions. This ecosystem to establish in the interface of both marine and continental environment, present its formation related to the sea-level fluctuations during the quaternary period, where the terrigenous and marine sediments are deposited in rivers valleys, edges of lagoons and bays. The knowledge of both particle distribution and minerals constituent of soils in estuarines areas, can aid to understand the processes of sedimentation and geochemistry in this site. This study was carried out with mangroves distributed along the São Paulo State coast, and aims to characterize the sedimentary environments in accordance with grain size and process of quaternary evolution, to determine qualitatively and semiquantitatively the mineralogical assemblage and to identify the smectites types in these soils. Samples were collected from 14 mangroves soils at the layers 0-20 and 60-80cm, and also was collected sediment in suspension of the Ribeira de Iguape River, and samples of different depths for dating. The clay, silt and total sand sizes and 5 sand fractions were determined, radiocarbon dating were carried out by liquid scintillation counting and accelerator mass spectrometry in humin fraction of the soil organic matter and by thermoluminescence of quartz grains. The mineralogical analyses were carried out by XRD, FTIR, TEM, SEM, DTA and GTA in silt and clay sizes and in the sediment in suspension, also was made the Greene-Kelly test to identify the smectites type. According to the results we concluded that the mangroves soils from São Paulo State have different textures varying from sandy up to very clay, also occuring high silt contents. All the mangroves are holocenic, with ages varying from 410 yr B.P. to 3,700 yr; the particle distribution is related to the current geomorphological setting of the estuary and the origin of coastal sediments. The mineralogical assemblage is constituted of pyrite, nontronite, kaolinite, illite, biotite, gibbsite, quartz, feldspars, and locally occurs goethite, vermiculite, halloysite and anatase; the aloctones minerals are from both the terrigenous and marine origin; the difference between geomorphological settings along the coastal plain rules mineral distribution, and still it was inferred the neoformation of esmectita and kaolinite and that the process of organic matter mineralization in these soils may be using Fe3+ from nontronite as an electron acceptor.

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Heydari, Maryam. "Applying Bayesian models to improve luminescence-based chronologies of Middle to Upper Palaeolithic sites in Iran." Thesis, Bordeaux 3, 2020. http://www.theses.fr/2020BOR30014.

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L’analyse statistique des données est un aspect crucial de la datation par luminescence. Pendant des décennies, le traitement de données a principalement eu recours à l’école de pensée classique, dite fréquentiste. Ce n’est que récemment qu’une alternative a pu être fournie grâce au développement de la modélisation bayésienne appliquée à la datation par luminescence dans un environnement R. Cette thèse a pour objectif premièrement, d’étudier les avantages de l’utilisation de ces modèles bayésiens en comparaison avec l’approche fréquentiste et deuxièmement, d’apporter les premières chronologies par luminescence pour des sites majeurs du Paléolithique moyen et supérieur en Iran. De par sa localisation au carrefour de l’Afrique, l’Europe et l’Asie centrale, le plateau iranien est essentiel pour retracer dans le temps les dispersions humaines. Malgré tout, il n’existe à l’heure actuelle que très peu de chronologies couvrant la période du Paléolithique en Iran. Cette thèse se concentre sur trois sites majeurs : Mirak, situé en marge du désert central iranien, le site de Gh¯ar-e Boof dans la région sud des Montagnes du Zagros, et Bawa Yawan, dans la région centrale des Montagnes du Zagros. La modélisation bayésienne des données chronologiques produites pour le site de Mirak, a abouti pour les assemblages du Paléolithique supérieur, intermédiaire et moyen à des intervalles de, respectivement 21–28 ka, 26–33 ka et 43– 55 ka (95% CI). Pour le gisement de Gh¯ar-e Boof, nous avons daté la culture du Paléolithique supérieure à 37–42 ka (95% CI), et la culture du Paléolithique moyen à 44–84 ka (95% CI). Pour le site de Bawa Yawan, des âges compris entre 56 et 90 ka (95% CI) ont été obtenus pour des assemblages attribués au Paléolithique moyen. L’étude chronologique a également révélé un âge compris dans l’intervalle 12–16 ka pour une unité attribuée à la culture de l’Epipaléolithique. Basée sur l’étude de ces gisements, cette thèse met en évidence l’intérêt de la mise en application des méthodes bayésiennes dans le cadre de la datation par luminescence. Nous avons notamment remarqué les avantages que présentent les modèles bayésiens testés pour tenir compte des erreurs systématiques partagées par les échantillons, ainsi pour que leur capacité à intégrer des informations chronologiques indépendantes, telles que les contraintes chrono-stratigraphiques ou les âges carbone 14. Ceci nous a ainsi permis d’améliorer la précision des chronologies paléolithiques pour l’Iran. De plus, cette thèse teste la capacité de ces modèles bayésiens à obtenir une dose centrale juste pour les échantillons bien blanchis, contrairement aux modèles fréquentistes, lorsque les signaux de quartz sont proches de la limite de saturation ou lorsque l’hétérogénéité du débit de dose bêta dans le sédiment environnant est élevée
Statistical data analysis is a fundamental aspect of luminescence dating. For decades, data processing predominantly employed the frequentist (classic) school of thinking. Only recently, development of Bayesian modelling specifically for luminescence dating in R environment has provided an alternative. This thesis aims firstly to discuss the benefits of applying Bayesian models over the frequentist approach, and secondly to provide the first luminescence-based chronologies for Middle-Upper Palaeolithic key sites in Iran. Due to its location at the intersection between Africa, Europe and Central Asia, the Iranian plateau is of importance in tracking human dispersal over time. Despite this, there are very few chronologies spanning the Palaeolithic period in Iran. This thesis focuses on three key sites: Mirak, located at the margin of the central Iranian desert, the site of Gh¯ar-e Boof in the southern Zagros Mountains, and Bawa Yawan in the central Zagros Mountains. Bayesian modelling of chronologies produced for the site of Mirak, date Upper, Intermediate and Middle Palaeolithic assemblages 21–28 ka, 26–33 ka and 43–55 ka (95% CI) respectively. For the site of Gh¯ar-e Boof, we dated the Upper Palaeolithic culture to 37–42 ka (95% CI) and the Middle Palaeolithic culture to 44–84 ka (95% CI). For the site of Bawa Yawan, ages spanning 56–90 ka (95% CI) were obtained for assemblages attributed to the Middle Palaeolithic. The chronological study also unravelled an age range of 12–16 ka for a unit attributed to the Epipalaeolithic culture. Based on the study of these sites, this thesis discusses the essential aspect for applying Bayesian methods in luminescence dating. In particular, we note the benefits of Bayesian models to address systematic shared errors between samples and the ability to include independent chronological information, such as stratigraphic constraints or radiocarbon ages. This has helped to improve the precision of the Palaeolithic chronologies for Iran. Furthermore, this thesis tests the ability of Bayesian models to obtain an accurate central dose for well-bleached samples compared to one frequentist model, when quartz signals are close to saturation or when beta-dose rate heterogeneity in the surrounding sediment is high

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Almond, Peter C. "Soils and geomorphology of a lowland rimu forest managed for sustainable timber production." Lincoln University, 1997. http://hdl.handle.net/10182/1782.

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Saltwater Forest is a Dacrydium cupressinum-dominated lowland forest covering 9000 ha in south Westland, South Island, New Zealand. Four thousand hectares is managed for sustainable production of indigenous timber. The aim of this study was to provide an integrated analysis of soils, soil-landform relationships, and soil-vegetation relationships at broad and detailed scales. The broad scale understandings provide a framework in which existing or future studies can be placed and the detailed studies elucidate sources of soil and forest variability. Glacial landforms dominate. They include late Pleistocene lateral, terminal and ablation moraines, and outwash aggradation and degradation terraces. Deposits and landforms from six glacial advances have been recognised ranging from latest Last (Otira) Glaciation to Penultimate (Waimea) Glaciation. The absolute ages of landforms were established by analysis of the thickness and soil stratigraphy of loess coverbeds, augmented with radiocarbon dating and phytolith and pollen analysis. In the prevailing high rainfall of Westland soil formation is rapid. The rate of loess accretion in Saltwater Forest (ca. 30 mm ka⁻¹) has been low enough that soil formation and loess accretion took place contemporaneously. Soils formed in this manner are known as upbuilding soils. The significant difference between upbuilding pedogenesis and pedogenesis in a topdown sense into an existing sediment body is that each subsoil increment of an upbuilding soil has experienced processes of all horizons above. In Saltwater Forest subsoils of upbuilding soils are strongly altered because they have experienced the extremely acid environment of the soil surface at some earlier time. Some soil chronosequence studies in Westland have included upbuilding soils formed in loess as the older members of the sequence. Rates and types of processes inferred from these soils should be reviewed because upbuilding is a different pedogenic pathway to topdown pedogenesis. Landform age and morphology were used as a primary stratification for a study of the soil pattern and nature of soil variability in the 4000 ha production area of Saltwater Forest. The age of landforms (> 14 ka) and rapid soil formation mean that soils are uniformly strongly weathered and leached. Soils include Humic Organic Soils, Perch-gley Podzols, Acid Gley Soils, Allophanic Brown Soils, and Orthic or Pan Podzols. The major influence on the nature of soils is site hydrology which is determined by macroscale features of landforms (slope, relief, drainage density), mesoscale effects related to position on landforms, and microscale influences determined by microtopography and individual tree effects. Much of the soil variability arises at microscales so that it is not possible to map areas of uniform soils at practical map scales. The distribution of soil variability across spatial scales, in relation to the intensity of forest management, dictates that it is most appropriate to map soil complexes with boundaries coinciding with landforms. Disturbance of canopy trees is an important agent in forest dynamics. The frequency of forest disturbance in the production area of Saltwater Forest varies in a systematic way among landforms in accord with changes in abundance of different soils. The frequency of forest turnover is highest on landforms with the greatest abundance of extremely poorly-drained Organic Soils. As the abundance of better-drained soils increases the frequency of forest turnover declines. Changes in turnover frequency are reflected in the mean size and density of canopy trees (Dacrydium cupressinum) among landforms. Terrace and ablation moraine landforms with the greatest abundance of extremely poorly-drained soils have on average the smallest trees growing most densely. The steep lateral moraines, characterised by well drained soils, have fewer, larger trees. The changes manifested at the landform scale are an integration of processes operating over much shorter range as a result of short-range soil variability. The systematic changes in forest structure and turnover frequency among landforms and soils have important implications for sustainable forest management.

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Дисертації з теми "Quartz; Thermoluminescence dating; Thermoluminescence"

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