The purpose of this study is to find datable interstadial sediments in the core area of the LateWeicheslian ice sheet extent. Based on geomorphological evidence, three coring sites wereidentified close to the Ultevis plateau in Norrbotten, northern Sweden. Sediment coring wascarried out in two pre-Late Weichselian stream channels and in a sediment basin. Stratigraphyfrom one of the sites, a 100 meter wide meltwater channel, was chosen for further analysis. Thestudied core was 5,93 m long and ended in a lower till unit. The core contained silt and sandbelow an upper till unit, indicating presence of interstadial sediments in the stratigraphy. Thecore was subsampled for luminescence dating. Two samples from above the upper till unit andtwo samples from below this unit were chosen for initial luminescence measurements onfeldspar. These preliminary measurements indicate a significant difference in paleodosebetween the upper samples and the lower. The upper samples displayed relatively highpaleodoses, possibly representing pre-Late Weichselian ages. This could imply presence of twointerstadials in the stratigraphy. The lower samples exhibited significantly higher paleodosesthan the upper ones, possibly indicating early-Weichselian or even Saalian ages for the lowersamples.

Loess deposits are terrestrial clastic sediments derived from aeolian deposition. Loess is transported in periglacial conditions and was mainly deposited in cold environments around glaciers during the Quaternary period. To be able to understand and interpret past climate and how it was changing, loess deposits can be used as an indicator for example wind circulation and dustiness in the atmosphere. However, good independent chronological control is essential for using loess as a past climate archive. This study has examined loess from Lowland Point in the southwest of England. The loess at Lowland Point is relatively thin at 180 cm compared with more studied loess deposits further east on continental Europe. To be able to date the k-feldspar mineral grains from the loess deposit at Lowland Point, two values should be constrained for each sample: the equivalent dose (DE), a quantitative factor of the amount of energy accumulated by the mineral grain during burial from ionising radiation, and the dose rate (DR), a rate of ionising radiation absorbed from the surrounding environment per year. By using the post infrared-infrared stimulated luminescence (post-IR IRSL) method, the DE values were obtained, and by examine radioactive isotopes in the samples, the DR values were attained. The results of each average age per sample depth was then identified and the loess deposit could be determined to the age about 10.8-22.4 ka, which is suggested to have been deposited by meltwater from the British Irish Ice Sheet and permafrost. / Lössjordar är avlagringar av markbundna klastiska sediment härledda från eolisk deposition och transporteras under periglaciala förhållanden för att huvudsakligen deponeras i kalla miljöer runt glaciärer under kvartärperioden. För att kunna förstå och tolka tidigare klimat och hur det förändrades kan lössavlagringar användas som en indikation över till exempel vindcirkulation och dammighet i atmosfären. Denna studie har undersökt löss från Lowland Point i sydvästra England. Lössen vid Lowland Point är relativt tunn, med en tjocklek på 180 cm, jämfört med mer studerade lössjordar. För att kunna datera kalifältspat från lössjorden vid Lowland Point var förhållandet mellan två komponenter av betydelse; ekvivalentdosen (DE), en kvantitativ faktor för den mängd energi som mineralkornet ackumulerar vid sedimentering, och doshastigheten (DR), en hastighet av den mängd energi som absorberas i den omgivande miljön per år. Genom att använda metoden post infraröd-infraröd stimulerad luminescens (post-IR IRSL) erhölls DE-värden och genom att undersöka radioaktiva isotoper i proverna hittades DR-värden. Resultaten av varje medelålder per provdjup identifierades sedan och lössavlagringen kunde bestämmas till en ålder av cirka 10,8–22,4 ka, vilket indikerar en möjlig avsättning av smältvatten från det brittiska irländska istäcket och permafrost.

名古屋大学年代測定総合研究センターシンポジウム報告

The largest wildfire ever observed in Greenland raged through its tundra during august 2017, and it is unknown if there have been similar wildfires in the area before satellite monitoring began in 1999. Arctic wildfires affect permafrost degradation, carbon storage of soils and the surface albedo of the Greenland Ice sheet – despite this, local fires have previously been ignored by researchers. Here, aeolian dust deposits are independently dated by radiocarbon and luminescence techniques and paleoenvironmental proxies and macrocharcoal contents reflecting local fires are analyzed. The dating results indicate that the onset of aeolian deposition coincides with the deglaciation of the area, suggesting that paleoenvironmental proxy records from aeolian dust deposits may extend the entire ice-free period of the area until approximately 8 ka BP. Luminescence signals are generally partially bleached, resulting in age over-estimation of several samples. This effect is quantified using the pIRIR/IR ratio and different integration limit intervals. No evidence for previous wildfires were found during the charcoal analysis, suggesting that the area around the assessed profile has never been burnt since its deglaciation. These first results show promise for the method, and in order to expand this to a regional estimate of the wildfire activity through the Holocene, analysis of more material is needed.

The objective of this study is to perform Optically Stimulated Luminescence (OSL) dating on the ceramic samples from different parts of the Laodikeia by using Infra Red Stimulated Luminescence (IRSL) on polyminerals. As a first step, a literature survey has been done about the dating system and the methodology of dating. The calibration of the system was done before carrying out the experiments. The six ceramic samples were collected from the site and dated. The mineral compositions of the samples were examined by X-ray Diffraction Analysis, which showed that all samples contain quartz, feldspars, calcites and together with other minerals. The equivalent dose was found by using Multiple Aliquot Additive Dose (MAAD) and Multiple Aliquot Regenerative Dose (MARD) techniques using Infra Red diode array of the system that gave the IRSL ages for samples. Alpha counter measured the dose components of uranium and thorium contributions to the annual dose. The potassium concentration was determined by Atomic Emission Spectrometry. The cosmic ray component of annual dose was evaluated by the Al2O3:C Thermoluminescence Dosimeter (TLD) discs which have been placed and kept for 8 and 11 months in the site. From the data the IRSL ages were calculated for six ceramic samples LDKY-1, LDKY-2, LDKY-3, LDKY-4, LDKY-5 and LDKY-6 with the help of the OSL system software. The IRSL ages for these samples, in the given order, are 737 &plusmn / 60, 1563 &plusmn / 120, 1445 &plusmn / 110, 1602 &plusmn / 120, 1034 &plusmn / 80 and 1034 &plusmn / 80 years by using MAAD technique. The IRSL ages for the same samples are 870 &plusmn / 60, 1550 &plusmn / 120, 1440 &plusmn / 110, 1600 &plusmn / 120, 1030 &plusmn / 80 and 1030 &plusmn / 70 years by using MARD technique.

La luminescence optique (OSL) a été mesurée sur dix-sept fragments de poterie collectés à Mailhot-Curran (BgFn-2), un site archéologique du Sylvicole supérieur tardif localisé dans le sud-ouest du Québec. Le but principal de ce projet était de dater ce site qui est considéré jusqu’à maintenant comme le plus récent site préhistorique de la concentration de Saint-Anicet, afin de poser un jalon dans la chronologie des sites de cette région. L’OSL a été utilisée conjointement à la datation par radiocarbone (14C) et la sériation du matériel archéologique. L’hypothèse archéologique propose que le village aurait été occupé pendant les années 1518 à 1530 de notre ère (Chapdelaine 2015a). Les résultats que nous proposons dans ce présent mémoire appuient cette proposition. Nous avons obtenu un âge de 490 ± 49 ans (année de référence : 2013), correspondant à l’année 1523 de notre ère avec une probabilité d’occupation du site Mailhot-Curran entre les années 1474 et 1572. Le programme de datation par luminescence optique a été réalisé sur des fragments de poterie domestique composés d’argile de la Mer de Champlain datant de la période du Quaternaire récent. La datation par stimulation infrarouge (IRSL) a été préférentiellement utilisée sur des aliquotes de grains fins polyminéraliques. Pour la détermination des doses équivalentes, un protocole SAR (Murray et Wintle 2000) modifié pour la mesure des feldspaths et incluant un lessivage optique a été utilisé (Lamothe et al. 2004). Les valeurs g ont été mesurées en suivant le protocole proposé par Auclair et al. (2003). La correction de Huntley et Lamothe (2001) a été utilisée afin de corriger les doses équivalentes mesurées pour la décroissance anormale du signal feldspathique. Les doses annuelles ont pour leur part été déterminées par des mesures réalisées in situ et en laboratoire. Les résultats que nous présentons dans ce mémoire sont affectés par une dispersion assez large. Cette variabilité a été prise en compte par des méthodes statistiques pour la détermination de l’âge probable de l’occupation du site Mailhot-Curran. / Optically stimulated luminescence (OSL) has been measured on 17 ceramic sherds collected at the Mailhot-Curran site (BgFn-2), a Late Woodland archaeological site located in south west Quebec. The main goal of this project was to date the youngest prehistoric village found in the Saint Anicet cluster to establish its position in the chronological framework of the area. OSL was used conjointly with radiocarbon dating (14C) and seriation of the archaeological remains. The archaeological hypothesis proposes an occupation of this village between 1518 and 1530 A.D. (Chapdelaine 2015a). The luminescence results we present in this master’s thesis are in agreement with this proposal : we obtained an age of 490 ± 49, which corresponds to A.D. 1523 with the probability of occupation at the Mailhot-Curran site between A.D. 1474 and 1572. The luminescence dating program was carried out on local ceramics composed of fired late Quaternary Champlain Sea clays. IRSL (infrared stimulated luminescence) was preferentially used on polymineral fine-grains aliquots. A modified SAR-IRSL protocol including optical bleaching was used to measure the equivalent doses (Murray and Wintle 2000, Lamothe et al. 2004). G values were measured following the protocol proposed by Auclair et al. (2003). The Huntley-Lamothe correction for anomalous fading (Huntley and Lamothe 2001) was used to adjust the equivalent dose. Annual doses were assessed by in situ and laboratory measurements. The results we present here are affected by a large range in the dates. This variability was taken into account by statistical methods in the determination of the age of the Mailhot-Curran site occupation.