La transition Archéen – Protérozoïque (~2,45 Ga) est marquée par des bouleversements environnementaux majeurs dans l’histoire de la Terre (oxygénation de l’atmosphère et glaciations globales). Les séquences sédimentaires qui enregistrent ces événements ont été très étudiées en Amérique du Nord (séquence Huronienne) et en Afrique du Sud (Transvaal). Une séquence analogue sur le craton de Pilbara en Australie Occidentale (groupe de Turee Creek, TCG) contient 3 niveaux de diamictites glaciaires. 3 forages continentaux (Turee Creek Drilling Project, TCDP) ont été réalisés pour étudier la séquence. La géochronologie U-Pb de monazite et zircon dans des échantillons de forage et de surface a daté la première glaciation à 2,45 Ga et la seconde à ~2,34 Ga. Des analyses Re-Os de pyrites de la seconde diamictite ont donné une isochrone à 2,31 Ga. Ces résultats ont permis de proposer un scenario de corrélation des glaciations paléoprotérozoïques enregistrées sur différents continents. Une ‘Snowball Earth’ aurait eu lieu à ~2,45 Ga sur au moins 5 cratons (Pilbara, Kaapvaal, Supérieur, Wyoming, Karélia). Une seconde glaciation aurait pu avoir lieu à ~2,31 Ga sur 4 cratons. L’ensemble des zircons détritiques du TCG ont une distribution d’âge avec des pics à 2,45, 2,54, 2,68, 2,82, 2,95 et 3,2 Ga. Un cristal de zircon Hadéen a été découvert et indique la présence d’une probable croûte différenciée dans le craton de Pilbara à 4,0 Ga. 70% des zircons ont des compositions isotopiques en Hf juvéniles, suggérant que le TCG a incorporé du matériel volcanique provenant de larges provinces ignées continentales à travers l’érosion des groupes sous jacents de Hamersley et Fortescue / The Archean – Proterozoic transition at 2.45 Ga is marked by major environmental changes in Earth’s history (atmosphere oxygenation and global glaciations). The origin and the relationships between these events are debated. Sedimentary sequences that record these events have been widely studied in North America (Huronian sequence) and South Africa (Transvaal). An analog sequence in the Pilbara craton in Western Australia (Turee Creek Group, TCG) contains 3 glacial horizons. 3 continental drill cores (Turee Creek Drilling Project, TCDP) were performed in order to investigate the sequence. U-Pb geochronology of monazite and zircon from drill core and surface samples allows to date the first paleoproterozoic glaciation at 2.45 Ga and a second glacial event at ~2.34 Ga. Re-Os analyses of pyrites from the second diamictite yielded an isochron at 2.31 Ga. These results enable to propose a correlation scenario of the paleoproterozoic glacial events recorded on different continents. A ‘Snowball Earth’ would have occured at 2.45 Ga at least on 5 cratons. A second glaciation could have occured at ~2.31 Ga on 4 cratons. Detrital zircons age spectrum highlights age peaks at 2.45, 2.54, 2.68, 2.82, 2.95 and 3.2 Ga. A crystal of Hadean zircon was discovered and indicate the existence of a probable differentiated crust within the Pilbara craton at 4.0 Ga. 70% of the analyzed zircons have juvenile Hf isotope composition, suggesting that the TCG incorporated volcanic material from continental large igneous provinces through the erosion of the underlying Hamersley and Fortescue groups

Les Andes de Mérida (Venezuela) est caractérisé par la présence de morphologie glaciaire bien préservée entre 2400-4978 m. Les études de ces morphologies glaciares font la contribution pour mieux comprendre et reconstruire la Dernière Glaciation aux Andes Vénézuéliennes. La reconstruction de la Dernière Glaciation (connue dans la région comme Glaciation Mérida) était limitée par la disponibilité de chronologie glaciaire. Cette thèse fait sa contribution à la reconstruction de la Dernière Glaciation et à la connaissance du paléoclimat depuis le Pléistocène Superieur. La méthodologie a involucré l´analyse géomorphologique et l´étude géochronologique. La morphologie glaciaire a été datée avec la technique de nucléides cosmogéniques produits in-situ (10Be). Cette technique est appropriée pour dater les matériels riches en quartz et la période d´intérêt. Les inférences des conditions paleoclimatiques ont été faites sur la base des analyses de la paléo ELA.Des différentes dynamiques glaciares ont été identifiées aux Andes centrales de Mérida. Dans les vallées de Mucubají et Mucuchache, la dynamique a été caractérisée par plusieurs étapes de avancé-arrêt des glaciaires dans un recul général de la glace. Dans les vallées de Gavidia et Mifafí, la disparition des glaciares a été très rapide avec la vitesse de recul plus haute (entre 4-7 km/ky). Divers caractéristiques morpho métriques comme la pente du fond de la vallée, la topographie de la zone d´accumulation (cirques glaciares avec les murs très incliné), des surfaces de la zone d´accumulation et son orientation ont aussi contrôlé les différents dynamiques glaciares.Les avancées des glaciares ont été identifiées entre 2500-4200 m. Les avancées glaciares pendant le MIS 3 ont été reconnues à Sierra Nevada. Ces avancées ont été liées aux hautes précipitations dans le nord de l´Amérique de Sud produites par l´activité de la Zone de Convergence Intertropical. Ces avancées ont été aussi reliées aux conditions plus chaudes et humides dans l´Hémisphère Nord (aussi ces conditions ont été identifiées aux Andes vénézuéliennes et sont connues comme l´Interstadío El Pedregal). Les avancées glaciares pendant le Dernière Maximum Glaciares ont été enregistrées en Sierra Nevada á Mucubají et Las Tapias entre 3100-3600 m. Principalement, les avancées glaciares MIS 2 sont arrivées pendant l´Oldest Dryas-El Caballo Estadío à 17 ka. Ces avancées glaciares ont été reliées aux températures froides dans l´Hémisphère Nord et les températures plus froides enregistrées dans les carottes de glaciares tropicaux.Mots clésDatation par cosmogéniques produits in-situ, morphologie glaciaire, Pléistocène, Dernière Glaciation, LGM, paléo ELA. / The central Mérida Andes (Venezuela) landscape is characterized by the presence of well-preserved glacial landforms located between 2400 and 4978 m a.s.l. Geomorphological studies of these glacial landforms significantly contribute to the Venezuelan Andes glaciations reconstructions. However, Last Glaciation (locally called Mérida Glaciation) was poorly reconstructed because of limited chronological data. This dissertation attempts to contribute to the Last Glaciation reconstruction and paleoclimate knowledge since the late Pleistocene. Accordance this necessity, the methodology involved geomorphological analysis and geochronological study. Glacial landforms were dated based on the Terrestrial Cosmogenic Nuclide dating (10Be). This method is suitable for date quartz-rich materials and for the period of interest. To deduce paleoclimate conditions an analysis based on paleo ELA was developed.In the central Mérida Andes different Late Pleistocene glacier dynamics were identified. In the Mucubají and the Mucuchache valleys, successive stages of glacier stop-advance were identified during an overall glacier withdrawal. In the Gavidia and Mifafí valleys, glacier withdrawal was rapid with the highest retreat rates (between 4-7 km/ky). Morphometric features as glaciers bottom valley slopes, accumulation zone topography (glaciers cirques with steep walls), areas and orientation controlled different glaciers dynamics.Glacier advances were evidenced between 2500-4200 m. MIS 3 glaciers advances has been recognized in the Sierra Nevada. These were related to the highest runoff in the north of South America produced by the Intertropical Convergence Zone (ITCZ) and the local warm and wet climate conditions (locally named El Pedregal Interstadial). LGM glacier advances were recorded in Sierra Nevada in the Mucubají and Las Tapias between 3100-3600 m. MIS 2 Glaciers advances mainly occurred during the Oldest Dryas- El Caballo Stadial at around 17 ka. These glaciers advances correlate to the cold temperatures in the North Hemisphere and the coldest temperatures recorded in tropical ice cores.KeywordsTerrestrial cosmogenic nuclides dating, TCN, cosmogenic dating, glacial landforms, Andes Mérida, Venezuela. Pleistocene, Last Glaciation, LGM, paleo ELA, tropic paleoclimate.

Snow occurs in the High Drakensberg of southern Africa approximately eight times per annum. Snow cover is frequently captured by Landsat satellite imagery, which provide data for the monitoring of snow cover in other regions of the world. Together with a digital elevation model, repetitive snow cover data are used to analyse the distribution of snow cover in the High Drakensberg study area. The effect that the regional and local topography, latitude, and climatic conditions have on the spatial distribution of snow and the function that temperature, wind, altitude, aspect and slope gradient play in the preservation of snow cover are examined. The results of the spatial study allow for the identification of sites that support the accumulation of snow. Specific active and relict geomorphological features were surveyed and correlated spatially to the contemporary snow cover. Among such features are linear debris ridges on south-facing valley slopes in the High Drakensberg. These appeared similar to glacial features found elsewhere in the world and are thus significant in a long-standing and highly conjectured debate over the validity of possible plateau, cirque and niche glaciation in the region. Late-lying snow cover favours gently sloping south- and southeast-facing aspects at altitudes from 3000 m ASL to just below the highest peaks in the region near 3450 m ASL, above which higher insolation levels on the flat mountain summits provides unfavourable conditions. Snow cover immediately adjacent to the Drakensberg escarpment ablates quickly whilst snow cover at high altitudes in the Lesotho interior experiences better preservation conditions. Latitude has no obvious impact on the distribution of snow cover due to the dominant role of topography in the High Drakensberg other than a limiting of snowfall to regions south of 29°S in late spring. Various synoptic conditions produce snowfall in the region, with cold fronts associated with midlatitude cyclones producing the majority of snow cover. A strong correlation exists between the spatial distribution of snow cover and specific geomorphological features. Observed linear debris ridges are located on slopes that experience frequent contemporary snow cover, lending credence for a glacial origin of the ridges during a period of colder environmental conditions.

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

Glaciation is considered one of the main natural processes that can have a significant impact on the long term performance of DGRs. The northern part of the American continent has been subjected to a series of strong glaciation and deglaciation events over the past million years. Glacial cycles cause loading and unloading, temperature changes and hydraulic head changes at the ground surface. These changes can be classified as transient boundary conditions. It is widely accepted that the periodic pattern of past glacial cycles during the Late Quaternary period are resultant of the Earth’s orbital geometry changes that is expected to continue in the future. Therefore, from the safety perspective of DGRs, such probable events need to be taken into account. The objective of this thesis is to develop a numerical model to investigate the thermo-hydro-mechanical-chemical (THMC) coupled processes that have resulted from long term past and future climate changes and glaciation cycles on a proposed DGR in sedimentary rocks in southern Ontario. The first application is done on a large geological cross section that includes the entire Michigan basin by using a hydro-mechanical (HM) coupled process. The results are compared with field data of anomalous pore water pressures from deep boreholes in sedimentary rocks of southern Ontario. In this work. The modeling results seem to support the hypothesis that at least the underpressures in the Ordovician formation could be partially attributed to past glaciation. The second application is made on site conditions by using the THMC model. The results for the pore water pressure, tracer profiles, permafrost depth and effective stress profile are compared with the available field data, the results show that the solute transport in the natural limestone and shale barrier formations is controlled by diffusion, which provide evidence that the main mechanism of transport at depth is diffusion-dominant. The third application is made on site conditions to determine the effect of underground changes in DGRs due to DGR construction. The results show that future glaciation loads will induce larger increases in effective stresses on the shaft. Furthermore, it is found that hypothetical nuclide transport in a failed shaft can be controlled by diffusion and advection. The simulation results show that the solute transported in a failed shaft can reach the shallow bedrock groundwater zone. These results might imply that a failed shaft will substantially lose its effectiveness as a barrier. The fourth application is proposed to investigate the geochemical evolution of sedimentary host rock in a near field scale. In this part, a new thermo-hydro-mechanical-geochemical simulator (COMSOL-PHREEQC) is developed. It is anticipated that there will be a geochemical reaction within the host rock that results from interaction with the water enriched with the CO2 generated by nuclear waste.

Keiminės terasos Lietuvos teritorijoje yra aptinkamos Vėlyvojo Nemuno apledėjimo Baltijos stadijos ledyno paliktame reljefe. Pagrindinis šio darbo tikslas – Vėlyvojo Nemuno apledėjimo srityje esančių keiminių terasų paplitimo, jų morfologijos, sandaros, kilmės ir padėties ištyrimas. Ankstesnėse publikacijose buvo tik konstatuojama keiminių terasų geomorfologinė padėtis ir aprašomi morfologiniai terasų požymiai. Pagrindiniu tyrimo metodu pasirinktas kartografinis. Keiminės terasos yra savarankiški ledyno pakraštiniai dariniai, susidarę tarp reljefo formų, susiformavusių supraglacialinėje ir terminoglacialinėje subaplinkose. Ledyno ledo dangos šlaitas buvo tik viena iš jas sudarančių nuogulų sedimentacinės erdvės ribų. Terasų vidinė sandara tiesiogiai priklauso nuo ją formavusių veiksnių. Pagal tai skiriamos fliuvioglacialinės, limnoglacialinės ir mišrios akvaglacialinės keiminės terasos. Darbe pateikta klasifikacija paremta keiminių terasų Lietuvos teritorijoje morfologijos, morfometrijos ir sandaros tyrimais. Atlikti tyrimai svarbūs fundamentiniu aspektu, nes nustatyta skirtingų keiminių terasų tipų morfogenezė, sandara ir susidarymo paleogeografinės sąlygos, degraduojant Vėlyvojo Nemuno apledėjimo ledynui, gali būti panaudota kituose regionuose sprendžiant analogiškų formų susidarymo klausimus. Darbą sudaro 167 psl., 88 paveikslai, 1 lentelė. Literatūros sąraše 173 bibliografiniai pavadinimai. / Kame terraces in the territory of Lithuania are found in the Late Nemunas glaciation Baltija stage relief. Investigation of the distribution, morphology, composition, origin and position of kame terraces in the Late Nemunas glaciation area is the main objective of the present study. The previous publications merely contained statements about the geomorphological position of kame terraces and descriptions of morphological features of terraces. The research was carried out by cartographic method. Kame terraces are isolated glacier marginal formations deposited between the landforms that formed in supraglacial and terminoglacial environments. The ice slope of a decaying glacier only represented one of the boundaries of sedimentation space. The structure of terraces was directly affected by the forming factors. According to the forming factors, kame terraces are classified as glaciofluvial, glaciolacustrine and mixed aquaglacial. The presented classification is based on the studies of morphology, morphometry and structure of kame terraces in the territory of Lithuania. The conducted study has a fundamental value since the established morphogenesis, structure and palaeogeographical conditions of formation of different types of kame terraces, created by the decaying Late Nemunas glacier, can be used for solution of the formation issues of similar forms in other regions. The dissertation is comprised of 167 pages, 88 illustrations and one table. The list of references has 173... [to full text]

Keiminės terasos Lietuvos teritorijoje yra aptinkamos Vėlyvojo Nemuno apledėjimo Baltijos stadijos ledyno paliktame reljefe. Pagrindinis šio darbo tikslas – Vėlyvojo Nemuno apledėjimo srityje esančių keiminių terasų paplitimo, jų morfologijos, sandaros, kilmės ir padėties ištyrimas. Ankstesnėse publikacijose buvo tik konstatuojama keiminių terasų geomorfologinė padėtis ir aprašomi morfologiniai terasų požymiai. Pagrindiniu tyrimo metodu pasirinktas kartografinis. Keiminės terasos yra savarankiški ledyno pakraštiniai dariniai, susidarę tarp reljefo formų, susiformavusių supraglacialinėje ir terminoglacialinėje subaplinkose. Ledyno ledo dangos šlaitas buvo tik viena iš jas sudarančių nuogulų sedimentacinės erdvės ribų. Terasų vidinė sandara tiesiogiai priklauso nuo ją formavusių veiksnių. Pagal tai skiriamos fliuvioglacialinės, limnoglacialinės ir mišrios akvaglacialinės keiminės terasos. Darbe pateikta klasifikacija paremta keiminių terasų Lietuvos teritorijoje morfologijos, morfometrijos ir sandaros tyrimais. Atlikti tyrimai svarbūs fundamentiniu aspektu, nes nustatyta skirtingų keiminių terasų tipų morfogenezė, sandara ir susidarymo paleogeografinės sąlygos, degraduojant Vėlyvojo Nemuno apledėjimo ledynui, gali būti panaudota kituose regionuose sprendžiant analogiškų formų susidarymo klausimus. Darbą sudaro 167 psl., 88 paveikslai, 1 lentelė. Literatūros sąraše 173 bibliografiniai pavadinimai. / Kame terraces in the territory of Lithuania are found in the Late Nemunas glaciation Baltija stage relief. Investigation of the distribution, morphology, composition, origin and position of kame terraces in the Late Nemunas glaciation area is the main objective of the present study. The previous publications merely contained statements about the geomorphological position of kame terraces and descriptions of morphological features of terraces. The research was carried out by cartographic method. Kame terraces are isolated glacier marginal formations deposited between the landforms that formed in supraglacial and terminoglacial environments. The ice slope of a decaying glacier only represented one of the boundaries of sedimentation space. The structure of terraces was directly affected by the forming factors. According to the forming factors, kame terraces are classified as glaciofluvial, glaciolacustrine and mixed aquaglacial. The presented classification is based on the studies of morphology, morphometry and structure of kame terraces in the territory of Lithuania. The conducted study has a fundamental value since the established morphogenesis, structure and palaeogeographical conditions of formation of different types of kame terraces, created by the decaying Late Nemunas glacier, can be used for solution of the formation issues of similar forms in other regions. The dissertation is comprised of 167 pages, 88 illustrations and one table. The list of references has 173... [to full text]

This thesis analyses the glacier fluctuations in New Zealand since late Pliocen until today (2017) and evaluates GLOFs (Glacier Lake Outburst Floods) hazards from all proglacial lakes of New Zealand. Background research of a wide range of scientific sources was used to describe New Zealand glacier fluctuations during the last ~2.6 Ma, uncover local climatic and tectonic specifics, describe uneven behaviour of different glacier types and summarise current knowledge about climatological forcings to New Zealand glaciers. Compared to the timing of glaciations in the Norther Hemisphere, an earlier onset of LGM (Last Glacial Maximum) and LIA (Little Ice Age) was recorded in New Zealand. A dramatic glacier advance of short- to medium-response time glaciers was recorded between 1983 and 1999. This advance was caused by changes of atmospheric and oceanic circulation patterns around New Zealand. A detailed study of the past events revealed that really few events were recorded in New Zealand history. While englacial outburst floods are relatively common from Franz Josef Glacier, no moraine dam rupture and only two GLOFs from a proglacial lake were recorded in New Zealand history. Inventory of proglacial lakes of New Zealand completed from remote sensing data was done to further evaluate the hazards of GLOFs. 25...

Abstract Numerous efforts have been made in recent decades to recover the climate history of the Arctic region. The present PhD study is one of them, focusing on terrestrial sediments which were deposited in the Arctic Ocean during the Cenozoic. The Arctic Ocean, surrounded by land on all sides, is among the most important marine archives of sediments that record information of palaeoclimates, including cold climates with extensive glaciation. Evidence of ancient glaciations is generally retraced by observing widespread terrestrial ice-rafted debris (IRD) deposits on the seafloor, as large amounts of IRD are transported by icebergs during deglacial phases. However, it has been shown that sea ice also transports abundant IRD from shallow continental shelves. What is worth noticing is that glaciers and sea ice influence climate variables differently, and therefore, to model climate in past glaciations, IRD released from these factors should be differentiated. The relative proportions of glacial IRD and non-glacial IRD were determined in this study from two central Arctic Ocean expedition site recoveries: the Integrated Ocean Drilling Program’s (IODP) Arctic Coring Expedition (ACEX) 302 composite core recovery and the Swedish Polar Research Expedition’s Arctic Ocean 1996 (AO96) piston core 96/12-1pc. The main objective was to characterise and quantify the process- and environment-related microtextures of quartz sand grain surfaces. The data were subjected to statistical methods and a multiproxy approach, and the results were used to define the dynamics and timing of palaeoglaciations. The results indicate that the signals of glacial and non-glacial continental processes and the involvement of iceberg versus sea-ice rafting can be distinguished by microtextural and statistical analyses. Improvements in the general interpretation of late Pleistocene Eurasian ice sheet distribution and dynamics are provided: late MIS 4 (ca. 62–67 ka) reflects a deglacial phase with increased fluvial activity, whereas MIS 3 at ca. 45 ka is related to glacial advance characterised by the oscillating and calving Barents-Kara ice sheet. Based on the results of this study, the early glacial ice on the Arctic continent can be retraced back to the late Palaeocene ca. 56 Ma. / Tiivistelmä Arktisen alueen ilmastohistoriaa on pyritty selvittämään usein eri tavoin viime vuosikymmenten aikana. Tässä tutkimuksessa on keskitytty Jäämereen kerrostuneiden mantereelta peräisin olevien sedimenttien ominaisuuksiin. Jäämeri on yksi tärkeimmistä mannerten ympäröimistä merialueista jonka pohjan sedimentteihin on tallentunut tietoa menneistä ilmasto-oloista, kuten laajoista jäätiköitymisistä. Jään kuljettaman sedimenttiaineksen runsas esiintyminen merenpohjan kerrostumissa on yleisesti tulkittu todisteeksi menneistä jäätiköitymisistä, sillä jäävuorikuljetus on runsainta mannerjäätikön sulamisvaiheessa. Myös merijää voi kuljettaa runsaasti sedimenttiainesta joka on peräisin matalalta mannerjalustavyöhykkeeltä. Jäätiköiden ja merijään vaikutus ilmastomuuttujiin on hyvin erilainen ja siksi on tärkeää selvittää niiden osallisuus eri ilmastovaiheissa. Tässä tutkimuksessa määritettiin jäävuorien ja merijään kuljettaman sedimenttiaineksen suhteelliset osuudet kahdesta keskeisen Jäämeren tutkimusmatkan kaira-aineistosta: Integrated Ocean Drilling Program (IODP) -ohjelman Arctic Coring Expedition 302 (ACEX) -tutkimusmatkan yhdistetystä kaira-aineistosta ja Swedish Polar Research Expedition Arctic Ocean 1996 (AO96) -tutkimusmatkan kaira-aineistosta 96/12-1pc. Tärkein tavoite oli kuvata ja laskennallisesti määrittää kvartsihiekkarakeiden pintamikrotekstuurit, jotka ovat syntyneet erilaisissa prosesseissa ja ympäristöissä. Aineistoa tarkasteltiin tilastollisin- ja moniaineistomenetelmin, ja tuloksia käytettiin jäätiköiden dynamiikan ja ajoituksen määrittämiseen. Tämän tutkimuksen johtopäätöksenä voidaan todeta että jäätikköön ja ei-jäätikköön liittyvät mantereiset prosessesit, sekä jäävuori- ja merijääkuljetuksen osallisuus, voidaan erottaa mikrotekstuuri- ja tilastollisen analyysin avulla. Tutkimus tarkentaa tulkintoja myöhäis-Pleistoseenin jäätiköiden alueellisesta levinneisyydestä ja dynamiikasta: myöhäinen MIS 4 (noin 62–67 ka) oli deglasiaalivaihetta jolloin fluviaalitoiminta oli aktiivista, kun taas MIS 3 noin 45 ka liittyy jäätiköitymisvaiheeseen jolloin Barentsin-Karan jääkenttä oskilloi ja jäävuorikuljetus oli runsasta. Tutkimuksen tuloksena voidaan myös tarkentaa varhaisten Arktisten jäätiköitymisten ajankohta myöhäiseen Paleoseeniin noin 56 Ma.

The objective of this thesis was to reconstruct the Sedimentary, Cryostratigraphic and Paleoclimatic history of Two Moose Lake, central Yukon using a new analytical technique for dating ice wedges using Dissolved Organic Carbon (DOC). During two field seasons in August 2013 and April 2014, 442 samples were collected from a newly exposed headwall of a thaw slump with 7 ice wedges and over 4m of sediment. Using cryostratigraphy, granulometry, stable isotopes and 18 14C-DOC ages, 4 stratigraphic units were delineated: 1) a sediment-rich ice layer inferred to be of glacial origin (>32ka BP); 2) a silt-rich layer deposited during the Holocene Thermal Maximum (~10 to 8.2ka BP); 3) a silt with organics layer deposited from ~8ka to 6.4ka BP, and 4) a paleo-active layer and modern active layer. 14C-DOC dating indicated two periods of ice wedge activity at Two Moose Lake, the first during the late Pleistocene (31,608 to 12,990 yr cal BP) and from the mid-Holocene to present (6,328 to 892 yr cal BP). The presence of late-Pleistocene aged ice wedges at Two Moose Lake supports the common belief of an unglaciated central Yukon during the most recent McConnell glaciation from 29.6 to 13ka BP. Values for δ18O from the Holocene- and Pleistocene-aged ice wedges were 2-3‰ and 5-9‰ depleted compared those of modern precipitation from Mayo (-22.32‰). Medium-resolution (2-4cm) sampling along with multiple 14C-DOC samples along a transect allowed for the creation of a continuous δ18O and temperature age profile to be developed from multiple ice wedges, showing a strong consistency between overlapping ages. The reconstruction of the paleoclimate of Two Moose lake is consistent with known events from southern Yukon including the Boutellier Inderstadial, a cold unglaciated central Yukon during the McConnell Glaciation, warming during the Holocene Thermal Maximum (HTM) followed by an extreme cooling event at 8.2ka BP, a cooling event at 4.2ka BP, and the subsequent warming to present temperatures.