| Titre | LiDAR-based quantitative assessment of drumlin to mega-scale glacial lineation continuums and flow of the paleo Seneca-Cayuga paleo-ice stream |
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| Auteur | Sookhan, S; Eyles, N; Bukhari, S; Paulen, R C |
| Source | GAC®-MAC 2021, London, Canada: Exploring Geosciences Through Time and Space/GAC®-MAC 2021, London, Canada : Explorer les géosciences à travers le temps et l'espace; L'Association géologique du
Canada-L'Association minéralogique du Canada, Réunion annuelle conjointe, Recueil des résumés vol. 44, 2021 p. 289  Accès ouvert |
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| Année | 2021 |
| Séries alt. | Ressources naturelles Canada, Contribution externe 20210298 |
| Éditeur | Association géologique du Canada |
| Réunion | Geological Association of Canada-Mineralogical Association of Canada Joint Annual Meeting 2021; London, ON; CA; Novembre 1-5, 2021 |
| Document | publication en série |
| Lang. | anglais |
| Media | en ligne; numérique |
| Formats | pdf |
| Province | Ontario |
| SNRC | 30N |
| Région | Lac Ontario; New York State; Finger Lakes; Oneida Lake; Mohawk River; Great Lakes |
| Lat/Long OENS | -78.0000 -75.2500 43.8667 41.0000 |
| Sujets | topographie glaciaire; drumlins; elements glaciaires; lacs proglaciaires; dépôts glaciaires; tills; clastes; antecedents glaciaires; Wisconsinien; déglaciation; écoulement glaciaire; evolution du bassin;
analyses statistiques; érosion; topographie du substratum rocheux; analyses pétrographiques; quartzites; établissement de modèles; Calotte glaciaire Laurentide; Bassin de Rochester ; Formation de Grimsby ; Données numériques d'élévation; courants
glaciaires; directions d'écoulement glaciaire; l'apprentissage machine; Intelligence artificielle; Méthodologie; géologie des dépôts meubles/géomorphologie; géophysique; Nature et environnement; Sciences et technologie; Phanérozoïque; Cénozoïque;
Quaternaire |
| Programme | GEM2 : La géocartographie de l'énergie et des minéraux Nord-est du Québec-Labrador, géologie des dépôts meubles de la région
d'Hudson/Ungava |
| Programme | GEM-GéoNord : La géocartographie de l'énergie et des minéraux Coordination du programme GEM |
| Diffusé | 2021 11 01 |
| Résumé | (disponible en anglais seulement)
Shortly after 14,500 ybp during the deglaciation of the Laurentide Ice Sheet in eastern North America, the 80 km wide Seneca-Cayuga paleo ice stream occupied
the overdeepened New York State Finger Lake basins. This presentation describes a new methodological framework for evaluating the topography of the former ice stream bed from high-resolution LiDAR DEM data, allowing mapping and analysis of almost
four thousand subglacially streamlined bedforms such as drumlins and mega-scale glacial lineations. Qualitative and quantitative techniques were applied to the statistical analysis of bedform elongation ratio and orientation using Natural Neighbour
Interpolation and unsupervised machine learning-based data clustering. Analysis reveals a geomorphic continuum of as many as seven morphotypes of streamlined bedforms from drumlins to mega-scale glacial lineations with intermediate 'channeled
drumlins' possibly recording erosion of parent drumlins. Spatial analysis using orientation Grouping Analysis identifies several flow-parallel sets of bedforms reflecting the presence of multiple ice flow units in the ice stream up to 10 km wide that
were topographically controlled by glacially-overdeepened basins of lakes Canandaigua, Seneca, and Cayuga (-151, -306, -242 below mean sea level respectively). Longitudinal variation in bedform elongation along as much as 60 km length of flow lines
is provisionally interpreted as a proxy for ice flow velocities which ranged from steady state flow (drumlins), intermediate velocities (channeled drumlins) to fast flow (mega-scale glacial lineations). Quantitative data also identifies faster axial
flow and slower flow along the margins of each ice flow unit. Fast flow was triggered at the grounding lines of flow units terminating in deep (as much as 600 m) proglacial lakes at the southern end of each overdeepened Finger Lake basin and
propagated northwards along each flow unit at different rates reflecting the size and depth of frontal waterbodies. Petrographic data from tills derived from distinctive Paleozoic quartzites outcropping in a narrow west-east belt perpendicular to
flow of each ice stream identifies extended longitudinal subglacial advection during fast flow consistent with very rapid bedform evolution. |
| Sommaire | (Résumé en langage clair et simple, non publié)
Cette présentation de conférence est basée sur un article récemment publié par les auteurs, sur les ruisseaux de glace de la région de Finger
Lakes, New York. Le message clé ici est l'application et l'interpolation de données LiDAR haute résolution pour mieux comprendre la morphologie des reliefs glaciaires et leur formation. |
| GEOSCAN ID | 329180 |
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