| Titre | LiDAR-based quantitative assessment of drumlin to mega-scale glacial lineation continuums and flow of the paleo Seneca-Cayuga paleo-ice stream |
| |
| Auteur | Sookhan, S; Eyles, N; Bukhari, S; Paulen, R C |
| Source | Quaternary Science Reviews vol. 263, 107003, 2021 p. 1-17, https://doi.org/10.1016/j.quascirev.2021.107003  Accès ouvert |
| Année | 2021 |
| Séries alt. | Ressources naturelles Canada, Contribution externe 20200707 |
| Éditeur | Elsevier |
| Document | publication en série |
| Lang. | anglais |
| DOI | https://doi.org/10.1016/j.quascirev.2021.107003 |
| Media | papier; en ligne; numérique |
| Formats | pdf; html |
| Région | Lac Ontario; New York State; Finger Lakes; Oneida Lake; Mohawk River |
| 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 |
| Illustrations | cartes de localisation; modèles altimétriques numériques; modèles 3D; organigrammes; cartes géolscientiques généralisées; graphiques; tableaux; modèles |
| 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 | GEM2 : La géocartographie de l'énergie et des minéraux Cartographie des dépôts meubles du sud du Mackenzie du corridor de Mackenzie |
| Diffusé | 2021 06 09 |
| 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. The topography of the former ice stream bed can be evaluated from high-resolution LiDAR DEM data, allowing mapping of almost four thousand subglacially streamlined bedforms such as drumlins and
mega-scale glacial lineations using Curvature-based Relief Separation. Qualitative and quantitative techniques were then applied to the statistical analysis of bedform elongation ratio and orientation using Natural Neighbor 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). Evolution in bedforms occurred rapidly likely over
a time frame of several hundred years. 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)
Nous avons identifié de nouvelles preuves géomorphologiques tirées de la cartographie LiDAR à haute résolution qui démontrent la présence
antérieure de coulées de glace dans les lacs Finger lors de la dernière glaciation et nous avons identifié leur rôle possible dans l'érosion et la surdépaisseur de ces bassins. |
| GEOSCAN ID | 328021 |
|
|