| Titre | Inherited clast dispersal patterns: implications for palaeoglaciology of the SE Keewatin Sector of the Laurentide Ice Sheet |
| Auteur | Trommelen, M S; Ross, M; Campbell, J E |
| Source | Boreas vol. 42, no. 3, 2013 p. 693-713, https://doi.org/10.1111/j.1502-3885.2012.00308.x |
| Année | 2013 |
| Séries alt. | Secteur des sciences de la Terre, Contribution externe 20110305 |
| Éditeur | Wiley |
| Document | publication en série |
| Lang. | anglais |
| DOI | https://doi.org/10.1111/j.1502-3885.2012.00308.x |
| Media | en ligne; numérique |
| Formats | pdf |
| Province | Manitoba |
| SNRC | 54L/13; 54M/04; 54M/05; 54M/12; 54M/13; 64I/15; 64I/16; 64P/01; 64P/02; 64P/07; 64P/08; 64P/09; 64P/10 |
| Lat/Long OENS | -97.0000 -95.5000 59.6667 58.7500 |
| Sujets | écoulement glaciaire; glace; tills; analyses de till; lithologie; topographie glaciaire; géologie des dépôts meubles/géomorphologie; Cénozoïque; Quaternaire |
| Illustrations | location maps |
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| Programme | Gisements polymétalliques - nord-est du Manitoba, GEM : La géocartographie de l'énergie et des minéraux |
| Résumé | (disponible en anglais seulement)
The net effect of ice-flow shifts resulting in the dilution or reworking of clasts on a single preserved till sheet is often unknown yet has major implications
for palaeoglaciology and mineral exploration. Herein, we analyse variations in till clast lithologies from a single till sheet, within palimpsest-type Glacial Terrain Zones in NE Manitoba, Canada, to better understand sediment - landform
relationships in this area of high landform inheritance. This near-ice-divide area is known to consist of a highly fragmented subglacial landscape, resulting from spatio-temporal variations in intensity of reworking and inheritance throughout
multiple glacial events (subglacial bed mosaic). We show that a seemingly homogenous 'Keewatin' till sheet is composed of local (>15 km) and continental-scale (~100-km-long carbonate train and 350 - 600 km long Dubawnt red erratic train) fan,
irregular (amoeboid) or lobate palimpsest dispersal patterns. Local dispersal is more complex than the preserved local landform flowset(s) record, but appears consistent with the overall glacial history reconstructed from regional flowset and
striation analyses. The resultant surface till is a spatial mosaic interpreted to reflect variable intensities in modification (overprinting) and preservation (inheritance) of a predominately pre-existing till sheet. A multifaceted approach
integrating till composition, regional landforms, ice-flow indicators, and stratigraphic knowledge is used to map relative spatio-temporal erosion/reworking intensity. |
| GEOSCAN ID | 289675 |
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