Colloque

Depositional Processes and Environmental Factors of Glacigenic Sedimentary Sequences

Daniel E. Lawson

Membre a labase

Daniel E. Lawson

Résumé du colloque

Process studies in the environments of modern glaciers provide useful models for analyzing sedimentary sequences of former glaciers and ice sheets. Ice marginal and subglacial sedimentary sequences result from the complex interaction of subaerial, subsurface and subglacial processes. Diamictons may be deposited by several of these processes and may or may not be classified genetically as tills, yet because of the nature of the environment will be transitional to one another in terms of their properties and contacts. Various controls on sedimentation determine the importance and timing of specific depositional processes and their interaction with one another, and thus facies associations and stratigraphic relationships. Environmental controls may include sediment source and supply, meltwater availability, glacier bed and ice marginal topography, glacier dynamics and thermal regime, and local climate. In addition, glacier hydrology, bed properties and mechanics of movement determine the nature of subglacial erosion and deposition. Sediment recycling may occur multiple times in the glacial environment and involve ice marginal and subglacial materials. Because of the complexity of sedimentation, detailed time-sequencing of glacigenic deposits is difficult; position within a stratigraphic sequence is not necessarily key to equivalency. Process facies are less important for stratigraphic analyses than are facies associations, which provide a better picture of the three dimensionality of the depositional environment, including time-stratigraphic relationships.

Contexte

Section :

Analyse des faciès glaciaires : méthodologie

Thème du colloque :

Analyse des faciès glaciaires : méthodologie

Hôte : Université du Québec à Montréal

Découvrez d'autres communications scientifiques

Dans le même colloque
Du même congressiste

Titre du colloque :

Analyse des faciès glaciaires : méthodologie

Depositional Processes and Environmental Factors of Glacigenic Sedimentary Sequences

Daniel E. Lawson

Faciès et structures dans les sédiments glaciaires wisconsiniens du Québec: Les niveaux d'interprét…

Gilbert Prichonnet

Les attributs texturaux et structuraux des faciès de till sur le bouclier canadien

Michel Bouchard

Voir tous les contenus de ce colloque

Autres communications du même congressiste :

Thème du colloque :

Analyse des faciès glaciaires : méthodologie

Depositional Processes and Environmental Factors of Glacigenic Sedimentary Sequences

Daniel E. Lawson