Bibliothèque Électronique Lac Saint-Pierre

Pleistocene palynostratigraphy in the St. Lawrence Valley and middle Estuary

Clet-Pellerin, M. et Occhietti, S. (2000). Pleistocene palynostratigraphy in the St. Lawrence Valley and middle Estuary. Quaternary International , 68-71 . p. 39-57. DOI: 10.1016/S1040-6182(00)00031-8.

Ce document n'est pas hébergé sur Bibliothèque Électronique Lac Saint-Pierre.

Résumé

The litho-biostratigraphic framework of the upper middle and upper Quaternary units of the St. Lawrence basin results from the interplay of ice advance/retreat, isostatic depression/rebound, fluvial processes and climatic changes. Each main climatic cycle is characterized by a sedimentary sequence representative of the associated changing depositional environments. The climatic significance of the units is assessed with reference to the pollen content, and the evolving trend of the inferred vegetation. Five assemblages are defined: (1) the mixed woods assemblage related to temperate deciduous forests, (2) the boreal forest subdivided into a balsam fir (A. balsamea) dominated assemblage, a pine (P. banksiana or P. divaricata) dominated assemblage, and a spruce dominated assemblage (Picea mariana), (3) the forest tundra (subarctic zone), (4) the shrub tundra with subarctic plants, and (5) the herb tundra (arctic zone). Three marine invasions, older than Late Wisconsinan, record a progressive vegetal recolonization: a pre-Illinoian marine episode, the post-Illinoian marine invasion of Guettard Sea (6-5 transition), and the Cartier Sea invasion (substage5b?). Three types of lake inundated the lowlands: (1) lake systems associated with interstadial or interglacial fluvial drainage, (2) deglacial lakes, with a gradual vegetal recolonization, (3) pre-glacial lakes, whose pollen indicates boreal forest replacement by forest tundra and herb tundra.

Type de document: Article scientifique
Statut du texte intégral: Autre
Mots-clés libres: Fleuve Saint-Laurent, Changement climatique, Végétation, Pollen, Lacs // St. Lawrence River, Climate change, Vegetation, Pollen, Lakes
Sujets: 2. Milieu physique > 2.1. Géologie
2. Milieu physique > 2.4. Hydrologie
3. Végétation, milieux humides
3. Végétation, milieux humides > 3.6. Forêt
9. Nouvelles pressions > 9.1. Changement climatique
Date de dépôt: 01 avr. 2017 16:06
Dernière modification: 01 avr. 2017 16:06
URI: http://belsp.uqtr.ca/id/eprint/1081

Actions (Identification requise)

Dernière vérification avant le dépôt Dernière vérification avant le dépôt
Coopérative de solidarité de la Réserve de la biosphère du Lac-Saint-Pierre
Concepteur de la BELSP : André Barabé, Ph. D.