Sangamonian Forest History and Climate in Atlantic Canada
Seven of the more than twenty five buried organic deposits in Atlantic Canada assigned to pre-Wisconsinan non-glacial intervals possibly relate to the climatic optimum of the Sangamon Interglaciation, that is substage 5e of the deep-sea oxygen isotope record. These sites are East Bay and Green Point...
| Published in: | Géographie physique et Quaternaire |
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| Main Author: | |
| Format: | Text |
| Language: | English |
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Les Presses de l'Université de Montréal
1990
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| Subjects: | |
| Online Access: | http://id.erudit.org/iderudit/032828ar https://doi.org/10.7202/032828ar |
| Summary: | Seven of the more than twenty five buried organic deposits in Atlantic Canada assigned to pre-Wisconsinan non-glacial intervals possibly relate to the climatic optimum of the Sangamon Interglaciation, that is substage 5e of the deep-sea oxygen isotope record. These sites are East Bay and Green Point on Cape Breton Island. Addington Forks and East Milford in mainland Nova Scotia. Le Bassin and Portage-du-Cap on the Iles de la Madeleine, Québec, and Woody Cove, Newfoundland. Except for Woody Cove, none of the sites records a complete climatic cycle, and the sequence of events must be pieced together from their disparate records. The spectra, characterized by significant amounts of thermophilous taxa that are not as abundant or present in the region today, are similar in general to Holocene spectra at sites immediately south of the lower Great Lakes. Comparison of the fossil spectra from five sites with modern surface spectra from eastern North America yields modern analogs which, if valid, indicate that the climate in Atlantic Canada during the climatic optimum of the last interglacial interval was more continental in character and considerably warmer than present. Des quelque vingt-cinq dépôts organiques enfouis datant d'intervalles non glaciaires pré-wisconsiniens, sept d'entre eux pourraient être attribués à l'optimum climatique de l'Interglaciaire du Sangamonien. c'est-à-dire le stade isotopique 5e. Ces sites sont les suivants: East Bay et Green Point, à l'île du Cap-Breton, Addington Forks et East Milford. en Nouvelle-Ecosse. Le Bassin et Portage-du-Cap, aux îles de la Madeleine, et Woody Cove, à Terre-Neuve. Aucun des sites, sauf celui de Woody Cove, n'a enregistré un cycle climatique complet, et la séquence des événements doit être reconstituée à partir d'inventaires disparates. Les spectres, caractérisés par des quantités importantes de taxons thermophiles qui ne sont plus aussi abondants ou même présents dans la région aujourd'hui, sont semblables de façon générale aux spectres holocènes de sites ... |
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