| Summary: | Regarded as a reference unit of the Sangamonian Interglacial in North America, the Don Formation was deposited however during a longer interval of time, including the interglacial climatic optimum of MIS 5e followed by an erosive and cool phase (intra-MIS 5e or MIS 5d), a boreal phase with a fir forest (late MIS 5e transition or MIS 5c), erosive episodes and the early part of a cold stadial (MIS 5d or MIS 5b). From the planar geometry of the beds exposed at the former Don Valley Brickyard in Toronto, the formation comprises five continuous allozones with lateral variations of thickness. Each allozone corresponds to dominant conditions of sedimentation in a shoreface of Lake Coleman within a limited accommodation space. Allozone D2 is correlated to other interglacial units of Eastern Canada, with ages between 128 and 115 ka. The interglacial climatic optimum is interrupted in the area by two cool events, the first one similar to the Tunturi event of Finland, the second one probably related to a Greenland Stadial. The heterogeneous upper Allozone D5 was deposited in shallow waters when a Northern Boreal Forest prevailed in the watershed. This zone is correlated to the Deschaillons Varves of the central St. Lawrence River Valley, deposited prior to the first regional Wisconsinan glacial advance in the central St. Lawrence River Valley and the resulting glacial Lake Scarborough Formation. From the 80 ka minimalU/Th age of the Deschaillons Varves and the 98 ± 8 ka TL age of the later marine La Pérade Clay, Allozone D5 was deposited during the beginning of one of the cold episodes of MIS 5. Unité de référence de l’Interglaciaire Sangamonien en Amérique du Nord, la Formation de Don a été en fait déposée pendant un plus long laps de temps, incluant l’optimum climatique interglaciaire du MIS 5e suivi d’une phase fraîche avec érosion, une phase boréale à sapinière (transition à la fin de MIS 5e ou MIS 5c), suivie de phases d’érosion et du début de l’un des stades subarctiques MIS 5d ou MIS 5b. À partir de la géométrie ...
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