The dating of events older than 50 ka, the limit of the radiocarbon method, has been a major drawback in assessing the chronology of the Quaternary. Several new methods have been applied to the dating of pre-late Wisconsinan organic beds in Nova Scotia. These methods include U/Th disequilibrium dating of wood and shells, amino-acid racemization dating of shells, and wood and electron spin resonance dating of shells. These methods are not without problems, and must be assessed together, and in concert with geologic evidence, in establishing a chronology.

Evidence of the penultimate interglacial (marine isotopic stage 7) has been found in southern Nova Scotia. A raised marine platform, forest beds beneath till, and glacially-resedimented marine deposits were all formed during the last interglacial or Sangamonian stage (stage 5). Middle Wisconsinan U/Th and radiocarbon dates are questionable, so the chronology of post-Sangamonian events is not well constrained. Post-Sangamonian erosional and depositional stratigraphy indicates that at least four phases of ice flow have affected the Nova Scotia region. The earliest of these flows was a major advance that crossed the Gulf of St. Lawrence and Bay of Fundy (ice-flow phase 1). Later, separate ice caps and divides formed in areas adjacent to the province and the province itself (ice-flow phases 2–4). There is evidence for ice retreat between phases 1 and 2 in offshore areas and locally on land. Nova Scotia was probably covered with ice throughout the Wisconsinan stage (marine isotopic stages 4 to 2).