Recurrence surfaces and pollen stratigraphy of a postglacial raised bog, Kings County, Nova Scotia

Abstract

Pollen analysis of a core from a postglacial raised bog at the head of the Annapolis River valley, Kings County, Nova Scotia, has revealed the presence of 5 periods of peat growth. These periods of peat growth are recognized by the occurrence of a light-colored waxy Sphagnum peat overlying a dark-colored humified Sphagnum peat. The stratigraphy and microfossil content of the light- and dark-colored peat layers are closely similar to those of European raised bogs. Recurrence surfaces in Europe have been dated by pollen stratigraphy, archeology, and by radiocarbon methods. Many recurrence surfaces have been found to be approximately the same age over wide areas. Periods of peat growth (as shown by the development of lighter colored less humified peats) have been shown to correspond with periods of increased atmospheric moisture. Testaceous rhizopods in the light-colored peat layers of Caribou bog confirm the similarity of the recurrence surfaces of this bog with those of western Europe and Scandinavia. Chronologic equivalence of the Caribou recurrence surfaces with those of western Europe and Scandinavia cannot be established from this study. Alkali-extracts of the peat have been used to characterize the sediment color differences above and below the recurrence surface horizons. A simpler technique, based on sieved fractions of the sediment is satisfactory and less time-consuming for describing differences in sediment color density. The pollen stratigraphy of core CAR-1 resembles the pollen sequence described by Auer from the same bog. Correlation of the Caribou bog sequence with data from Gillis Lake on Cape Breton Island and from Aroostook County, Maine, is also discussed. There is no evidence for any major climatic reversal. The pollen data indicate a gradually warming climate with minor oscillations of moisture (and perhaps temperature).