A Multiproxy Investigation of Late-Glacial Climate and Vegetation Change at Pine Ridge Pond, Southwest New Brunswick, Canada

• Published in: Quaternary Research
• Main Authors: Levesque, André J., Cwynar, Les C., Walker, Ian R.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press (CUP) 1994
• Subjects: Arctic; Canada; Cassiope hypnoides; Dwarf birch; Tundra
• Online Access: http://dx.doi.org/10.1006/qres.1994.1082; http://api.elsevier.com/content/article/PII:S0033589484710829?httpAccept=text/xml; http://api.elsevier.com/content/article/PII:S0033589484710829?httpAccept=text/plain; https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0033589400037376

Abstract Pollen, plant macrofossil, chironomid, and lithological analyses of late-glacial sediment from Pine Ridge Pond all indicate that the warming following deglaciation was punctuated on two separate occasions by a return to colder climes; initially by a brief and moderate cold episode (the Killarney Oscillation), followed shortly by the Younger Dryas. The Killarney Oscillation, AMS 14 C dated at between 11,290 and 10,960 yr B.P., is characterized by abrupt and simultaneous increases in Betula (birch) pollen and Betula glandulosa (dwarf birch) macrofossils and a decline in tree pollen. The Younger Dryas is distinguished by the reversion of a short-lived closed Picea (spruce) forest to a prolonged forest-tundra stage (ca. 10, 820 to 9500(?) yr B.P.), during which macrofossils of arctic/alpine plants such as Salix herbaces, Cassiope hypnoides, Armeria maritima, and Thalictrum alpinum make their sole late-glacial appearance. Chironomid-inferred summer surface-water temperatures indicate a cooling of approximately 8 and 12°C during the Killarney Oscillation and Younger Dryas, respectively, and coarse-sand analysis indicates increased erosion on the landscape during these same intervals.