Environmental responses to rapid climate change during the younger dryas chronozone (YDC) in Acadia National Park, Maine (phase I)

Spigel, Kevin

Precoring trips during November 2009 and January 2010. "Research objectives for phase I: 1) To obtain a lake sediment record panning the time period from the Late-Glacial to the present. 2) Top provide3 additional spatial and temporal constraints on the Younger Dryas climatic event in Maine through radiocarbon dating and high-resolution LOI analysis. 3) To determine environmental responses to cooler and drier conditions during the YDC. Major Findings: · The Bowl contains sediments that are of sufficient age to contain the YDC as determined from the radiocarbon chronology...Given this, the Bowl will be the focus of additional research efforts on the part of the PI and his students at Unity College to complete remaining phases of the project not discussed here. · LOI results and stratigraphic indicators are contained in the sediment record that suggest the Younger Dryas climatic event did occur in this region at a time that is consistent with other records from New England. The indicators used in reaching this conclusion are the lack of organic matter during the YDC, lack of coarse material above YDC sediments. This evidence is seen in other Maine Lakes. LOI results are below. · Patterns seen in the organic matter curve highlight a clear end of YDC cooling at 11,800 cal yr BP. Following the YDC, increased lake productivity associated with warming during the Holocene period continues up to the modern period. Low levels of carbonates reflect a lack of bedrock/groundwater carbonate input and provide little in terms of environmental indicators. LOI Residue values suggest widespread erosion occurred prior to 12,000 cal yr BP and leveled off during the Holocene. Future Work: · Improve the temporal resolution of the age-depth chronology thorough dating. · Interpret environmental magnetics data. · Obtain additional research permits necessary to gather surface soil samples from hill slopes surrounding The Bowl for additional environmental magnetism testing. · Begin pollen analysis. · Begin charcoal analysis." There is an abstract relating to this study by the author online at: http://meridian.aag.org/callforpapers/program/AbstractDetail.cfm?AbstractID=37992