Paper No. 50
Presentation Time: 9:15 PM


KEENHOLD, Bryn W.1, STEWART, Alexander K.1 and RODBELL, Donald T.2, (1)Department of Geology, St. Lawrence University, Canton, NY 13617, (2)Geology, Union College, Schenectady, NY 12308-3107,

The relative desolation of the northwestern Adirondacks has limited studies in glacial and deglacial reconstructions of the region. Because of the straining of advancing glacial ice from the lowlands to the Adirondack highlands, kame-and-kettle terrain is predominant in this region; affording excellent terrain for “bog” coring. Fox fen (44.382N, 74.757W; 472 masl), a 70-hectare oligotrophic peatland located in Colton Township, was selected due to its proximity to NY Route 56, property access and because it is the largest peatland in the Adirondack Park visible from a major roadway. A bathymetric map was generated by tile probing in order to select the deepest point (17.2m). This location was cored using a modified Livingstone piston corer, which recovered approximately 16m of sediment. In addition to core stratigraphy analysis, magnetic susceptibility readings were taken at 1-cm intervals and loss on ignition was performed every 10cm through the upper 15.7m and every 2cm through the basal silts. As a result, four distinguishable units were interpreted: 1) basal inorganic glacial silts (1.46m thick), 2) fine-detrital gyttja (7.2m), 3) coarse-detrital gyttja (5.2m) and 4) peat (3.3m). Data suggest that this fen started as a proglacial lake basin, which transitioned into an organic-rich, post-glacial lake. Subsequent to lacustrine infilling, the site developed into an oligotrophic fen, which has paludified two smaller basins to the north and south. Correlation to regional records of post-glacial lacustrine sedimentation suggests that this transition occurred during the early Holocene synchronous with the development of a spruce-rich boreal forest in the region. In addition, variations in carbonate content imply subregional changes in drainage patterns penecontemporaneous to glacial retreat. Data collected from this fen begin to improve our understanding of glacial and deglacial events in this poorly understood region.