ABSTRACT
The Kenyon Island Group lies within the Great Sacandaga Lake's largest
and most unnavigable shallow water shoal. The shoal measures approximately
5.0 mi2. The Kenyon Islands, including Mead and Deer Islands,
occupy approximately 3/4 mi2 during the months of annual high
lake level. During the late shallow water season of 1998, a NE to SW diagonal
transect of nine core samples were collected by a Geoprobe coring device,
with recoveries between 8' and 16' deep sections. In this study these cores
were used to identify the stratigraphy, classify the sediment grain sizes,
evaluate the abundance of economic minerals, and calculate the most cost
effective and environmentally sound method of deepening the lakebed for
navigation and recreational purposes and reconfiguring the new real property
created.
Here I present evidence for the existence of a previously unidentified
large moraine field, of approximately 12 mi2, located between
two different end moraines of the Pleistocene Epoch. Today, about 1/3 of
that moraine field surrounds the Kenyon Island Group, within the shorelines
of the Great Sacandaga Lake. The south and east end moraine is visible
in an arcuate path which includes the two major Kenyon Islands and Deer
Island. The south and east end moraine is approximately 3/4 mile wide and
is confined by the valley walls of the Sacandaga Basin. This end moraine
must have been at least 300 feet high during the Pleistocene Epoch. The
north and west moraine was deposited before the south and east end moraine
and is also visible in exposures around the lake. This forms moraine rock
fields in arcuate bands, which are confined by the valley walls of the
Sacandaga Basin. The north and west end moraine was originally 1/2 miles
wide and must have stood at least 120 feet high.
The moraine field contains all the classic landmarks including kames,
kettle lakes, eskers, drumlins, flutes and fossil streambeds. The moraine
field sediments that exist are no more than 45 feet thick beneath the lakebed
and 45 to 120 feet thick outside the shorelines and above bedrock. The
bedrock maybe Cambrian, including Little Falls Dolomite, Theresa Dolomite
and/or Potsdam Sandstone.
This thesis proposes a remedy involving dredging and earth-moving heavy
equipment to permanently deepen part of the lakebed of the Great Sacandaga
Lake that is currently of little use because the area is typically too
shallow for regular lake navigation. If there are minerals within the sediments
of the study area that are of current economic importance and have values
significant enough to pay for a lakebed deepening, the geochemistry, mineralogy
and mineral chemistry will reveal them. These minerals can then be identified
and evaluated as the mechanism that will support the tremendous costs associated
with such a major deepening effort. The long term outcome of a Great Sacandaga
Lake deepening, beside improving the navigational, recreational, and fisheries
of the lake will create room for an additional 200 billion gallons of water,
which could be priceless in the next frontier.
The moraine field sediment profile in the study area may be unique
to the whole of the Great Sacandaga Lake. The question of dredging the
lakebed versus simpler earth-moving heavy equipment to reconfigure the
lakebed, anywhere else in the Great Sacandaga Lake, will most certainly
require further research and could yield different results.
Ambrosino, A.M., 2001. Sediment characteristics around the Kenyon Island
Group, Great Sacandaga Lake (NY): economic potential of dredging and land
reclamation. Unpublished MSc. thesis, State University of New York at Albany.
194 pp., +x
University at Albany Science Library call number: SCIENCE Oversize
(*) QE 40 Z899 2001 A43
Return to MS Theses completed in the Geological
Sciences Program, University at Albany