ABSTRACT: Ordovician Oil Potential in New York State?
Joseph E. Robinson
A recent deep test in northern Cayuga County, New York State, encountered an unusual section in the Lower Ordovician that suggests there may be petroleum potential in the lower Paleozoic sandstones of the northern Appalachian basin. Instead of the clean, white, medium-grained sandstone that usually comprises the Theresa-Potsdam section in this area, the Keysor No. 1 well found the upper 120 ft replaced by a dark-colored, organic-rich silt. This new section had a strong petroliferous odor and was composed of organic material, fine shale particles, and silt-sized quartz grains. Geochemical analysis indicated the organics are rich in petroleum-related hydrocarbons. If the matrix had been a medium- or coarse-grained sandstone, there might have been reservoir potential.
Interpretation suggests that the well encountered a stream valley that was incised into the Lower Ordovician sandstones which were exposed during the Middle Ordovician, Knox erosional episode. The organic silts would have concentrated in the deep valleys during the following transgression when minor shale deposition was common. Valley fill materials display considerable lateral variation and there may well be petroleum reservoirs located elsewhere along this or other ancient stream valleys.
AAPG Search and Discovery Article #90998 AAPG Eastern Section Meeting, London, Ontario, Canada, September 10-12, 1990