Northern Vermont and the Noyan, Quebec Natural Gas Prospect: Stratigraphic and Structural Relations
Laurence R. Becker, Marjorie H. Gale, and Jonathan Kim
Vermont Geological Survey, Waterbury, Vermont, 05671
Quebec lands are under government oil and gas lease at the border of Vermont and New York by Junex, Inc. A seismic line (Q118) 5 km north of the Vermont border spans the autochthonous (west) to para-autochthonous (east) domains bounded by the Tracy Brook and Aston faults. The correlation of this line with the Shell, Saint-Armand ouest No. 1 test well on the east side of Missisquoi Bay in Lake Champlain shows normal faults which extend into Precambrian basement and thrust faults which override some of the normal faults (Sejourne et al., 2003). The Noyan Prospect, located along the line north of Alburg, Vermont, is estimated by the leaseholders (CCNMathews/Junex press release, 2001) to have in situ gas potential of 20.67 Bcf distributed between 5 stratigraphic units to a depth of 3,330 meters: Stony Point, Trenton, Chazy, Beekmantown and Potsdam.
Based on mapping in northern Vermont, the Cambro-Ordovician section is estimated to be 1500 meters thick. Depth to basement is not well constrained but estimated to be less than 2 km in the Champlain Islands. A 1964 American Petrofina test well in South Alburg is consistent with this depth. Seismic data in Quebec shows basement depths of 3 to 4.5 km. An interpreted cross section indicates that depth to basement increases both to the north and east. Thrust faults in Alburg override normal faults in the lower plate which is consistent with the Quebec interpretation. Alternatively, extensional tectonics may have controlled the thin limestone horizon in the Alburg well.
AAPG Search and Discovery Article #90059©2006 AAPG Eastern Section Meeting, Buffalo, New York