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by Us Department of Geological Survey; Jackson, Kerby
by U.S. Department of the Interior; U.S. Geological Survey
by Us Dept. of Geological Survey; Jackson, Kerby
by United States Geological Survey; Jackson, Kerby
by Us Dept of Geological Survey; Jackson, Kerby
by Flammer, Gordon H.; U.S. Geological Survey
by U.S. Geological Survey; Department of the Interior
by Indiana Geological and Water Survey
by Jackson, Kerby; Washington Geological Survey