G. D. Eberlein, Michael Churkin, Jr., Claire Carter, H. C. Berg, and A. T. Ovenshine
DEPARTMENT OF THE INTERIOR GEOLOGICAL SURVEY GEOLOGY OF THE CRAIG QUADRANGLE, ALASKA By G. D. Eberlein, Michael Churkin, Jr., Claire Carter, H. C. Berg, and A. T. Ovenshine Open-File Report 83-91 This report is preliminary and has not been reviewed for conformity with U.S. Geological Survey editorial standards and strati graphic nomenclature Menlo Park, California 1983 Geology of the Craig Quadrangle, Alaska By G. D. Eberlein, Michael Churkin, Jr., Claire Carter, H. C. Berg, and A. T. Ovenshine Introduction This report consists of the following: 1) Geologic map (1:250,000) (Fig. 1); includes Figs. 2-4, index maps 2) Description of map units 3) Map showing key fossil and geochronology localities (Fig. 5) 4) Table listing key fossil collections 5) Correlation diagram showing Silurian and Lower Devonian facies changes in the northwestern part of the quadrangle (Fig. 6) 6) Sequence of Paleozoic restored cross sections within the Alexander terrane showing a history of upward shoaling volcanic-arc activity (Fig. 7). The Craig quadrangle contains parts of three northwest-trending tectonostratigraphic terranes (Berg and others, 1972, 1978). From southwest to northeast they are the Alexander terrane, the Gravina-Nutzotin belt, and the Taku terrane. The Alexander terrane of Paleozoic sedimentary and volcanic rocks, and Paleozoic and Mesozoic plutonic rocks, underlies the Prince of Wales Island region southwest of Clarence Strait. Supracrustal rocks of the Alexander terrane range in age from Early Ordovician into the Pennsylvanian, are unmetamorphosed and richly fossiliferous, and aopear to stratigraphically overlie pre-Middle Ordovician metamorphic rocks of the Wales Group (Eberlein and Churkin, 1970).
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