Colville sedimentary basin 

(Cretaceous and Cenozoic) 

(Northern Alaska, unit Ks)

Consists chiefly of a long-lived Jurassic, Cretaceous, and Paleogene succession of marine sedimentary 
rocks that extends for about several hundred km across northern Alaska, north of the Brooks Range. 
Consists of: (1) a proto-Colville basin sequence that consists of the Early Cretaceous Okpikruak, Ogotoruk, 
Telavirak, Kisimilok Formations; and (2) Colville basin sequence of Cretaceous Fortress Mountain 
Formation, Bathtub Graywacke, Torok Formation, Nanushuk Group, Hue Shale, Colville Group, Canning 
Formation, Sagavanirktok Formation, and Gubik Formation. Major units depicted on stratigraphic columns 
for various terranes of Arctic Alaska superterrane (unit AAN). Various major sedimentary cycles are 
distinguished. Distribution of megacycles, and paleocurrent and seismic data indicate that the Colville 
basin sequence was filled longitudinally as sediment prograded from the west toward the northeast in the 
late Early Cretaceous, and onward onto the eastern North Slope in the Late Cretaceous and Cenozoic. 
Compositional change interpreted as related to progressive unroofing of terranes to the south. 
REFERENCES: Mull, 1985; Moore and others, 1992