Revised Cretaceous and Tertiary stratigraphic nomenclature in the Colville Basin, Northern Alaska

Abstract

Crossbedded fluvial sandstones and conglomerates in basal part of White Hills Member of Sagavanirktok Formation along the Toolik River. .. .. . 40. Bluff along east bank of Sagavanirktok River and southern end of Franklin Bluffs, showing contrast between Franklin Bluffs Member of Sagavanirktok Formation and brown-weathering, lignite-bearing silty mudstone of upper part of White Hills Member .

A Probable Neoceratopsian Manus Track from the Nanushuk Formation (Albian, Northern Alaska)

“…Faunal evidence indicates that most of the formation is Albian and that only the uppermost part is Cenomanian (Mull et al, 2003). Constraints on the age of the Killik Bend outcrop considered here come from samples collected at this location as well as at the eastern and western "Horseshoe" measured sections which are located approximately 75 km farther upstream along the Colville River that seismic correlations tailed sections of the area and the relatively nearby area of the Awuna River area.…”

“…The Nanushuk Formation is present throughout the northern foothills belt and subsurface of the central and western North Slope coastal plain and the rock unit is a succession of complexly intertonguing marine and nonmarine strata interpreted as marine shelf, deltaic, strandplain, fluvial, and alluvial overbank deposits (Ahlbrandt, 1979;Huffman, 1985;Huffman et al, 1988;Mull et al, 2003;LePain et al, 2008LePain et al, , 2009Wartes and Decker, 2008). The thickness of the unit ranges from 2,750 m in the west to a zero edge approximately 75 km east of Umiat and in the area of the present day Colville River delta.…”

“…The thickness of the unit ranges from 2,750 m in the west to a zero edge approximately 75 km east of Umiat and in the area of the present day Colville River delta. The present day distribution of the Nanushuk Formation is limited to the northern foothills belt and coastal plain where it consists of a lower, dominantly marine succession of intertonguing shallow-marine shale, siltstone, and sandstone, and an upper, dominantly nonmarine succession of intertonguing mudstone, sandstone, conglomerate and minor coal (Mull et al, 2003). The contact between these units is typically gradational due to interfingering.…”

Late paleocene flora of the northern Alaska Peninsula: the role of transberingian plant migrations and climatic change

“…They are overlain and, in part, laterally substituted by terrigenous and coal-bearing deposits of the Prince Creek Formation of the Colville Group (Late Cretaceous-Paleocene). These in turn are overlain by sandstones and conglomerates belonging to the basal Sagwon Member of the Sagavanirktok Formation, dated to the Late Paleocene-Miocene (Mull and Harris, 1989;Mull et al, 2003). In the region under study, the upper part of the Prince Creek Formation is best exposed in the Sagwon Bluffs section, an outcrop on the left bank of the Sagavanirktok River (Fig.…”

“…In the region under study, the upper part of the Prince Creek Formation is best exposed in the Sagwon Bluffs section, an outcrop on the left bank of the Sagavanirktok River (Fig. 1), and is composed of intercalating conglomerates, weakly cemented sandstones, siltstones, coaly shales, and coals (in total up to six or seven more or less continuous seams) reportedly up to 7 m (Mull et al, 2003). These deposits are interpreted as having accumulated in a coastal fluvial and lacustrine-dominated alluvial lowland.…”