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Upper Colville River, Alaska

        Upper Colville Fossil Images Unassigned Fossil Images 85JTP18

 

This interactive map of part of the Colville River, Northern Alaska, shows the locations of plant fossil collections made by J.T. Parrish and R.A. Spicer in 1985 and 1989. Click on a number for more details on that site. The red outlined area links to another map showing positions of florules (plant fossil assemblages) collected by C.J. Smiley along both the Colville and Chandler Rivers.

Interactive map of the Upper Colville River Hotspot linking to 85RAS09 Hotspot linking to Smiley's Colville and Chandler River localities. Hotspot linking to 85RAS02 Hotspot linking to 85RAS01 Hotspot linking to 85RAS03 Hotspot linking to 85RAS04 Hotspot linking to 85RAS05 Hotspot linking to 85RAS06 Hotspot linking to 85RAS07 Hotspot linking to 85RAS08 Hotspot linking to 85RAS10 Hotspot linking to 85RAS11 Hotspot linking to 85RAS12 Hotspot linking to 85RAS13 Hotspot linking to 85RAS14 Hotspot linking to 85RAS13 Hotspot linking to 85RAS16 Hotspot linking to 85RAS17 Hotspot linking to 85RAS18 Hotspot linking to 85RAS19 Hotspot linking to 89RAS1_3 Hotspot linking to 89RAS04 Hotspot linking to 89RAS05 Hotspot linking to 89RAS06 Hotspot linking to 89RAS07 Hotspot linking to 89RAS09 Hotspot linking to 89RAS10 Hotspot linking to 89RAS11 Hotspot linking to 89RAS12 Hotspot linking to 89RAS164_320 Hotspot linking to Smiley's Colville and Chandler River localities. Hotspot linking to 85RAS02 Hotspot linking to 85RAS01 Hotspot linking to 85RAS03 Hotspot linking to 85RAS04 Hotspot linking to 85RAS05 Hotspot linking to 85RAS06 Hotspot linking to 85RAS07 Hotspot linking to 85RAS08 Hotspot linking to 85RAS09 Hotspot linking to 85RAS10 Hotspot linking to 85RAS11 Hotspot linking to 85RAS12 Hotspot linking to 85RAS13 Hotspot linking to 85RAS14 Hotspot linking to 85RAS13 Hotspot linking to 85RAS16 Hotspot linking to 85RAS17 Hotspot linking to 85RAS18 Hotspot linking to 85RAS19 Hotspot linking to 89RAS1_3 Hotspot linking to 89RAS04 Hotspot linking to 89RAS05 Hotspot linking to 89RAS06 Hotspot linking to 89RAS07 Hotspot linking to 89RAS09 Hotspot linking to 89RAS10 Hotspot linking to 89RAS11 Hotspot linking to 89RAS12 Hotspot linking to 89RAS164_320

Locality 85JTP18

Ninuluk Bluffs. The base of the section consists of gray shales and represents the marine Ninuluk Formation of Chapman et al. (1964). This is the uppermost part of the Nanushuk Formation of Mull et al. (2003) and is correlative with the non-marine units of the Niakogon Tongue of the Nunushuk Group of Chapman et al. (1964). This is overlain by a fine light olive sandstone which in turn is overlain by a dark gray crumbly clay. Above this is a mudstone/shale succession is followed by a 2 m thick very fine and finely laminated sandstone with small scale crossbedding. This is overlain by a 30 cm thick brown clay. There then follows a succession of clays, carbonaceous shale, a thin (20 cm thick) olive brown sandstone and then a weathered coal associated with nodular and platey ironstones approximately 7-8 cm thick. Above the coal are gray/brown silty weathered shales. The silty shales contain conifer remains and plant hash and water-worn wood is abundant in the sandstones. The succession continues upward with a gray clay underlying a 2-3 cm thick ironstone layer, above which is a 7-8 cm thick mottled gray/brown clay that passes up into 30 cm of olive green poorly indurated fine to medium sand with coal lenses. The coaly partings continue into the base of an overlying well indurated 'salt and pepper' fine sandstone which approximately 1m above has a finely fragmented Inoceramus debris layer suggesting marine deposition. Approximately 2.4 m above this Inoceramus layer the sandstone passes into a 5-6 m thick clay/silt/mudstone succession that passes up into gray/brown mottled clays (pedogenically altered?) in a predominantly fine sandstone succession. Although parts of the succession are covered the presence of a shaley coal approximately 7-8 cm thick above the predominantly sandstone unit suggests a return to non-marine deposition. This coal is the first of several thin coal/carbonaceous shale horizons interspersed by gray mudstones spanning a vertical distance of 5-6 m, but fully non marine conditions were apparently not developed immediately because the basal coal is overlain by a dark gray indurated (calcified?) mudstone that weathers to bright orange at the top of which is a shell horizon. Within this coaly succession occurs a 3-4 cm thick bentonite. The top of this coaly succession is marked by a 45 cm thick fine sandstone.

Lithologic log of the Ninuluk Bluffs section  

 

Lithologic log of the Ninuluk Bluffs section based on observations by J.T. Parrish in August 1985.
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