The eastern flank of the Mackenzie Mountains has a complex history of multiple glaciations by both the Laurentide and Cordilleran ice sheets, recorded in thick sequences of glacial sediments that were documented at 3 locations (Katherine Creek, Little Bear River, Inlin Brook) by:
Duk-Rodkin, A., R.W. Barendregt, C. Tarnocai, and F.M. Phillips. 1996. Late Tertiary to late Quaternary record in the Mackenzie Mountains, Northwest Territories, Canada: stratigraphy, paleosols, paleomagnetism, and chlorine-36. Canadian Journal of Earth Sciences 33 (6): 875-895. https://doi.org/10.1139/e96-066
Of the 3 sites, the exposure on Inlin Brook, a tributary of the Keele River, was the least well-documented, so in summer 2004 Dr. Paul Sanborn joined a field party of the Geological Survey of Canada (GSC) based at Tulita, NWT, and was given helicopter support to visit Inlin Brook (August 5-8). A brief visit was also made to the Little Bear River site.
On August 9-10, Sanborn joined Alejandra Duk-Rodkin (GSC) and Rene Barendregt (U Lethbridge) in helicopter-assisted field work at sites in the Franklin Mountains and elsewhere east of the Mackenzie River.
Photograph depicts the Mackenzie Valley and the Franklin Mountains. Pipeline is visible.
Photograph depicts the Mackenzie Valley and the Franklin Mountains. Pipeline is visible.
Photograph depicts the Mackenzie Valley and the Franklin Mountains.
Photograph depicts the Mackenzie Valley and the Franklin Mountains.
Photograph depicts the Mackenzie Valley and the Franklin Mountains.
Photograph depicts scientists Alejandra Duk-Rodkin (GSC) and Rene Barendregt (U Lethbridge) working at the Norman Range site.
Photograph depicts scientists Alejandra Duk-Rodkin (GSC) and Rene Barendregt (U Lethbridge) working at the Norman Range site.
Photograph depicts scientists Paul Sanborn and Rene Barendregt (U Lethbridge) working at the Norman Range site.
As part of a multidisciplinary team led by Grant Zazula (then a Ph.D. student at Simon Fraser University; later a palaeontologist with the Government of Yukon) and Duane Froese (Professor, University of Alberta), Dr. Paul Sanborn examined a set of buried paleosols (fossil soils) preserved in frozen sediments exposed by placer mining in the spring of 2004.
The findings were published in:
Zazula, G.D., D.G. Froese, S.A. Elias, S. Kuzmina, C. La Farge, A.V. Reyes, P.T. Sanborn, C.E. Schweger, C.A.S. Smith, and R.W. Mathewes. 2006. Vegetation buried under Dawson tephra (25,300 14C yr BP) and locally diverse late Pleistocene paleoenvironments of Goldbottom Creek, Yukon, Canada. Palaeogeography, Palaeoclimatology, Palaeoecology 242: 253–286.
https://doi.org/10.1016/j.palaeo.2006.06.005
The Lost Chicken Mine, a placer gold mine in eastern Alaska, approximately 120 km west of Dawson City, Yukon, is an important fossil locality for the late Pliocene (approximately 2.5 – 3.0 million years ago). A comprehensive account of the stratigraphy and paleontology of this site was given by:
Matthews, J.V., Jr., J.A. Westgate, L. Ovenden, L.D. Carter, and T. Fouch. 2003. Stratigraphy, fossils, and age of sediments at the upper pit of the Lost Chicken gold mine: new information on the late Pliocene environment of east central Alaska. Quaternary Research 60: 9-18. https://doi.org/10.1016/S0033-5894(03)00087-5
Dr. Paul Sanborn visited the site on July 20, 2004, as part of a group led by Duane Froese (Professor, University of Alberta). The group concentrated on a single exposure (~ 2 m thick) straddling the Lost Chicken tephra, a volcanic ash bed (2.9 ± 0.4 myr) which is a major stratigraphic marker at the site. Sanborn described, photographed, and sampled this exposure, and obtained a basic set of characterization data. Intact samples were collected but thin sections were never produced.