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Lying at the large-scale tectonic boundary between the Yukon Tanana and northern extremity of the Stikinia and Quesnellia terranes, mafic eruptions have occurred over the past 4 million years in the Fort Selkirk area. Eruptions have included effusive (lava), explosive activity, and subglacial and subaqueous eruptions that produced hyaloclastite complexes. Eruptions have dammed or disrupted Yukon River at least five times. These volcanic rocks and interstratified sediments are collectively referred to as the Fort Selkirk Volcanic Group. Eruptions occurred from seven centers with activity progressively moving north. An explanation for the northern migration of volcanism is elusive at present. Key words: Quaternary volcanism, lava dams, Yukon geology, Yukon River, Introduction The Fort Selkirk Volcanic Group (FSVG) (Bostock 1936) in central Yukon has been the subject of numerous stratigraphic and geochemical investigations since the first documentation of basalt lavas along [...]

Geotechnical drilling for a tunnel between Port Moody and Burnaby, BC, Canada, uncovered a buried fjord. Its sedimentary fill has a thickness of at least 130 m and extends more than 37 m below present mean sea level. Recovered sediments record cyclical growth and decay of successive Cordilleran ice sheets. The oldest sediments comprise 58 m of almost stoneless silt conformably overlying ice-proximal sediments and till, which in turn overlie bedrock. These sediments may predate Marine Isotope Stage (MIS) 4. Glacial sediments assigned to MIS 4 overlie this basal succession and, in turn, are overlain by MIS 3 interstadial sediments and sediments from two MIS 2 glacial advances. Indicators of relative sea-level elevations that bracket glacial deposits of MIS 4 and 2 indicate the cyclic existence of moat-like isostatic depressions in the front of expanding ice sheets. Compared with present sea level, these depressions were at least 160 m during the onsets of MIS 4 and MIS 2. Assuming a maximum eustatic drawdown of 120 m during MIS 2, isostatic depression may have exceeded 200 m during retreat of glacial ice from the Evergreen tunnel area. This is consistent with region-specific low mantle viscosity and rapid Cordilleran Ice Sheet buildup and wasting. [ABSTRACT FROM AUTHOR]

Abstract: The impact of Tintina Fault displacement on the development of the Yukon River and drainage basins of central Yukon is investigated through geophysical and hydrological modeling of digital terrain [...]

Meteorite hit the Carancas, a small village in Peru on September 2007. The researchers and scientists rushed to the spot to study the place and remaining pierces left by the incident is presented.

The northern ice-free corridor encompasses the Mackenzie Mountains. Research on this ice-free corridor was conducted and scientists are now suggesting that the ice-free corridor was not a feasible route for the early Americans.

The Foothills erratics train of Alberta was carried into place during coalescence between montane glaciers and the Laurentide ice sheet. Its age has been controversial: Late Wisconsinan and pre-Wisconsinan ages have been assigned to it. Cosmogenic 36Cl exposure dating was carried out on erratics over a 130 km segment of the erratics train. Seven of eight age determinations support emplacement during the late Wisconsinan glaciation. These ages eliminate the possibility of an ice-free corridor during the last glacial maximum. They are also consistent with the hypothesis that the Laurentide ice sheet was the most extensive of all Pleistocene continental ice sheets in western Canada.