Henry Loope M.S. candidate
My MS research is focused on glacial stratigraphy and chronology of ice retreat in northwestern Ontario. I've looked at a series of excellent exposures (~20 m in height - see pics below) along the Whitefish River west of Thunder Bay, ON. I also have several Livingstone sediment cores from lakes inside and outside the Marks Moraine to try and confirm the age of the Marks (thought to be equivalent to the Marquette Stadial - 10,025 14C yrs BP - from the southern Superior Basin). I'm trying to test: 1) If ice retreated far enough north to allow Lake Agassiz water to drain directly into the Lake Superior Basin at the beginning of the Younger Dryas (11,000 - 10,000 14C yrs BP) -- Agassiz water is thought to have triggered the Younger Dryas via an influx of freshwater to the North Atlantic; 2) If the Marks Moraine is synchronous with the Marquette Stadial (10,025 14C yrs BP) of the southern Superior Basin; 3) If Rainy Lobe and Superior Lobe tills can be differentiated geochemically and the implications of differing geochemistry and stratigraphy seen in the Whitefish River valley.
SRTM 90 m DEM of a section of northwest Ontario with mapped moraines. White line west of Thunder Bay are exposures along the Whitefish River which were described.
Hymers Cut
Flint Cut
Harstone Cut
Lake coring using a modified (hydraulically assisted) Livingstone system - Tom Lowell (U. of Cincinnati) at the helm
Livingstone core showing contact between glaciolacustrine clays (to the left) and post-glacial lacustrine sediment of higher organic content
I also have an ongoing interest of the late Pleistocene and Holocene landscape evolution of the Upper Peninsula of Michigan. While at the University of Nebraska-Lincoln (B.S., 2004), I dated some interior eolian dunes in eastern Upper Michigan with optically stimulated luminescence (OSL). Interior (> ~5 km from Lake Superior) eolian dunes are ubiquitous in the eastern UP (see figure and Arbogast et al., 2002, Geology 30, p. 55-58). Climate change has been put forth as a mechanism of vegetation destruction and hence dune activity in the Great Plains (e.g. the Nebraska Sand Hills have seen multiple episodes of dune activity linked to climate deterioration during the Holocene). Arbogast et al. (2002) dated several interior dunes in the eastern UP using OSL and found a mid-Holocene signal (~7 to 5.5 ka) of dune activity. A combination of climate change (during the Hypsithermal-Altithermal) and base level change are invoked by Arbogast et al. (2002) to explain dune activity. I sampled dunes found within the former extent of Lake Minong, a higher precursor to Lake Superior and found a late Pleistocene and early Holocene signal (10.2 to 8.3 ka) most likely related to the destruction of Lake Minong. These dunes were emplaced as littoral sands became exposed as lake level fell (potentially rapidly). Thus, there may be multiple signals of dune activity in eastern Upper Michigan.
DEM of a portion of the eastern UP
Luce 442 OSL sample locality NW of Newberry
Maple Block North OSL sample site - located on the former lake plain of Lake Minong