Date post: | 20-Jan-2016 |
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Landslides and Ground Water Permeability with Respect to theContact of Glacial Lake Vermont
and the Champlain SeaSediments at Town Line Brook,
Winooski, VT
Michala PeabodyLara Vowles
Location Map
Town Line Brook Timeline
• 13,000 years ago retreat of Laurentide Ice Sheet developed Glacial Lake Vermont
• 12,000-10,000 years ago continued retreat of Ice Sheet permitted formation of The Champlain Sea
• Land rebounded causing the formation of Lake Champlain
• Town Line Brook developed creating a v-shaped valley running into the Winooski River.
Objectives• Determine the Exact
contact between Lake VT and Champlain Sea
• Determine how different sediments affect groundwater permeability
• Determine how this affects landslides
Methods• Dig out trenches to
find contact• Use pocket vane tester
to determine shear strength of sediments
• Use level & rod to create a cross section of area
• Obtain a core sample of contact
Elevation (meters)
Distance (meters)
Vertical Exaggeration 1:2
EastWest
Top Hole
Middle Hole
Bottom Hole
Contact Point Town Line Brook
0
1
2
3
4
5
6
7
8
9
10
40 38 36 34 32 30 28 26 24 22 20 18 16 14 12 10 8 6 4 2 0
Cross Section
Results...starting @ top
• Champlain Sea sediments: alternating fine sand and silt layers
Top Hole
Results...cont.
Middle Hole Bottom Hole
Results...Contact!
• Distinct layer of oozing slime consisting of fine silt and sand
• Situated above hard packed Glacial Lake VT sediments
The Core
Check it Out!!
Results...below contact
• Hard packed
• Thin varved layers
• Alternating red / gray
• Creation of mini-landslide developing at contact
Mini-LandslideCreated by Lara & Michala...oops
Aerial Photographs1962
Aerial Photographs1988
Aerial Photographs1999
“In landslides, as in life. It’s the little things that count.”
~S.P. “Slump or Slide, Density Decides”
Much Thanks to Stephen Wright!!