gwiles April 13th, 2012
The College of Wooster Geomorphology class set out to explore the Holmesville Moraine, a 20 minute drive south of Wooster straight down the Killbuck River Valley. It was a beautiful day, except for the rain. The first stop was Holmesville Sand and Gravel, a company which mines and sorts the deposit and sells it for various building and homeowner applications. We ended up classifying this as a Kame Moraine as most of the sediment is sand and gravel intermixed with diamict all piled up into a great cross valley ridge. This is likely the dam for Glacial Lake Killbuck, which was impounded to the north.
The Separator – This machine and associated conveyors sorts the gravel from the sand from the silt.
Sorted piles – note the varying angles of repose.
The dredge sucks sand from 70 feet down in this lake. It is then piped to the Separator.
Fine-grained sand and silt is returned to the lake – note the delta. A wave-dominated delta that is revealed with a modest drop in lake level.
Continue reading this post to see why the group is dumbfounded.
Ice-contact stratified drift – sediments range from diamicts to stratified sands and gravels. Many of the gravels are cemented. Note that the lower left is a bedrock contact. This is the guts of the kame moraine.
Cemented sand and gravel – note the evenly-space joints where the rivelets have excavated the materials – joints from unloading?
Cemented and partially stratified diamict – this unit is a major challenge to remove in mining.
Raindrop imprints on mudcracks.
Ditch draining the floor of former Glacial Lake Craigton – note the peaty sediments and the tiles. Note the meandering thalweg within the ditch.