Keweenaw Boulder Garden Revitalized Kame Terrace On Campus, Used as a Teaching Laboratory
DescriptionMichigan Techs campus is built on a kame terrace with an age of approximately 10ka. The lag boulders were removed when the campus was originally constructed but we have since found and replaced them with boulders from outwash quarries of the region. The boulder garden is thus constructed from carefully selected boulders that represent the range of mid continent rift lithologies. These include fluvial redbed sandstones, alluvial fan conglomerates, rhyolites and continental tholeiite basalt lavas which exhibit broad textural variations including mineralized zeolite and prehnite pumpellyite facies amygdaloids, segregation cylinders and pegatititic lenses, and ophitic textured flow interiors. Boulders are smooth and well exposed surfaces which expose large areas of the rock, similar to a good outcrop. Together the boulder garden represents all the main rift rocks in one place. All boulders are easily accessible by people. As a lab facility there are a variety of exercises that can be done (identification of amygdaloidal minerals, basalt flow anatomy, identification of up and down directions in sediments and lava flows, reading the rocks of the rift).
In addition to the geological teaching applications the garden introduces geological beauty and awareness to the central campus. It creates an environment filled with information about both the glacial and rift geologic history where all university community see it every day.