Holyoke Range from War Memorial
Continental Rifting
Thirty years ago, this field was in pasture rented to Charles Jacque and his family for their Jersey dairy herd. The dairy operation stopped in the early
1980’s. Then, about 20 years ago, the Town and the College joined forces with the US Fish & Wildlife Service to clear the field of invasive shrubs to create grassland bird habitat.
Professor Ethan Clotfelter and others have installed more than 200 tree swallow nest boxes used for faculty and student research projects.
Looking south from this field, you can see a good view of the mountains in the distance, the Holyoke Range. In the Geology Defines the Landscape exhibit at the Beneski Museum of Natural History, major topographic features of this view are related to the underlying bedrock geology. The crest of the range is held up by the resistant volcanic rocks of the approximately 200 million year old Holyoke basalt.
During the early Jurassic, the supercontinent Pangea was breaking apart. As the crust separated, it stretched and thinned, leaving space for magma to rise up to the surface. Later in time, faulting raised and tilted this lava flow, the edge of which is the crest of the Holyoke Range (not visible from this side). The skyline of the Holyoke Range is interrupted where the Holyoke basalt has been offset along a series of faults.
Eventually, the rifting in the Pioneer Valley ceased and resumed further east where the Atlantic Ocean formed and the seafloor continues to spread. Evidence for this scene can be found in the local rock units on display in the Beneski Museum.