Moran dyke (780 Ma, Wyoming, USA)

Neoproterozoic mafic dike exposed along the east face of Mount Moran, Teton Range, Wyoming.

Based on paleomagnetism and 40Ar/39Ar geochronology, the dike is considered to be part of the 780 Ma Gunbarrel mafic magmtic event (February 2004 LIP of the month).

At the top of Mount Moran, the dike is nonconformably overlain by the Cambrian Flathead Sandstone.

Photograph by Stephen S. Harlan

See: Harland, S.S., Heaman, L., LeCheminant, A.N., and Premo, W.R., 2003. The Gunbarrel mafic magmatic event: A key 780 Ma time marker for Rodinia plate reconstructions. Geology, 31:1053-1056.