ResearchPast ProjectsOptical analyses of Devonain metavolcanic rocks, Brooks Range (Alaska)
Niklas Strandberg (BSc student)
Microphotograph of deformed cummingtonite from the Central Belt of the Brooks Range.
The Cretaceous Brooks Range fold and thrust belt trends east – west over c. 1000 km. This study focuses on the transition from the Central Belt to the Schist Belt which preserve distinct metamorphic conditions. Investigation of mineral paragenesis by optical microscope analysis documents greenschist and amphibolite facies metamorphic conditions in the Central Belt, with greenschist and possibly blueschist conditions in the Schist Belt. Both regions preserve brittle overprinting ductile deformation fabrics. This suggests that the two Belts at least share a later metamorphic history that reflects Late Cretaceous extension.