Foraker-McGonagall plutons, Denali Fault zone, AK

Fig. 2The Foraker and McGonagall plutons have been interpreted as offset fragments of a once coherent plutonic body, indicating ca. 38 km of strike-slip separation since emplacement ca. 38 Ma.  However, this offset is at odds with numerous other estimates including modern slip-rate measurements.  Our research involves detailed field characterization, geochronology, isotopic tracer studies, bulk rock geochemistry, and hornblende barometry to evaluate two major questions: 1) are the Foraker and McGonagall plutons dismembered fragments of the same pluton, and 2) what were the intrusive mechanisms that facilitated melt transfer along a major, long-lived, strike slip system.