238U-230Th disequilibrium dating of chevkinite from La Primavera, Jalisco, Mexico

This thesis describes a new ion microprobe method for dating the accessory mineral chevkinite using in situ ion microprobe measurement of 238U-230Th disequilibrium. Chevkinite is an accessory mineral found in igneous rocks ranging from kimberlites to peralkaline granites and rhyolites, it also contains high concentrations of U and Th (up to 2 wt%) which makes it a good candidate for the application of U-Th dating. Our study analyzes chevkinite and zircon grains from four La Primavera domes. (See more in text.)