Zircon morphology has long been an important parameter in the study of petrogenesis in igneous and metamorphic rocks and provenance in sedimentary rocks. Fourier shape analysis is a much more sensitive technique for morphological analysis than the more widely used elongation ratio. Secondly, subtle variations in shape can also be determined by Fourier shape analysis.
Zircon populations from three compositionally similar granitic plutons from the Western Intrusive Series of the Sierra Nevada batholith differ significantly in average morphology as determined by Fourier shape analysis. This technique resolves a two-dimensional shape into multiple shape components (harmonics) with each component making an independent contribution to the total shape. Seven of the nine harmonics analyzed are statistically significant in orthogonal comparisons of the zircon populations.
Information carried by each harmonic should be of use in determining the significance of zircon morphology in petrogenetic studies and will prove especially useful where differences are subtle.