SPATIOTEMPORAL DYNAMICS IN OSCILLATORY ZONED MAGMATIC PLAGIOCLASE

This work presents a quantitative analysis of spatiotemporal patterns that form during the growth of oscillatory zoned plagioclase. These pa tterns were imaged using Nomarski interference contrast imaging of etc hed polished surfaces. Analysis of these imaged patterns yields new in formation and constraints on how patterns form, and consequently on ho w oscillatory zoned crystals may develop in magmatic systems. Utilizin g mathematical techniques recently developed for the analysis of dynam ical systems, we show that the irregular nature of oscillatory zoning is not compatible with random or stochastic processes. The analysis of our observations suggests that the plagioclase-liquid system is a det erministic nonlinear system whose attractor has a relatively low dimen sion. Finally, comparison of our empirical results with computer model s of other dynamical systems implies that as few as two variables may be sufficient to describe the dynamics of the plagioclase-liquid syste m.