FRACTAL CLUSTERING OF METAMORPHIC VEINS

Metamorphic veins record the fracture-controlled flow of fluids throug hout the oceanic and continental crust. I show that the spatial distri butions of veins from three diverse metamorphic settings are fractal a nd self-similar. Vein densities were measured by counting the number o f macroscopic veins intersected along linear transects. The localities included wollastonite-quartz veins in marbles, for which the fractal dimension D is 0.46, actinolite-chlorite veins in hydrothermally alter ed oceanic diabases (D = 0.81), and epidote-quartz veins in contact-me tamorphosed basalts (D = 0.25-0.63). The fractal clustering of veins p rovides a geometric framework for understanding spatial and temporal p atterns of fluid flow and mineral reaction during metamorphism.