Melt extraction and accumulation from partially molten rocks
Current models for melt segregation and ascent are not adequate to accurately describe transport and accumulation in combination. We propose that transport is discontinuous and in batches, and that accumulation occurs by stepwise merging of batches. A simple numerical model of jostling spheres that merge when they touch was used to represent stepwise accumulation and transport of batches by propagation of hydrofractures. Results of the numerical model indicate that such a system may quickly develop into a self-organised critical (SOC) state. In this state, the distribution of melt batch volumes can be described by a power law, with an exponent m that lies between 2/3 and 1. Once a self-orga…
New experiment to model self-organized critical transport and accumulation of melt and hydrocarbons from their source rocks
A new, simple, and easily reproducible experiment was designed to simulate the production, accumulation, and transport of melt within rock. The transport was found to be of the self-organized critical type. The emergence of self-organized criticality is explained by the availability of hydrofracture propagation as a rapid or ballistic transport mechanism. This mechanism also serves as a mechanism for stepwise accumulation. These findings are confirmed by a numerical model, which shows the emergence of self-organized critical behavior when Darcian transport cannot accommodate transport and the dormant transport mechanism of hydrofracture propagation is activated. Ballistic and self-organized…