The Shallow Evolutionary Characteristics of Silicic Magmas: Thermal, Fluid Dynamical and Petrological Modeling Predicted on new Theories of Deeper Silicic Magma Genesis for More Accurate Physical and Geological Inverse Predictive Potential re: Holistic Shallow Chamber and Plumbing System.

Cathina Gunn de Rosas and Dr. Glen Mattioli
Department of Earth and Environmental Science, University of Texas at Arlington

New theories of MOHO-depth silicic magma genesis (Annen et al, “The Genesis of Intermediate and Silicic Magmas in Deep Crustal Hot Zones” (doi:10.1093/petrology/egi084) demand a reconfigured shallow storage and ascent model that adequately describes observation, experience and genetic properties. My work is in pursuit of construction such a model. Firstly, we will empirically and theoretically evaluate petrologic behaviors of the mantle/crust material (under a modified geotherm at the Moho) as a “hot zone” area of accumulating basalt melt injections, as an accommodation zone for dykes through which low viscosity melts travel, and (more shallowly) as a residence for partially evolved magma in chambers that feed directly to the surface. These observations will maintain close ties to thermodynamic responses, feedbacks and adjustments, which will be used to inform the thermodynamic state of the system at each step. Secondly, geodetic measurements taken over many years at active volcanoes (most notably, the Soufriere Hills volcano in Montserrat) will be used to develop models of surficial modification due to injection and ejection of new materials and to inversely evaluate that behavior in light of the modified system parameters suggested by our research. Finally, we will examine the seismic signatures of volcanic events as a key inverse modeling constraint. One of the most interesting aspects of this shallow thermal model will be its applicability to geothermal energy technology in the future. A new understanding of thermal behavior in the shallow crust may enable the pursuit of creative and revolutionary new clean, safe and ubiquitous energy reserves for global consumption.

AAPG Search and Discovery Article #90152©2012 AAPG Southwest Section Meeting, Fort Worth, Texas, 19-22 May 2012