Chemical, Physical and Temporal Evolution of Magmatic Systems

Our understanding of the physical and chemical processes that regulate the evolution of magmatic systems has improved tremendously since the foundations were laid down 100 years ago by Bowen. The concept of crustal magma chambers has progressively evolved from molten-rock vats to thermally, chemically and physically heterogeneous reservoirs that are kept active by the periodic injection of magma. This new model, while more complex, provides a better framework to interpret volcanic activity and decipher the information contained in intrusive and extrusive rocks.
Igneous/metamorphic petrology, geochemistry, geochronology and numerical modelling all contributed towards this new picture of crustal magmatic systems. This book provides an overview of the wide range of approaches that can nowadays be used to understand the chemical, physical and temporal evolution of magmatic and volcanic systems.
Experimental petrology of monotonous intermediate magmas
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Published:January 01, 2015
Abstract
Large-volume, high-crystallinity, chemically homogeneous ignimbrites, dubbed ‘monotonous intermediates’, provide a unique opportunity to investigate the evolution of crustal magmatic reservoirs. We present the results of hydrothermal experiments on a dacite from Fish Canyon Tuff (FCT) in Colorado (USA), a classic example of a monotonous intermediate deposit, in order to characterize the variations in chemical and physical properties of hydrous dacite magmas as a function of temperature. The experiments (200 MPa, 720–1100°C) span the inferred pre-eruptive conditions of FCT magmas, and are shown to provide the best match to the chemical and physical properties of the erupted magmas at 790±10°C...
- bubbles
- buoyancy
- Cenozoic
- chemical composition
- chemical properties
- Colorado
- cooling
- crust
- crystallization
- crystals
- dacites
- degassing
- density
- electron microscopy data
- emplacement
- enthalpy
- equations
- eruptions
- experimental studies
- Fish Canyon Tuff
- glasses
- granitic composition
- heating
- hysteresis
- igneous rocks
- intrusions
- laboratory studies
- magma chambers
- magmas
- magmatism
- mass balance
- mathematical methods
- mechanism
- melting
- melts
- methods
- mineral assemblages
- mineral composition
- North America
- Oligocene
- Paleogene
- petrology
- phase equilibria
- physical properties
- point counts
- rheology
- Rocky Mountains
- San Juan Mountains
- SEM data
- temperature
- Tertiary
- thermodynamic properties
- U. S. Rocky Mountains
- United States
- viscosity
- volatilization
- volcanic rocks
- volcanism
- water content
- monotonous intermediate magmas