The volcanic/plutonic ratio in space and time, on Earth and beyond; How efficiently do magmas reach the surface during planetary evolution?
Year: 2024
Type: article
Abstract: With the recognition of multiple crustal cross sections on our planet, the advent of high-precision geochronology , and the ever-increasing application of geophysical imaging beneath volcanoes, we now know that volcanic rocks are the tip of a magmatic “heat”berg, overlying a significant igneous plumbing system that leaves many types of plutonic rocks in the crust. The ratio of volcanic to plutonic rocks in a given magmatic province (the V/P ratio) varies in space and in time as a function of several parameters controlled by the tectonic setting , geological age of the magmatic province, duration of magmatic activity, rheology of the crust, physical properties of the magma and state of the magma reservoirs . This contribution intends to explore these different parameters, in order to better constrain how the V/P ratios evolve in space and time in the course of planetary crust evolution. In particular, we stress that the efficiency of phase separation (in particular crystal / melt separation) in crustal magma reservoirs, fundamental to igneous differentiation and crust formation, is a key factor in controlling the V/P ratios. This efficiency, in turns, depends on parameters such as magma fluxes (“mantle productivity”) and chemical compositions (including volatile content), as well as the mechanical properties of the multi-phase magma and of its the crustal container. The emergence of thermo-mechanical modeling tools coupling the magma reservoir with its surrounding wall-rocks is paving the way to a more quantitative understanding of the fundamental processes that control the fate of magmas traversing through planetary crusts.
Source: Lithos
Authors: Olivier Bachmann, Christian Huber
Institutions: ETH Zurich, Brown University
Language: English
Subfield: Geophysics
Field: Earth and Planetary Sciences
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $3,350
OpenAlex ID: W4403083236