Description

These examples demonstrate the simulator capabilities for modelling fluid flow in a compacting porous medium. The employed model differs from previous formulations by considering fluid transport in the frame of reference moving with the solid phase. Using the numerical implementation of the proposed model, we simulate magmatic fluid transport in the Earth's upper crust. We account for the thermal softening of rocks, the plastic deformation of the solid matrix through decompaction weakening, and realistic fluid properties in a wide range of depths, including those above and below the brittle-ductile transition (BDT). First, we present 1-D and 2-D benchmark simulations of the solitary porosity waves. Then we present an example showing that our simulation approach can resolve the localized flow in the ductile zone and numerous hydrothermal convection cells in the brittle zone. The example demonstrates the influence of decompaction weakening on high-porosity channels forming in the ductile zone and their interaction with the convection in the brittle zone. The simulation example shows that compaction causes magmatic fluid focusing and accumulation in high-porosity lenses beneath the low-porosity BDT zone.

 

Associated files

File	Version	Description
POROWAVE-1D.RUN	2021.C	Input file for a benchmark simulation of a 1-D porosity wave (1-D study in the appendix).
POROWAVE-2D.RUN	2021.C	Input file for a benchmark simulation of 2-D porosity waves (2-D study in the appendix).
POROWAVE-BDT.RUN	2021.C	Input file to the modelling of fluid transport in the upper crust above, below and through the brittle-ductile transition zone (2-D study; cross-section of the Earth's crust).
PORVMULT.INC	-	The include file to the 2-D study (the initial porosity distribution).

References

1. Utkin I., Afanasyev A. Decompaction weakening as a mechanism of fluid focusing in hydrothermal systems// 2021 JGR. Solid Earth. Submitted to the journal.