```{tags}
category:benchmark
feature:2d
feature:cartesian
feature:nonlinear-solver
feature:elasticity
feature:plasticity
feature:compositional-fields
feature:community-benchmark
```

(sec:benchmarks:viscoelastic_plastic_shear_bands:gerya_2019)=
# Visco(elastic)-plastic shear bands after Gerya (2019)

The files in [this directory](https://github.com/geodynamics/aspect/tree/main/benchmarks/viscoelastic_plastic_shear_bands/gerya_2019)
reproduce or analyze the results of
a benchmark for the shortening visco(elastic)-plastic block in
the absence of gravity.

The benchmark is a modified version of Exercise 13.2 from
Introduction to Numerical Geodynamic Modeling (Taras Gerya,
2019, doi:<https://doi.org/10.1017/9781316534243>).

Detailed file description:

- `gerya_2019_vp.prm`: Parameter file for the visco-plastic
version of the shortening benchmark.

- `gerya_2019_vep.prm`: Parameter file that is derived from
gera_2019_vep.prm and modifies the rheological model to
include viscoelasticity (i.e., viscoelastic-plastic rheology).

- `gerya_2019_analysis.py`: Python script that loads in
solution data and compares strain rate profiles.