skill-melting

星标10

分支3

更新时间2026年5月22日 15:52

MDOODZ partial melting module — melt model indices, solidus/liquidus parameterizations, melt fraction computation, melt weakening, per-phase melt configuration, kinetic relaxation, and melting scenario examples.

安装

用 Codex 或 Claude 帮你安装复制这段 Prompt，粘贴到 Codex、Claude 或其他助手里，让它检查 Skill 页面并帮你完成安装。

来源

tduretz

tduretz/MDOODZ7.0

打开 GitHub 仓库查看创作者相关仓库

下载

Partial Melting

Overview

MDOODZ supports pressure-dependent partial melting via parameterized solidus/liquidus curves. Melting is computed per marker using the marker's temperature and pressure. The melt fraction field (X) is stored at cell centres and written to HDF5 as Centers/X.

Enabling Melting

Global Switches (in `.txt` file)

Parameter	Default	Description
`melting`	0	Enable melting globally (0=off, 1=on)
`force_melt_weak`	0	Enable melt-induced viscosity weakening (0=off, 1=on)
`melt_weak`	0.0	Activation volume override for weakening [J/mol] — typical: 30.0

Per-Phase Parameter (in `.txt` PHASE PROPERTIES blocks)

Parameter	Default	Description
`melt`	0	Melt model index (0=off, see table below)
`tau_kin`	0.0	Kinetic relaxation time constant [s] — 0.0 = instantaneous equilibrium

Melt Model Indices

`melt`	Name	Solidus	Liquidus	Latent heat	Reference
1	Simple T-dependent	600°C + 273 K (fixed)	1200°C + 273 K (fixed)	320 kJ/kg	Stüwe (1995)
10	Crustal/sediment (P-dependent)	P-dependent formula	1423 + 0.105·P (MPa)	380 kJ/kg	—
11	Felsic/crustal (P-dependent)	P-dependent formula	1262 + 0.09·P (MPa)	300 kJ/kg	Schenker et al. (2012)
40	Mantle peridotite (P-dependent)	P-dependent formula	2073 + 0.114·P (MPa)	400 kJ/kg	—
41	Mantle wet olivine (P-dependent)	P-dependent formula	2073 + 0.114·P (MPa)	300 kJ/kg	Schenker et al. (2012)

Choosing the Right Model

Phase type	Recommended `melt`	Rationale
Continental crust (e.g., quartzite, anorthite, granite)	11	Felsic solidus, Schenker 2012
Sediments	10 or 11	Lower solidus than mantle
Lithospheric mantle (dry olivine)	41	P-dependent peridotite
Asthenosphere (wet olivine)	41	Same model, wet conditions
Diabase / mafic lower crust	11	Treated as crustal

Melt Fraction Computation

Source: MDLIB/MeltingRoutines.c, function PartialMelting()

Equilibrium melt fraction:

φ_eq = (exp(α·T) − exp(α·T_s)) / (exp(α·T_l) − exp(α·T_s))

where T_s = solidus temperature, T_l = liquidus temperature, both P-dependent.

With kinetic relaxation (tau_kin > 0):

φ = (dt / (τ_k + dt)) · φ_eq + (τ_k / (τ_k + dt)) · φ_0

where φ_0 is the previous melt fraction and τ_k = tau_kin.

Clamped to [0, 1].

Melt Weakening

When force_melt_weak = 1 and melt_weak > 0, the code overrides the dislocation creep activation volume for melt-bearing phases:

if (model->force_melt_weak == 1) mat->apwl[k] = model->melt_weak;

This effectively reduces viscosity in regions with high melt fraction. The melt_weak value replaces the power-law activation volume (Vpwl), making melt-bearing regions weaker.

Typical value: melt_weak = 30.0 (used in RiftingMelting, RiftingCombinedYield, and other scenarios).

Interaction with Other Features

With `eta_vp` (viscoplastic regularisation)

When combining melting with plasticity (plast = 1 or plast = 2), eta_vp must be large enough to stabilise the weakened rheology.

Model scale	Without melting	With melting
Lithospheric rifting	eta_vp ≥ 1e19	eta_vp ≥ 2.5e20
Localised chamber	eta_vp ≥ 1e18	eta_vp ≥ 1e19

Stability warning: eta_vp = 1e19 with melting = 1 at lithospheric scale can produce instabilities (negative viscosity, values ~1e60) after ~100 steps. Use eta_vp = 2.5e20 or higher.

With combined yield (`plast = 2`)

No special interaction — plast = 2 works with melting. Ensure T_st and eta_vp are set per phase.

Example Configuration

### Global (in header of .txt)
melting           = 1
force_melt_weak   = 1
melt_weak         = 30.0

### Per phase
ID   = 0           // Continental crust
melt = 11          // Schenker 2012 felsic

ID   = 1           // Lithospheric mantle
melt = 41          // Schenker 2012 mantle

ID   = 2           // Asthenosphere
melt = 41          // Schenker 2012 mantle

Scenarios Using Melting

Scenario	Melt models used	Application
`RiftingMelting`	11 (crust), 41 (mantle)	Extension with decompression melting
`RiftingCombinedYield`	11 (crust), 41 (mantle)	Rifting + combined mode-I/II yield
`SubductionMelting`	Fluid-released melting	Slab-edge weakening
`TCMagmaticSystem`	10, 11	Thermo-chemical magmatic evolution
`PressurizedMagmaChamber`	— (thermal only)	Pressurised intrusion
`MeltingOverpressure`	—	Melting-induced overpressure
`ChristmasTree`	Multi-branch	Dike geometry

Key Source Files

Melting computation: MDLIB/MeltingRoutines.c
Melt weakening: MDLIB/FlowLaws.c (activation volume override)
Parameter parsing: MDLIB/InputOutput.c
HDF5 output: Centers/X (melt fraction field)

同仓库更多 Skills

同仓库

skill-anisotropy

tduretz/MDOODZ7.0

MDOODZ mechanical anisotropy module — director-based fabric tracking, anisotropy factors (δ_n, δ_s), viscous transverse isotropy, ViscosityConciseAniso, finite strain evolution, anisotropic rifting methodology, and anisotropy scenario examples.

2026-05-2210

skill-benchmarking

tduretz/MDOODZ7.0

MDOODZ performance benchmarking — running benchmarks, interpreting perf.csv, grid scaling studies, thread scaling, comparing machines, and the benchmark.sh script.

2026-05-2210

skill-build-and-run

tduretz/MDOODZ7.0

Build, compile, and run MDOODZ simulations — CMake configuration, make targets (build, build-dev, run, clean), dependency installation (SuiteSparse, HDF5, BLAS/LAPACK), OpenMP parallelisation, env.cmake setup, and common troubleshooting.

2026-05-2210

skill-code-glossary

tduretz/MDOODZ7.0

Code-to-physics glossary for MDOODZ — variable names, struct fields, function names mapped to physical meaning, equations, SI units, grid naming conventions, creep mechanism abbreviations, and solver process stages.

2026-05-2210

skill-debugging

tduretz/MDOODZ7.0

Debugging a failing MDOODZ model — the three failure families (CHOLMOD non-positive-definite, Powell-Hestenes non-convergence, first-iteration NaN), the error-string lookup table, the eta-contrast reality, the two anisotropy recipes, the single-variable bisection cookbook, and the known MDLIB anisotropy bugs with their fix commits. Use when a run crashes, won't factor, won't converge, NaNs, or stalls mid-production.

2026-05-2210

skill-logging

tduretz/MDOODZ7.0

MDOODZ logging system — LOG_INFO/WARN/ERR/DBG/TIME macros, .txt configuration parameters (log_dest, log_level, log_timestamp, log_ts_mode, log_metadata), colored console output, ANSI-stripped log files, phase timing instrumentation, and metadata prefixes.

2026-05-2210

name	skill-melting
description	MDOODZ partial melting module — melt model indices, solidus/liquidus parameterizations, melt fraction computation, melt weakening, per-phase melt configuration, kinetic relaxation, and melting scenario examples.

Partial Melting

Overview

Enabling Melting

Global Switches (in `.txt` file)

Parameter	Default	Description
`melting`	0	Enable melting globally (0=off, 1=on)
`force_melt_weak`	0	Enable melt-induced viscosity weakening (0=off, 1=on)
`melt_weak`	0.0	Activation volume override for weakening [J/mol] — typical: 30.0

Per-Phase Parameter (in `.txt` PHASE PROPERTIES blocks)

Parameter	Default	Description
`melt`	0	Melt model index (0=off, see table below)
`tau_kin`	0.0	Kinetic relaxation time constant [s] — 0.0 = instantaneous equilibrium

Melt Model Indices

`melt`	Name	Solidus	Liquidus	Latent heat	Reference
1	Simple T-dependent	600°C + 273 K (fixed)	1200°C + 273 K (fixed)	320 kJ/kg	Stüwe (1995)
10	Crustal/sediment (P-dependent)	P-dependent formula	1423 + 0.105·P (MPa)	380 kJ/kg	—
11	Felsic/crustal (P-dependent)	P-dependent formula	1262 + 0.09·P (MPa)	300 kJ/kg	Schenker et al. (2012)
40	Mantle peridotite (P-dependent)	P-dependent formula	2073 + 0.114·P (MPa)	400 kJ/kg	—
41	Mantle wet olivine (P-dependent)	P-dependent formula	2073 + 0.114·P (MPa)	300 kJ/kg	Schenker et al. (2012)

Choosing the Right Model

Phase type	Recommended `melt`	Rationale
Continental crust (e.g., quartzite, anorthite, granite)	11	Felsic solidus, Schenker 2012
Sediments	10 or 11	Lower solidus than mantle
Lithospheric mantle (dry olivine)	41	P-dependent peridotite
Asthenosphere (wet olivine)	41	Same model, wet conditions
Diabase / mafic lower crust	11	Treated as crustal

Melt Fraction Computation

Source: MDLIB/MeltingRoutines.c, function PartialMelting()

Equilibrium melt fraction:

φ_eq = (exp(α·T) − exp(α·T_s)) / (exp(α·T_l) − exp(α·T_s))

where T_s = solidus temperature, T_l = liquidus temperature, both P-dependent.

With kinetic relaxation (tau_kin > 0):

φ = (dt / (τ_k + dt)) · φ_eq + (τ_k / (τ_k + dt)) · φ_0

where φ_0 is the previous melt fraction and τ_k = tau_kin.

Clamped to [0, 1].

Melt Weakening

When force_melt_weak = 1 and melt_weak > 0, the code overrides the dislocation creep activation volume for melt-bearing phases:

if (model->force_melt_weak == 1) mat->apwl[k] = model->melt_weak;

This effectively reduces viscosity in regions with high melt fraction. The melt_weak value replaces the power-law activation volume (Vpwl), making melt-bearing regions weaker.

Typical value: melt_weak = 30.0 (used in RiftingMelting, RiftingCombinedYield, and other scenarios).

Interaction with Other Features

With `eta_vp` (viscoplastic regularisation)

When combining melting with plasticity (plast = 1 or plast = 2), eta_vp must be large enough to stabilise the weakened rheology.

Model scale	Without melting	With melting
Lithospheric rifting	eta_vp ≥ 1e19	eta_vp ≥ 2.5e20
Localised chamber	eta_vp ≥ 1e18	eta_vp ≥ 1e19

Stability warning: eta_vp = 1e19 with melting = 1 at lithospheric scale can produce instabilities (negative viscosity, values ~1e60) after ~100 steps. Use eta_vp = 2.5e20 or higher.

With combined yield (`plast = 2`)

No special interaction — plast = 2 works with melting. Ensure T_st and eta_vp are set per phase.

Example Configuration

### Global (in header of .txt)
melting           = 1
force_melt_weak   = 1
melt_weak         = 30.0

### Per phase
ID   = 0           // Continental crust
melt = 11          // Schenker 2012 felsic

ID   = 1           // Lithospheric mantle
melt = 41          // Schenker 2012 mantle

ID   = 2           // Asthenosphere
melt = 41          // Schenker 2012 mantle

Scenarios Using Melting

Scenario	Melt models used	Application
`RiftingMelting`	11 (crust), 41 (mantle)	Extension with decompression melting
`RiftingCombinedYield`	11 (crust), 41 (mantle)	Rifting + combined mode-I/II yield
`SubductionMelting`	Fluid-released melting	Slab-edge weakening
`TCMagmaticSystem`	10, 11	Thermo-chemical magmatic evolution
`PressurizedMagmaChamber`	— (thermal only)	Pressurised intrusion
`MeltingOverpressure`	—	Melting-induced overpressure
`ChristmasTree`	Multi-branch	Dike geometry

Key Source Files

Melting computation: MDLIB/MeltingRoutines.c
Melt weakening: MDLIB/FlowLaws.c (activation volume override)
Parameter parsing: MDLIB/InputOutput.c
HDF5 output: Centers/X (melt fraction field)

skill-melting

Partial Melting

Overview

Enabling Melting

Global Switches (in .txt file)

Per-Phase Parameter (in .txt PHASE PROPERTIES blocks)

Melt Model Indices

Choosing the Right Model

Melt Fraction Computation

Melt Weakening

Interaction with Other Features

With eta_vp (viscoplastic regularisation)

With combined yield (plast = 2)

Example Configuration

Scenarios Using Melting

Key Source Files

同仓库更多 Skills

同仓库更多 Skills

Partial Melting

Overview

Enabling Melting

Global Switches (in .txt file)

Per-Phase Parameter (in .txt PHASE PROPERTIES blocks)

Melt Model Indices

Choosing the Right Model

Melt Fraction Computation

Melt Weakening

Interaction with Other Features

With eta_vp (viscoplastic regularisation)

With combined yield (plast = 2)

Example Configuration

Scenarios Using Melting

Key Source Files

Global Switches (in `.txt` file)

Per-Phase Parameter (in `.txt` PHASE PROPERTIES blocks)

With `eta_vp` (viscoplastic regularisation)

With combined yield (`plast = 2`)

Global Switches (in `.txt` file)

Per-Phase Parameter (in `.txt` PHASE PROPERTIES blocks)

With `eta_vp` (viscoplastic regularisation)

With combined yield (`plast = 2`)