2D Hydrated Subducting Plate#
A simple setup of a subducting plate in a Cartesian box which contains hydrated lithologies. There are four lithologies, a 3 km thick sediment layer, a 4 km thick mid-ocean ridge basalt (MORB) layer, a 4 thick gabbro layer, and a 9 km thick peridotite layer. The lithologies are specified to have an upper bound on the amount of bound water that they can hold of 3 wt%, 1 wt%, 0.5 wt%, and 2 wt% for sediment, MORB, gabbro, and peridotite, respectively.
The relevant part of the World Builder file for prescribing the water content within the unsubducted oceanic plate looks like this:
22 {"model":"oceanic plate", "name":"Subducting Plate",
23 "min depth":0, "max depth":300e3,
24 "coordinates" :[[2000e3,100e3],[2000e3,-100e3],[3000e3,-100e3],[3000e3,100e3]],
25 "temperature models":[{"model":"plate model",
26 "min depth":0, "max depth":300e3,
27 "top temperature":273, "bottom temperature":-1,
28 "spreading velocity":0.1,
29 "ridge coordinates": [[[8000e3,-100e3],[8000e3,100e3]]]}],
30
31 "composition models": [
32 {"model":"tian water content", "compositions":[0], "min depth": 0, "max depth": 3e3, "lithology":"sediment", "initial water content":3, "cutoff pressure":1},
33 {"model":"tian water content", "compositions":[0], "min depth": 3e3, "max depth": 7e3, "lithology":"MORB", "initial water content":1, "cutoff pressure":16},
34 {"model":"tian water content", "compositions":[0], "min depth": 7e3, "max depth": 11e3, "lithology":"gabbro", "initial water content":0.5, "cutoff pressure":26},
35 {"model":"tian water content", "compositions":[0], "min depth": 11e3, "max depth": 20e3, "lithology":"peridotite", "initial water content":2, "cutoff pressure":10}]
36 },
while the relevant part of the World Builder file for prescribing the water content within the subducting oceanic plate looks like this:
38 {"model":"subducting plate", "name":"Slab",
39 "coordinates":[[2000e3,-100e3],[2000e3,100e3]],
40 "dip point":[0,0],"max depth":10000e3,
41 "segments":[{"length":250e3,"thickness":[300e3],"top truncation":[-50e3],"angle":[0,60]},
42 {"length":300e3, "thickness":[300e3],"top truncation":[-50e3], "angle":[60,80]},
43 {"length":500e3, "thickness":[300e3],"top truncation":[-50e3], "angle":[80,60]},
44 {"length":300e3, "thickness":[300e3],"top truncation":[-50e3], "angle":[60,40]},
45 {"length":300e3, "thickness":[300e3],"top truncation":[-50e3], "angle":[40,20]}],
46
47 "composition models":[
48 {"model":"tian water content", "compositions":[0], "density":3300, "min distance slab top":0, "max distance slab top":3e3, "lithology":"sediment", "initial water content":3, "cutoff pressure":1},
49 {"model":"tian water content", "compositions":[0], "density":3300, "min distance slab top":3e3, "max distance slab top":7e3, "lithology":"MORB", "initial water content":1, "cutoff pressure":16},
50 {"model":"tian water content", "compositions":[0], "density":3300, "min distance slab top":7e3, "max distance slab top":11e3, "lithology":"gabbro", "initial water content":0.5, "cutoff pressure":26},
51 {"model":"tian water content", "compositions":[0], "density":3300, "min distance slab top":11e3, "max distance slab top":20e3, "lithology":"peridotite", "initial water content":2, "cutoff pressure":10}],
52
53 "temperature models":[{"model":"mass conserving",
54 "reference model name": "plate model",
55 "density":3300,
56 "adiabatic heating":true,
57 "spreading velocity":0.1,
58 "subducting velocity":0.1,
59 "ridge coordinates":[[[8000e3,-100e3],[8000e3,100e3]]],
60 "coupling depth":80e3,
61 "forearc cooling factor":1.0,
62 "taper distance":100e3,
63 "min distance slab top":-200e3, "max distance slab top":300e3}]
64 }
65 ]
And the bound water content within the subducting plate looks like this:
The background is coloured by the bound wt% water, and isotherms are overlain on top at from 273 K to 1373 K at intervals of 100 K.#