Transcript Document
Crust to Core workshop:
An introduction to Perple_X
Part 3: What data is Perple_X actually using?
Ins titut
e of Mi neral og
y and Petrology
Perple_X finds an optimum set of pseudocompounds for the P, T, X conditions of interest.
This is based on available information on the H, S,
V of end-members, combining these into solutionphases.
Perple_X finds an optimum set of pseudocompounds for the P, T, X conditions of interest.
This is based on available information on the H, S,
V of end-members, combining these into solutionphases.
Ignoring some complexity (e.g.X), we could write a
simple equilibria that we could solve by hand
Kyanite = Al2SiO5 = Sillimanite
TSKyanite PVKyanite TSSillimanite PVSillimanite
It is univariant, so each P has one unique T at which
this occurs, we just need S and V for each phase…
Extract of THERMOCALC molar thermodynamic properties, Table 5 of Holland & Powell, 1998
Ky anite
Sillimanite
H
sd(H) S
-2593.13 0.7 83.5
-2585.89 0.7 95.5
V
4.414
4.986
a
0.2794
0.2802
b
-0.7124
-0.69
c
-2055.6
-1375.7
d
-2.2894
-2.3994
aû
Tc
4.04 1590
2.21 1320 2200
S max
V max
4
0.035
Extract of THERMOCALC molar thermodynamic properties, Table 5 of Holland & Powell, 1998
Ky anite
Sillimanite
H
sd(H) S
-2593.13 0.7 83.5
-2585.89 0.7 95.5
V
4.414
4.986
a
0.2794
0.2802
b
-0.7124
-0.69
c
-2055.6
-1375.7
d
-2.2894
-2.3994
aû
Tc
4.04 1590
2.21 1320 2200
S max
V max
4
0.035
But these are the values for V, S (and H) at 25 ˚C, atmospheric pressure!
Extract of THERMOCALC molar thermodynamic properties, Table 5 of Holland & Powell, 1998
Ky anite
Sillimanite
H
sd(H) S
-2593.13 0.7 83.5
-2585.89 0.7 95.5
V
4.414
4.986
a
0.2794
0.2802
b
-0.7124
-0.69
c
-2055.6
-1375.7
d
-2.2894
-2.3994
aû
Tc
4.04 1590
2.21 1320 2200
CP a bT cT
CP = J mol-1 K-1
CP of kyanite as a function of T, using
tabulated values of a, b, c, d
2
dT
S max
V max
4
0.035
1/ 2
Extract of THERMOCALC molar thermodynamic properties, Table 5 of Holland & Powell, 1998
Ky anite
Sillimanite
H
sd(H) S
-2593.13 0.7 83.5
-2585.89 0.7 95.5
V
4.414
4.986
a
0.2794
0.2802
b
-0.7124
-0.69
c
-2055.6
-1375.7
d
-2.2894
-2.3994
aû
Tc
4.04 1590
2.21 1320 2200
CP a bT cT
CP = J mol-1 K-1
ST S0 SMax / 1000 Q298
2
T
298
CP
T
dT
2
dT
S max
V max
4
0.035
1/ 2
Extract of THERMOCALC molar thermodynamic properties, Table 5 of Holland & Powell, 1998
Ky anite
Sillimanite
H
sd(H) S
-2593.13 0.7 83.5
-2585.89 0.7 95.5
V
4.414
4.986
a
0.2794
0.2802
b
-0.7124
-0.69
c
-2055.6
-1375.7
d
-2.2894
-2.3994
aû
Tc
4.04 1590
2.21 1320 2200
CP a bT cT
CP = J mol-1 K-1
ST S0 SMax / 1000 Q298
2
T
298
CP
T
dT
2
dT
S max
V max
4
0.035
1/ 2
Extract of THERMOCALC molar thermodynamic properties, Table 5 of Holland & Powell, 1998
Ky anite
Sillimanite
H
sd(H) S
-2593.13 0.7 83.5
-2585.89 0.7 95.5
V
4.414
4.986
a
0.2794
0.2802
b
-0.7124
-0.69
c
-2055.6
-1375.7
d
-2.2894
-2.3994
aû
Tc
4.04 1590
2.21 1320 2200
CP a bT cT
CP = J mol-1 K-1
ST S0 SMax / 1000 Q298
T
ST S0 SMax / 1000 Q298
T
2
2
298
CP
4
0.035
1/ 2
dT
a bT cT
298
dT
V max
T
ST S0 SMax / 1000 Q298 a ln
2
2
S max
2
dT
1/ 2
dT
T
T b T 298 c 1 1 2d 1 1
2
2
298
2 T
298
T
298
Extract of THERMOCALC molar thermodynamic properties, Table 5 of Holland & Powell, 1998
Ky anite
Sillimanite
H
sd(H) S
-2593.13 0.7 83.5
-2585.89 0.7 95.5
V
4.414
4.986
V at 25 ˚C, 1 atm
a
0.2794
0.2802
b
-0.7124
-0.69
c
-2055.6
-1375.7
d
-2.2894
-2.3994
aû
Tc
4.04 1590
2.21 1320 2200
Thermal expansivity, K-1
S max
V max
4
0.035
Extract of THERMOCALC molar thermodynamic properties, Table 5 of Holland & Powell, 1998
Ky anite
Sillimanite
H
sd(H) S
-2593.13 0.7 83.5
-2585.89 0.7 95.5
V
4.414
4.986
V at 25 ˚C, 1 atm
a
0.2794
0.2802
c
-2055.6
-1375.7
d
-2.2894
-2.3994
aû
Tc
4.04 1590
2.21 1320 2200
Thermal expansivity, K-1
V1,T V0 VMaxQ298 1 a T 298 20a
2
b
-0.7124
-0.69
o
V at T of interest, 1 atm
o
T
298
S max
V max
4
0.035
Extract of THERMOCALC molar thermodynamic properties, Table 5 of Holland & Powell, 1998
Ky anite
Sillimanite
H
sd(H) S
-2593.13 0.7 83.5
-2585.89 0.7 95.5
V
4.414
4.986
a
0.2794
0.2802
V1,T V0 VMaxQ298 1 a T 298 20a
2
o
o
b
-0.7124
-0.69
T
c
-2055.6
-1375.7
298
d
-2.2894
-2.3994
aû
Tc
4.04 1590
2.21 1320 2200
S max
V max
4
0.035
Bulk modulus (degree of
incompressibility)
V at T of interest, 1 atm
P
1
VdP
V1, T T
4P
1
3
T
3/ 4
1
Extract of THERMOCALC molar thermodynamic properties, Table 5 of Holland & Powell, 1998
Ky anite
Sillimanite
H
sd(H) S
-2593.13 0.7 83.5
-2585.89 0.7 95.5
V
4.414
4.986
a
0.2794
0.2802
V1,T V0 VMaxQ298 1 a T 298 20a
2
o
o
b
-0.7124
-0.69
T
c
-2055.6
-1375.7
298
d
-2.2894
-2.3994
aû
Tc
4.04 1590
2.21 1320 2200
S max
V max
4
0.035
Bulk modulus (degree of
incompressibility)
V at T of interest, 1 atm
Volume at the P and T of interest
(based on the Murnaghan EoS)
P
1
VdP
V1, T T
4P
1
3
T
3/ 4
1
Extract of THERMOCALC molar thermodynamic properties, Table 5 of Holland & Powell, 1998
Ky anite
Sillimanite
H
sd(H) S
-2593.13 0.7 83.5
-2585.89 0.7 95.5
V
4.414
4.986
a
0.2794
0.2802
b
-0.7124
-0.69
c
-2055.6
-1375.7
d
-2.2894
-2.3994
aû
Tc
4.04 1590
2.21 1320 2200
We can thus use the tabulated data, with the correct set
of equations, to extrapolate the thermodynamic
properties (V, S & H) to the P and T of interest - this is
part of what THERMOCALC does.
This handling of data is explained more fully in:
HOLLAND, T. J. B. & POWELL, R. (1998), J.
Metamorphic Geology, v16, 309-343.
S max
V max
4
0.035