Practical Aspects of Mineral Thermobarometry
Chlorite activity coding
FMASH
Listed below is the chlorite code from the example file thdkfm.txt. The variable Q is half the order parameter defined as X(Al,M4)-X(Al,M1). It would be better to use N for this variable, since Q usually stands for the order parameter itself.
%__________________________________________________________________
chl 4
x(chl) 0.35
y(chl) 0.51
Q(chl) 0.485
p(afchl) 1 1 1 2 -1 y -1 Q
p(clin) 2 1 0 1 2 Q
2 0 1 -2/5 x 3 1 -1 y
p(daph) 1 2 0 1 2/5 x 3 1 -1 y
p(ames) 1 1 0 2 1 y -1 Q
sf
W(afch,clin) 18 0 0
W(afchl,daph) 14.5 0 0
W(afchl,ames) 20 0 0
W(clin,daph) 2.5 0 0
W(clin,ames) 18 0 0
W(daph,ames) 13.5 0 0
10
x(Fe,M23) 1 1 0 1 1 x
x(Mg,M23) 1 1 1 1 -1 x
x(Al,M1) 1 1 0 2 1 y -1 Q
x(Fe,M1) 1 2 0 1 1 x 1 2 -1 y 1 Q
x(Mg,M1) 1 2 1 1 -1 x 1 2 -1 y 1 Q
x(Al,M4) 1 1 0 2 1 y 1 Q
x(Fe,M4) 1 2 0 1 1 x 1 2 -1 y -1 Q
x(Mg,M4) 1 2 1 1 -1 x 1 2 -1 y -1 Q
x(Al,T2) 1 1 0 1 1 y
x(Si,T2) 1 1 1 1 -1 y
afchl 1 4 x(Mg,M23) 4 x(Mg,M1) 1 x(Mg,M4) 1 x(Si,T2) 2
check 0 0 0
clin 4 5 x(Mg,M23) 4 x(Mg,M1) 1 x(Al,M4) 1 x(Al,T2) 1 x(Si,T2) 1
check 0 1/2 1/2
daph 4 5 x(Fe,M23) 4 x(Fe,M1) 1 x(Al,M4) 1 x(Al,T2) 1 x(Si,T2) 1
check 1 1/2 1/2
ames 1 4 x(Mg,M23) 4 x(Al,M1) 1 x(Al,M4) 1 x(Al,T2) 2
check 0 1 0
% __________________________________________________________________
MnFMASH
This is the same model extended to treat Mn-bearing chlorites. Mn, Fe and Mg are presumed to be evenly partitioned across the sites they occupy.
% Mn-bearing chlorite with Al ordering - recoded DJW 27 Aug 03
chl 5
x(chl) 0.35 % Fe/(Fe+Mg+Mn)
y(chl) 0.51 % X(Al,T2) (clin = 0.5)
N(chl) 0.48 % order parameter Q/2 = [x(Al,M4)-x(Al,M1)]/2
m(chl) 0.001 % Mn/(Fe+Mg+Mn)
p(afchl) 1 1 1 2 -1 y -1 N
p(clin) 2 1 0 1 2 N
2 0 2 -2/5 x -2/5 m 3 1 -1 y
p(daph) 1 2 0 1 2/5 x 3 1 -1 y
p(ames) 1 1 0 2 1 y -1 N
p(mnchl) 1 2 0 1 2/5 m 3 1 -1 y
sf
W(afch,clin) 18 0 0
W(afchl,daph) 14.5 0 0
W(afchl,ames) 20 0 0
W(afchl,mnchl) 0 0 0
W(clin,daph) 2.5 0 0
W(clin,ames) 18 0 0
W(clin,mnchl) 0 0 0
W(daph,ames) 13.5 0 0
W(daph,mnchl) 0 0 0
W(ames,mnchl) 0 0 0
13
x(Fe,M23) 1 1 0 1 1 x
x(Mg,M23) 1 1 1 2 -1 x -1 m
x(Mn,M23) 1 1 0 1 1 m
x(Al,M1) 1 1 0 2 1 y -1 N
x(Fe,M1) 1 2 0 1 1 x 1 2 -1 y 1 N
x(Mg,M1) 1 2 1 2 -1 x -1 m 1 2 -1 y 1 N
x(Mn,M1) 1 2 0 1 1 m 1 2 -1 y 1 N
x(Al,M4) 1 1 0 2 1 y 1 N
x(Fe,M4) 1 2 0 1 1 x 1 2 -1 y -1 N
x(Mg,M4) 1 2 1 2 -1 x -1 m 1 2 -1 y -1 N
x(Mn,M4) 1 2 0 1 1 m 1 2 -1 y -1 N
x(Al,T2) 1 1 0 1 1 y
x(Si,T2) 1 1 1 1 -1 y
afchl 1 4 x(Mg,M23) 4 x(Mg,M1) 1 x(Mg,M4) 1 x(Si,T2) 2
check 0 0 0 0
clin 4 5 x(Mg,M23) 4 x(Mg,M1) 1 x(Al,M4) 1 x(Al,T2) 1 x(Si,T2) 1
check 0 1/2 1/2 0
daph 4 5 x(Fe,M23) 4 x(Fe,M1) 1 x(Al,M4) 1 x(Al,T2) 1 x(Si,T2) 1
check 1 1/2 1/2 0
ames 1 4 x(Mg,M23) 4 x(Al,M1) 1 x(Al,M4) 1 x(Al,T2) 2
check 0 1 0 0
mnchl 4 5 x(Mn,M23) 4 x(Mn,M1) 1 x(Al,M4) 1 x(Al,T2) 1 x(Si,T2) 1
check 0 1/2 1/2 1
Content last modified 28 Aug 03