Auxiliary Material submission for Paper 2007JB005075


Plagioclase recrystallization and preferred orientation in layered mylonites: 
Evaluation of flow laws for the lower crust


Luc Mehl 
MIT/WHOI Joint Program, Woods Hole, Massachusetts, USA

Greg Hirth 
Department of Geological Sciences, Brown University, Providence, Rhode Island, USA

Mehl, L., and G. Hirth (2008), Plagioclase preferred orientation in layered mylonites: 
Evaluation of flow laws for the lower crust, J. Geophys. Res., 113, B05202, 
doi:10.1029/2007JB005075.



Introduction



This auxiliary material provides chemical compositions used to calculate equilibrium 
temperatures for the Southwest Indian Ridge gabbro mylonites (text section 4.5.2).  
Clinopyroxene compositions are listed in Table S1, orthopyroxene compositions are listed in 
Table S2, and olivine compositions are listed in Table S3. Recrystallized grain orientations 
for plagioclase, clinopyroxene, orthopyroxene, olivine, ilmenite and magnetite are presented 
in pole figures in Figures S1 and S2". Refer to Table 1 in the text for microstructure data. 
The orientations of subgrains within plagioclase porphyroclasts are shown in Figure S3. 
The relationships between plagioclase porphyroclasts and recrystallized plagioclase layers 
in shear zone 188-3.2A are shown in Figure S4. 

1. 2007jb005075-ts01.txt Clinopyroxene microprobe analyses.
1.1 Column "oxide", chemical oxide

1.2 Column "149-3.1core", core analysis for sample 149-3.1
1.3 Column "149-3.1rim", rim analysis for sample 149-3.1
1.4 Column "149-3.1core", core analysis for sample 149-3.1
1.5 Column "149-3.1rim", rim analysis for sample 149-3.1

1.6 Column "149-3.2core", core analysis for sample 149-3.2
1.7 Column "149-3.2rim", rim analysis for sample 149-3.2

1.8 Column "149-3.2core", core analysis for sample 149-3.2

1.9 Column "149-3.2rim", rim analysis for sample 149-3.2
1.10 Column "155-1core", core analysis for sample 155-1
1.11 Column "155-1rim", rim analysis for sample 155-1
1.12 Column "155-1core", core analysis for sample 155-1
1.13 Column "155-1rim", rim analysis for sample 155-1

1.14 Column "188-3.2Acore", core analysis for sample 188-3.2A
1.15 Column "188-3.2Arim", rim analysis for sample 188-3.2A
1.16 Column "188-3.2Acore", core analysis for sample 188-3.2A
1.17 Column "188-3.2Arim", rim analysis for sample 188-3.2A


2. 2007jb005075-ts02.txt Orthopyroxene microprobe analyses.
2.1 Column "oxide", chemical oxide
2.2 Column "149-3.1core", core analysis for sample 149-3.1
2.3 Column "149-3.1rim", rim analysis for sample 149-3.1
2.4 Column "149-3.1core", core analysis for sample 149-3.1

2.5 Column "149-3.1rim", rim analysis for sample 149-3.1
2.6 Column "149-3.2core", core analysis for sample 149-3.2
2.7 Column "149-3.2rim", rim analysis for sample 149-3.2

2.8 Column "149-3.2core", core analysis for sample 149-3.2
2.9 Column "149-3.2rim", rim analysis for sample 149-3.2
2.10 Column "155-1core", core analysis for sample 155-1
2.11 Column "155-1rim", rim analysis for sample 155-1
2.12 Column "155-1core", core analysis for sample 155-1

2.13 Column "155-1rim", rim analysis for sample 155-1
2.14 Column "188-3.2Acore", core analysis for sample 188-3.2A
2.15 Column "188-3.2Arim", rim analysis for sample 188-3.2A
2.16 Column "188-3.2Acore", core analysis for sample 188-3.2A
2.17 Column "188-3.2Arim", rim analysis for sample 188-3.2A


3. 2007jb005075-ts03.txt Olivine microprobe analyses.

3.1 Column "oxide", chemical oxide
3.2 Column "155-1core", core analysis for sample 155-1
3.3 Column "155-1rim", rim analysis for sample 155-1
3.4 Column "188-3.2Acore", core analysis for sample 188-3.2A

3.5 Column "188-3.2Arim", rim analysis for sample 188-3.2A


4. 2007jb005075-fs01.eps Pole figures for plagioclase (plag), olivine, clinopyroxene (cpx), 
magnetite, and ilmenite for shear zones 090-4, 147-6, 149-3.1, and 149-3.2. Refer to Figure 6 
for plotting conventions and Table 1 for microstructure data. The pole figure in 149-3.2C 
shows a host-controlled relationship with porphyroclast 149-3.2D in Figure S3. 

5. 2007jb005075-fs02.eps Pole figures for plagioclase (plag), olivine, and clinopyroxene (cpx), 
for shear zones 155-1, 188-3.2A, and 188-3.2B. Refer to Figure 6 for plotting conventions and 
Table 1 for microstructure data. Layer 155-1C is the only analyzed monophase mylonite layer 
with a weak LPO. This layer is separated into four 50-grain domains to illustrate the spatial 
change in orientations. The combined fabric (sum) shows the weak total fabric. 
Layer 155-1D is the only analyzed gabbro mylonite layer with a strong LPO.



6. 2007jb005075-fs03.eps Orientation relationships between plagioclase porphyroclasts and 
recrystallized tails in sample 188-3.2A. Porphyroclasts are shaded gray, recrystallized tail 
boundaries are indicated by thin lines, the area analyzed for orientation and misorientation 
angle distribution is shown by a dashed line. Subgrain orientation within individual 
porphyroclasts is plotted in single pole figures. The average (010) plane orientation is 
indicated by a dashed line. Recrystallized grain orientations are presented in [100], (010), 
and (001) pole figures. Each pole figure has 50 grains, see Figure 6 for plotting conventions. 
The thin curve in the misorientation angle distribution plots represents the expected 
distribution for random plagioclase orientations. Next neighbor grain pairs are in gray (n = 49), 
random neighbor pairs are in black (n = 1225). (d) is collected from a polyphase layer, n next 
neighbor = 103, n random neighbor = 22993.

7. 2007jb005075-fs04.eps Pole figures for subgrains within porphyroclasts. Refer to Figure 8 
for plotting convention.