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Table T5. Background alteration modes observed in thin section.

Olivine alteration relative proportions
Unit Number of
samples		 Igneous
mode 		Alteration
(%) 		Serpentine
(%) 		Clay
minerals
(%) 		Amphibole
(%) 		Talc
(%) 		Chlorite
(%) 		Other
(%) 		     
I background 7 8 80 11 22 30 19 15 4      
II background 29 14 64 26 17 13 21 18 4      
I/II cataclastic 3 13 100 54 22 9 12 — 4      
III background 17 37 68 42 17 25 9 4 2      
III cataclastic 23 11 99 18 11 16 3 50 2      
Clinopyroxene alteration relative proportions
Unit Number of
samples		 Igneous
mode 		Alteration
(%) 		Pale
amphibole
(%) 		Clay
minerals
(%) 		Green
amphibole
(%) 		Secondary
clinopyroxene
(%) 		Chlorite
(%) 		Other
(%) 		     
I background 7 30 20 22 — 71 — 8 —      
II background 29 28 30 68 1 22 <1 8 1      
I/II cataclastic 3 22 37 74 — 26 — — —      
III background 17 20 50 58 23 17 — 0 2      
III cataclastic 23 24 64 35 2 34 <1 24 4      
Orthopyroxene alteration relative proportions
Unit Number of
samples		 Igneous
mode 		Alteration
(%) 		Pale and
green
amphibole
(%) 		Talc
(%) 		Chlorite
(%) 		Serpentine
(%) 		Clay minerals
(%) 		Other
(%) 		     
I background 7 5 40 40 20 — 8 24 8      
II background 29 6 28 73 8 17 1 — —      
I/II cataclastic 3 10 90 20 — 20 20 40 —      
III background 17 1 0 — — — — — —      
III cataclastic 23 — — — — — — — —      
Plagioclase alteration relative proportions
Unit Number of
samples		 Igneous
mode		 Alteration
(%) 		Amphibole Epidote/
clinozoisite
(%) 		Chlorite
(%) 		Clay Prehnite
(%) 		Garnet Secondary
plagioclase
(%) 		Zeolite
(%) 		Carbonate
(%)
I background 7 60 10 2 5 37 — 18 — 36 3 —
II background 29 61 16 <1 <1 33 3 48 2 9 5 1
I/II cataclastic 3 65 32 — — 29 — 39 — 6 26 —
III background 17 45 48 3 3 38 — 49 <1 4 3 <1
III cataclastic 23 70 69 <1 8 20 4 57 <1 6 4 <1
Overall alteration and relative proportions of alteration minerals
Unit Number of
samples		 Alteration
(%)		 Amphibole
(%) 		Chlorite
(%) 		Prehnite
(%) 		Secondary
plagioclase
(%) 		Serpentine
(%) 		Talc
(%) 		Clay
minerals
(%) 		Zeolite
(%) 		Carbonate
(%) 		 
I background 7 19 42 18 5 11 4 8 10 1 —  
II background 29 29 35 21 17 3 9 7 7 2 <1  
I/II cataclastic 3 50 22 16 16 2 17 3 13 11 —  
III background 17 55 26 17 19 2 19 4 12 1 <1  
III cataclastic 23 70 18 27 40 4 3 0 5 3 <1  

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