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Table T4. Example plutonic rock alteration log, Expedition 312.

Exp. Hole Core Section Pieces Interval (cm) Total
length
(cm)		 Unit Total % alteration Alteration after olivine % olivine altered Alteration after clinopyroxene % cpx altered
Top Bottom Talc Amph Chl Smec Hem Py Other Hbl Act Chl/Sm Oxide Epi Other
312 1256D 212R 1 6–7 24 32 6 80b 100                 X X   X     100
312 1256D 213R 1 13 44 52 8 81 100                 X X         100
312 1256D 214R 1 1–9 0 36 20 81 70                 X X         100
312 1256D 214R 1 9–16 26 83 55 82 40                 X X X       40
312 1256D 214R 1 21–25 26 28 15 82 100                 X X X       100
312 1256D 214R 1 15–20 76 111 28 83 60                 X X X       50
312 1256D 214R 1 26–28 130 145 10 84 70                 X X X       50
312 1256D 214R 2 1–6 0 31 25 84 50                 X X X       50
312 1256D 214R 2 7–20 32 145 100 85 60                 X X X       50
312 1256D 214R 3 1–5 0 41 35 85 60                 X X X       50

Notes: Amph = amphibole (undistinguished), Chl = chlorite, Smec = Mg-smectite, Hem = hematite (±iron oxyhydroxide), Py = pyrite, Hbl = hornblende, Act = actinolite, Chl/sm = mixed-layer chlorite smectite, Ep = epidote, 2nd plag = secondary plagioclase, Zeo = zeolite, Preh = prehnite, Qz = quartz, opx = orthopyroxene. For the complete plutonic alteration log, see PLUTLOG.XLS in “Supplementary material.”


Exp. Hole Core Section Pieces Interval (cm) Alteration after plagioclase % plag altered Alteration after opx % opx altered Alteration
of oxides 		Comments
Top Bottom 2nd plag Zeo Preh Epi Chl/Sm Qz Act Other Chl Hem Other
312 1256D 212R 1 6–7 24 32 X     X X X X   100           Quartz diorite
312 1256D 213R 1 13 44 52 X X ?   X       100           1 cm band ‡ fine grained; sheared? 1 cm epidote patch
312 1256D 214R 1 1–9 0 36 X X   X X       70            
312 1256D 214R 1 9–16 26 83 X X X X X X     60            
312 1256D 214R 1 21–25 26 28 X X X X X       100            
312 1256D 214R 1 15–20 76 111 X X X X X X     60            
312 1256D 214R 1 26–28 130 145 X X X   X       70            
312 1256D 214R 2 1–6 0 31 X ? ?           50 X X        
312 1256D 214R 2 7–20 32 145 X   ?   X       70            
312 1256D 214R 3 1–5 0 41 X   ?       X   70 X X        

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