Table 1: Results of thin section analysis

Sample / Rock Type / Phenocrystsa / Groundmass / Alterationc / Vesicles / Zeolites
Number / pl / ol / cpx / opx / opaques / biotite / amph / Texture / high / med. / low
M-002 / Basaltic / f-mb / f-m / f-m / f / intersertal / X / X
andesite / 30-35 / <1 / 1-2 / 1
M-003 / trachydacite / f-m / f / f / f / f / intersertal / X
3-5 / <1 / <1 / <1 / <1
M-004 / basalt / f-m / f / f-m / f-m / f / intersertal / X
35-40 / 1 / 5 / 1 / <1
M-007 / trachydacite / f-m / f / f / f / f / Intersertal, / X / X
3 / <1 / 1 / <1 / <1 / trachytic
M-008 / basalt / f-m / f-m? / f-m / F / f / intersertal / X
25-30 / <1 / <1 / <1 / <1
M-011 / basaltic / f-m / f / f / f / f / f / Intersertal, / X
andesite / 25-30 / <1 / <1 / <1 / <1 / <1 / poikalitic
M-013 / trachy- / f-m / f / f-m / f-m / f / f / f / intersertal / X / X / X
andesite / 20-25 / <1 / <1 / 1-2 / 1 / <1 / <1
M-015 / trachy- / f-m / f / f / f / f / f / intersertal / X
andesite / 25-30 / <1 / 2 / 2 / 1 / <1
M-017 / basalt / f-m / f / f / f / intersertal / X / X
40-45 / <1 / <1 / <1
M-018 / basaltic / f-m / f / f-m / f-m / f / intersertal / X / X
andesite / 25-30 / 1 / 2-3 / 2-3 / <1

aSize and whole rock percentages by volume; pl=plagioclase, ol=olivine, cpx=clinopyroxene, opx=orthopyroxene, amph=amphibole

bphenocryst sizes: f=fine-grained (<1mm), m=medium-grained (1-5mm)

calteration is based on percentages of secondary minerals: 0-25%=low, 25-50%=med., and >50%=high