TABLE XI. 
Correlation of the two Groups of Rocks upon a Chemical Basis. 
Volcanic Rocks of 
Sepulchre Mountain. 
Intrusive Rocks of Electric Peak. 
SiO^/e 
No. 
Name. 
Essential Minerals. 
Name. 
Essential Minerals. 
65.24 
2670 
phenocryi 
f s J groundmass 
d iorite-porphy rite 
quartz,biotite, plagioclase, hornblende. | quartz and alkali fieldspar. 
67-54 
2676 
. . . 
quartz-mica-diorite . 1 
biotite, hornblende, plagioclase (orthoclase), quartz. 
67.49 
3680 
dacite ... 
quartz, biotite, hornlllende, plagioclase. j holocrystalline, quartz and feldspar. 
66.05 
2668 
quartz-mica-diorite . 
biotite, hornblende, plagioclase (orthoclase), quartz. 
65.97 
3001 
diorite-porphyrite 
biotite, hornblende, plagioclase (orthoclase), quartz. 
65.66 
3017 
dacite .... 
quartz, biotite, horn 
jlende, plagioclase. | holocrystalline, quartz, feldspar. 
65.60 
2695 
quartz-mica-diorite . 
biotite, hornblende (pyroxene), plagioclase (orthoclase), quartz. 
65.50 
394 
hornblende-mica-andesite 
hornblende, biotite, 
plagioclase. | holocrystalline, quartz, feldspar. 
65.II 
2724 
quartz-mica-diorite . 
biotite, hornblende, augite, hypersthene, plagioclase (orthoclase), quartz. 
64.85 
3008 
quartz-mica-diorite . 
hornblende, biotite, plagioclase (orthoclase), quartz. 
64.27 
2736 
hornblende-mica-andesite 
hornblende, biotite, 
plagioclase, magnetite. | holocrystalline, quartz, feldspar. 
61.50 
154 
. 
hornblende-mica-porphyrite 
biotite, hornblende, plagioclase, magnetite. | feldspar and quartz. 
60.30 
217 
hornblende-pyroxene-andesite 
hornblende, augitc, 
hypersthene, plagioclase, magnetite. | glassy, microlitic. 
58-49 
2089 
hornblende-porphyrite 
j hornblende, plagioclase, magnetite, j feldspar and quartz. 
58-05 
2692 
diorite .... 
biotite, hornblende, augite, hypersthene, magnetite, plagioclase, (quartz). 
57 38 
2679 
pyroxene-porpbyrite . 
augite, hypersthene, biotite, magnetite, plagioclase, quartz. 
57-17 
221 
pyroxene-andesite 
augite, hypersthene, 
( plagioclase. J brown glass, microlitic. 
56.61 
214 
hornblende-pyroxene-andesite 
hornblende-augite-hypersthene, plagioclase. 1 glassy, microlitic. 
56.28 
2669 
diorite .... 
biotite, hornblende, augite, hypersthene, magnetite, plagioclase, quartz. 
55-92 
694 
hornblende-andesite 
hornblende, plagioclase. j microcrystalline. 
55-83 
219 
pyroxene-andesite 
augite, hypersthene, 
plagioclase. | glassy, microlitic. 
