The Geology and Petrography of Crater Lake National Park, 1902
PART II.
HYPERSTHENE-DACITES.
CHEMICAL ANALYSES OF DACITES.
The following analyses were made in the laboratory of the United States Geological Survey:
Analyses of Crater Lake dacites.
[Analyses by H. N. Stokes.]
—- | 102. | 113. | 114. | 130. | 143. | 151. |
SiO | 70.77 | 70.10 | 68.17 | 71.87 | 56.85 | 67.41 |
Al2O3 | 14.83 | 15.18 | 15.60 | 14.53 | 18.31 | 15.76 |
Fe2O3 | 1.35 | 1.78 | 2.31 | 1.28 | 2.88 | 1.88 |
FeO | 1.25 | 1.09 | .94 | 1.02 | 3.15 | 1.76 |
MgO | .64 | .74 | 1.02 | .48 | 3.92 | 1.35 |
CaO | 2.12 | 2.27 | 2.76 | 1.59 | 7.20 | 3.36 |
Na2O | 5.07 | 5.15 | 5.15 | 5.08 | 3.89 | 4.54 |
K2O | 2.68 | 2.58 | 2.46 | 2.84 | 1.23 | 2.36 |
H2O | .07 | .10 | .09 | .06 | .16 | .09 |
H2O+ | .33 | .19 | .45 | .22 | .95 | .54 |
TiO2 | .38 | .48 | .54 | .41 | 1.08 | .56 |
ZrO2 | .05 | .04 | None. | .04 | ||
CO2 | None. | None. | None. | None. | None. | None. |
P2O5 | .13 | .13 | .13 | .10 | .22 | .12 |
SO3 | None. | None. | None. | None. | None. | |
Cl | .11 | .03 | Trace. | Trace. | ||
F | Undet. | Undet. | Undet. | Trace. | ||
S | None. | None. | None. | None. | None. | a.02 |
Cr2O3 | None. | None. | None. | None. | None. | None. |
NiO | None. | None. | None. | None. | ||
MnO | Trace. | Trace. | Trace. | Trace. | Trace. | Trace. |
BaO | .08 | .08 | .06 | .08 | .04 | .06 |
SrO |
.02 | .03 | .03 | .03 | Trace. | Trace. |
Li2O | Trace. | Trace. | Trace. | Faint tr. | None. | Trace. |
Total | 99.88 | 99.97 | 99.71 | 99.63 | 99.88 | 99.81 |
aOr SO3 = .04. Whether present as S or SO3 undetermined.NOTE.—O=Cl.
No. 102. Hypersthene-dacite, vitrophyric type, south edge of Llao Rock flow. See page 106. No. 113. Lithoidal hypersthene-dacite, water’s edge, head of Cleetwood Cove. See page 113. No. 114. Streaked, vitrophyric hypersthene-dacite, near Wineglass, Grotto Cove, on the east side of the lake. See page 114. No. 130. Hypersthene-dacite, lithoidal type, from a small dike that cuts the older flows immediately below Llao Rock. No. 143. A dark-colored secretion found among the dacitic ejectamenta. See page 130. No. 151. A light-colored secretion found among the dacitic ejectamenta. See page 139. |
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