Page:The Journal of geology (IA journalofgeology11893univ).pdf/187

This page has been proofread, but needs to be validated.
THE VOLCANIC ROCKS OF THE ANDES.
171

TABLE I.

Chemical Analyses of Volcanic Lavas from Colombia.
1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15.
SiO2 56.91
.948 		57.24
.954 		59.13
.985 		60.05
1.000 		61.04
1.017 		61.09
1.018 		61.26
1.021 		63.36
1.056 		63.50
1.058 		63.56
1.059 		65.39
1.089 		66.03
1.100 		67.30
1.121 		68.41
1.140 		69.56
1.159
TiO2 .85 .45 .95 .95
Al2O3 18.18
.178 		18.02
.176 		17.00
.166 		15.59
.152 		15.72
.154 		15.96
.156 		16.15
.158 		16.35
.160 		15.34
.150 		15.43
.151 		15.49
.151 		14.57
.142 		17.55
.172 		16.08
.156 		15.65
.153
Fe2O3 4.65
.029 		3.46
.021 		7.03 6.95
.043 		5.03
.031 		4.29
.026 		4.39
.027 		2.12
.013 		3.22
.020 		3.02
.018 		2.80
.017 		2.57
.016 		1.47
.009 		2.12
.013 		1.24
.007
FeO 3.61
.050 		4.13
.057 		.65
.009 		2.15
.029 		2.03
.028 		2.66
.037 		3.05
.042 		1.71
.023 		2.43
.033 		1.99
.027 		1.19
.016 		1.67
.023 		1.44
.020 		.91
.011
MgO 3.49
.087 		3.77
.094 		3.61
.090 		3.61
.090 		1.06
.026 		2.91
.073 		3.28
.082 		2.50
.062 		2.55
.064 		2.06
.051 		1.89
.047 		1.04
.026 		1.14
.028 		.82
.020
CaO 7.11
.127 		7.78
.138 		6.67
.119 		6.43
.114 		5.34
.095 		6.66
.115 		5.75
.102 		4.79
.085 		4.31
.077 		4.33
.077 		4.48
.080 		3.38
.060 		3.48
.062 		3.52
.063 		2.52
.045
Na2O 4.02
.064 		5.54 4.80
.077 		3.83
.061 		4.02
.064 		2.89
.046 		4.93
.079 		3.58
.057 		4.84
.078 		4.02
.064 		4.56
.073 		3.71
.059 		3.90
.063 		4.52
.073 		4.09
.066
K2O 1.61
.017 		1.37
.014 		1.76
.018 		2.66
.028 		2.51
.026 		2.65
.028 		2.92
.031 		2.75
.029 		2.41
.025 		1.59
.016 		2.70
.029 		2.13
.022 		2.24
.023 		2.19
.023
P2O5 .25 .25 .22 .13 .17 .11 .09 .13 .13
SO3 .05
H2O .36 .06 .16 .47 .58 1.44 .15 .99 1.99 1.09 .55 2.07 .80 .33 2.92
100.19 100.00 100.44 100.60 99.10 100.85 100.57 100.16 100.01 99.02 98.20 99.47 99.84 100.03
  1. Pyroxene-andesite. N. W. foot of the Purgatorio. Pasto.
  2. Olivine-pyroxene-andesite. Pasto.
  3. Pyroxene-andesite. Cerro negro de Mayasquer.
  4. Pyroxene-andesite. Azufral de Túquerres.
  5. Hornblende-andesite. Peñon de Pitayó.
  6. Hornblende-andesite. Loma de Ales.
  7. Pyroxene-andesite. Lava of 1869. Pasto.
  8. Hornblende-pyroxene-dacite, (with olivine and biotite) Cerro negro de Mayasquer.
  9. Hornblende-pyroxene-dacite. Chiles.
  10. Hornblende-dacite. (With biotite and pyroxene.) Llanos de las Mesas, Tajumbina.
  11. Pyroxene-dacite. Cumbal.
  12. Hornblende-pyroxene-dacite. Hondon, Chiles.
  13. Hornblende-biotite-dacite. Azufral de Túquerres.
  14. Hornblende-biotite-dacite. Azufral de Túquerres.
  15. Hornblende-biotite-dacite. Loma de Ales.
This article is issued from Wikisource. The text is available under Creative Commons Attribution-Share Alike 4.0 unless otherwise noted. Additional terms may apply for the media files.