= 
Er Ans 
er £0} 
DESCRIPTION OF ROCKS AND ANALYSES 23 
1 A B Molecular ili Figures 
en, Ba Mineral composition („Norm“) of Osann 
ers | cent. 
SiO, 44.43) 44.49] 45.08] 0.741 | 50.711Or ........... a 200.7 
AI,O, 18.61) 13.05'|14.217) 0.183 | 12.101 Ab... ......... 19.32? F..56.40) A... 3.1 
Fe,O, JAS. 2,78 ,.72.8810l022. 11, — Al. nn. 31 CHEN 
| FeO 6.62! 8.24| 8.59| 0.092 I 9.29|Cor .....-..-- 2.33 722200 
| MgO 10.14 11.23) 7.01) 0.254 | 16.82 Sgn) 5803 st |W eee sas FEE 
CaO 6.78) 8.58} 10.20) 0.121 | 8.05 ; Le Aa) 
Na,O 2.29) 3.16] 3.99) 0.037) 2.45] * MesiO 13.47 CLES 
K,O 0.92 2.95) 1.79| 0.010 | 0.65,/7Y a uf 3.68 P..17.15) f...14.0 
H,O at 105° | 1.58) 0.5 0.15] — | — Mg,SiO OS hk... 0.88 
Oi 105° 12.4 0.05 — |. | ee Soe da 0..11.89 7... 0.95 
Co, 0.02| 0.86] 2.42] 0.001 | — A 
TiO, 1:70] 2.69) 2.93) 0.021 | — ES RURGRN et 
P,O 0.33} 0.92] 0.62] 0.002 | — 
275 VEN TEN NEE SL a An 
= OL ET a RE Behe 
S ; LAGE N | el 0.05 
MnO 0.23) 0.17} 0.22) 0.004 | — SEN RFU FRAGEN 
NiO trace! 0.07;/nmone} — | — <'fem 37.80 
BaO 002} — | 0.117) 0.0001) — H,O... 4.02 
99.61) 99.71|100.41 100.00 100.55 
Spec. gr. | 2.861) — | 3.01 Magmatic symbol: III, 5, 4, 4 
| Auvergnose | 
1. Olivine-trachydolerite, Bennet island. Dr. N. Sahlbom, analyst. 
A. Olivine-trachydolerite, volcanic neck Mt. Halvdan, Spitsbergen. 
Prof. Dittrich, analyst. 4 
B. Olivin-trachyandesite, Mary Muss bay, Jan Mayen. Dr. Har- 
wood, analyst. ? 
Although the analysis differs conspicuously from those of the 
normal Arctic basalts in the low silica and high alumina content, 
the magmatic symbol is nearly accordant with the bulk of them, 
1 Including 2.109/0 ZrO, and 0.0290 Cr,O,. 2 Including 0.05% V,O, and 0.01 9/0 
Cr,O;. 3 Including 0.05%o SrO, 
4 V. M. Goldschmidt, I. c. 
5 A. Holmes, 1. c. p. 204. 
