40 | ARCTIC BASALT PLATEAU 
3. Basalt, Adzva river. H. Backlund, analyst. 
A. , King Charles land, Spitsbergen. Dr. N. Sahlbom, 
analyst. ! 
No volumetrical determination of the mineral constituents was 
undertaken, because the amount of glass varies from place to place 
in the same specimen, and no supports of a uniform composition 
of the glass are offered: the fluctuating content of magnetite skele- 
tons in the glass residue seems to corroborate this supposition. 
A comparison of the two analyses tabulated above (3 and A) 
shows the close resemblance of them; they belong both to the 
camptonose subrang, contain nearly equally high quantities of 
MgO--FeO and are both characterized by a pyroxene of the en- 
statite-augite-group, this constituent being extremely well developed 
in the basalt of King Charles land and the olivine mineral being 
completely resorbed,? whilst in the Adzva rock the more glassy 
consolidation interrupted a development in the same direction. This 
resemblance seems to be in no part an accidental one, but seeks. 
Gah — |, Sphaerules from the basalt. H. Bac k- 
I | II | lund, analyst. 
| Il. Hullite from the Kinkell-basalt, Scot- 
| SiO, Sl age land. Heddle, analyst. (Transact. Edinb. 
Al,O, Toney fee EA Roy. Soc. 1879. 29. p. 89.) 
MOR 2.41] | Ku 
| FeO ee 
MgO 8.00 8.65 
CaO fe Drouin). Brod 
| Na,O er none? 
| K,O 0.19 | 0.67 
| HzO.at 110° | 15.87 8.04 
OLS OKO ears MOS hela 1348 
| TiO, | 0.18 | not det. | 
| MnO | not det. | 1.56 
99.4 100. 
1 A. Hamberg, Die Basalte des König Karls Landes. Geol. Fören. i Stockholm 
Förh. 1899. 27. p. 509. 
2 H. Backlund, Über einige Diabase aus arktischem Gebiet. Tscherm. Min. u.. 
Petr. Mitt. 1907. 26. p. 378. 
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