W. S. Bayley — Augite and Plagioclase, etc. 515 



proved the absence of phosphorus both as terrestrial phosphate 

 and meteoric phosphide. In the published analysis of awaruite 

 by W. Skey no phosphorus is given. Catarinite and octibbe- 

 hite contain 0*05 per cent and (HO per cent respectively. 



By etching with nitric acid Widmannstatten "figures cannot 

 be produced upon a polished surface of the nickel-iron. The 

 metal seems to be homogeneous, and the little sulphide to 

 occur in the fissures. Awaruite is passive toward an acid solu- 

 tion of copper sulphate, and only with difficulty and long heat- 

 ing is the nickel-iron from Oregon completely dissolved with 

 replacement of the copper in a sulphate solution. This passive 

 state is uncommon with the ordinary nickel-iron of meteorites, 

 but the high percentage of nickel may account for this property. 

 Concentrated nitric acid dissolves the alloy. 



Daubre'e* points out that meteorites and analogous terrestrial 

 rocks differ in that the former contain in a reduced state certain 

 substances which appear in the latter in the state of oxides. 

 This idea could be extended to include metamorphism in its 

 broadest sense. Serpentine is rarely found in meteorites, 

 although "Wdhler has recognized it in some carbonaceous meteo- 

 rites. In the two cases of awaruite and josephinite, serpentine 

 is the principal silicate derived in the former from olivine and 

 enstatite. Daubreelite is metamorphosed into chrome-iron, 

 and this may possibly be the explanation of the origin of the 

 latter, that the double sulphide of chromium and iron existed 

 in the ferro-magnesian silicates before or at the time of their 

 serpentinization, and was then oxidized to chromite. 



The evidence cited in the previous paragraphs points to the 

 terrestrial origin of the pebbles which form the subject of this 

 paper, and here the question of origin must rest till the nickel- 

 iferous iron is found in situ. 



The name josephinite is given in honor of the county, its 

 locality, in accordance with the custom in use for naming 

 analogous substances. 



Laboratory, TJ. S. Geological Survey, March, 1892. 



Art. LX1Y. — A Fibrous Inter growth of Augite and Plagio- 

 clase, resembling a reaction rim, in a Minnesota Gabbro j 

 by W. S. Bayley. 



Lsr the course of an investigation into the microscopical 

 characteristics of the gabbro forming the great flow,, or flows, 

 near the base of the Ke ween a wan series of rocks in north - 



* Etudes Synthetiques de Geologie Experimental par A. Daubree, 1879, p. 578. 



