CONCERNING THE ORIGIN OF THE METAL IN 

 METEORITES 



By George P. Merrill 

 Head Curator of Geology, United States National Muneum 



The peculiar relationship existing between the metallic and sili- 

 cate portions of a stony meteorite has been noted by several, and 

 particiilarh' the earlier workers. The present writer has on more 

 than one occasion (noted later) made reference to it and also to the 

 work of others. In discussing the matter among his contemporaries 

 he finds, however, a considerable difference of opinion such as has 

 led to the preparation of this paper in which he reviews these 

 opinions and gives the results of his own observations. 



In his discussion of the composition of the Lodran meteoric stone, 

 Tschermak wrote ' as long ago as 1870 : 



Das Nicheleisen und der Magnetkies miissen spiiter fest geworden sein als die 

 iibrigen Mineralien, und ibre Bilduug diirfte zu gleicher Zeit mit jeuen Verlinder- 

 ungen vor sich gegangen sein, welche der Olivin erlitten zu haben scheiut. 



With reference to the metallic constituent of the Homestead meteor- 

 ite, Gumbel wrote, five years later : 



Noch hiiufinger ersebeinen die aus Meteoreisen bestehenden koi'ncben der 

 Gesteinmasse in meist zackigen, winkel'g gebogenen, oft in feine Spitzen aus- 

 laufenden Klumpcheu beigemengt, welcbe so innig an die nicht metalischen 

 Tbeile sich ausscbmiegen als ob das Eisen erst zuletzt etwa durch Reduction 

 an der Stelle ausgeschieden worden ware, wo es sich vorfindet.^ 



So far as I am aware these are the first suggestions of their kind, 

 though they seem to have attracted little attention from other 

 workers. 



Before entering upon the discussion of these and other views yet 

 to be noted, the following illustrations of actual conditions are given. 



Figure 1, Plate 1, is from a photomicrograph of the chondritic 

 stone from Anthony, Kans., recently described.^ The dark center (1) 

 is troilite; the lighter border (2) metal, which forms, as it were, a 



> Sitzbericht d. k. Akad. der Wiss. II Abtheil., 1870. 



* Sitzbericht MUnchen Akad. der Wiss., vol. 5, 1875, p. 325. 



' Proc. Nat. Acad, of Sciences, vol. 10, p. 306. 



No. 2742.— PROCEEDINGS U. S. NATIONAL MUSEUM. VOL. 73, ART. 21. 

 96270—28 I 



