Keyes—Meteorites on the Painted Desert. 147 
Bearing Upon Meteoritic Source of the Ores. 
In the consideration of the petrologic aspects of the 
larger stony masses termed meteorites in the same man- 
ner as that by which the igneous rocks of the globe are 
examined, suggestive relationships are at once estab- 
lished. They appear to have a very important bearing 
upon the source of the ore materials. Of the four main 
groups usually recognized among the common terrestrial 
rocks of igneous origin the ultra-basic class is quite rare. 
Among the stony meteorites the rock-species distin- 
guished are not only largely ultra-basic in character but 
the cosmical series begins with the most basic of the 
earthly classes and continues through yet unnamed series 
in which the metals form a large proportion of their 
make-up. 
So long ago as 1871 Meunier*® recognized nearly 50 
lithologic types among the meteorites, of most of which 
he later** deseribed the microscopical characters and 
among which he noted a wide range of metallic elements. 
The metals occurring in meteorites include nearly all 
of those found in the common ores. Gold and silver are 
the only conspicuous metals which do not yet appear to 
exist abundantly in celestial minerals. There are, how- 
ever, good grounds why these two metals have not been 
reported; and other equally good reasons why certain 
other metals seemingly occur only sparingly; so that the 
apparent absence of some of these elements in the compo- 
sition of known meteorites in no way precludes their de- 
rivation from this source. . 
In explanation of the notable difference in the relative 
abundance of elements in terrestrial and sideral rocks 
it is suggested by Farrington*®’ that there are good 
grounds for believing this unlikeness to be apparent 
“Geol. des. Metéorites: Moniteur scientifique Quesneville, 1 et 15 
février. 1871. 
* Bull. Soc. d’Hist. nat. d’Autun. 16. 1893; and Ibid. 17. 1895. 
* Journ. Geol. 9:394. 1901. 
