Keyes — Meteorites on the Painted Desert. 145 



every 24 hours there are, according to Young, 40 no less 

 than from 15,000,000 to 20,000,000 of meteorites entering 

 the earth's atmosphere. The collection of some thou- 

 sands of meteoritic stones and irons in the Canyon Diablo 

 district no longer demands the intervention of special 

 explanations to account for their reality. 



It is however, to the desert regions of our earth that 

 we must turn in order to gain our chief knowledge con- 

 cerning the exact nature, great volume, and general pre- 

 valency of the meteoritic augmentation to the earth's 

 mass. 



Abysmal Sea Deposits. The great abundance of those 

 peculiar masses brought up in deep-sea dredgings called 

 chondres which occur throughout the abysmal deposits 

 covering the floor of the ocean is especially noted by Mur- 

 ray and Renard 41 in the reports of the Challenger expe- 

 dition. These masses are largely composed of basic min- 

 erals closely related to the earthy minerals known as 

 bronzite and with small doubt are of cosmic origin. The 

 materials from the bottom of the deep seas should be 

 examined anew in the light of their possible celestial 

 origin. 



Dark Bands in Arctic Snow-fields. The banded appear- 

 ance of arctic glaciers has seldom found adequate expla- 

 nation. Its main cause appears to be due to layers of 

 fine dust and minute rock-fragments. Nordenskiold 42 in 

 particular calls attention to the distinct layered appear- 

 ance of certain arctic snow-fields in which the dark zones 

 were found to be imparted by minute black grains most 

 of which were metallic in character. Chamberlain 43 in 

 presenting some fine photographic views of the fronts 

 of the Bryant, Krakokla and other Greenland glaciers 

 specifically emphasizes the marked banded appearance. 

 Although he incidentally states that the dark bands are 



40 Astronomy, 472. 1898. 



"Narrative of the Cruise of H. M. S. Challenger, 2:809. 1885. 



"Comptes rendus de 1'Acad. d. Sci., 77:463. 1873. 



■"Jour. Geol. 3:568. 1895. 



