THE METEOR CRATER OF CANYON DIABLO, ARIZONA ; 

 ITS HISTORY, ORIGIN, AND ASSOCIATED METEORIC 

 IRONS 



By GEORGE P. MERRILL 

 Head Curator of Geology, U. S. National Museum 



(With 15 plates) 

 CONTENTS 



Page 



I. Introduction 461 



II. Geology and physiography of region 462 



III. The crater 463 



Historical references 463 



External appearance 464 



Details of structure 464 



IV. The crater floor 47° 



Physiography 470 



Results of borings 470 



Petrographic description of rock products 472 



V. The meteoric irons 478 



History of early finds 47§ 



Distribution of the irons 480 



Chemical and mineralogical properties .' . 481 



VI. The iron shale and shale balls 484 



Occurrence, composition, and origin 484 



The shale balls 486 



VII. Origin of the crater 487 



Opinions for and against the meteoric hypothesis 487 



VIII. Summary 489 



Consideration of evidence 489 



Velocity of meteorites and possible depth of penetration 490 



Hypothetical considerations and conclusion 494 



Introduction 



Interest in the question of the possible meteoric origin of the 

 remarkable crater-form depression lying a few miles south of the 

 Santa Fe Railroad and not far from Canyon Diablo, in Coconino 

 County, Arizona, has lately been revived by development work carried 

 on under the direction of the Standard Iron Company of Philadelphia, 

 and the publication of preliminary results and conclusions in the 



461 



