THE S TR UC TURE OF ME TE O RITES I 8 3 



Faults. — Evidence of movement along a plane sufficient to 

 produce well-marked faults in meteorites is not abundant. The 

 slickensides already described prove slight movement, but how 

 much, so far as the stony meteorites are concerned, it is difficult 

 to say on account of the absence of bedding planes and other 

 criteria of measurement. In the iron meteorites, however, the 

 bands of the Widmanstatten figures afford a means of measure- 

 ment. Sections of several such meteorites, viz., Bridgewater, 

 Carlton, Magura, Puquios, and Descubridora, in this way exhibit 

 faulting. In the Puquios meteorite the faulting is of somewhat 

 complicated character, the kamacite bands showing slight dis- 

 location in various directions. The largest fault extends the 

 entire length of the mass, and has a throw of 1 /q of an inch 

 (3 mm). Some crushing and branching also appears along this 

 line of faulting. Other less extensive lines of faulting occur. 

 The amount of throw seen in the Descubridora meteorite is more 

 extensive than in the Puquios, being a distance of from ^ to y 2 

 an inch (6 to 12mm). Owing to the toughness and tenacity of 

 iron meteorites at ordinary temperatures, Howell has suggested 

 that such faulting could only have been produced when the mass 

 was highly heated, as, for instance, in its passage near the sun. 

 He found that a piece of the Toluca meteorite, although very 

 tough when cold, would crumble under the hammer when heated 

 to a white heat. He states that it also seems necessary to assume 

 a contact with some other body, as well as a heating, in order 

 to account for the faults. In opposition to this view by Howell 

 the faulting is believed by Brezina, according to a label in the 

 Vienna Museum, to have been the result of the impact of the 

 mass on the earth. 



Bent plates. — These are somewhat allied to faults, there 

 having been differential motion in the mass, but not a sufficient 

 amount to produce fracture. Naturally, they are to be noted 

 only in the iron meteorites. Carlton, Glorieta Mountain, 

 Jamestown, Ranchito, and Toluca are some of the meteorites in 

 which they have been observed. The bent plates appear upon 

 an etched surface as curved Widmanstatten figures. They 



