NO. 5 HEXAHEDRITES — HENDERSON 9 



prompted the question, "Are these irons related?" Farrington (1915) 

 said : "Early writers are inclined to group into one fall similar 

 meteorites, even though separated by thousands of miles of distance, 

 but later observations have failed to confirm this view." 



Several widely scattered large hexahedrites are known from north- 

 ern Mexico. Many of these have been sectioned and now are con- 

 sidered to be parts of the Coahuila meteorite. Thus, names given to 

 individual masses, such as Sanchez Estate, Hacienda, Potosi, Fort 

 Duncan, etc., are now relegated to synonomy, and all are collectively 

 known as the Coahuila meteorite. Farrington (1915) accepted the 

 Coahuila group as a shower and said, "In the State of Coahuila, 

 Mexico, numbers of meteoritic irons of a rare class, hexahedrites, are 

 found one or two hundred miles apart. It hardly seems likely that 

 separate falls of these rare meteorites would occur within such a 

 limited area." 



Twenty-five hexahedrites have been found since Farrington wrote 

 as he did in 1915. A number of these coincide with some of the 

 geographic groupings noted by earlier writers. Of the new geo- 

 graphic groups found since Farrington's time, the most important is 

 the Chilean group. In general, the places where hexahedrites were 

 found suggest the probability that they fell as showers. 



It is assumed that all the Coahuila meteorites come from latitude 

 28°40' N. and longitude 102°50' W., a midpoint in the scatter of 

 those specimens in northern Coahuila. Earlier writers even sug- 

 gested that some hexahedrites from Virginia, Georgia, and Kentucl<y 

 were related to the Coahuila irons. Although it is possible that the 

 hexahedrites from these eastern States are part of the Coahuila 

 shower, this study lists them as hexahedrites from southeastern 

 United States (see table 6). 



If it is reasonable for Fletcher (1890) to regard the Coahuila irons 

 as a shower, it would seem equally admissable to include some of 

 the hexahedrites found slightly north and east of Coahuila in Texas 

 and toward the Oklahoma border, as part of the same shower. 

 Since the hexahedrites in this portion of Texas are as closely spaced 

 as the hexahedrites in other geographic areas, they are grouped 

 with the irons scattered around Coahuila (see table 5). 



MECHANISM FOR SCATTERING METEORITES 



The above distribution of hexahedrites would be accounted for if 

 two or more large hexahedrites approached the earth on essentially 

 parallel trajectories. Under these circumstances the second or third 



