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NEW METEORITES. 



BY OLIVER CUMMINGS FARRINGTON. 



AHUMADA 



This meteorite was found in the spring of 1909, 60 miles east of 

 Ahumada, State of Chihuahua, Mexico. The latitude and longitude of 

 this locality are 30° 40 N., 105 30 W. Nothing is known of the time of 

 fall of the mass. Although extended search was made in the region for 

 other masses, none was discovered. Through Mr. Lazard Cahn the 

 single mass found was procured entire by the Museum (Mus. No. 

 Me 780). Its weight was 1 16 lbs. (52,548 grams). The general shape of the 

 mass is irregularly ovoid, its longest diameter being 17 inches (43 cm.) 

 and its diameter at right angles to this 10 inches (25 cm.). The surface 

 is irregularly roughened and pitted, but was probably somewhat modi- 

 fied by weathering. The meteorite is an iron-stone composed of a 

 spongy mass of nickel-iron the pores of which are filled with chrysolite. 

 In weathering, the chrysolite has yielded first so that the metal projects 

 in points and ridges. Some portions of the surface appear to retain 

 pittings produced during the aerial flight of the mass but these may be 

 due to weathering. The general appearance of the mass is shown in 

 Plate I, Fig. 1, and the appearance of a section in Fig. 2 of the same 

 plate. The meteorite is a pallasite of Brezina'sRokicky group, and 

 is the first iron-stone meteorite thus far reported from Mexico. The 

 chrysolite of the meteorite is dark, nearly black in color, and as it appears 

 in sections occupies relatively greater space than the nickel -iron. Some 

 of the chrysolite masses are of large size, one noted being 1 inch (2.5 cm.) 

 in diameter. Their outlines as seen in section are nearly always angular 

 rather than rounded although some are irregularly rounded. Still the 

 angular character of the chrysolite is not so strongly marked as in Eagle 

 Station for example and the meteorite, so far as this character is con- 

 cerned, may be regarded as more or less intermediate between the Kras- 

 nojarsk and Rokicky pallasites. While the chrysolite of the interior is 

 dark and opaque, on the outer border of the meteorite, where it has been 

 exposed to weathering, it is reddish brown. In small grains it is trans- 

 parent and colorless to smoky green. Penetrating the substance of the 

 grains, at times irregularly and again in more or less parallel layers, a 

 black, opaque substance may be seen. The presence of this undoubtedly 



