COMPOSiTION AND TEXTURE 105 



occur, but the first two types are nevertheless very clearly marked in the 

 general structure. The Wickelkamazit frequently, though not always, 

 produces a merely local swelling of the coarser bands. Taenite in jagged, 

 irregular, and occasionally interrupted lines surrounds the kamacite of 

 all types (see plate 7, figure 1). The plessite is of the structureless 

 variety {Fleckiger plessit). 



NE UMA NN LINES 



The kamacite bands when etched to any considerable depth reveal 

 beautiful Neumann lines (Schraffirter Kamazit)^ as shown in plate 7, 

 figure 4. 



REICHENBA CH'S LAMELLjE—SCHREIBERSITE 



The schreibersite, which is prominent on etched surfaces by reason of 

 its brilliant luster and its great susceptibility to oxidation, is arranged 

 in rather distinct lines within the kamacite ( Reich enbach's lamellse). 

 Always enveloped in kamacite, the largest area within the principal sec- 

 tion (see plate 7, figures 1 and 2) has a wide aureole of kamacite about 

 it. Being at the front surface of the meteorite, its fusion on one side has 

 produced a noticeable depression on that surface. The hardness of this 

 mineral was at the limit for the band saws used in cutting, even small 

 areas of schreibersite sufficing to break them, and the hardness and 

 brittleness were, moreover, serious obstacles in the way of securing well 

 polished surfaces for etching. The analysis shows that schreibersite com- 

 prises about 1 per cent of the entire mass of the meteorite. The mineral 

 is developed in relatively thin plates, often of considerable size. The 

 one which figures in all the sections (see plate 6, figures 1, 2, and 3) was 

 also encountered in the saw-cut which extends partly through the me- 

 teorite at a distance of 2 to 4 centimeters from the sawed end (see e e, 

 figure 2), and must therefore have been not less than 82 or 4 centimeters 

 in length. The small branches of this crystal exhibited in plate 6, figure 2, 

 conform to the Reichenbach lines. 



The fractures noticed on the front surface of the meteorite are seen in 

 section on the forward margin of the etched surfaces as local^, small 

 dark lines extending into the mass for a depth of 1 or 2 millimeters. 

 These are evidently filled with an oxidation product (perhaps the 

 ^' Eisenglas ^^ of some authors). 



Owing to the markedly swollen character of the kamacite bands ( Wul- 

 stiger Kamazit), it is difficult to determine whether any slight distortion, 

 such as would be induced by bending of the disc, has occurred. It can 

 hardly have been more than a few degrees at the most, since the general 

 direction of the bands is well maintained across the section. 



XV— Bull. Geol. Soc. Am., Vol. 14, 1902 



