240 MEMOIRS NATIONAL ACADEMY OF SCIENCES, VOL. XIII. 



Honduras. See Rosario. 



HOPEWELL MOUNDS. 



Ross County, Ohio. 



Iron. Medium octahedrite (Om) of Brezina. 



Prehistoric; described 1902. 



Weight, 130 grama (5 ounces). 



This meteorite was described by Farrington * as follows : 



Among the objects obtained from the Hopewell Mounds of Ohio, and now in the anthropological collections of the 

 Field Museum are a number made of iron . These include a part of a head and ear ornament, some celts, a number of 

 beade, and lastly a small unwTOUght mass weighing about 130 grams (5 ounces). Dr. G. A. Dorsey, to whom I am 

 indebted for calling my attention to them, informs me that they were all found associated with a single human skeleton 

 near an altar of one of the mounds. They were considerably oxidized, so that the original metal is in most cases obliter- 

 ated, but the unwrought mass above mentioned was found to be oxidized only on the surface. A qualitative analysis 

 of some filings from this mass showed the presence of nickel, and indicated, as might be expected since no other source 

 of iron probably lay open to the Mound Builders, that the objects were made of meteoric iron. Upon removing the 

 rust from one surface and submitting the area so exposed to the etching action of nitric acid, the meteoric nature of the 

 iron was proved beyond question by the appearance of Widmanstatten figures. The nature of these figures is shown 

 by figures where the structure of bands of kamacite separated by thin ribbons of tsenite can be plainly discerned. The 

 width and continuity of the kamacite bands varies considerably. Some are at least 1 mm. in width and from these 

 they grade down to not over twice the width of the corresponding taenite ribbon. While many are continuous in a 

 general way for a length of from 10 to 20 mm. the taenite runs through them all in a series of anastomosing branches, and 

 in places gives the impression of a network in which grains of kamacite are embedded. The contour of the figures is for 

 the most part curved and wavy, especially near the borders of the section. The most reasonable explanation for this 

 seems to be the treatment probably given the mass by the ancient workmen. If heated until it became somewhat 

 plastic and then hammered, just such curving of the plates might be produced. Owing to the distortion of the figures 

 it is impossible to positively classify the iron. Apparently it is an octahedral iron having lamellae of medium width. 

 While two alloys, kamacite and taenite, are plainly discernible, no troilite or schreibersite can be seen, although the 

 presence of the two latter is indicated by the percentages of sulphur and phosphorus found on analysis. At one end of 

 the mass are three large irregular pores such as might have been produced by the falling out of crystals of chrysolite 

 or other stony matter. There is no other evidence, however, that such stony matter was at one time present and the 

 cavities may have been produced in a purely mechanical way. This seems rather the more probable from the fact 

 that the rest of the mass is quite compact. The iron is rather soft, cutting easily with a hack-saw, and malleable. It is 

 active to copper sulphate. 



For purposes of quantitative analysis a small piece was sawed from one end of the mass and cleaned from rust by 

 filing and scraping. The analysis, made by Mr. H. W. Nichols, and using the methods adopted for the Los Reyes 

 meteorite, gave the following results: 



Amount of substance taken, 2,166.3 grams. 



Fe Ni Co Cu Mn Sn S P 



95.20 4.64 0.404 0.035 Trace. Trace. 0.13 0.07 =100.48 



The other meteorites known to have been found in Indian mounds of this country are those of Oktibbeha County, 

 Mississippi, and the Turner Mounds, Ohio. In the Oktibbeha County iron the quantity of nickel reaches 59.7 per cent, 

 and this sufficiently distinguishes it from any other known meteorite. The Turner Mound meteorites include masses 

 from two different mounds, which were analyzed by Kinnicutt with the following results: 



From Mound No. 3. From Mound No. 4. 

 1 2 



Fe 86.66 88.37 89.00 



Ni 12.67 10.90 10.65 



Co 0.33 0.44 0.45 



It will be remembered that Kunz concluded from a comparison of the Turner Mounds meteorites with those of 

 Kiowa County, Kansas, that on account of the marked similarity in constitution and structure they belonged to the 

 same fall. The Hopewell Mounds are only about 75 miles distant from the Turner Mounds in an easterly direction, 

 and it might be expected that the same meteoric iron would have been used for the construction of the objects found 

 in these mounds. The results of the analysis above given do not, however, permit this conclusion, the differences in 

 the percentages being greater than are known to occur among the individuals of a single fall. Comparison of etching 

 figures is out of the question on account of the distortion of those of the Hopewell Mounds specimen, but the lack of 

 any content of chrysolite such as characterizes the Turner Mounds masses is a further point of difference. It seems 

 impossible at present, therefore, to connect the Hopewell Mounds mass with any known meteorite, and the specimen 

 will therefore be designated as the Hopewell Mounds meteorite. 



