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BUREAU OF AMERICAN ETHNOLOGY 



[BULL. 60 



in the hand simpi}', or with a light haft attached, in the work of 

 breaking up the fragments and in trimming them down to the 

 desired contour. Most of the stone is a tough kiva, and the periph- 

 eries show the usual evidences of battering. 



It is well known that the ancient dwelling sites of the general 

 region, including the Valley of Mexico, are strewn 

 Flake Knives with countless knives which have been derived by 



fracture from faceted cylindrical nuclei, partially 

 exhausted specimens of which are widely distributed, and evidence of 

 the getting out of these nuclei Avas to be expected on the quarry site. 

 Examination developed the fact that here the rejectage deposits 

 abound in abortive nuclei (fig. 97), Avhicli were re- 

 Makfn"- ^°^ ^^^^^^ jected because lacking in some of the qualities neces- 

 sary to successful flake blade-making. It was re()uisite 

 that the material should be fine-grained, flawless, and uniform in tex- 

 ture; the shape had to be roughly cylindrical, and it was essential that 





Fig. 95. Section of the great deposit of ilakage, obsidian mines, Mountain of the Knives, 



Mexico. 



one end should be smoothly S(|uared olT. so that the flaking tool would 

 have the proper surface for receixing the stroke or other form of im- 

 pact required for removing the long slender blades. Of course, the 

 flake kni\"es were not made on the quarry site, as the edges of the 

 blades were so delicate that transportation would have subjected them 

 to injury; therefore the selected nuclei were carried away, and the 

 knives made by expert workmen, whenever and wherever they were 

 required. It is impossible to form even an approximate estimate of 

 the number of successful nuclei produced and carried away, l)ut the 

 product of the work on this site must have been enormous. Examples 

 of tlie exhausted cores found widely distributed over the Valley of 

 Mexico are shown in figure 98. 



