^LMEs"""! ■ A<^E OF THE SHOPS. . 19 



veuted the free growth of the lower part of the trunk, stunted the tree 

 and caused the growth of the eucircliug excresceuce, and that the roots 

 of the tree have not, since the quarrying- operations ceased, grown suf- 

 ficiently to penetrate to any extent the mass of flinty refuse surround- 

 ing the island of original ground. If these indications give a correct 

 impression of the sequence of events, the quarry work was done during 

 the lifetime of this tree, which is now probably not more than loO years 

 in age. 



The appearance of freshness in the deposits of flakes and failures 

 does not favor the idea of great age. Many of the shops are so well 

 preserved and the flint refuse so white and so free from weathering 

 that a long period can not have passed since the work was done. The 

 oldest tree actually growing on or in the quarry shop refuse is not over 

 75 years in age. It is j)0ssible that the flinty refuse remaining long free 

 from soil did not encourage the growth of vegetation, so that trees grew 

 only on the spaces between the pits not deeply covered with flint; and, 

 again, the accumulations of leaves and small growth in the pits may 

 have caused the destruction of the young forest trees by affording fuel 

 to forest fires. At any rate we shall have to use with much caution 

 the argument against great age, based on the growth of large forest 

 trees only on the spaces between the pits. 



Having considered all points, I am strongly impressed with the belief 

 that the period of occupation was not very remote, and that the last 

 work done may come to or very nearly to the occupation of the region 

 by the white man. It is not impossible that a study of the inhabited 

 sites along the neighboring streams may in time yield data for deter- 

 mining something with respect to the period and to the peoples by 

 whom the quarry work was conducted. 



