/ 



148 BUBEAU OF AMERICAN ETHNOLOGY " [bull. 52 



CHRONOLOGIC BEARING 



The many hundreds of rehcs included in the collection were all 

 obtained from the surface. None are known to have held any 

 synchronous relation with the geologic formations, save with the sur- 

 face soil, the shifting sands and sand dunes, and such other recently 

 rearranged deposits as are constantly forming under the never- 

 ceasing action of wind, water, and gi'avity along the outcropping 

 edges of imperfectly consolidated strata. The chronologic order of 

 these unstable deposits is of little consequence in these investigations 

 since no sequence involving measurable periods of time can be estab- 

 lished. 



The facts that all varieties of the artifacts bear the same relation 

 to habitable sites and to the seashore of to-day throughout nearly the 

 entire region and that shapes and processes of manufacutre in all the 

 groups, though differing in certain respects, have important features 

 in common, as alread}^ pointed out, antagonize any theory of wide 

 separation of periods. 



The relation of the pebble-working sites to the coast line of to-day 

 has a most important bearing on the theory of geologic antiquity for 

 any of the relics of man's handiwork. It is seen that these sites 

 which yield such large numbers of both the dark-pebble and the 

 white-quartzite artifacts are ranged along the bluffs and slopes 

 facing the sea. But the ocean front is not a stable line. It is not 

 to-day where it was a century or a millenium ago. During the early 

 stages of the Recent period (by which is meant the time since the 

 land surface assumed aj)pr()ximately its jjresent relative altitude) it 

 probably la}' farther out to the south and east. If this assumption 

 be correct, it should he explained why the people of the auroral days 

 of this period brought the pebbles from a distant shore to work them 

 up and utilize them in the localities examined by Doctor Hrdlicka. 

 It would seem that if the pebble artifacts belong to the Recent period 

 at all, they belong to its closing phases, during which the relations 

 of the land and sea were practically the same as we find them to-day. 



Again, if the pebble-using people occupied the region during either 

 Quaternary or Pliocene time, how shall we arrange to have them 

 occupy a series of sites along the line which just now happens to 

 have become the shore of the sea between Mar del Plata and Bahia 

 Blanca ? Or are we to suppose that these people occupied the whole 

 of the pampean region so fully during any one of these periods that 

 the sea front at any and every stage of its recession toward the high- 

 land should yield to the archeologists of the time the rich harvest 

 reaped by our re])resentatives to-day? The number of specimens 

 required to stock the whole of the pampas at this rate would be beyond 

 the possibility of computation. 



