prestwich joseph step forward determining (1 risultati)

Soft cover. Condizione: Very Good.  Prestwich, Joseph. ++A Step Forward in Determining the Great Antiquity of Man++"Theoretical considerations on the conditions under which the (drift) deposits containing the remains of extinct mammalia and flint implements were accumulated, and on their geological age. - On the Loess of the valleys of the South of England, and of the Somme and the Seine." London, Taylor and Francis, 1862 Extracted from the Philosophical Transactions. Pp 2447-309, with two geological maps (in color). VG, crisp copy. "In 1859 Prestwich began investigating claims made in France concerning the occurrence and age of shaped flints and bones of extinct mammals found by Boucher de Perthes in the valley-gravels of the Somme. Prestwich confirmed these claims and showed conclusively that the flints were man-made implements; that they were made when now-extinct mammals were living; and that the implements and bones occurred in, and were contemporaneous with, deposits laid down at an early stage in the development of the valley and were thus of an age to be measured in tens of thousands, if not hundreds of thousands, of years. Prestwich was thus the first authority to confirm Boucher de Perthes's evidence for the remote antiquity of man. In connection with this work Prestwich eventually demonstrated that rivers produce the valleys in which they flow, showing, in particular, that river terraces are normal features of valley development." Encyclopedia dot com.