CORRELATION OF THE TIME DIVISIONS 451 



Summing up this evidence, Mayet observes (opposite citation, page 4) : 



"(1) At the base of the terraces of 30 meters [= Tyrrhenian stage oJ: 

 Deperet] we find the Chellean industry with amygdaloid utensils and warm 

 fauna associated. An erosion of the upper part of this terrace of 30 meters is 

 often observed, so that the front is worn away into debris at the foot of the 

 terrace. This secondary erosion is the cause of frequent errors of calculation 

 in terrace altitudes and consequently of the age of the terrace formation 

 itself.'* (See figure 4 for cross-section of the terraces on the River Somme at 

 Saint Acheul, northern France.) 



Chelles on the Marne River (figure 5). — Here the ra vine-like erosion 

 of the gravels constituting the terrace of 30 meters and the terrace of 20 

 meters is displayed with remarkable clearness. The light-colored ancient 

 sands of the upper terrace contain the Chellean industry. The deeper- 

 colored, more recent sands of the lower terrace contain the Mousteriau 

 industry. In the photographs of the quarry sections of Chelles, especially 

 those taken in the ballastiere Trioux, the strongly undulated line of 

 unconformity marking the contact between the light Chellean sands 

 below and the dark Mousterian sands above is very apparent. 



Like other flint industries, the Chellean represents a prolonged evolu- 

 tion, divisible into three stages (compare Osborn, 1915.2), as follows: 



Late Chellean. — First appearance of Late Chellean. — Well a d v a n c e d 

 the oval coups de poing; also of long- Chellean industry at Torralba, Spain 

 pointed coups de poing, in most cases (Obermaier, 1921). Fauna includes 

 flaked on both sides, with little of the the same African mammals (hippo- 

 crust of the flint nodule adhering and potamus. straight-tusked elephant, 

 the edges still unsymmetrical. Merck's rhinoceros ) as that of the 



early Chellean, with a mingling of 

 the forest and meadow fauna of west- 

 ern Europe, including the new mim 

 moth (Elephas trogontherii) . 



Early Chellean. — First appearance Early Chellean. — Occurs on the 30- 

 of the amygdaloid coups de poing, al- foot terrace at Chelles, on the 

 mond shaped. All flint implements Somme: at Gray's Thurrock and II- 

 unsymmetrical and with sinuous ford, on the Thames. Warm temper- 

 edges. Small implements, including ate fauna, including the hippopota- 

 scrapers {racloirs), planes (grat- mus, straight-tusked elephant (E. 

 toirs), borers (percoirs). antiquus), Merck's rhinoceros (R. 



merckii), but generally lacking the 

 saber-tooth tiger (Machwrodus) , the 

 Etruscan rhinoceros (R. etruscus), 

 and other species of pre-Chellean 

 times. 



