QUATERNARY DEPOSITS OF BRITISH ISLES BROOKS. 355 



all the Neocene beds of [Mount Dore ; they are angular and sometimes 

 striated and polished. A. Michel-Levy considered the formation to 

 be glacial, but it is not a true moraine. M. Boule considered it to be 

 a volcanic agglomerate, but Haug believes it to be similar to the 

 palagonite formations of Iceland formed during the melting of 

 glaciers by volcanic eruptions. The mammalian fauna closely re- 

 sembles that of the Val d'Arno in Italy — Ursus arvemensis, Machae- 

 rodus crenatklens^ Hipparwn sp., Eqwus sfen^onis, Taplrus arver- 

 nensis, Rliinocei^s etruscus^ Bos elatus^ Mastodon arvemensis, Ele- 

 phas priTnigenius {?). The liorizon seems to be Gunzian. 



To the same horizon belong the Mastodon sands of le Velay, in 

 the Loire Valley, formed when the river lay much above its present 

 level. These consist of 100 meters of sands, with cold diatoms and 

 temperate higher plants. The sands contain several basaltic flows 

 find agglomerates. The fauna is similar to that of Perrier, but in- 

 cludes also Rhinoceros Icptorhinus, Hyaena, and Mastodon horsoni, 

 while A. Laurent and Broquin found at Crozas (Llaute Loire) asso- 

 ciated with the two species of Mastodon, a molar of Elephas primi- 

 genius. 



In the Perrier Valley this formation is overlain by the " sub- 

 basaltic alluvium " of Cantal and Velay. Near Puy M. Boule found 

 in a fine gray bed overlying the coarser Mastodon sand^ Machae- 

 rodus saimellei. Hyaena hrevirostHs, Equus stcnonis, Rhinoceros 

 etruscus. Hippopotamus major, Cervus pardinensis. Bos elatus, and 

 Elephas meridionalis. The presence of Hippopotamus indicates a 

 temperate climate, but the fauna shows the beds to be still early 

 Quaternary, so that the " subbasaltic alluvium " must fall in the 

 Gunz-Mindel interglacial. 



These alluvial deposits are overlain by immense flows of plateau 

 basalt, in which the later Quaternary valleys are deeply cut. On this 

 sheet of basalt in the Cantal rest the oldest undoubted glacial remains, 

 those of the " plateau glacial " of M. Boule. It is very well developed 

 in Cantal and on Mount Dore, but there is no trace of it in Velay. 

 The plateaus are covered by thousands of small roches moutonnees 

 often striated, and with erratics on the lee side. No moraines have 

 been found, but to the west, near Bort, are fluvio-glacial terraces 200 

 meters above the Dordogne. 



In this old glacial level, the valleys of the Dordogne, the Cere, and 

 all the great valleys of the Plateau Central, were cut during the fol- 

 lowing interglacial. In river deposits in these valleys in the 

 Auvergne are remains of Arvicola sp., Equus cahallus, Rh. Merchi, 

 HippopotaTnus ampTiihius, Cervus eXaphus, C. intermedins, C. soli- 

 hacus, Megaceros, Bison prisons and Elephas cf. meridionalis. In 

 the valleys of the Jordanne and the Cere, in the Cantal, P. Marty 

 and M. Boule have described very fresh lateral and frontal moraines 



