PLEISTOCENE CAVE-DEPOSITS. 105 



CHAPTER VII. 



CAVE-DEPOSITS OF THE PLEISTOCENE PEEIOD — Continued. 



Bone-caves of Belgium — The Trou Magrite — Contrast between lower and upper 

 deposits — Trou de la Naulette — Human bones associated with, remains of 

 extinct animals — The Cavern of Goyet — The Trou du Frontal — Age of sepul- 

 chral cavity — Caves of Germany and France — General conclusions as to 

 caves — Evidence of progress during Palaeolithic Period — Reindeer period in 

 Belgium and France — Cold climatic conditions during the closing stage of 

 Palaeolithic Period — Alternations of genial and cold climates in earlier stages 

 of same period — Break between Palaeolithic and Neolithic Ages. 



In the valley of the Lesse, nearly all the caves occur towards the 

 middle of the escarpment at a height of between 65 feet and 

 115 feet (20 and 35 metres) above the river. One of the most 

 important is the Tron Magrite at Pont-a-Lesse. The deposits 

 in this cave consist of a basement-bed, eight feet thick, of gravel 

 and water-worn stones, over which comes the usual stratified 

 silt, containing intercalated with it four distinct layers of broken 

 bones, which evidently represent the dioris or refuse strewed 

 over the floor at so many successive periods when the cave was 

 tenanted by man. The stratified silt that separates one refuse- 

 heap from another indicates, on the other hand, the occurrence 

 of so many inundations by which the human occupation of the 

 cave was interrupted. 



There are some remarkable differences between the lower 

 and upper "floors." In the former, remains of the extinct 

 animals are very numerous, while in the latter they are less so, 

 those floors being characterised by the abundance of bones of 

 reindeer and horse. Again, the stone implements in the lower 



