28 WAITING IN THE WILDERNESS 



"There ain't no such animal," I replied. But 

 there was in one age just such a beast. 



All one day the scientist was out with me. We 

 climbed to the top of the plateau and went to a 

 dry canon about twelve miles from camp. On 

 the way over I asked him if all fossils were formed 

 beneath volcanic ashes. He replied that many 

 were formed beneath wind-blown sand, a few in 

 caves, numbers in fissures or cracks that earth- 

 quakes make in every kind of surface rock, and 

 now and then an animal sank into a bog, swamp, 

 or quicksand and became a fossil. There are 

 many ways and places in which animals or plants 

 change to fossils but the most common place 

 is in the mud bottom of a lake or the seashore. 

 Perhaps the majority of fossils are formed in 

 the mud of river deltas below water level. The 

 water in circulating removes the animal or vege- 

 table matter of remains buried below water level 

 and deposits mineral matter in its place. Most 

 fossils thus are mineralized stone. Rarely is any 

 of the original animal or plant preserved. 



He went on to say that any record left by the 

 life of other ages is a fossil. The impression of a 

 leaf, so often seen on sandstone, a mould left 

 after a buried body decays, a track made in mud, 

 later turned to stone, are fossils. Among the 

 other things not often thought of as being fossils 

 are amber and coal. 



