As The Quartz Insensibly Passes Into The Sandstone, It Seems Probable That The Former Owes Its Origin To The Sandstone Having Been Heated To Such A Degree That It Became Viscid, And Upon Cooling Crystallized.

While in the soft state it must have been pushed up through the overlying beds.

In many parts of the island the bottoms of the valleys are covered in an extraordinary manner by myriads of great loose angular fragments of the quartz rock, forming "streams of stones." These have been mentioned with surprise be every voyager since the time of Pernety. The blocks are not water-worn, their angles being only a little blunted; they vary in size from one or two feet in diameter to ten, or even more than twenty times as much. They are not thrown together into irregular piles, but are spread out into level sheets or great streams. It is not possible to ascertain their thickness, but the water of small streamlets can be heard trickling through the stones many feet below the surface. The actual depth is probably great, because the crevices between the lower fragments must long ago have been filled up with sand. The width of these sheets of stones varied from a few hundred feet to a mile; but the peaty soil daily encroaches on the borders, and even forms islets wherever a few fragments happen to lie close together. In a valley south of Berkeley Sound, which some of our party called the "great valley of fragments," it was necessary to cross an uninterrupted band half a mile wide, by jumping from one pointed stone to another.

Enter page number Go  Previous Next
Page 302 of 776
Words from 80903 to 81174 of 208183