2c;6 THE ANTIQUITY OF MAN IN TASMANIA. 



features into those of the present day. A rise of the sea 

 level of 300 feet would be svifficient, and assuming the 

 rate to be 3 feet per century, altogether 10,000 years 

 would be required. According to my estimat-e 60,000 

 years would have lapsed since the end of the glacial 

 (Wurmian) period. This figure agrees remarkably well 

 with those obtained elsewhere. It is estimated that 

 56,000 years lapsed since the end of the glacial period in 

 America. The German geologist Penk estimates that 

 50,000 years rather than less have lapsed in Europe; 

 others, like Hildebrand, estimate the time to be 30,000 

 years. However, it seems to be pretty certain that not 

 less than 24,000 years, but probably not more than 

 60,000 years, have lapsed since the end of the last glacial 

 period. 



The last 10,000 years of this period witnessed tremen- 

 dous changes in Tasmania — those changes which are re- 

 sponsible for our present-day features. They must have 

 commenced wath a subsidence of the surface between 

 39deg. and 4ideg. southern lat. and I45deg. and I46deg. 

 long. It is not only probable, but pretty certain that this 

 catastrophe was accompanied by earthquakes and vol- 

 canic eruptions. All along the northern coast of Tas- 

 mania we find the remains of lava streams. Though 

 some of them seem due to local eruptions, others cannot 

 have possibly come from the south — i.e., Tasmania; 

 their origin miust be in the north, where Bass Strait is 

 now. For instance, the cap of basalt on Freestone Blufif, 

 near Wynyard, must be considered as a rest of such a 

 stream. 



We have another remarkable proof that the first area 

 of subsidence as represented by the 45-fathom line must 

 be connected with volcanic eruptions. We see that all 

 the younger volcanic rocks of the Midlands and 

 Southern Tasmania are situated on a line which forms 

 the southern continuation of the main axis of the trough 

 formed by the 45-fathom line. (See PI. II., Fig. 3.) It is 

 perhaps probable that a fissure, resulting from the 

 squeezing up of Tasmania gave first rise to these vol- 

 canic outbursts. 



The lava streams of the great volcano in Bass Strait 

 which flowed towards south blocked the course of the 

 rivers flowing north, the water was dammed up and be- 



