BY FRITZ NOETLING, M.A., PH.D. 105 



1913. 



also absent. Accordingly the rock is considered a Basalt 

 in which Fayalite has replaced Augite and Olivine. 

 Whether under these conditions it is correct to term this 

 rock a "basalt"' appears somewhat doubtful to me, par- 

 ticularly when we consider that it greatly differs in its 

 structure from the true Olivine Basalt. However, it 

 would be confusing to introduce a new name, and until 

 the terminology has been revised, I prefer to use the 

 name Basalt. 



Mr. R. M. Johnston states that he obtained some bones 

 and teeth probably belonging to a small marsupial related 

 to Hi/pslprymnus in the cooling joints of an older sheet of 

 Basalt. I have shown above that w© have no reason to 

 suppose that tliere was more than one eruption, and the 

 probability that these bones are of much later age, and 

 were washed into a cooling joint, has to be taken into 

 serious consideration. As at the same time these bones 

 are very poorly preserved, and do not allow for determina- 

 tion, except a vague resemblance to a family of marsupials, 

 they might as well be left out altogether. 



But if the possibility that the bones became subse- 

 quently washed into the cooling joints could be finally dis- 

 proved, and Mr. Johnston's view become an established 

 fact, the presence of the modern genus Hypsiprymnus 

 would speak for a very recent age of the Basalt, and 

 severely shake the opinion of its Eocene a^e. 



5. Tectonical Features. 

 (PI. iv., viii., and ix.), 



A careful examination of the strata shows that the 

 leaf beds of the northern portion are slightly bent up- 

 w^ards where they abut against the fault- This is con- 

 clusive proof that there is no overthrow, as Mr. R. M. 

 Johnston assumes ; but that the northern portion has slid 

 down along the fault. Therefore, if we wish to know the 

 position of the strata before their dislocation we must lift 

 the northern portion for about 80 feet, and place it ba-ck 

 in its onginal position. 



I have attempted such a reconstruction on Plate ix., 

 but we see that if the sunken portion is lifted and replaced 

 in its original position a fresh difficulty presents itself. It 

 has been shown that the total thickness of the leaf beds is 

 much smaller in the southern than in the northern portion. 

 Therefore, if the leaf beds of the northern poi-tion are 

 really tlie continuation of those of the southern one, a con- 



