825 



neighbouring islands could be adduced, but the foregoing sufficiently 

 shows that the evolution of the geanticline has evolved during the 

 mountain building process very irregular movements at a compara- 

 tively short distance. 



Tilting Islands. 



Among those we reckon e.g. the island of Misool, to the North 

 of Ceram. Corals are thriving well, as well on the south- as on the 

 northcoast, but elevated coral reefs occur only in the flat northern 

 part of the island, whereas they are lacking entirely along the steeper 

 south coast up to some way past the watershed. The island may 

 be said to have tilted, if we assume that the south coast has subsided 

 along the line of a fault at the same time when the north coast 

 has moved upwards. This should seem to be very likely especially 

 with the island of Misool, because Wanner') has established the 

 presence of a number of faults in the archipelago along the south 

 coast bordering on the north side of the deep sea-basin between 

 Misool and New Guinea on the one side and Ceram on the other. 

 However, similar reef-formations may also originate in another 

 way, where tilting is out of the question, because the movement is 

 not performed by the island as such, but because in the initial and 

 the terminal stage different parts of a developing geanticline present 

 themselves as islands. In Fig. 1 we have only to look upon the 

 geanticline in P\B^Q^ as the initial stage and in /^7i<^ as the terminal 

 stage. In the latter the geanticline has subsided deeper below the 

 sea-surface, but on the north coast an upraised reefcap will be 

 seen. With rising geanticlines a similar distribution of the elevated 

 reefs will also be seen, e.g. in the manner illustrated in Fig. 2. 



Fig. 2. 



In the terminal stage P'A'B' only upraised reefs will occur on 

 the north side of the new island, viz. between A' and the north 

 coast. Then the island is not merely tilted, but exhibits that part 

 of a rising geanticline, which at a certain time emerges from the sea. 



1) J. Wanner. Beitrage zur geologischen Kenntniss der Insel Misol, Tijdsch. 

 Kon. Ned. Aardrijksk. Gen. 1910, p. 498. 



