81Ü 



more elevated thick reef lias been preserved, tlioiigli it had been 

 longer exposed to the eroding forces. If at a higher level a reef- 

 cap is lacking, it is impossible to detect whether also here erosion 

 has been at play, or whether this area has been u[)lifted from the 

 sea ever since the beginning of the crnstal movements. 



It follows, then, that the influence of erosion upon the form of 

 the reefcap can be estimated only foi' the tract beneath the highest 

 reefs, which have been left intact b}' erosion. 



Injiuence of faults. 



The influence of faults on the form of reefcops is, on the whole, 

 confined to the dislocation of connected parts, which are brought in 

 various positions at different levels. Faults having played a promi- 

 nent part in the youngest crnstal movements in the eastern archipel- 

 ago, the form of the reefcaps may be supposed to have been 

 largely affected by them. Verbeek M e.g. assumes a fault across the 

 peninsula of Huamiial in Southwest Ceram, where the terraces of 

 coral limestone appear south of Luhu to the height of 350 m. above 

 sea level, while the lime more to the north scarcely leaches 100 m. 

 In the continuation of this fault we find Hatusua (the eastern side 

 Piru-bay), Paiilohi and Tehoro (on Taluti-bay), which were afflicted 

 more violently than other places by the earth- and seaquake of 30 

 September 1899, and also the steep south-eastern coast of Buru. 



When faulting takes place in the neighbourhood of the coasts, 

 downward as well as upward movements may be observed at short 

 intervals and the growth of the living corals may exert its influence 

 upon the shape of the forming reefcaps longer than usual. 



IVie inclination of the geanticlinal axes. 



In discussing the growth of the reefcaps it has been stated (hat 

 every point of a forming reef will move along curves of various 

 shapes. The horizontal component of the rate of movement, at a 

 given moment is the resultant of two directions which are at I'ight 

 angles to each other, one of which coincides with the geanticlinal axis. 



The vertical component determines the rising of the row of islands. 

 The difference in the rate and the direction of the movements at 

 different points gives rise to the morphological changes of the sur- 

 face of the geanticlines of which we shall first consider those along 

 the geanticlinal axis. 



1) R. D. M. Verbeek. Molukken Verslag, -laarb. v. h. Mijnwezen. Wet. Ged. 1908, 

 biz. 550. French ; Rapport sur les Moluques. 



