809 



a. the 'available data do not justify ns in separating a group of 

 older melaphjres from tiie so-called anibonites; 



h. there is no reason for classing as a separate group the anibonites 

 which present some typical characteristics, as regards their age. 



c. together with the locks with a vitreous crust of Timor and 

 the accompanying rocks they should be included under one group 

 of the same probably tertiary or young-mesozoic age, assumed by 

 Verbeek ') for some of these rocks. 



We conclude, then, that the so-called "young-meso-voicanic igneons 

 rocks" are, also considered by us to he of tertiary or young-mesozoic 

 aye, but most likely the number of rocks to be brought together 

 under (his group may be much larger. 



It may also be stated that andesitic to basaltic and augitic rocks 

 of islands of the Misool-archipelago are held by Wanner*) to belong 

 to the cretaceous system. 



Ad 5. 



It has been suggested of the tertiary igneous rocks that their age 

 in the Moluccas and in Celebes nowhere goes back to the eocene, 

 since the nummulitic limestones are entirely devoid of debris of 

 andesites, which on the contrary occurs abundantly in the miocene. 

 rocks. 



In the following pages we will comprise the Southern part of 

 Central Celebes, because recent investigations have furnished us with 

 important data concerning the age of tertiary igneous rocks. 



That the leucite- and nepheline rocks are not the oldest tertiary 

 igneous rocks, as Verbeek ^) presumed, because the volcano Lunis 

 in Besuki (Java) consists of an older rim of leiicite-basalt with a 

 younger cone of hornblende-andesite, appears from the following 

 considerations : 



<i. Close to the east of the Gg Lurus, leucite-free rocks are found *) 

 side by side with leucite-bearing rocks in the old craterwall of 

 the Gg Ringgit composed of leucite rocks. These leucite-free rocks 

 (olivine- and basalts rich in iron ore, olivine-poor basalts or olivine- 

 bearing augite-andesites and ampliil)ole-augite-andesites) must there- 

 fore be older than a great part of the leucite I'ocks. 



1) R. D. M. Verbeek. Molukken Verslag. 1. c. p. 360. 



') J. Wanner. Beitr. zar Geol. Kenntniss der Insel Misol. Tijdsclir. Kon. Ned. 

 Aardr. Gen. XXVIl. 1910. p 194. 



3) R. D. M. Verbeek. Molukken Verslag. 1. c. p. 757. 



*) H. A. Brouwer. Ueber leucitreiche bis leiicitfreie Gesteine vom Gg. Beser 

 (Ost Java) Central Blatl f. Min. etc. 1914. p. 1. 



