808 



and cordierite, recognised in rocks of Ambon, originate from the 

 substratum, while the considerable amount of bronzite tjpefies the 

 ambonites, it is true, so that they are designated by a separate 

 name, but this does not necessarily point to a difference in age. 



In discussing the "oid-meso-volcanic igneous rocks" we have 

 already observed that a great number of the rocks of this group 

 may very well be looked upon as a much younger, young-mesozoic or 

 tertiary formation. We alluded tirst of all to the melaphyres, some 

 with a vitreous crust, of Ambon, Kelang, Wetter and Timor's 

 northcoast and the quartz-porphyries and dacites of the same coast. 

 Whereas Vehbekk does not separate the melaphyres of Timor and 

 asserts this to be a reason for surmising that melaphyres of various 

 ages occur in the eastern archipelago, and that, for example, in 

 Ambon the melaphyres can be divided into two groups, I on the 

 other hand feel inclined to class together the rocks of Ambon and 

 to sepaiate in Timor an older group (among which the permian 

 melaphyres) from a younger (among which the rocks with the 

 vitreous cnist of the northcoast). 



The mela|)hyres with a vitreous crust of Timor's north coast, 

 namely, are of a totally diff'erent character and appear under totally 

 diff"erent conditions, from the permian melaphyre-like rocks of the 

 island. The former are limited to the north coast and united as one 

 whole with other basic and also with more acid rocks (quartz- 

 porphyries, dacites) presenting a great similarity to the known Ambon 

 rocks. A typical feature for instance is the occurrence of melaphyres 

 with vitreous crust, common to the rocks of either island. The glassy 

 Java melaphyre, which Verbkkk invariably called cretaceous^), but 

 now considers to be older with reference to the data from Timor, 

 can, oil this basis, be comprised again among the cretaceous system, 

 and the rocks of Timor's north coast. Wetter, Ambon and South- 

 West-Ceram can for the present be all assigned to the tertiary or 

 young-mesozoic rocks. To this it may be added that Martin ') adopts 

 a probable tertiary age for the rocks in Ambon. 



When summarising the above we arrive at the following con- 

 clusions: 



') R. D. M. Verbeek and R. Fennema. Geologische Beschrijving van Java en 

 Madoera, Amsterdam 1896. 



') K. Martin. Einige Worte über den Wawani. sowie iiber Spultenbildungen 

 und Strandverschiebungen in den Molukken, Tijdschr. Kon. Ned. Aardr. Gen. XVI. 

 1899. p. 709 seqq. 



Ibid. Reiseu in den Molukken. Geol. Teii. Leiden. 1903. Nachtrage. 



