776 
The large island of Jamdena of the Tenimber-group consists — at 
all events in part — of mesozoic rocks. As regards the Kei-islands 
we found there only in one spot of small extent near the east coast 
amidst limestones of eocene age mica sandstone and ferriferous rocks, 
strongly resembling mesozoic rocks. *) 
The eocene in. Groot-Kei is not folded intensely; the miocene is 
not folded at all.?) More to the west the strata seem to be folded 
more intensely, for in a new island near Ut (Klein-Kei-group) 
contorted, about vertical strata of probably eocene limestone were 
found. The tectonic relation of the above-mentioned mica sandstone 
and ferriferous rocks to the widely spread tertiary limestones and 
marls in Groot-Kei, has not been explained yet, neither is it possible 
yet to fix the eastern limit, once reached by the overthrusts of the 
Timor-Ceram curve near the Kei-islands. Perhaps here also the 
overthrust mountain-range has already made an outward bend; 
the old-miocene of Groot-Kei however lies about horizontal. 
The Aru-islands. 
These islands form a small elevation inside and near the border 
of the tract which we consider to be the “Vorland”. They may 
perhaps also be considered as bulges similar to those which are 
elsewhere believed to result from the pressure to which the most 
exposed part of the “Vorland” is subjected. 
On the occurrence of rocks older than Permian rocks. 
In the Western Alps the central parts of the chain are formed by 
a series of autochtonous massifs (Mercantour, Montblanc, Aar Massif 
and others) which belong to the ancient hercynian mountains. Part 
of the overthrust sheets was pushed over these massifs and deposited 
north of them. For Australia the equivalents of the hereynian folding 
of Europe are known, but nothing is known for certain in this respect 
for the curving rows of islands under consideration. In the large 
island of Timor, which has been pretty well explored, we have no 
certainty about older rocks than those of Permian age, and MoLENGRAAFF 
says about this island: ““The Fatu sheet is like the Tethyssheet, 
composed of rocks ranging in age from Permian to Eocene and 
probably to Miocene”. 
Indeed, so-called “old slate rocks’ occur in numerous islands. 
1) H. A. Brouwer. Geologische verkenningen in de oostelijke Molukken. Verh. 
Geol. Mijnb. Gen. 1916, p. 47. 
*) R. D. M. VerBreK. Molukken Verslag. loc. cit., p. 501. 
