( 147 ) 
youngest sediments which still have undergone folding belong to the 
Cenomanian epoch whilst the tertiary sandstone which overlies the 
tilted rocks of the range inconformably is probably of miocene age. 
One may assume that the Central-Borneo mountain range probably 
is the result of the oldest foldings of the Alpine system of crustal 
movements. 
Mesozoic Radiolarian rocks have been described from various other 
parts of the East Indian Archipelago *) e. g. from Ceram, Boeroe, 
Rotti, Savoe, Celebes, but our knowledge of the tectonic conditions of 
these islands is still inadequate, and one can only say that the presence 
of these rocks in our archipelago, which is wholly situated in the 
area of the so-called Alpine folding system, is not at variance with 
the theory outlined above. 
The upper-jurassic Radiolarian cherts of the Grisons and other 
parts of the Alps, the jurassic Radiolarian rocks of the Coast Range 
of California, and also the miocene oceanic deep-sea deposits of 
Trinidad, Barbados and Cuba, all belong to the same Alpine mountain 
system, originated during the same period of crustal movements. 
The cherts with Radiolaria of the Culm period, which are found 
for instance in the Harts mountains, in Devonshire, Cornwall etc. 
form part of a more ancient system of folding, of the Hercynian 
(variscian-armorican) mountain chain. 
The cherts with Radiolaria of the lower Silurian of Scotland belong 
to a still older system of folding i.e. the Caledonian mountain system. 
The devonian Radiolarites of New South Wales have been found 
in palaeozoic rocks probably folded in the carboniferous period. 
It is clear from these examples to which various others might be 
added, that the fossil oceanic, abyssic sediments are exclusively found 
in strata, which form part of mountain systems due to folding or 
are in any case limited to the labile portions of the earth’s crust, 
the areas of geosynclinals. 
The rarity of these rocks and their peculiar distribution are argu¬ 
ments in favour of the permanence of continents and oceanic basins, 
but with this restriction that the permanence only applies to such 
parts of continents and oceanic basins as lie outside the geosynclinals, 
therefore in favour of the permanence or rather geological longe¬ 
vity of the continental blocks in Haug’s sense. 
x ) On this the following may be consulted: R. D. M. Verbeek, MolukkenReport 
p.p. 767, 773, 803 et seq.; and K. Martin. “Ein zweiter Beitrag zur Frage nach 
der Entstehung des Ostindischen Archipels.” Geogr. Zeitschr. XIII. p. 425, 1907. 
