1149 
neogene ingression the central part of the island must have been 
subjected to continual upheavals, for only in this way could it 
Balaméa agar O Bangucy 
7:8000 000. 
Batoe Tpenagel 
Er # ONE Nt Aiham Helo + 
+ Oedjoe Hatlang 
pads Ge Sey 
Ve Np BaloeNverrp. SEAT 
: ys eo ONS oe he + SI 
bret reien 27° 5 4 Kiks 5 meyers ty LAP GRAMZOPZ. 
bal, Gino mtD. lnedy 
° 
¢ 
> ° 
a had 
9 E 
6 d 
3 qQ 
3 
ed 
° 
a 
3 
x 
+ Oligomiocene limestones. 
Central core not or only partly covered by the sea during the most significant 
neogene ingression. 
procure the incredible masses of detritus which were required for 
building up the neogene deposits in the East, the South-East, and 
the North-West, which are several thousands of metres thick and 
which during ‘their deposition, when they had not yet been pushed 
up by the latest folding-process, covered a much larger area than 
at present. In the neogene period, therefore, the old centre of the 
land of Borneo was a very pronounced geanticlinal region, whereas 
the marginal zones in the N.W. and S.E. were true geosynclines. 
It is probable that the material of the recent deposits in the eastern 
syncline came from the West, i.e. entirely from the old Borneo 
