245 
mentioned above, so that they could be slightly different facies of 
rocks of about the same age. 
In the valley of Wai Nief these white, grey and reddish limestones 
and marls, in which sometimes layers and nodules of hornrocks 
are found, are clearly visible on both sides of the river with a 
rather regular dip to the south-west. These rocks, from a provisiory 
examination of some samples by Dr. L. Rurrmn, appeared to contain 
chiefly various Globigerinidae and some of them also Pulvinulina 
ef. tumida Brady. Although from the examination of these few 
samples the age of the formation could not be fixed beyond doubt, 
Dr. Rutten writes to me that the material examined seems to him 
to be positively of tertiary age, probably post-eocene. This formation, 
at the base of which oolitie limestones are found, is denudated over 
a surface of some square km.; it is entirely surrounded by flysch- 
rocks and is occasionally covered by them. In close connection with 
these flysch-rocks brownish-red radiolarites and basic eruptive rocks 
occur, this fact indicating a chaotic tectonic structure‘) contrary to 
the rather slight folding of the tertiary rocks mentioned above. 
Methanegases and oil emerge from the limestones and marls, as 
well as from the surrounding flysch-rocks. By supposing the flysch 
to be overthrust over the limestones and marls, which are visible 
in a “fenster”, we can satisfactorily account for the facts stated 
above. The oil and the methanegases would occur primary in the 
limestones and marls or in deeper-seated rocks; and even there where 
gase or oil emerges from flysch-rocks, their original place has not 
necessarily to be sought for in these rocks’). The latter might be 
true for East-Ceram as well as for the mud spring on the isle of 
Mitak of the Tenimber-group. 
In Western New-Guinea normally folded Tertiary, as far as is 
known, occurs without mesozoic cover, and the limit of the over- 
thrust mountain chains might then, in connection with the occurrence 
of a “fenster” of rather slightly folded Tertiary rocks in Kast-Ceram, 
be sought to the east of this island, under the surface of the sea. 
On the east coast of Groot-Kei I occasionally found sandstones 
and iron-bearing rocks with mesozoic features, of which the tectonic 
relation with the tertiary limestones and marls has not yet been 
explained, the overthrust mountain chains might continue over the 
Tenimber islands and Babber to Timor. 
1) J. WANNER. Triaspetrefakten der Molukken und des Timorarchipels. Neues 
Jahrbuch für Min. ete. Beil. Band. XXIV, p. 173. 
2) In East-Ceram, at present, some boring is being done in the limestones without 
flysch cover, that are denudated in the valley of the W. Nief. 
