BORNEO 217 



with them a tolerably advanced civilisation, as we can see 

 from Pigafetta's description, their influence did not pene- 

 trate far into the interior. 



3. Geology and Physical Features. 



Borneo in pre-Tertiary days exhibited a very different 

 configuration from that of the present time. It consisted 

 almost certainly of a mass of islands, now represented 

 by the central range, Kinabalu, the Sarawak and 

 western districts, the Tana Laut Mountains, etc., which 

 in geological structure resembled the islands of Bangha 

 and Blitong. In his work on the geology and minera- 

 logy of Borneo, Dr. Tbeodor Posewitz remarks that in 

 this ancient archipelago crystalline scliists played on]}' 

 a subordinate part. " The rocks belonged mainly to 

 the ' Old Slate Formation ' of Devonian age, and in the 

 northern portion of the islands to the Carboniferous. 

 The stratigraphical position of these strata was dis- 

 turbed by the eruption of igneous rocks, granites, antl 

 diorites. The eruption took place partly after the forma- 

 tion of the Devonian, partly in pre-Devonian times. . . . 

 Then began a deposition of sedimentary matter in the 

 seas surrounding the islands. The Eocene strata contain- 

 ing the thick coal-beds were formed, and then disturbed 

 by the eruption of andesite. Further, younger Tertiary 

 beds containing brown coal were deposited. The separate 

 islands were now united, the Tertiary beds being de- 

 posited not only between them, but also as a belt on all 

 sides. The configuration of Borneo was thus brought 

 nearer to its present shape, first acquiring a form similar 

 to that possessed at the present day by the neighbouring 

 island of Celebes. Wide arms of the sea ran far into the 



