605 ' 



rone-shaped Goenoeng Pantjar, 870 in. in height, recognized from 

 afar as a typical volcano, and, indeed, indicated on V and F's map 

 as "Old Andesite". This is highly surprising as, with the exception 

 of a tew huge Andesite blocks — perhaps the outcrop of a dyke — 

 we can only descry, either round or on the mountain, bluish white, 

 more a less silicified shales, again without any trace of volcanic 

 material. Moreover we find on the western base another calcareojis 

 sandstone, built up mainly of quartz-splinters. In this rock volcanic 

 material is also lacking. The pebbly shale is so hard in some places, 

 that the natives use it as flint. In Profile II we assumed, that the 

 nucleus of tlie coniform G. Pantjar is constituted by an andesite 

 mass, occasionally also a granular crystalline rock (see notes of 

 interrogation) and that the silicified shale, a silicification perhaps due 

 to contact-metamorphism, covers the volcanic nucleus, as a mantle. 

 Two geysers on the northern slope of the G. Pantjar lend support 

 to this view. 



In the Tji Teureup as well as in a rivulet east of the G. Pan- 

 tjar loose fragments of Andesite were found, which unmistakably 

 include tertiary shale. Though it seems reasonable to look for the 

 origin of these andesite blocks in the southern massif of the "Old 

 Andesites", still it may be possible that they arise farther away in 

 the Gedeh massif. On this account their discovery is not conclusive 

 for the relatively recent date of the "Old Andesite". 



In the profile across the G. Pantjar (N°. 11) the axis of the 

 Pr. Maoeng anticline is found rather to the North of this mountain, 

 as shales sloping southward were still noted to the N.E. of the 

 G. Pantjar. In the northern arm of the anticline lies in this profile 

 the G. Hambalang which, like the moi-e eastern G. Karang, looks 

 from afar — e.g. from the road Batavia-Buitenzorg — like a plane 

 distinctly sloping northward. On the G. Hambalang the disclosures 

 of the Tertiary are few and far between, as it is largely overlaid 

 by volcanic material of a recent date. Due east from the G Ham- 

 balang the Tji Leungsi exhibits an almost uninterrupted disclosure 

 of the Tertiary. On its left bank, at one place in the youngest parts 

 of the clay-formation, a Cycloclypei-coral limestone has been inter- 

 calated, which towards the east rapidly increases'in thickness, emerges 

 there through the steep south slope of the G. Karang as a white 

 outcrop, and spreads horizontally to the North of G. Karang all over 

 the area as far as Kalapa Noengal (Profil III). These lime-stones 

 contain besides Cycloclypeus also Lepidocyclina and Amphistegina.^) 



ij At one place in the youngest part of the shale-formation the Cycloclypeus 

 lime stones are covered by peculiar felspathic sands. 



44 

 Proceedings Royal Acad. Amsterdam. Vol. XX. 



