NOTICES OP THE GEOLOAY OF THE EAST COAST OF JOHOItE. 629 
T. Pungai and T. Kin&war are the extremities of the same hill 
range bifurcated in the usual manner, and the great difference in 
the aspect of the two points arises entirely from the difference in the 
degree of the plutonic influence to which they have been subjected. 
At the former, ferruginous emissions have predominated. Hence 
the masses of black and shining hydrous iron ores and less ironmask- 
ed rock. At the latter, the rock has merely been seamed, and at 
particular places saturated, with siliceous exhalations only slightly 
ferruginous, which have made it hard and tough, and enabled the 
more indurated portions to resist the abrasion of the sea. When a 
portion of the ironmasked Pungai rock falls down, it remains al¬ 
most indestructable, while fragments of the Kinawar ledges are soon 
broken up. To complete the contrast, at Pungai the direction of the 
Point itself coincides with the strike of the strata, at Kinawfir the 
two lines are transverse to each other. 
Tdnjong Lompdtdn . 
The rock to the south of the Point, where seen, was a very mica¬ 
ceous or talcose* shale. At one spot there were numerous iron- 
masked blocks similar in appearance to those at T. Pungai. Some 
which externally were brownish black, smooth and glossy offered when 
fragments were broken, 'the appearance of a coralline structure. 
These I find on examination to be clearly ironmasked coral, and it 
must have been such specimens that Dr. Bland described as burnt 
coral and considered as an evidence of volcanic action. A few years 
ago I should without hesitation have come to the same conclusion, 
for the appearance of these blocks is precisely that of masses of slag. 
But the transformations which the oxidation of iron effects in all 
rocks of the Peninsula in which it abounds are so great, and fre¬ 
quently so entirely assimilate them in appearance to volcanic scorisej' 
that it is necessary to separate altogether the question, how the rocks 
acquired this volcanic aspect, from the enquiry, how the cause of this 
change was itself introduced. To the first, the presence of iron in 
the”rock and its oxidation, seem, in most cases, to be the true an- 
* My specimens are mislaid or lost. 
j- Laterite has this other characteristic in common with volcanic rocks 
that it sometimes appears isolated and overlying sedimentary strata, ow¬ 
ing to the vapours and currents which produced it having most readily as¬ 
cended through fissures, and diffused themselves where the rock was most 
porous or most saturated with water. 
