110 
GEOLOGY. 
Some of these cretaceous cliffs, which are nearly perpendicular, 
as at the Otahu cliffs, are from 700 to 800 feet high, and consist 
of bluish chalk marls, from eight to twelve feet thick, with bands 
from two to three feet thick, of a white crystalline limestone, 
occasionally assuming a pale yellow colour, giving to the whole a 
ribbon-like appearance. In those sections where the limestone is 
found upon the granite, we observe very interesting phenomena, 
indicating that during the deposition of the limestone, great 
disturbances had taken place, either by earthquakes or by changes 
in the direction of great submarine currents. In many places the 
cretaceous rocks, limestones, chalk marls, or greensands, are seen 
lying directly upon the surface of the granite, which is sometimes 
smooth, as if by attrition, and sometimes rugged, as if acted upon 
by waves or by submarine currents. These sedimentary rocks 
frequently contain no fragments of hypogene rock, and so continue 
for twenty or thirty feet, when they assume what at first blush 
would appear to be quite a granitoid appearance. In a calcareous 
base are disseminated quartz grains, crystals of feldspar, and scales 
of mica, in such abundance, that it is necessary to examine it 
closely in order to convince oneself of its mechanical origin. In 
other places the granite is overlaid by a breccia consisting of large 
angular pieces of granite and mica schists, imbedded in a base of 
a green semi-crystalline limestone, which is besides full of quartz 
grains and mica. The greater the interval between the sedi¬ 
mentary deposits and the granite the smaller are the angular 
pieces, the limestone itself becoming more whitish. At a distance 
of thirty or forty feet from the granite, the angular pieces 
altogether cease, and mica scales are only occasionally found. 
The limestone itself begins to assume an earthy texture, and 
eighty feet from the granite changes into a chalk-marl. In other 
places, above twenty or thirty feet of quietly deposited matter, 
fresh revolutions appear to have taken place, and large beds of 
breccia, similar to those before described, again make their 
appearance. 
As far as I could judge from the boulders brought down by the 
streamlets, the granite is associated with hornblendic rocks and 
traps ; and the existence of sandstones, like those underlying the 
Grey and Buller formation, induced me to believe that the same 
rocks, as well as several metamorphic rocks, existed here, overlying 
the granite, which had protruded through them. The cretaceous 
formation leaves the coast at the mouth of the Wanganui, and 
strikes in a north-easterly direction towards the Tasman moun¬ 
tains, the detritus ol which, gneiss granite and metamorphic 
schists, is again brought to the sea by the larger streams. As 
described in the foregoing part, between the Tasman mountains 
and the sea, we again meet with the great drift formation through 
which all the different rivers have worked their way. At the north¬ 
eastern end of the Karamea plains, sandstone ranges are found, 
