GEOLOGY. 
107 
rocks terminate, the formation for half a mile is obscure, the 
country consisting of low wooded hills, covered with boulders and 
till. \V e then again reach the Davy mountains, the declivities of 
which slope abruptly to the sea shore, and the following strata 
are exposed, taken in descending order, and travelling northward: 
a sandy clay, whitish yellow, with concretions of clay iron-stone 
and iron pyrites, assuming as we advanced more the character of 
an argillaceous sandstone, of a reddish colour, resembling a 
Keuper sandstone, and being from fifty to sixty feet thick. In 
this sandstone I found the cast of a monotis. This was succeeded 
by a very compact greenish flaggy limestone, from 100 to 120 
feet thick, sometimes silicious, with remains of crinoideans. Then 
a band of carbonaceous shale, often assuming the character of an 
impure coal, and about four feet thick. Delow this seam lay a 
conglomerate, or rather a pebble bed, at least 400 feet thick, con¬ 
sisting of well rounded pebbles, seldom larger than the fist, of a 
green compact sandstone, which constituted the greater part of 
the conglomerate, with occasionally pieces of quartz and jasper, 
but without any traces of plutonic or eruptive rocks. These peb¬ 
bles were embedded in a white quartzose sand, the particles of 
which, although not cemented, cohered strongly, and formed here 
and there, where free from pebbles, bands from three to four feet 
of a white sandstone, consisting purely of small crystals or grains 
of quartz. All these beds have been very much disturbed, 
exhibiting various large faults, by which the strata have been 
dislocated vertically for at least 200 feet. 
At the mouth of the Wai-a-whenua this conglomerate pre¬ 
dominates. In the bed of the river I found grit, shale, and pieces 
of coal, which, on ascending the river for some distance, became 
more frequent and angular. It was evident that the coal-bearing 
strata, which near the sea had been denuded, still existed here, 
forming, about a mile up the river, where the mountain began to 
rise considerably, very steep walls ; but my time was too limited 
to permit of my ascending further to examine them. 
From this point to Maukurinui, lying in the centre of the Davy 
mountains, a distance of three to four miles, the strata were very 
much disturbed, exhibiting numerous flexures and faults, so that 
it required the greatest care to reduce into order their apparently 
confused condition. The strata below the above described con¬ 
glomerate, consisted of a sandstone, in stripes, from a foot to 
sixteen inches thick, of a greenish and bluish grey. colour, the 
green being arenaceous and the others argillaceous, giving to the 
rock a ribbon-like appearance. Amongst these bands appeared 
now and then small beds of conglomerate, with pieces of drift¬ 
wood changed into coal; total thickness, several hundred feet. 
A bluish clay slate, with slaty cleavage,_ twenty-five feet, un¬ 
derlaid by a very compact sandstone, which, in its upper part, 
is of a more greenish colour. Towards the centre of the chain 
