104 
GEOLOGY. 
The Paparoha chain, and its continuation to the north of the 
Buller (the Papahaua range), are of great practical interest, 
because it is amongst them that we meet with highly valuable and 
extensive coal-fields, of which the Grrey river, shortly before it 
reaches the sea, has exposed a magnificent section, to the ex¬ 
amination of which I devoted some considerable time. The 
Paparoha central range is surrounded by granites of very various 
character, and itself consists of gneiss, mica slates, eklogites, 
quartz schists, and sandstones, which seem to occur in the centre 
of the chain, the whole cut through or otherwise associated with 
traps, amphibolites, and dioritic porphyries. 
The Davy mountains, of a younger formation, lie on the south¬ 
western side of the granite, which, near the Mico Cliffs, reaches the 
sea; they strike north and south, w r ith a dip towards the east and 
w r est, forming a fold, and exhibiting near the Grrey, where the 
range slopes down, a qua-quaversal dip. This range has been de¬ 
nuded in the upper part of the fold, and the strata underlying 
the coal-bearing formation are exposed, of which, having an oppor¬ 
tunity of examining them on the coast, I shall speak in the sequel. 
It is evident that the disturbing force which threw the strata 
towards the west, thus forming the arch or fold, has been exer¬ 
cised by the granite on the eastern side of the Davy mountains, 
as well as by the eruptive rocks which have invaded the strata, as 
for instance the dioritic porphyry near the Kokiwi river. 
An almost complete section of the coal-bearing and overlying 
strata is exposed on the banks of the Grrey, of each of which the 
following table gives the approximative thickness only, with the 
exception of the coal seams, wTiich I carefully measured. 
A. Ferruginous sandstone (grindstone) with concretions of clay iroi 
stone. 
B. Clays, brown and dark grey, occasionally bluish . 
C. Ferruginous sandstone, like A. 
D. Brownish yellow clays, with mica . . . ] 
E. Calcareous sandstones, changing into grits, the latter with sma 
seams of shale. 
F. Seven small seams of coal, from four inches to sixteen inches' wit 
shales and micaceous grits between 
G. Micaceous sandstones and grits, with small seams of coal an 
trees changed into coal .... 
H. Main seam of homogeneous pure coal at the eastern side of thefol 
And at the western side 
L Grits, often very micaceous, often coloured by carbonic' matter 
H. beam ot impure shaly coal .... 
L. Grits, layers of very micaceous slaty sandstones and coal, th 
latter probably derived from driftwood . 
M. Coalseam.. 
N. Grits and shales, with some layers of mica 
O. Coalseam .... ... 
B. Grits and shales . 
The w orked i int 1 o 0 it eam ’ V6ry muck cra ' ck edthickness’ as far as ! 
FT. IN. 
255 0 
160 0 
70 0 
60 0 
120 0 
9 0 
21 0 
12 7 
17 2 
190 0 
4 0 
80 0 
1 2 
5 0 
4 6 
15 0 
12 1 
