380 Transactions.—Geology. 
flanks of Ruahine—a great area of, say seventy miles by forty, about one 
million and three-quarters of acres. 
But it is no easy matter to prove whether the coal measures underlie in 
this area or not. The upper tertiaries attain a great thickness throughout, 
and as they, doubtless, lie uncomformably on the coal measures, it would 
be very difficult at any one point to form an estimate of the depth at which 
the coal seams might be expected. 
Possibly a lengthened and steady examination of the country by a com- 
petent geologist might show some outcrops of the coal, or, what is just as 
likely, this might be discovered by accident. 
It would undoubtedly be a matter of great importance, now that the 
country is being opened by railways, to discover an extensive coal field on 
the West Coast, even should the coal be of medium quality only. It would 
probably be of similar character to that of the Waikato. 
I believe that no outcrop of the coal has been found to the southward of 
Tangarakau. It would be of importance to find it nearer the coast, even as 
far west as the line of fault; but the thickness of the upper tertiaries 
probably presents the same difficulties there as those before mentioned. 
It is by no means impossible that coal may be found on the eastern oF 
Wairarapa side of the main range. The cucullea beds are found in the 
valley of the Pahaoa River, and I think also in those of the Tauheru and 
the Whareama ; but, certainly in some cases, and possibly in all, these beds 
rest on rocks older than the coal measures, probably triassic. Still the sub- 
ject is worth investigation. 
The western line of strike and of outcrop from Tangarakau, even as far 
as the Thames, is certainly a most remarkable fracture as regards its length 
and exposure of the outcrop of the coal seams. Of course the actual out- 
crop may lie a few miles either east or west of the line, as a lengthened 
fracture of rock could hardly be in a strict mathematical straight line ; but 
the actual approximation to straightness of the line is very striking. 
One difficulty in the discovery of what exists below is that the rivers 
lying between the Whanganui and Ruahine Range, viz., the Wangaehu, the 
Turakina, the Rangitikei and its tributaries, do not cut so deep into the 
tertiaries as the Whanganui River does, therefore prima facie, an exposure 
of an outcrop of coal is more likely to be found in the vicinity of the latter 
river than of those lying further to the east. 
But the area is large, besides being densely wooded and difficult to tra- 
verse, and local dislocations inay possibly be found to expose the coal seams 
if they exist. 
Having now disposed of our local coal 
: : question, I will make a venture into 
theory and into the question of the origin of coal. The generally received 
wee 
