454 Geology of 



The seams f and h are being worked. It will be seen from thia 

 list that the large seam of 6 feet observed higher up the valley has 

 not been met with, but I have no doubt that either one of the seams 

 enumerated above enlarges further on, or that two seams will join to 

 form a thicker one. Two remarkable breaks in the otherwise regular 

 seams (sections No. 5 and 6 on plate 9), which I wish to notice here, 

 bear upon this point. In the one case the seam li continues quite 

 regularly for a number of chains in the workings on the left bank of 

 Surveyor's G-ully, after which it disappears altogether, and a new seam 

 of about 2 feet thick, separated from the former, by 1 foot 6 inches- 

 of shale takes its place, gradually thickening. It is thus evident 

 that both seams have been formed in two separate basins, the lower 

 being of course older than the upper one. A similar and still more 

 clearly denned occurrence was observed on the opposite or right bank 

 of Surveyor's Gully, when the same seam li enlarged at one time to a 

 thickness of 7 feet 9 inches with a band of shale of 2 inches in the 

 centre. However, after 6 yards, the upper seam thins out rapidly, the 

 lower one only continuing. 



Of the new ventures lately opened none is of greater interest from 

 a geological point of view than the Springfield Colliery. It is situated 

 at Kowhai corner, where a volcanic eruption of dolerites has taken 

 place, the rock forming on the summit of a nearly isolated hill a 

 crateriform rim, from which a lava- stream has run in a south-easterly 

 direction. This lava -stream, together with a dyke of a fine grained 

 dolerite of considerable thickness, forming a projection above the 

 "Waipara beds, has preserved the lower deposits from destruction. The 

 coal has at the same time been partially altered. When I visited the 

 mine in 1S76, the following beds were exposed in ascending order : 



ft, in. 



Brown Coal ... ... ... ... 2 11 



Shale ... ... ... ... ... 4 2 



Coal 4 



Shale ... ... ... ... ... 2 1 



Coal 1 



Shale, only exposed in part ... 



I understand that whilst the other seams have diminished, the 4 feet 

 seam has improved in thickness the more it has been opened up, being 

 now 4 feet 6 inches thick. Section No. 5 on plate 3 gives a section 

 of the colliery under consideration, whilst No. 7 on the same plate 

 shows the principal details of the Kowhai corner hill more to the 



