452 Geology of 



Passing over to the eastern slopes of the Alps, the most important 

 district in Canterbury where coal-bearing strata of some extent haye 

 been proved to exist, is situated some 30 to 40 miles west from 

 Christchurch. This district, called the Malvern Hills, was first 

 examined by me in 1361-62, but more systematically during 1870-71, 

 the results of my surveys having been published in the Eeports of 

 Geological Explorations during 1871-72. Since that report has 

 appeared, a few more discoveries have made us acquainted with 

 several new localities where coal crops out, of which the principal one 

 is that where the Springfield Company has opened up a colliery a few 

 years ago. In the publication referred to, I have shown that only 

 those portions of the coal seams which were subjected to igneous 

 action, have undergone metamorphism in the immediate neighbour- 

 hood, and to such a local extent, that sometimes the upper portion of 

 large coal seams over which a basaltic lava-stream has been flowing, is 

 altered to an anthracite coal, whilst the lower portion has remained 

 an unaltered brown coal. The same limited effect has been produced 

 where the volcanic rocks in the form of more or less vertical dykes 

 have ascended through the carboniferous strata, the coal seams being 

 affected in a similar manner on both sides of the dyke, for a short 

 distance only. The surveys of the coal measures under consideration 

 have proved that during the sinking of the land the material for the 

 formation of brown coal seams was accumulating all over the district 

 under review, only those portions having been preserved where 

 favourable circumstances were existing, such, for instance, as the 

 coulees of basaltic rocks having flowed over them. In other cases, 

 hard fossiliferous sandstones have acted in the same manner. Conse- 

 quently we find that the coal seams not only are fringing the slopes 

 of the palaeozoic ranges, appearing in that case as marginal seams, and 

 at altitudes from SCO to 1500 feet, but outl'ers of more or less extent 

 occur up to 3500 feet above the present sea level. Of the marginal 

 coal seams, those in which the Canterbury Collieiy (Jebson'sJ, the 

 Homebush Colliery (Deans'), and the AVallsend Colliery on the 

 northern bank of the Selwyn, are situated, have not been altered by 

 volcanic eruptions, the large coulees of anamesite by which the upper 

 series of the TA^aipara formation is here covered, being too far distant 

 to have had any appreciable effect upon the coal seams. 



Beginning with the Canterbury Colliery, we observe that the whole 

 series from the first seams worked in 1S61 to the ferruginous 

 sandstone forming its base, stretches 12^ chains along the banks of 

 the river, dipping on the average at an angle of 19 degrees to the 



