300 Geology of 



a calcareous matrix, and changing on the one hand into a melaphyre 

 tufa, on the other into almost pure limestone. These igneous rocks 

 form the greater portion of the iron-hound coast, haying hy their 

 hardness hitherto so effectually resisted the never ceasing action of 

 the powerful surf. More to the north of the Abbey rocks, the 

 sections are not only more complicated, but the eruptive rocks seem to 

 occur at various horizons, and are accompanied by beds of limestones, 

 of which one consists of the lithographic limestone now being worked 

 by Messrs. Docherty and McArthur. Marls, sandstones, and con- 

 glomerates appear above this limestone, and thus form the highest 

 beds in this series, which more to the south seem all to have been 

 destroyed. The whole is almost devoid of fossils, and those which I 

 found consisted only of imperfect casts in some of the green sands, 

 amongst which, however, I recognised Panopaea, Katica, and a small 

 radiately striated Pecten. Some of the greensands are so full of f ucoid 

 impressions, that the whole forms a mass of flattened stems, lying 

 across each other in all directions, so that many of these beds may best 

 be described as f ucoid sandstones. The lower beds have generally an 

 inconsiderable dip to the west, whilst the upper series, including the 

 coulees of melaphyre, stand at a very high angle, sometimes almost 

 vertical. The lower conglomerates consist mostly of pebbles of 

 quartz, and are thus easily distinguished from the upper conglomerates, 

 formed of all the different kinds of rocks of which the lower portion 

 of the central chain and the granitic outliers are formed. As before 

 observed, it is difficult to co-relate these beds with those of the East 

 Coast, owing to the absence of characteristic fossils ; however, similar 

 streams of basic rocks have been erupted at different intervals in the 

 Malvern Hills during the cretaceo -tertiary period, so that in that 

 respect similar features on both sides of the Alps are presented to us, 

 in what I consider to be the same horizon. 



iGXEors Rocks. 

 The most important zone on the eastern side of the central chain, 

 where igneous rocks are largely developed, is situated in the Malvern 

 Hills. In one locality at the Kowai corner, they form a small hill 

 of a crateriform appearance, with a lava stream running in a 

 southerly direction. The rocks on the summit of this little system 

 are granitoid, whilst some dykelike projections, passing through them, 

 have a fine grained texture. Here also the rule holds good that that 

 portion which has cooled more slowly in the form of dykes is more- 



