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" eyes " or lenticles and their relations to the surrounding schists that we 

 must look for a solution of many of the problems connected with the origin 

 of the latter. It is proved that in many cases the schist is the result of 

 dynamic metamorphism acting upon a rock having the composition of the 

 " eyes," but the present state of our knowledge certainly does not warrant 

 the assumption that this is invariably the case. 



Malvern. The central chain of the Malverns is composed of schists, 

 gneisses and massive rocks, generally showing on the large scale more or 

 less parallel structure. The last mentioned rocks often become basic in 

 character by the excessive abundance of ferro-magnesian constituents 

 especially hornblende. Some of the hornblende-schists are substantially 

 identical in structure and composition with rocks known to have been 

 formed by the metamorphosis of dolerites (diabases). Such rocks occur 

 near the road side at Wind's Point. They consist of green hornblende 

 (a, yellowish green ; /3, deep green ; 7, bluish green) turbid and colourless 

 felspar possibly associated with some quartz, granules of sphene with 

 occasional kernels of iron ore and sometimes a little epidote. In some 

 sections the forms of lath-shaped felspars can be recognized and also the 

 forms of the original plates and skeletons of ilmenite. 



In addition to the above rocks of more or less doubtful origin we h'nd 

 definitely recognizable igneous rocks of basic composition. These occur 

 as dykes in the central chain and also in the adjacent Hollybush sandstone. 

 The original rocks were dolerites and hornblende-dolerites. In their 

 present condition they may be described as diabases, hornblende-diabases 

 or as proterobases and epidiorites. 



A typical ophitic diabase with ilmenite-plates and chlorite occurs as a 

 dyke in the Hollybush sandstone between Eastnor Castle and Midsummer 

 Hill. This is the type so common in the Lower Palaeozoic rocks of North 

 Wales and Ireland. A precisely similar rock occurs on the west side of 

 Swinyards Hill. A rock from a quarry near the Wych is of the same 

 general character. The augite is, however, in parts replaced by uralitic 

 hornblende. This may be described as a uralitic diabase or proterobase. 



Epidiorites in which the form of the ilmenite is often preserved occur 

 on the east side of Swinyards Hill, at the south end of the east spur of 

 Midsummer Hill, at the south-west end of Ragged Stone Hill, near the 

 Wych and in the North Hill. In some of these a flaser structure has been 

 developed by interstitial movement and in one case distinct planes of 

 movement shearing the ilmenite plates was observed. 



Ireland. The sheets of igneous rock forming the plateaux in the north- 

 east of Ireland are essentially similar in character to those of the west of 

 Scotland. The dominant rock is an ophitic olivine-dolerite, similar in every 

 respect to those represented in Fig 1, Plate IX., and Figs. 1 and 2, Plate X. 

 Associated with these we find rocks of a more basaltic character containing 

 minute lath-shaped felspars, granular augites and a variable amount 

 of interstitial matter. At Carnmoney Hill, near Belfast, there occurs a rock 

 which deserves more than a passing notice. It is an ophitic dolerite (1) with 



(1) Olivine is not recognizable in the slide possessed by the writer. 



