304 C. St. Arnaud Coles — A Quartzite and Syenite Rock. 



V. — An exposure of Quartzitk and Syenitic Eock 

 NEAK Martlet, Worcestershire. 



By Chakles St. Aenatjd Coles. 



THE section in which these rocks are exposed is seen in a field 

 at a distance of about a quarter of a mile from the -village of 

 Hartley and due north of Berrow Hill Farm. Here is a small 

 excavation for road stone, but it does not appear to have been 

 vporked lately. Both the quartzite and syenitic rock are exposed, 

 the latter being very decomposed. The relations of the rocks to one 

 another appear to be as follows (see Figure) : — Below, at A, the 

 quartzite is seen to stand out conspicuously. Eound this, as at B, 

 is a thin layer of powdery rotten rock, differing but little from the 

 rest of the decomposed syenite, forming a crust at C, but evidently 

 marking the junction of the quartzite and syenite ; the latter being 

 at D and E sufficiently undecomposed to allow of its being sliced. 

 Above comes a loose bi-eccia consisting of fragments of these rocks, 

 but this is evidently surface soil. 





ocu.re d ^iV'l- 



<>y soil etc M/P' 



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Syenitic Eock-exposuee, near Martlet, Worcestershire. 

 Diagrammatic section brought to one plane. A = Quartzite ; B, C = Decomposed 

 Syenite, that at C forming a slope ; D, E = Undecomposed Syenite; F=surface soil. 



This section appears to correspond in position with that noticed 

 by Professor Phillips ("On the Malvern and Abberley Hills," p. 8). 

 However, no quartzite is mentioned by him, and the Old Ked, 

 Coal-measures, and Trias figured by him are not now visible. It 

 seems probable, therefore, that the old excavation has been filled in, 

 and that the present one has been worked to a greater depth, owing, 

 most likely, to the discovery of the hard quartzite. A careful 

 examination of the two rocks shows that their apparent relation, 

 as mentioned above, in all probability is not the real one. 



The syenitic rock, as has been mentioned, is very decomposed, but 

 two specimens have been sliced. The structure is holocrystalline. 

 Green mica and a felspar are the most prominent minerals, 

 but there is also a little quartz. The felspar occurs in large, 

 irregular, and fractured crystals, but is so kaolinized as to make 

 it impossible to state with certainty whether it is plagioclase or 

 orthoclase, but probably both are present. The mica is also much 



