106 



IGNEOUS ROCKS, CHARNWOOD FOREST 



gES?y. blende * This r ° ck passes im P e rceptibly into syenite and 

 — granite. 



Wall 



39. 



Syenitic rock, Broad Hill. Greenish rock com- 

 posed of pink felspar, with a little hornblende and granular 



quartz 



40. 

 felspar. 



Hi 



Hornblende and pink 



41.— Greenstone, Coptoak Farm. Similar to 40, but 



more felspathic. 



42. — Greenstone, Bowdon Hill. 



blende, the felspar predominating. 



Felspar and horn- 



43. — Greenstone, syenitic. Grooby. Pink felspar and 

 hornblende, well crystallized, wit]] a few small granules of 

 quartz. 



44.— Greenstone, syenitic. Marhfield. Pink felspar and 

 hornblende well crystallized. Felspar rather predominates. 



45. — Greenstone, syenitic, Grooby. Pink felspar and 

 hornblende as above. 



46.— Syenite, Cliff Hill. Felspar, quartz, and horn- 

 blende. 



The igneous rocks from 37 to 46 pierce the Cambrian 

 rocks of Charnwood Forest and the neighbourhood, and 

 probably form parts of a great mass concealed below. Some 

 of them are, however, entirely surrounded by unaltered 

 New red marl, which conceals the Cambrian rocks amid 

 which they lie. The Cambrian rocks in their neighbour- 

 hood are so much altered, that, becoming porphyritic, it is 

 often impossible to trace an accurate boundary line between 



Between Grace 



• them and the undoubted igneous rock. 





Wood 



Nos 



derived. Some part of it seems to be undoubtedly igneous, 

 - as in the case of No. 39. Other parts show every degree 

 of gradation, from a common unaltered slaty character to 

 rocks that on a small scale seem to be igneous, but on a 

 large scale on the ground, show traces of stratification and 

 other signs proving them to be of sedimentary origin, only 





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