226 Reviens — J. H. Collins — West of England Mining Region. 



I. — Observations on the West of England Mining Region. By 

 J. H. Collins, P.G.S. 8vo; pp. xxi, 683, with 18 plates. 

 Plymouth: William Brendoa and Son, Ltd. 1912. 



rpHIS substantial book, issued as volume xiv of the Transactions of 

 JL the Royal Geological Society of Cornwall, embodies the results 

 of the author's long-continued personal observations and researches 

 on the mineral deposits and mining geology of Cornwall and parts of 

 Devon and West Somerset. Remarkable as it seems, the author 

 affirms that the germs of most of the generally accepted conclusions 

 on the origin and development of the ore-deposits were put forth bv 

 geological writers in the eighteenth century. These were amplified 

 later on and established by Carne, R. Were Fox, De la Beche, 

 Henvvood, and others, while the details of Nature's methods have 

 been dealt with by more recent writers. The 6 inch Geological 

 Survey of Cornwall, commenced in 1897 by Mr. Ussher in East 

 Cornwall and by Mr. J. B. Hill in West Cornwall, has been completed 

 so far as the mining areas are concerned, and all known particulars 

 relating to active and abandoned mines, with sections and plans, 

 have been published. The work, indeed, has been carried as far as 

 Tavistock in Devon.' Referring to this undertaking the author 

 observes that " The recent re-survey of our area, besides clearing 

 up many stratigraphical problems, has thrown much light on its 

 petrography", but he, rather humorously, adds "That as regards 

 our ore deposits it has propounded more problems than it has solved". 

 It is admitted that the oldest rocks determined by fossil evidence 

 are Ordovician, and that there is little doubt that there are earlier 

 rocks at Start Point, the Lizai'd, and elsewhere in West Cornwall, 

 rocks which are not metalliferous to any important extent. In 

 1881 the author first called attention to the possible Cambrian age 

 of the rocks on the western borders of the Falmouth estuary at 

 Ponsanooth* (siliceous slaty rocks since grouped by Mr. Hill with 

 the Mylor Series), but in the present work the author does not 

 particuUirly refer to them, nor does he mention the Silurian rocks 

 discovei'ed by Mr. Upfield Green and Mr. C. D. Sherborn at 

 Porthluney and Porthalla.^ The fossiliferous Ordovician rocks of 

 Perhaver, Gorran Haven, are regarded by Mr. Philip Lake as 

 'apparently Llandeilo'.* These conclusions are important as the 

 field-evidence obtained by the Geological Survey indicates the 

 proximity on the one hand of the relics of Silurian strata to the Gorran 

 quartzites, and on the other hand the downward succession from the 

 quartzites to the Veryan limestones, cherts, etc., Portscatho, Falmouth, 

 and Mylor Series ; so that these divisions are not probably ' Upper 



' See Notice of Memoir on Tavistock, etc., p. 227. 



'^ Journ. Boy. Inst. Cornwall, vii. 



3 Geol. Mag., 1906, p. 33. 



•• C. Reid, Geology of Mevagissey (Geol. Survey), 1907, p. 39. 



