THE 



GEOLOGICAL MAGAZINE 



NEW SERIES. DECADE III. VOL. IX. 



No. VI.— JUNE, 1892. 



OK,ia-I2sr.A.Xi .A-iaTIGLES. 



'. — On Certain Affinities Between the Devonian Eocks of 

 South Devon and the Metamokphic Schists. 



By A. E. Hunt, M.A. 



Part I. 



(PLATES VI. AND VII.) 



N submitting the following paper to the readers of the Geological 

 Magazine, I am conscious that some apology is needed for 

 entering upon so difficult a subject. My position is as follows : — In 

 1879 the late Mr. E. B. Tawney joined me in the investigation of a 

 series of detached blocks trawled from time to time by the Brixham 

 fishermen. The character of certain of these stones having suggested 

 to Mr. Tawney the idea that the schists of South Devon might 

 possibly be of pre-Cambrian age,' he visited the district in 1880, 

 with the expectation of being the first to advance that hypothesis. 

 The evidence of the schists themselves failed to satisfy Mr. Tawney 

 on the point in question, and his premature death prevented his 

 attacking the problem on a subsequent occasion, as he had hoped to 

 be able to do. 



On Mr. Tawney 's death in December, 1882, Prof. Bonney was 

 good enough to take his place in supplying me with microscopic 

 analyses of the Channel blocks. In the following Easter, a week 

 spent among the metamorphic rocks of South Devon resulted in a 

 paper published in the Quarterly Journal of the Geological Society, 

 in November of the same year, in which Prof. Bonney expressed 

 the opinion that the South Devon schists might be safely regarded 

 " as Archaean, and as a prolongation of the massif so distinctly 

 indicated in the Lizard, to which also belonged the gneiss of the 

 Eddystone," Q. J. G. S., vol. xl. p. 23. 



It may be observed that the original investigation of the Channel 

 blocks was undertaken for the purpose of elucidating, if possible, 

 the Start and Bolt problem, and that my first paper was lent to 

 Mr. Pengelly in MS. for use in preparing his own paper, "The 

 Metamorphosis of the Eocks extending from Hope Cove to Start 

 Bay." The two were published in sequence at the Ilfracombe 

 meeting of the Devonshire Association in 1879. 



In 1879 Mr. Pengelly maintained the Devonian age of the meta- 

 morphic schists. During 1880-82 Mr. Tawney reserved his opinion, 



1 Trans. Devon Assoc, vol. xxi. p. 468. 



DECADE III. VOL. IX. NO. VI, 16 



