1903. 1^7 



A GEOLOGICAL RENAISSANCE.^ 



BY PROF. G. A. J. COLK, F.G.S. 



The revised edition of part of the well-known ** Memoir to 

 Sheets 102 and 112," of which a second edition appeared in 

 1875, is virtually a new work. Sheet 102 is omitted from its 

 scope, and yet it contains 160 pages against the 76 of the 

 previous Memoir. Despite the general principle, at present 

 adopted by the Survey, of interfering as little as possible with 

 the descriptions of the "solid" geology, a number of wise 

 changes have been made in the text, and the path has been 

 opened for a systematic revision of the district. The detailed 

 investigation of the " drift " deposits naturally occupies a large 

 part of the Memoir ; and the new edition of Sheet 112 appears 

 at the same time, and at once replaces the " solid" map that 

 went before it. By the use of colour-printing, the Ordnance 

 Survey Office in Phoenix Park has found it possible to issue 

 this map at only 6^. more than the price of the ordinary 

 uncoloured topographical sheet. The contoured edition of 

 that sheet, issued in 1900, has been used as a basis ; and the 

 system of colours and stipplings selected by the geologists 

 interferes very little with its clearness. The promontory of 

 Howth has, in fact, presented the only serious difficulty, and 

 a plain colour might with advantage be substituted for the 

 remarkable pattern formed by the triple series of green lines, 

 sprinkled with red and yellow confetti, which at present adorns 

 the shales. 



The detail of the map is extraordinary, and provides a picture 

 of the succession of surface-deposits round Dublin through- 

 out post-Pliocene times. The map and memoir together 

 will become classical, not only as a record of facts already 

 known, but as abounding in original contributions to Irish 



1 (i ) Geological Survey of Ireland, Sheet 112, Drift Edition. 



Dubhu, 1902 (actually 1903). Price is. 6d. 

 (ii.) The Geology of the Country around Dublin (Explanatiou 

 of Sheet 112 of the Geological Survey of Ireland). By G. W. 

 Lamplugh, J, R. Kilroe, A. M'Heury, H. J. Seymour, aud W. B, 

 Wright. Dubliu, 1903. Price 3^. 



