556 Recieics — A. Harler — Rocks of Slnje. 



later deposits in England and Wales, but has not hitherto been 

 recorded from Ireland. 



o. Ehodesia. — A useful pamphlet on "The Geology of Southern 

 Khodesia," by Mr. F. P. Mennell, has been issued by the Rhodesia 

 Museum at Bulawayo. This is accompanied by pictorial and other 

 illustrations, and by a sketch geological map on the scale of an inch 

 to four miles. The author deals with the igneous rocks and schists, 

 the coal series, superficial deposits, and scenery. 



I^ IE "V I E AAT S. 



L — Memoirs of the Geological Survey of the United Kingdom. 



The Tertiary Igneous Rocks of Skye. By Alfred Hakker, 

 M.A., F.R.S., with Notes by 0. T. Clough, M.A., F.G.S. 

 pp. xi, 481, 84 text-figui-es, 27 plates, and one coloured map. 

 (Glasgow, 1904. Price 9s.) 



rpHE appearance of this memoir awakens the echoes of past 

 JL controversies. The region with which it deals shows within 

 a narrow compass such a complex group of rocks that diversities of 

 opinion might well arise as to their mutual relations. Broadly 

 speaking, two series of igneous rocks occur, an acid and a basic, 

 ranging in both cases from plutonic masses and intrusive sills and 

 dykes to lava-flows; and the views first enunciated, according to 

 which the plutonic masses were regarded as ttie denuded cores of 

 volcanoes from which the lavas (first the acid and then the basic) 

 had been poured out, appeared to be a simple and reasonable ex- 

 planation of the facts observed. 



As is well known, very different views from the above as to the 

 sequence of these igneous rocks were held by the late Director- 

 General of the Survey, under whose direction, in fact, was planned 

 much of the work the result of which is recorded in the present 

 memoir. The result of Mr. Barker's researches, it may be here 

 briefly stated, has been to convince him of the correctness of 

 Sir Archibald Geikie's main conclusions that the basaltic lavas 

 which cover such an extent of country in the Western Isles of 

 Scotland and in the north of Ireland are amongst the earliest 

 volcanic rocks of the region and were probably due to fissure- 

 eruptions, that the gabbro-masses were intruded into them and are 

 consequently of later date, and that finally these basic rocks were 

 invaded by the granites and granophyres. Supporters of the earlier 

 views will find, therefore, little encouragement in these pages, 

 although here and there a glimpse may be caught of difficulties in 

 the case of phenomena easily capable of misinterpretation, such as 

 the presence in the earlier basic agglomerates of fragments of gabbro 

 and granophyre identical in character with the later rocks which 

 constitute the main mass of the Cuillins and the Red Hills, and the 

 occurrence of basic dykes which travei'se certain rocks freely and 



