Reviews — Iron-ores and Bauxite of N.E. Ireland. 87 



not all seem to be found together. By far the most important 

 section is that at the Giant's Causeway, where the zone indicates an 

 interbasaltic epoch of long duration, this conclusion being supported 

 by the presence of frequent thick beds of lignite. At numerous 

 localities thin bands of the bright-red bole occur at other horizons, 

 i.e. unconnected with the main interbasaltic zone. It is suggested 

 that these red bands mark periods of rest between the flows, giving 

 time for the decomposition of the successive surfaces of the basalt. 

 In East Antrim the series is represented by two types — red and brown 

 pisolitic iron-ore and lithomarge, or grey bauxitic claj^s. As noticed 

 in the previous memoir, one type usually occurs to the exclusion 

 of the other. The two sections' on Island Magee show that lithomarge 

 is due entii-ely to the decomposition of the basalt in situ, and is 

 not composed of volcanic ash as was formerly thought. Some 

 alterations in the boundary-line between the upper and lower basalt 

 have been necessary in this area, but in the Mid-Antrim district they 

 are not of great importance so far as the area of the mineral deposits is 

 concerned. In the latter district the best iron-ore and bauxite 

 prospects have already been taken up by companies, and details of the 

 various mines are given. Great changes of level occur in the zone, 

 and some may be accounted for by the irregular surface of the lower 

 basalt on which the deposit was formed. There seems to have been 

 a fairly regular drop to the south of about 100 feet to the mile, 

 but of course the original floor of the lignite, iron-ore, and bauxite 

 deposits was probably more or less horizontal. 



There is but little to add to existing knowledge of the rocks of 

 Ballypalady and Tardree in the Southern district, but the recent 

 sinking of pits in the Lough Neagh clays has rendered a few new 

 facts available. At Claremont, north-east of Cranford Bay, there is 

 a section of considerable interest, because it suggests that some of the 

 lignite beds in the clays are derived from the interbasaltic zone by 

 denudation. A new explanation for the origin of the remarkable 

 Coagh. Conglomerate is brought forward, namely, that it is a much 

 weathered basalt in which the spheroidal structure is highly 

 developed. 



Following the description of the outcrop of this zone is a chapter 

 on the plant-remains by Dr. C. E. Moss, who gives a cautious view 

 of the evidence tbey afford. The Antrim leaf-beds seem to give 

 fairly reliable evidence of climatic conditions, but as regards further 

 evidence Dr. Moss quotes Starkie Gardner's conclusion as still 

 applicable, that " where nothing definite is known, it would be no 

 service to science to add further to the guesses ". 



Analyses of the ores have been collected from various sources, and 

 are arranged in order as the localities are dealt with in the text. 

 There are two appendices, one by Mr. J. D. Kilroe and the other by 

 Professor G. A. J. Cole. The former discusses the westerly extension of 

 the Upper Basalts, and arrives at the conclusion that the great series 

 to the west of Bann may be to a large extent Upper Basalt. 

 Professor Cole in dealing with the problem of the Lough Neagh clays 

 regards the evidence now available as indicating the post-basaltic age 

 of these clays. If this view be accepted — and the absence of dykes 



