Reviews — Ancient Buried Forest. 39 



The second publication above quoted contains some new and 

 interesting material. It is mainly taken up by a tabulation of 

 analyses of British iron-ores mined in 1917, but the brief introduction 

 of two pages gives in a very condensed form a summary of the 

 statistics of production for 1917. Of 15,028,000 tons mined in that 

 year 89-5 per cent was phosphoric and of low iron-content, the 

 remainder being high-grade haematite ore with low phosphorus, 

 obtained almost entirely from Cumberland and Lancashire. The 

 phosphoric ores derived from the Jurassic formation make up 

 80*6 per cent of the total production e the rest coming from the 

 Coal-measures, with an almost negligibl amount (under 1 per cent) 

 from other sources. 



These facts may be summarized as follows: — 



per cent. tons. 



Lias . . . . 59-5 8,947,520 



21-1 3,169,110 



8-1 1,194,882 

 ■ 0-8 129,961 



10-5 1,586,429 



Inferior Oolite 

 Coal-measures 

 Miscellaneous 

 Hasmatite ores 



100-0 15,027,902 



Thus it appears that at the present time the Jurassic System is the 

 dominant factor in the iron-ore industry of this country, while the 

 one-time importance of the Carboniferous is rapidly waning. It is, 

 perhaps worth bearing in mind that it was the introduction of the 

 basic Bessemer process that rendered possible the utilization of these 

 low-grade ores, both in Britain and in Lorraine. Without this the 

 cqurse of recent industrial development must have been very 

 different. Fortunately the mining of the Jurassic ores of the 

 Midlands is a very simple matter, being quarrying rather than 

 mining, and the introduction of suitable machinery has done much 

 to stimulate large and economical production in a time of labour 

 sbortage. 



R. H. R. 



V. — An Ancient Buried Forest near Biccarton: its Bearing 

 on the Mode of Formation of the Canterbury Plains. By 

 R. Speight, M.Sc, F.Gr.S. Trans. Kew Zealand Inst., vol. xlix, 

 pp. 361-4, with 1 plate, 1916. 



THE Canterbury Plains which form the eastern part of the South 

 Island have been built up almost entirety by the alluvial cones 

 brought down by the rivers from the western mountain chains. 

 This deposition of alluvial gravel has been accompanied by a down- 

 ward movement of the land, and timber is often found in boreholes 

 as much as 450 feet below the surface. The stumpB of the trees 

 which formed the forest described in this paper were found in 

 place on a bed of clay, under 12 feet of gravel, at a height of 

 about 50 feet above the sea, in a pit near Riccarton. Some of the 

 trunks were standing, but most of them had been snapped off very 



