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S. S. Buckman — Biver Development. 



at the same time. The theory postulates for its main features two 

 well - known anticlinal systems, the backbone of Wales, with 

 approximately north-south direction, dipping south towards the 

 syncline connected with the South Wales Coalfield, and the South 

 Wales-Mendip-Pewsey-Wealden anticline, with approximately west 

 to east direction, dipping east. Minor anticlines may be disregarded 

 for the present. 



When an anticline of Malvernian direction dips south and is 

 denuded the lines of outcrop converge southwards (Fig. 4, 1-4). If 

 this denuded anticline be covered by a later deposit, be again uplifted, 

 and denuded, the line of outcrop of the later deposit will diverge more 

 from south to north than those of the earlier deposits (Fig. 4, A, A). 

 The same laws will apply to an Armorican axis dipping east — turn 

 the apex of Fig. 4 to the right hand. When one anticline is crossed 

 by another denudation will give circular to ellipsoidal lines of 

 outcrop, the latter shown almost perfectly in the structure of 

 the Weald. 



Fig. 6. — Combination of south -dipping Malvernian axis and east-dipping Armorican 

 axis, showing the rock outcrop which would be produced and the dip streams 

 which would be initiated. The wavy lines represent the streams. Z, the 

 stream which developed to become the Severn. (Anticlinal axis not necessarily 

 equal-sided.) 



Here I may remark that a good example of a system of anticlines 

 crossing one another at right angles, and also of curving anticlines 

 on account of lateral thrust, is shown in the mosaic floor of the 

 central hall of the Natural History Museum, South Kensington. 



Taking the two anticlines of Malvernian and Armorican directions, 

 with their respective south and east dips, combining them according 

 to the principles laid down, allowing for three main overlaps — 



