XXIV CONTENTS. 



P.VGR 



France at successive periods Mont Dor an extinct volcano Vclay Plomb 

 (lu Cantal Train of minor volcanos stretching from Auvergne to the Vivarais 

 Monts Domes Puy de Come Puy Rouge Ravines excavated through 

 lava Currents of lava at different heights Subjacent alluviums of distinct 

 ages The more modern lavas of Central France may belong to the Miocene 

 period The integrity of the cones not inconsistent with this opinion No 

 eruptions dining the historical era Division of volcanos into ante-diluvian 

 and post-diluvian inadmissible Theories respecting the effects of the Flood 

 considered Hypothesis of a partial flood Of a universal deluge Theory 

 of Dr. Buckland as controverted by Dr. Fleming Recapitulation . 257 



CHAPTER XX. 



Eocene formations, continued Basin of the Cotentin, or Valognes Rennes 

 Basin of Belgium, or the Netherlands Aixin Provence Fossil insects 

 Tertiary strata of England Basins of London and Hampshire Different 

 groups Plastic clay and sand London clay Bagshot sand Fresh-water 

 strata of the Isle of Wight Palaeotherium and other fossil mammalia of 

 Binstead English Eocene strata conformable to chalk Outliers on the 

 elevated parts of the chalk Inferences drawn from their occurrence Sketch 

 of a theory of the origin of the English tertiary strata . , 275 



CHAPTER XXI. 



Denudation of secondary strata during the deposition of the English 

 Eocene formations Valley of the Weald between the North and South Downs 

 Map Secondary rocks of the Weald divisible into five groups North and 

 South Downs Section across the valley of the Weald Anticlinal axis 

 True scale of heights Rise and denudation of the strata gradual Chalk 

 escarpments once sea-cliffs Lower terrace of ' firestonc,' how caused 

 Parallel ridges and valleys formed by harder and softer beds No ruins of 

 the chalk on the central district of the Weald Explanation of this pheno- 

 menon Double system of valleys, the longitudinal and the transverse 

 Transverse how formed Gorges intersecting the chalk Lewes Coomb 

 Transverse valley of the Adur . . . . .285 



CHAPTER XXII. 



Denudation of the Valley of the Weald, continued The alternative of the 

 proposition that the chalk of tbe North and South Downs were once continu- 

 ous, considered Dr. Buckland on the Valley of Kingsdere Rise and 

 denudation of secondary rocks gradual Concomitant deposition of tertiary 

 strata gradual Composition of the latter such as would result from the 

 wreck of the secondary rocks Valleys and furrows on the chalk how caused 



