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CONTENTS. 
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France at successive periods — Mont Dor an extinct volcano— -Velay — Plomb 
du 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 during 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 — Palseotherium and other fossil mammalia of 
Biustead— 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 ' firestone,' 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 the North and South Downs were once continu- 
ous, considered— Dr. Buckland on the Valley of Kingsclere — 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 
