vi CONTENTS. 



CHAPTER IV. 



CONSOLIDATION OF STRATA AND PETRIFACTION OF FOSSILS. 



Chemical and mechanical deposits Cementing together of particles Hard, 

 ening by exposure to air (p. 52.) Concretionary nodules Consolidating 

 effects of pressure Mineralization of organic remains (p. 55.) Impressions 

 and casts how formed Fos^iTwood Gb'ppert's experiments Precipitation 

 of stony matter most rapid where^ putrefaction is going on Source of lime 

 in solution (p. 59.) Silex derived from decomposition of felspar Proofs of 

 the lapidification of some fossils soon after burial, of others when much 

 decayed. 



CHAPTER V. 



ELEVATION OF STRATA ABOVE THE SEA HORIZONTAL AND INCLINED 

 STRATIFICATION. 



Why the elevated position of marine strata should be referred to the rising up 

 of the land, not to the going down of the sea Upheaval of extensive masses 



of horizontal strata (p. 63.) Inclined and vertical stratification Anticlinal 

 and synclinal lines Examples of bent strata in east of Scotland (p. 66.) 

 Theory of folding by lateral movement Dip and strike (p. 69.) Structure 

 of the Jura Rocks broken by flexure Inverted position of disturbed strata 

 (p. 73.) Unconformable stratification Fractures of strata Polished sur- 

 faces Faults Appearance of repeated alternations produced by them 

 (p. 77.) Origin of great faults. 



CHAPTER VI. 



DENUDATION, AND THE PRODUCTION OF ALLUVIUM. 



Denudation defined Its amount equal to the entire mass of stratified deposits 

 in the earth's crust Horizontal sandstone denuded in Ross-shire Levelled 

 surface of countries in which great faults occur (p. 81.) Connexion of 

 denudation and alluvial formations Alluvium, how distinguished from rocks 

 in situ (p. 84.) Ancient alluviums called diluvium Origin of these 

 Erratic blocks and accompanying gravel (p. 86.) Theory of their transporta- 

 tion by ice. 



CHAPTER VII. 



VOLCANIC ROCKS. 



Trap rocks Name, whence derived Their igneous origin at first doubted 

 Their general appearance and character Volcanic cones and craters, 

 how formed (p. 91.) Mineral composition and texture of volcanic rocks 

 Varieties of felspar Hornblende and augite Isomorphism (p. 94.) Rocks, 

 how to be studied Basalt, greenstone, trachyte, porphyry, scoria, amygda- 

 loid (p. 96.) lava, tuff Alphabetical list, and explanation of names and 

 synonyms, of volcanic rocks (p. 99.) Table 'of the analyses of minerals most 

 abundant in the volcanic and hypogene rocks. 



