CONTENTS. 



Chapter I. — On the different Classes of Rocks. 



Geology denned — Successive formation of the earth's crust — Classification of 

 rocks according to their origin and age — Aqueous rocks — Volcanic rocks — 

 Plutonic rocks — Metamorphic rocks — The term primitive, 'why erroneously 

 applied to the crystalline formations .... Page 1 



Chapter II. — Aqueous Rocks — Their Composition and Forms of Stratification. 



Mineral composition of strata — Arenaceous rocks — Argillaceous — Calcareous — 

 Gypsum — Forms of stratification — Diagonal arrangement — Ripple-mark 10 



Chapter IIL — Arrangement of Fossils in Strata — Freshwater and Marine. 



Limestones formed of corals and shells — Proofs of gradual increase of strata de- 

 rived from fossils — Tripoli and semi-opal formed of infusoria — Chalk derived 

 principally from organic bodies — Distinction of freshwater from marine forma- 

 tions — Alternation of marine and freshwater deposits - - - 21 



Chapter IV. — Consolidation of Strata and Petrifaction of Fossils. 



Chemical and mechanical deposits — Cementing together of particles — Concre- 

 tionary nodules — Consolidating effects of pressure — Mineralization of organic 

 remains — Impressions and casts how formed — Fossil -wood — Source of lime and 

 silex in solution - - - - - - - -33 



Chapter V. — Elevation of Strata above the Sea — Horizontal and Inclined 

 Stratification. 



Position of marine strata, -why referred to the rising up of the land, not to the 

 going down of the sea — Upheaval of horizontal strata — Inclined and vertical 

 stratification — Anticlinal and synclinal lines — Theory of folding by lateral 

 movement — Creeps — Dip and strike — Structure of the Jura — Inverted posi- 

 tion of disturbed strata — Unconformable stratification — Fractures of strata — 

 Faults ------ - - - 44 



Chapter VI. — Denudation-. 



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

 the earth's crust — Levelled surface of countries in which great faults occur — 

 Denuding power of the ocean — Origin of Valleys — Obliteration of sea-cliffs — 

 Inland sea-cliffs and terraces - - - - - - 66 



Chapter VIL — Alluvium. 



Alluvium described — Due to complicated causes — Of various ages — How distin- 

 guished from rocks in situ — River-terraces — Parallel roads of Glen Roy 79 



Chapter VIIL — Chronological Classification of Rocks. 



Aqueous, plutonic, volcanic, and metamorphic rocks, considered chronologically 

 — Lehman's division into primitive and secondary — Werner's addition of a 

 transition class — Neptunian theory — Hutton on igneous origin of granite — 

 The name of " primary" for granite and the term " transition" why faulty — 

 Chronological nomenclature adopted in this "work, so far as regards primary, 

 secondary, and tertiary periods .... - 89 



