CONTENTS. PART I. CHAPTER L page Introductory observations ...... 1 Arrangement of the subject ...... 4 General classification of crystalline rocks .... 5 General classification of geological formations ... 6 CHAPTER II. Classification of British Strata . . . . . .17 PART II. Granitic Rocks. CHAPTER I. Granite and Granitoid Rocks. Nature and composition ....... 20 Foliated Granite......... 23 Graphic Granite ......... 23 Geological age ......... 24 Mode of occurrence . . . . . . . .24 Mode of formation, irruptive and metamorphic . . .25 Chemical composition . . . . . . . .27 Varieties of Granite, and examples . . . . .29 Specialities.......... 30 CHAPTER II. Granites of Scotland. Peterhead . . ........ 32 Aberdeen and Kirkcudbrightshire . . . . .33 Strontian, Argyleshire, Isle of Arran, Isle of Mull, &c. . . 34
