The Student's Elements of Geology   By: Charles Lyell (1797-1875)

BY SIR CHARLES LYELL, BART., F.R.S.,

AUTHOR OF "THE PRINCIPLES OF GEOLOGY," "THE ANTIQUITY OF MAN," ETC.

(FIGURE A. FROM BOTTOM TO TOP: PRIMARY OR PALEOZOIC. Bronteus flabellifer. SECONDARY OR MESOZOIC. Ammonites rhotomagensis. TERTIARY OR CAINOZOIC. Nummulites laevigata.)

(FIGURE B. Thecosmilia annularis.)

WITH MORE THAN 600 ILLUSTRATIONS ON WOOD.

PREFACE.

The LAST or sixth EDITION of my "Elements of Geology" was already out of print before the end of 1868, in which year I brought out the tenth edition of my "Principles of Geology."

In writing the last mentioned work I had been called upon to pass in review almost all the leading points of speculation and controversy to which the rapid advance of the science had given rise, and when I proposed to bring out a new edition of the "Elements" I was strongly urged by my friends not to repeat these theoretical discussions, but to confine myself in the new treatise to those parts of the "Elements" which were most indispensable to a beginner. This was to revert, to a certain extent, to the original plan of the first edition; but I found, after omitting a great number of subjects, that the necessity of bringing up to the day those which remained, and adverting, however briefly, to new discoveries, made it most difficult to confine the proposed abridgment within moderate limits. Some chapters had to be entirely recast, some additional illustrations to be introduced, and figures of some organic remains to be replaced by new ones from specimens more perfect than those which had been at my command on former occasions. By these changes the work assumed a form so different from the sixth edition of the "Elements," that I resolved to give it a new title and call it the "Student's Elements of Geology."

In executing this task I have found it very difficult to meet the requirements of those who are entirely ignorant of the science. It is only the adept who has already overcome the first steps as an observer, and is familiar with many of the technical terms, who can profit by a brief and concise manual. Beginners wish for a short and cheap book in which they may find a full explanation of the leading facts and principles of Geology. Their wants, I fear, somewhat resemble those of the old woman in New England, who asked a bookseller to supply her with "the cheapest Bible in the largest possible print."

But notwithstanding the difficulty of reconciling brevity with the copiousness of illustration demanded by those who have not yet mastered the rudiments of the science, I have endeavoured to abridge the work in the manner above hinted at, so as to place it within the reach of many to whom it was before inaccessible.

CHARLES LYELL.

73 Harley Street, London, December, 1870.

CONTENTS.

CHAPTER I.

ON THE DIFFERENT CLASSES OF ROCKS.

Geology defined. Successive Formation of the Earth's Crust. Classification of Rocks according to their Origin and Age. Aqueous Rocks. Their Stratification and imbedded Fossils. Volcanic Rocks, with and without Cones and Craters. Plutonic Rocks, and their Relation to the Volcanic. Metamorphic Rocks, and their probable Origin. The term Primitive, why erroneously applied to the Crystalline Formations. Leading Division of the Work.

CHAPTER II.

AQUEOUS ROCKS THEIR COMPOSITION AND FORMS OF STRATIFICATION.

Mineral Composition of Strata. Siliceous Rocks. Argillaceous. Calcareous. Gypsum. Forms of Stratification. Original Horizontality. Thinning out. Diagonal Arrangement. Ripple mark.

CHAPTER III.

ARRANGEMENT OF FOSSILS IN STRATA FRESH WATER AND MARINE.