Elements of geology / by Charles Lyell.

  • Charles Lyell
Date:
1838
Catalogue details

Licence: Public Domain Mark

Credit: Elements of geology / by Charles Lyell. Source: Wellcome Collection.

    55/582 page 25
    .Mrnj ' 1 ' • ' ’ w>- ^ bVl r v- CHAPTER II. AQUEOUS ROCKS THEIR COMPOSITION AND FORMS OF STRATIFICATION. Mineral composition of strata—Arenaceous rocks — Argil- laceous—Calcareous — Gypsum—Forms of stratification — Original horizontally — thinning out — Diagonal ar- rangement— Ripple mark. First, then, in pursuance of the arrangement explained in the last chapter, we have to examine the aqueous or sedimentary rocks, which are for the most part distinctly stratified, and contain fossils. We are to consider them with reference to their mineral composition, external appearance, position, mode of origin, and other characters which belong to them as aqueous formations, without reference to their age, or the various geological periods when they may have origi- nated. I have already given an outline of the data which lead to the belief that the stratified and fossiliferous rocks were originally deposited under water; but, before entering into a more detailed investigation, it will be desirable to say something of the ordinary materials of which such strata are composed. These may be said to belong principally to three divisions, the arenaceous, the argillaceous, and the calcareous which are formed c
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