On brecciated formations / by John Ruskin.

  • John Ruskin
Date:
[1867]
Catalogue details

Licence: Public Domain Mark

Credit: On brecciated formations / by John Ruskin. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

    3/6
    November, 1867], '; /. ON BRECCIATED FORMATIONS. By John Buskin. Esq., F.G.S. (PLATE XX.) (Continued from the August Number, p. 339). I WROTE the first of these papers more with a view of obtaining some help in my own work than with any purpose of carrying forward the discussion of the subject myself. But no help having been given me, I must proceed cautiously alone, and arrange the order of my questions; since, when I have done my best as care- iully as I can, the papers will be nothing but a series of suggestions lor others to pursue at their pleasure. Let me first give the sense in which I use some necessary words : 1. (supposing cavities in rocks are produced by any accident, or y original structure (as hollows left by gas in lava), and after- wards filled by the slow introduction of a substance which forms an element of the rock m which the cavities are formed, and is finally FntlTlT r CaT^eS’in Pr°P°rtion t0 its neater or less abundance in the lock , I call the process “ secretion.” the cavities are filled with a substance not present (or not m sufficient quantity present), in the surrounding rock mid erefoie necessarily brought into them from a distance, 1 call the process, if slow, “infiltration” ; if violent, “injection.” t is evident that water percolating a rock may carry a substance present m the mass of it, by infiltration, into the Zities^^*5 £*the'aspect^'the f there are structural differences isteut S * f th *7° Condltlons fiereafter to be noticed. The ex- conditions m°LStfe 18 however to be admitted among fore^ elemeata. : * moistare> tatroduciag caTraferto o^suoh’mSf®?11^01 ^ is tho 8iml’Iesl in^*™ool »rwowd to thoM whw?are i^LdZ^of LcS.” vapoul'm «“« °f *** which TZn c&