. Elements of geology : a text-book for colleges and for the general reader. Geology. Fig. 213.—Irregularities in Veins. Fig. 214.—Irregularities in Veins. of country rock in the midst of a vein is called a "horse" Many of these irregularities are probably the result of movements after the fis- sure was formed, or even after it was filled. Thus, if a b c d (Fig. 213) be one wall of an irregular vein, then it is probable that a' V d d' was the original position of this wall; but, before it was filled, it slipped up to its present position. Or, an open fissure may pinch together in pla
. Elements of geology : a text-book for colleges and for the general reader. Geology. Fig. 213.—Irregularities in Veins. Fig. 214.—Irregularities in Veins. of country rock in the midst of a vein is called a "horse" Many of these irregularities are probably the result of movements after the fis- sure was formed, or even after it was filled. Thus, if a b c d (Fig. 213) be one wall of an irregular vein, then it is probable that a' V d d' was the original position of this wall; but, before it was filled, it slipped up to its present position. Or, an open fissure may pinch together in places by what is called creeping of the strata of the wall, i. e., a mash- ing and filling in by pressure of superincumbent weight. Again, movements may reopen a fissure after it is filled. In such cases, if the adhesion of the filling to the wall is strong, portions of the wall-rock are torn away ; and, if a second filling takes place, a " horse " is formed. Thus a a a and bbb (Fig. 214) represent the two original walls of an irregular vein; but subsequent movement reopened the fissure to V V V. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original LeConte, Joseph, 1823-1901. New York : D. Appleton and Co.
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