. Elements of geology, or, The ancient changes of the earth and its inhabitants as illustrated by geological monuments. Geology. Ch. V.] ANTICLINAL AND SYNCLINAL LINES. 57. Slope of valley 20°, dip of strata 20°, in opposite directions. Fte- 76- a valley, which declines in an opposite direction at 20°.* These rules may often be of great practical utility; for the different degrees of dip occurring in the two cases represented in figures 74 and 75, may occasionally be en- countered in following the same line of flexure at points a few miles distant from each other. A miner un- acquainted with t
. Elements of geology, or, The ancient changes of the earth and its inhabitants as illustrated by geological monuments. Geology. Ch. V.] ANTICLINAL AND SYNCLINAL LINES. 57. Slope of valley 20°, dip of strata 20°, in opposite directions. Fte- 76- a valley, which declines in an opposite direction at 20°.* These rules may often be of great practical utility; for the different degrees of dip occurring in the two cases represented in figures 74 and 75, may occasionally be en- countered in following the same line of flexure at points a few miles distant from each other. A miner un- acquainted with the rule, who had first explored the valley (fig. 74), may have sunk a vertical shaft below the coal-seam A, until he reached the inferior bed B. He might then pass to the valley fig. 75, and discovering there also the out- crop of two coal-seams, might begin his workings in the uppermost in the expectation of coming down to the other bed A, which would be observed cropping out lower down the valley. But a glance at the section will demonstrate the futility of such hopes. In the majority of cases, an anticlinal axis forms a ridge, and a syn- clinal axis a valley, as in A, B, fig. 62, p. 48; but there are exceptions to this rule, the beds sometimes sloping in- wards from either side of a mountain, as in On following one of the anticlinal ridsres Fig. 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 Lyell, Charles, Sir, 1797-1875. New York, D. Appleton and co.
Size: 1999px × 1250px
Photo credit: © Paul Fearn / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1860, booksubjectgeology, bookyear1868
