The pictorial sketch-book of Pennsylvania : or, its scenery, internal improvements, resources, and agriculture, popularly described . o turn ourbook over, and open it only half-way, exactlyin the middle, and the line between the twopages will present the synclinal line, or thatpoint towards which the strata tend, as exhi-bited in fig. 36. In speaking of strata, in mining phrase-ology, they are said to be conformable whentheir general planes are parallel, no matterwhat may be their dip, as in figure 37, whereboth the upper horizontal strata, a, and thelower inclined series b, are conformable to
The pictorial sketch-book of Pennsylvania : or, its scenery, internal improvements, resources, and agriculture, popularly described . o turn ourbook over, and open it only half-way, exactlyin the middle, and the line between the twopages will present the synclinal line, or thatpoint towards which the strata tend, as exhi-bited in fig. 36. In speaking of strata, in mining phrase-ology, they are said to be conformable whentheir general planes are parallel, no matterwhat may be their dip, as in figure 37, whereboth the upper horizontal strata, a, and thelower inclined series b, are conformable toeach other. When a series of upper strata,however, rest on a lower formation, withoutany conformity to the position of the latter,they bespeak a more modern series, showingthat the newest of the underlaying group musthave been deposited before the oldest of the thus occupy an unconformable position, as exhibited in thesame fig. 37, wherein the upper horizontal beds, a, are uncon-formable to the lower inclined deposits, b. This simple illustrationis very important, because it often shows the position of coal veins13*. 150 OFF-HAND SKETCHES.
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Keywords: ., bookcentury1800, bookdecade, booksubjectminesandmineralresources
