. The pictorial sketch-book of Pennsylvania, or, Its scenery, internal improvements, resources, and agriculture, populary described . FIGURE 45. well as the interior strata, are first dislocated by enormous fissures,causeji by the upheaval of the region of which they form a part. U 154 OFF-HAND SKETCHES. Fig. 45 represents such an upheaval, and shows the steep escarpementswhich follow as a natural consequence. It is in these fissures, there-fore, that the formation of valleys commences, gradually enlarginguntil two or more unite. It is thus that most of the mountains eastof the Alleghany have
. The pictorial sketch-book of Pennsylvania, or, Its scenery, internal improvements, resources, and agriculture, populary described . FIGURE 45. well as the interior strata, are first dislocated by enormous fissures,causeji by the upheaval of the region of which they form a part. U 154 OFF-HAND SKETCHES. Fig. 45 represents such an upheaval, and shows the steep escarpementswhich follow as a natural consequence. It is in these fissures, there-fore, that the formation of valleys commences, gradually enlarginguntil two or more unite. It is thus that most of the mountains eastof the Alleghany have been formed, the water traversing them havingcarried off the material lying over them, and thus left steep and. FIGURE 40.
Size: 2693px × 928px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade, booksubjectminesandmineralresources
