Laboratory Manual for Introductory Geology 4e

EXERCISE 10.15
Name:
Course:
Interpreting Structurally Controlled Landscapes (continued)
Section:
Date:
(d) What is the overall trend of fold hinges in the portion of the Valley and Ridge Province depicted
in the enlargement?
(e) If fold hinges trend roughly perpendicular to the direction of compression, in what direction was the compressive “push”
during the development of the folds in the Valley and Ridge Province? (Geologists have determined that these folds formed
when Africa collided with eastern North America at the end of the Paleozoic Era.)
Shaded relief of central Pennsylvania.
Pennsylvania Valley and Ridge
Province; the ridges are underlain
by resistant sandstone layers.
Pennsylvania Plateau
Province; the pattern of rivers
and tributaries is called a
dendritic drainage pattern.
266 CHAPTER 10 INTERPRETING GEOLOGIC STRUCTURES