Travel Reference
In-Depth Information
Figure 4. Cross sections showing the formation of the Teton Range.
View looking north,
4a,
shows the situation just before faulting started, where the features
named in quotation marks are not yet formed.
4b
shows the situation today. The fault is
indicated by a solid line, which continues as a dashed line in order to show where the fault
was before the rocks were eroded. Point B started out opposite point A, but the eastern
side moved down while the western side rose, separating the two points by about 19,000
feet (5,800 m). Primarily we notice how the Grand Teton towers over Jenny Lake, but the
tension pulling the plates apart is east-west. The fault motion relieves the tension by mov-
ing point B eastward from adjacent to point A to a point indicated by the vertical dotted
line. The ancient sedimentary rocks, which are about 525 million years old, were depos-
