By applying the various principles, draw a cross section of an area in which the following sequences of events occurred. The relative time relationship for all events should be clear to you from your single cross section that shows what the geology looks like at present.
a. Metamorphism took place during the Archean. During later Precambrian time, uplift and erosion reduced the area to a plane.
b. Three layers of marine sedimentary rock (limestone) were deposited on the plane during Ordovician through Devonian time.
c. Although sedimentation may have taken place during the Mississippian through Permian, there are presently no sedimentary rocks of that age in the area.
d. A vertical dike intruded all rocks that existed here during the Permian.
e. A layer of sandstone was deposited during the Triassic.
f. All of the rocks were tilted 45 during the Cretaceous. This was followed by erosion to a planar surface.
g. The area dropped below sea level, and two layers of Tertiary sedimentary rock were deposited on the erosion surface.
h. Uplift and erosion during the Quaternary resulted in a slightly hilly surface.
i. Following erosion, a vertical dike fed a small volcano
Geology - Miriam, Tuesday, February 23, 2016 at 5:18pm
All of the rocks were tilted 45 degrees during the early Cretaceous. This was followed by erosion to a planar surface.