Page 173 - Laboratory Manual in Physical Geology

ACTIVITY 5.9 Infer the Geologic History of Southeastern Pennsylvania

Name: ______________________________________ Course/Section: ______________________ Date: ___________

Review FIGURE 5.15 . Then study the portion of a geologic map of Pennsylvania below. The green-colored areas are exposures of

200–220 million-year-old Mesozoic sand and mud that were deposited in lakes, streams, and fields of a long, narrow valley. The
red-colored areas are bodies of basalt about 190 million years old. Paleozoic and Precambrian rocks are more than 252 million
years old and colored pale brown.
L. Ontario
Buffalo Albany
L. Erie Ithaca Boston
STUDY 0 5 10 15 20 km
AREA
New York 0 5 10 miles
Philadelphia
Washington

N Paleozoic
Richmond rocks
A
Raleigh
Reading
B
Doylestown
Mesozoic
Rocks
Pottstown Mesozoic
B A sedimentary
rocks

Paleozoic
rocks

A. Based on their geometries (as viewed from above, in map view), what kind of igneous bodies on the map are labeled A?

B. Based on their geometries (as viewed from above, in map view), what kind of igneous bodies on the map are labeled B (more

than one answer is possible)?

C. REFLECT & DISCUSS If you could have seen the landscape that existed in this part of Pennsylvania about 200 million
years ago (when the bodies of igneous rock were lava), then what else would you have seen on the landscape besides valleys,
streams, lakes, and fields? Explain your reasoning.

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