DISCUSS If you could have seen the landscape that existed in this part of Pennsylvania about 200 million years ago, what else would you have seen on the landscape besides valleys, streams, lakes, and fields?

Lab 5 Ingneous Rocks and Processes

Learning GOAL You will examine a geologic map showing just 3 rock units of different ages and types, and make a reasonable geologic interpretation of the area based on an idealized example of a similar geological setting. Review Fig. 5.25. Then study the portion of a geologic map of Pennsylvania in Fig. A5.9.1. 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.

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York delphia gton

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Paleozoic rocks

• Reading

Mesozoic Rocks

Pottstown • 4L
IAA fi • Doylestovm

Mesozoic sedimentary rocks
Figure A5.9.1 •
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), what else would you have seen on the landscape besides valleys, streams, lakes, and fields? Explain your reasoning.