Rydal-Meadowbrook Civic Association

The Geology of Abington

Rocks are classified by mineral and chemical composition; and also by the processes that formed them. Rocks are thus separated into igneous, sedimentary, and metamorphic rocks. There are metamorphic formations in the Rydal-Meadowbrook section of Abington. According to the U.S. Geological Survey, the eastern side of Abington sits upon a geology of the Middle Proterozoic period. Also known as the Mesoproterozoic Era, it occurred between 1600 and 1000 million years ago. The major events of this era are the formation of the Rodinia supercontinent and the breakup of the Columbia supercontinent.

To the west of Edge Hill, the land formed during the Lower Mesozoic era. This began with the Triassic about 250 to 200 million years ago, followed by the Jurassic, which occured about 199 to .6 million years ago. The "Age of Reptiles" was marked by the major Triassic–Jurassic extinction event.  

Sources and Links:
USGA National Atlas
Pennsylvania Geologic Survey
Map of Pennsylvania (PDF)