The Geology of the Two Lights and Crescent Beach State Parks Area, Cape Elizabeth, Maine


Rugged cliffs and ledges at Two Lights State Park contrast sharply with the low, gracefully sweeping sand beach at nearby Crescent Beach State Park. During coastal storms when ocean waves make their assault on the shoreline, towering breakers crash with unbelievable power onto the ledges at Two Lights, sending billows of spray high into the air. At Crescent Beach, the large wind-driven waves roll toward the beach and break into thundering walls of water, expending their final energy as turbulent foam, washing up the beach face to return seaward before the next swash sweeps by. The tremendous energy of storm waves clearly demonstrates the dynamic processes at work today shaping the coastal zone. At Two Lights, wave erosion is slowly but relentlessly wearing back the land, grinding rocky ledges into pebbles and sand. In contrast, the waves and longshore currents at Crescent Beach deposit sand to form and mold the beauty of the beach.

But this is not where the geologic story of this area begins. To understand that story, the geologist ponders such questions as how the rock ledges were formed from sediments; how they were recrystallized by heat and pressure; how dynamic forces caused them to become tilted, folded, and broken; how these deformed and recrystallized rocks were gradually brought to the earth's surface; how large ice sheets affected the area during the last million years; and how ocean processes sculptured the final coastal landscape. We shall begin our exploration of geologic history with an examination of the area's rocks and the structures preserved in them.

Preface   Introduction   Rocks   Geologic History   Glaciation   Conclusion   Glossary

Last updated on January 16, 2008