Ringing Rocks County Park contains a 7-acre boulder field with an unusual feature: about a third of these rocks clang with a metallic ring when struck.
The boulder field reached its current position about 12,000 years ago when the last Ice Age melted the great Wisconsin Glacier away from this part of Bucks County Pennsylvania. The rocks of this flora-free field are made of a volcanic basalt called diabase (which happens to be the main component of the earth’s crust). The aluminum and iron that feature prominently in diabase is only part of what make these rocks “sing”. Another explanation for their auditory qualities is that the interiors of the ringing boulders have a great amount of tensile stress, with the “pulled out” molecules allowing for sound waves to resonate at levels the human ear can detect.
In 1918, a man named Abel B Haring donated the boulder field to the Bucks County Historical Society to protect these unusual rocks from being quarried. But by now the park has added much more land, bringing the forested area around the boulder field up to 129 acres, including High Falls (third slide), the largest waterfall in Bucks County.
