The Ordovician Bellefonte Formation is a mapped bedrock unit in central Pennsylvania.

The Bellefonte is defined as a medium-gray, brownish-weathering, medium-bedded dolomite and minor sandstone.

[1] The Tea Creek Member is a medium gray argillaceous limestone.

[2] Deposition of formations such as the Bellefonte Dolomite occurred in environments equivalent to the modern Bahama lagoons, east of Miami.

[3] Relative age dating of the Bald Eagle places it in the Ordovician period.