Bedrock geology determines the extent of limestone habitats in Pennsylvania. Blue areas are strongly calcareous, while light blue are moderately calcareous. Glacial deposits in the northwest are also calcareous, and most fens are found along the yellow and orange veins indicating the presence of these sediments

Bedrock geology determines the extent of limestone habitats in Pennsylvania. Blue areas are strongly calcareous, while light blue are moderately calcareous. Glacial deposits in the northwest are also calcareous, and most fens are found along the yellow and orange veins indicating the presence of these sediments