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Geology is the study of Earth -- the materials that make it up, the processes that act on those materials, and the history of the planet and its life forms. The rocks under a specific area have a significant impact on how that land can best be used.

The earth’s rocks and surface deposits influence the occurrence and quality of water resources that we need to survive. They provide the energy and mineral resources we need to maintain our modern lifestyle. These materials support our buildings and roads, and determine the nutrients available in the soil for plants and food crops.

Pennsylvania has many types of rocks, each with its own unique properties. These rocks have been shaped by mountain-building and erosive forces.

The varied topography defines six distinct physiographic provinces in our state. Each province has its own economic advantages and geologic hazards and plays an important role in our everyday life.

Basic geologic information can be used for many purposes:

  • To locate and develop economic resources
  • To minimize environmental impacts of development
  • To understand, avoid, and cope with geologic hazards such as landslides and sinkholes
  • To improve land use planning and decision making
  • To understand and protect sources of groundwater
  • To draw visitors to unique geologic features and help educate them

Bureau of Geological Survey

The DCNR Bureau of Geological Survey, also known as the Pennsylvania Geological Survey, is a good place to start an inquiry into the geology of Pennsylvania.

Survey geologists:

  • Research the state’s geologic resources and topography
  • Map the surface and underground rocks and geologic structures across the state
  • Make their findings available through publications and outreach