Lebanon County is a county located in the U.S. state of Pennsylvania. As of the 2010 census, the population was 133,568. Its county seat is Lebanon. The county was formed from portions of Dauphin and Lancaster counties in 1813, with minor boundary revisions in 1814 and 1821. Lebanon County comprises the Lebanon, PA Metropolitan Statistical Area, which is also included in the Harrisburg-York-Lebanon, PA Combined Statistical Area.
sedimentary rocks change with heat and pressure and become metamorphic rock then rocks melt into magma.
Metamorphic rocks can form from either sedimentary or igneous rocks. The sedimentary particles from which a sedimentary rock is formed can be derived from a metamorphic, an igneous, or another sedimentary rock. All three rock types can be melted to form a magma. Thus, the cycle has continued over the ages, constantly forming new rocks, breaking those down in various ways, and forming still younger rocks. Rocks at the surface of the earth range in age from over three billion years old to a few hundred years old.