Pennsylvania Landforms

Mrs. Shull

What is geography? That sounds like geology.Geography is the study of the shape of the

land.Does all of Pennsylvania have the same

landforms?NO!There are lots of different geographic areas in

Pennsylvania.

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The Allegheny Plateau.A plateau is a relatively level area that is raised

up above the rest of the land. Plateaus are often cut by steep-sided valleys

called canyons.“Mountains” and valleys – most mountains are

about the same height.Streams have a branching, tree-like – or

dendritic- pattern.Ridges and valleys – long, narrow ridges and

broad valleys.The Susquehanna River flows around the

ridge.

Muncy Creek Gaging Station

http://waterdata.usgs.gov/nwis/uv?01553005

The Grand Canyon

Was this area once covered by water?YES! A large body of water once covered the land here.The rocks were formed from sediments being laid down,

then compressed – or “pressed” together.The land was “uplifted” – or raised, and the water

drained away.The land was eroded, or washed, away by stream

water.Freezing and thawing helped to “break up” the rock.Did a glacier cover the land where we live?

NO. But, it came pretty close. Areas to the north of us, and in the Poconos in Pennsylvania were covered by glaciers.

The rock beds, which were formed the same way as the ones above, were then “squashed” or folded by colliding land masses.Europe and Africa collided with North America.

After the land was uplifted and drained, streams started eroding away the weaker rocks, making big valleys.

Boulder field made from ice within the soil and rock, causing the rocks to “creep”.

From being located “near” glaciers, the climate was cold enough to freeze the water in the soil.

Dye Trace

Sinking Stream

YES. There are some areas where you can find caves.

How did caves form?The rock in which caves form is called

limestone. It is easily dissolved away by water.The water dissolves “pockets” of the limestone,

leaving caves.

Sinkholes

Pop Quiz! What kind of rocks do we find around

Muncy?A. IgneousB. SedimentaryC. Metamorphic

• How were the mountains around Muncy formed?

• Was Muncy covered by a glacier?• What kind of weathering causes caves and

sinkholes?