Mineral Resources
A
mineral resource
is any useful substance
found in the earth that has not been formed by plant
and animal remains. Pennsylvania is fortunate to
rank among the top 10 states inmineral ore
production in the United States.
Our state’s industrial economy benefits greatly
from its deposits of iron ore, sand, stone, and
gravel. Our state ranks 10th in the production of iron
ore. This ore isminedmostly in Berks and Lebanon
counties. Iron ore is used tomake steel.
Stone is found in every Pennsylvania county. Our
state hovers between 1st and 2nd in the production
of stone. Our most important stones are limestone
and slate. Limestone is plentifully located in Centre
and York counties. Crushed limestone is used for
producing cement and lime as well as for producing
steel. In order to help crops grow better, it is spread
over farm fields. Slate is quarried in Lehigh and
Northumberland counties. This stone is used on
roofs, chalkboards, and flooring.
The sand and gravel resources in our state are
found in nearly one-half of Pennsylvania’s counties.
Gravel is used with cement for the production of
concrete products. Sand is usedmainly in the
manufacturing of glass. Glass is one of themost
useful products in the world. One company has
developed thousands of kinds of glass. Founded in
1883, the Pittsburgh Plate Glass Company, renamed
PPG Industries, has 150manufacturing locations
around the world. It is the 2nd largest glass
company in our country.
Human Resources
With over 12.5million people living in our state,
Pennsylvania ranks as the 6thmost populated state
in our nation. Remember, we are ranked 33rd in
terms of our land area size. According to the 2009
population estimate, our average
population density
is 274 people per squaremile. That is well above
our country’s average of 76 people per squaremile.
Our least populated county is Forest and our most
populated county is Philadelphia.
Our state’s population consists of people from
many different countries throughout the world.
People havemigrated to Pennsylvania fromall
continents (except Antarctica). Throughout our
state’s history, our population base has shifted from
more than 95% of the people being from rural areas
to 70% of the people living in urban areas.
The TunkhannockViaduct took advantage of the booming
concrete industry in our state. It was the largest reinforced
concrete structure of its kind when it opened in the early
1900s. Aviaduct is a long, high bridge comprised of many
smaller spans of bridge.
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Understanding Pennsylvania
