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As the name implies, the streams of this area have cut deep valleys with steep sided-slopes on the surrounding ridges. Some of the gorges are at least 1,000 feet (305 m) deep. Much of the area was forested at the end of the 19th century, and much of the area is owned by the Pennsylvania Bureau of Forestry.
The Allegheny Group, often termed the Allegheny Formation, [2] is a Pennsylvanian-age geological unit in the Appalachian Plateau.It is a major coal-bearing unit in the eastern United States, extending through western and central Pennsylvania, western Maryland and West Virginia, and southeastern Ohio.
Tantalum is also produced in Thailand and Malaysia as a by-product of the tin mining there. During gravitational separation of the ores from placer deposits, not only is cassiterite (SnO 2) found, but a small percentage of tantalite also included. The slag from the tin smelters then contains economically useful amounts of tantalum, which is ...
The mineral group tantalite [(Fe, Mn)Ta 2 O 6] is the primary source of the chemical element tantalum, a corrosion (heat and acid) resistant metal.It is chemically similar to columbite, and the two are often grouped together as a semi-singular mineral called coltan or "columbite-tantalite" in many mineral guides.
Outcrop of the Devonian Catskill Formation with a well-displayed thrust fault, located about 3 miles west of the village of Juniata Crossing on the north side of Route 30, Bedford County, Pennsylvania. Fossil coral of the Devonian Keyser Formation in the New Enterprise New Paris Quarry, Chestnut Ridge Bedford County, Pennsylvania.
A piece of columbite–tantalite, size 6.0 × 2.5 × 2.1 cm. Coltan (short for columbite–tantalites and known industrially as tantalite) is a dull black metallic ore from which the elements niobium and tantalum are extracted.
Extent of the Pittsburgh coal seam in Pennsylvania, Ohio and West Virginia, excluding the deposit in Maryland. Note that the southwestern portion of the seam is of negligible economic importance. The Pittsburgh coal seam is the thickest and most extensive coal bed in the Appalachian Basin; [ 1 ] hence, it is the most economically important coal ...
Pennsylvania is one of 13 original colonies that share a border with Canada. Pennsylvania is 180 miles (290 km) north to south and 310 miles (500 km) east to west. The total land area is 44,817 square miles (116,080 km 2)—739,200 acres (2,991 km 2) of which are bodies of water. It is the 33rd largest state in the United States.