| Cross Mountain | |
|---|---|
 Cross Mountain (note the tower on the summit) | |
| Highest point | |
| Elevation | 2,062 ft (628 m) |
| Geography | |
| Location | Franklin County, Pennsylvania, U.S. |
| Parent range | Appalachian Mountains |
| Topo map | USGS Clear Spring (MD, PA) Quadrangle |
Cross Mountain is the highest peak in the Bear Pond Mountains, a sub range of the Appalachian Mountains. This grouping of mountains straddle the Maryland and Pennsylvania border.
The Bear Pond Mountains are a sub-range in the Appalachian Mountains, that straddle Pennsylvania and Maryland in the United States. These mountains are a part of the Ridge and Valley Appalachians and reach their highest point at Cross Mountain (Pennsylvania) 2,062 feet (628 m). A unique geologic feature known as the "Punchbowl" occurs in this range. This feature was created by the weathered shales of the Ordovician age in the center of a south-plunging anticline, having been eroded to expose a large amphitheater like feature (punchbowl). Cross and Hearthstone Mountain are made of hard resistant quartzite of the Tuscarora Formation of the Silurian age, which form the walls of the bowl.
The Appalachian Mountains, often called the Appalachians, are a system of mountains in eastern North America. The Appalachians first formed roughly 480 million years ago during the Ordovician Period. They once reached elevations similar to those of the Alps and the Rocky Mountains before experiencing natural erosion. The Appalachian chain is a barrier to east–west travel, as it forms a series of alternating ridgelines and valleys oriented in opposition to most highways and railroads running east–west.
Maryland is a state in the Mid-Atlantic region of the United States, bordering Virginia, West Virginia, and the District of Columbia to its south and west; Pennsylvania to its north; and Delaware to its east. The state's largest city is Baltimore, and its capital is Annapolis. Among its occasional nicknames are Old Line State, the Free State, and the Chesapeake Bay State. It is named after the English queen Henrietta Maria, known in England as Queen Mary.
Cross Mountain and Hearthstone Mountain 2,021 feet (616 m) which is on the Maryland side, form a unique geologic formation known as the "Punchbowl". This feature was created by the weathered shales of the Ordovician age in the center of a south-plunging anticline, having been eroded to expose a large amphitheater like feature (punchbowl). Cross and Hearthstone Mountain are made of hard resistant quartzite of the Tuscarora Formation of the Silurian age.
The Ordovician is a geologic period and system, the second of six periods of the Paleozoic Era. The Ordovician spans 41.2 million years from the end of the Cambrian Period 485.4 million years ago (Mya) to the start of the Silurian Period 443.8 Mya.
In structural geology, an anticline is a type of fold that is an arch-like shape and has its oldest beds at its core. A typical anticline is convex up in which the hinge or crest is the location where the curvature is greatest, and the limbs are the sides of the fold that dip away from the hinge. Anticlines can be recognized and differentiated from antiforms by a sequence of rock layers that become progressively older toward the center of the fold. Therefore, if age relationships between various rock strata are unknown, the term antiform should be used.
Quartzite is a hard, non-foliated metamorphic rock which was originally pure quartz sandstone. Sandstone is converted into quartzite through heating and pressure usually related to tectonic compression within orogenic belts. Pure quartzite is usually white to grey, though quartzites often occur in various shades of pink and red due to varying amounts of iron oxide (Fe2O3). Other colors, such as yellow, green, blue and orange, are due to other minerals.
Cross Mountain is also the site of a deactivated microwave relay station, that was used during the Cold War. The unit was encased in a 103 ft. tower, and known as the "Cannonball" site 2. The site was closed in 1977. Access to the summit is still restricted.
The Cold War was a period of geopolitical tension between the Soviet Union with its satellite states, and the United States with its allies after World War II. A common historiography of the conflict begins between 1946, the year U.S. diplomat George F. Kennan's "Long Telegram" from Moscow cemented a U.S. foreign policy of containment of Soviet expansionism threatening strategically vital regions, and the Truman Doctrine of 1947, and ending between the Revolutions of 1989 and the 1991 collapse of the USSR, which ended communism in Eastern Europe. The term "cold" is used because there was no large-scale fighting directly between the two sides, but they each supported major regional conflicts known as proxy wars.
