Human Influence on the Appalachian Mountains

The Appalachian Mountains, located along the eastern edge of the United States, have existed since before humans lived there. Since the Europeans arrived in America, they have been mined, warred in, and built on. This activity has affected the natural geology and ecology of the region.

How the Appalachian Mountain Range Formed

During the early Paleozoic Era what would become North America was at the equator, and the Appalachian region was a passive plate margin. The region periodically became submerged under shallow seas and thick layers of sediment and carbonate rock were deposited. When the seas receded land sediment and erosion dominated the area (Moreno, 2000).
Approximately 440-480 million years ago in the Ordovician Period, the Taconic orogeny, or period of mountain-building, occurred. A micro-continent, Iapetus, collided with the east coast of America, and this resulted in the creation of a mountain range (IRAPP, 2001 and Moreno, 2000). Volcanoes formed, and thrust faulting moved the older sedimentary rock in the region. As the mountains rose, however, erosion began to wear them down (Moreno, 2000).

Throughout the next 250 million years the Caledonian, Acadian, Ouachita, Hercynian, and Allegheny orogenies occurred and continued the mountain-building process (Moreno, 2000).

During the Pennsylvanian Period, about 300 million years ago, the continents began to drift together to form the supercontinent of Pangaea. When Pangaea pulled apart in the Late Triassic or Early Mesozoic Periods the tectonic forces that had created so many mountains were slowed and erosion began to wear the mountains away. At the end of the Mesozoic Era the Appalachian Mountains had been eroded to almost nothing, and it was not until the Cenozoic Era that the region uplifted again and created what we now call the Appalachian Mountain Range (Moreno, 2000).

The range is now about half its original height. There is also evidence of some involvement in the last glaciation in New England (Johnson, 1980, as cited in Rebick and Sonne).

The Geology of the Region

The Appalachian Mountains have been called a “Microcosm of the Earth” because within them there is evidence of nearly every geological event the Earth has gone through. There is limestone, which grows in shallow, tropical water and calcium carbonate, found often in coral reefs. But there is also evidence of dinosaurs, early plants, and deep ocean trenches (Reusch and Reusch, 2001).

The Southern portion of the Appalachian Mountains has been divided into four geomorphic provinces that share geologic features (Schwartz, 2002).

� The Piedmont consists of Precambrian and Paleozoic metamorphosed sedimentary and volcanic rocks with granite intrusions. This region has been eroded to a low relief (Schwartz, 2002).
� The Blue Ridge region consists of Precambrian and Cambrian metamorphosed sedimentary and volcanic rock, but has the highest relief of any area of the Appalachian Mountains. These rocks were thrust over rocks in the Valley and Ridge province. Two important national parks are located in this province, the Shenandoah and Greak Smoky Mountain National Parks (Schwartz, 2002).
� The Valley and Ridge region is home to thick Paleozoic sedimentary rocks and has abundant folds and thrust faults (Schwartz, 2002).
� The Appalachian Plateau contains Paleozoic sediments and much limestone. It also contains Mammoth Caves National Park; the caves exist due to the prevalence of limestone in the region (Schwartz, 2002).

The Blue Ridge Mountains contain a long, wide valley that is the collection of three major drainages, and includes the Shenandoah Valley. The valley is underlain by rock more easily eroded than those of the Blue Ridge (Spencer and Bank, 1998). The only flat route through the Appalachians lies in the Hudson River valley. Other landmarks include the Appalachian Valley, a 2400km (approx 1500 mile) trench that divides the mountains between the east and west (Slayden, 2001).

Located in Maine is Acadia National Park, an area which was has had its vegetation and soil stripped by glacial erosion. It also more fully experienced the Acadian orogeny during the Devonian period, and has been eroded by wave action. It contains “suspect terrane”, a province with geologic features that sharply contrast with that of nearby provinces, from the Avalon terrane during the Acadian orogeny (Schwartz, 2002).

Great Smoky Mountains National Park is the most-visited National Park and the geology of the Shenandoah National Park is similar, but the deformation in the Great Smoky Mountains is more intense, with two major thrust faults, the Greenbrier and Great Smoky Faults. Thrust faults are the dominant feature of the Shenandoah National park, and movement is believed to be as much as 240km (150 miles) westward. The typical rock in the park is Catoctin metamorphosed basalt, Pedlar gneiss, and Old Rag granite (Schwartz, 2002).

West of the Shenandoah Valley is the Valley and Ridge province, an area characterized by parallel ridges separated by stream valleys. Both the James and Potomac rivers begin in this area. This region developed anticlines and synclines during its collision with Africa and Europe in Pangaea. This area is also composed entirely of sedimentary rocks, especially sandstone, shale, and limestone. Shale and limestone make up the valleys, while sandstone is dominant on the mountain peaks (Spencer and Bank, 1998).

The fossilized remains of trilobites can be found in shale regions. Crinoids and bryozoans can also be found fossilized in this region. Limestone also holds shells and other evidence of ancient sea life in the region (Spencer and Bank, 1998).

Human History

The Southern Appalachians were first inhabited by humans around 12,000 years ago. Native Americans camped and hunted throughout the region. Slowly the inhabitants began to make use of the different pieces of the land and settle down, though evidence of gardening does not appear until the period between 300 B.C. and A. D. 600. The year 1540 is the first time Europeans set foot in the Southern Appalachians (Yarnell, 1998).

The Europeans brought social disruption and change from then-established towns, but also brought environmental disruption, with new plants and animals from Europe and Africa entering the landscape. Early Europeans settled in the Valley and Ridge province, and especially in the Shenandoah Valley. Farmers cleared fields and when those they had already cleared yielded less abundant crops they would clear new lands, allowing secondary forests to grow for 20 years or more (Yarnell, 1998).

In the 19th century industry began to develop in the Southern Appalachians, carding factories for wool and distilleries began to appear. In the 1830’s the lumbering business became bigger, and logging routes were traversed on the Little and Big Coal Rivers from 1836 until after the Civil War. Mining also became a large industry at this point in the history of the Southern Appalachians. Salt and saltpeter (potassium nitrate) were necessary products that the mountainous region contained. There were over 50 saltpeter mines at one point, and mining was particularly vigorous during the Revolution, War of 1812, and the Civil War, when the demand for gunpowder was high (Yarnell, 1998).

Iron-making began in Kentucky in 1791 and became another locally important industry. Running these furnaces sometimes caused deforestation of nearby areas, and the furnaces had to be closed for the forests to grow back sufficiently. Competition with wood limited coal mining before the Civil War, and most of the coal was used in the salt and iron industries. Later the coal industry became more important, and in 1840 304,000 tons were mined in two valleys (Yarnell, 1998).

Other mining in the region included copper, gold, lead and zinc. Copper had been mined since prehistoric times in this region, but it was the interest in gold, silver, lead, iron, marble, slate, quartz, and porcelain clay that began environmental problems. Mining operations opened pits in the ground, increased the demand for lumber, and damaged water and vegetation in the vicinity with acidic fumes from smelting (Yarnell, 1998).

In 1828 Georgia’s Appalachians played host to the nation’s first gold rush, and those interested in the gold that the mountains had to offer changed the landscape of the Blue Ridge mountains. The development of hydraulic mining, which produced more gold than traditional panning, was the preferred method. After trees were cleared from a mountainside, engineers would dam a high source of water and channel it to water cannons, which would shoot the water onto the cleared mountainside, washing away the earth that contained the gold. The dirt would run down flumes that trapped the finer pieces and sent larger ones further downhill to the mill for crushing and sorting (Davis, Gold Mining, 2002).

During the Civil War the environment went through many changes, mountaineers were required to hunt more game, and women and children were less able to tend as many crops, thus increasing the erosion. Some regrowth of forests occurred, but military demand on the forests for lumber, roads, and game cancelled out any real gain in forestation (Yarnell, 1998).
Afterward, coal mining became a more important industry. More and more people were using coal instead of wood to heat their homes. At first mining was done with minimal environmental damage using a combination of underground and surface extraction (Davis, Coal Mining, 2002).

However, when the demand rose, new technologies were put into play. By the mid-1800’s miners were using horse-drawn steel scrapers, drills, and black powder to mine coal beds. These processes made more lasting and permanent visible damage to the landscape. After the 1870’s the use of coal began to spread beyond the region, and more and more industrial technologies were used to keep up with the demand (Davis, Coal Mining, 2002).

In the late 1800’s coal mining required large amounts of wooden supports, and deforestation occurred in mining regions. Acid mine drainage polluted thousands of streams in the area by the 1920’s, and since the 1950’s coal has been mined by the strip-mine method. This method involves scraping away the soil and upper rock of a mountain to get at the coal ore underneath (Davis, Coal Mining, 2002).

Mining and lumbering both grew with the railroads as well, and farmers often sold lands to railroad speculators, not knowing the damage that would come to the land. Most damage did not happen until after 1890, when railroads became more important (Yarnell, 1998).

In the late 1800s some began to focus on the environment of the region, and in the late 1890’s the Appalachian National Park Association was created. This did not stop mining and lumbering practices in the Appalachian Mountains, and mechanization of the railroads increased soil leaching, erosion, flooding, and fire frequency. Throughout the 1900s there was an increase in pressure to preserve the environment of the Appalachian Mountains. Recently many operations have gone underway to preserve the environment of the region (Yarnell, 1998).

The Great Smoky Mountains National Park is the most-visited National Park in the area however, the Park’s location near highly developed areas has caused problems. These problems include pollutants from oil and coal burning plants and acid rain that has damaged the Park’s vegetation. In 1976 this Park was established as a Biosphere reserve and is being monitored for pollution effects on plant and animal life (Schwartz, 2002).

Conclusions

Clearly humans in their short span of living among the Appalachian Mountains have affected it greatly. The building of mines, dams, and deforestation has changed the amount of erosion in the region, and polluted much of the region. In the whole length of the geologic history of the region, much of the changes in the landscape have taken place in the last few centuries, as opposed to the millions of years that were needed to create the mountains.

Further, if we are not careful with the natural resources the Appalachian Mountains provide, they will not last forever and we will have greatly damaged a beautiful area of the United States. We can help to put things back the way they were, but we cannot create the mountains again.