How do fold mountains change the the earth surface?

Answer 1

Mountains have an interesting birth, life, and very long slow 'death'. They are 'born' when tectonic plates shift, rub against each other, and create a fold in the earth. The Appalachian Mountains run diagonally from northern New England States, southwest into New York, Pennsylvania (where it becomes part of the Alleheny Mountains), into Virginia (where the Blue Ridge Mts sit) and West Virginia, southwest into Tennessee and Kentucky, and from West Virginia through the mid-Atlantic States into Georgia. The Appalachian Mountains, older than the Rocky Mountains, is estimated to have formed when all the continents were still joined as the supercontinent, Pangaea. At that time, the Eastern US States were in the Atlantic Ocean; a tectonic plate under the ocean moved, forcing the land into a fold. As Pangaea broke apart and the Atlantic Ocean changed it's seaboard boundary, the Appalachian Mountains became visible. Though a mountain range, their rounded slopes give evidence of their age, as well as fossils. Experts also believe that at one time, the Appalachian Mountains had volcanoes that last erupted millions of years ago.

Geologically, the Appalachian's rounded slopes are comparable to the "early middle age of humans". Several mountains still have high elevations, matching some of nearly the same heights in New Zealand. But the Appalachians are still very old.

Erosion, one of the greatest forces on land masses, began as soon as The Appalachian Mountains formed. The development of forest and plant life, beginning millions of years ago, protected the slopes from rapid erosion as did the cessation of earthquakes from these once magestic mountains. However, as we all learned in school, erosion is a continual process, serving to enrich the soil in lush valleys surrounding these mountains.

When colonists landed at Plymouth Rock and much later when William Penn founded Pennsylvania, all of the Appalachians (along with the Allegheny Range and the Blue Ridge Mountains) were covered by thick, lush, healthy forests of mature trees, thick varieties of plants, and abundant wildlife. Since mountain travel was too difficult, it wasn't until the late 1700s that settlers followed earlier explorers across the mountains to new lands. Young George Washington, a surveyor at age 17, ventured across the Blue Ridge Mountains in Virginia, where he found evidence of Native American hunting lodges. Experts in migration patterns of early colonists show that most colonists followed the foot trails made by Indians along mountain ridges and waterways. Animal life continues to flourish in eastern and western mountainous regions, including the Rockies which are much, much younger than the Appalachian Mountains.

Experts are in dispute about what might transpire during the Appalachian Mountains "old age" and "death". Certainly, erosion will continue, slowly reducing the height and width of these mountain ridges. However, this will be largely unnoticeable, as it will occur over millions of years. Another possibility is that a millions-of-years old volcano might become active again. Since this mountain chain has had many tunnels dug into it for coal mining and road tunnels, some experts have hypothesized that these manmade intrusions could weaken the mountain structure, leading to more devastation if a volcano would again fill with magma. Other experts believe, like a middle-aged woman, the Appalachian Mountains are long past their ability to produce a new volcano. Certainly, there is no written record of any volcano in that range since the first white men stepped onto the New World.

Today, even with tunnels and paved roads, mountains still pose considerable challenges to and for people. For example, some peaks are so high in the Appalachians that fog enshrouds the mountain into the afternoon on some days. However, that moisture helps the valleys on both sides of the range. Rains and erosin also enrich valley farmlands.

Answer 2

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