The
Blue Ridge, or
Blue Ridge Mountains, is a
physiographic province of the larger
Appalachian Mountains range. This province consists of northern and southern physiographic regions, which divide near the
Roanoke River gap.
The mountain range is located in the
eastern United States, starting at its southern-most portion in
Georgia, then ending northward in
Pennsylvania. To the west of the Blue Ridge, between it and the bulk of the Appalachians, lies the
Great Appalachian Valley, bordered on the west by the
Ridge and Valley province of the Appalachian range.
The Blue Ridge Mountains are noted for their bluish color when seen from a distance. Trees put the "blue" in Blue Ridge, from the
isoprene released into the atmosphere, thereby contributing to the characteristic haze on the mountains and their distinctive color.
Within the Blue Ridge province are two major national parks: the
Shenandoah National Park in the northern section and the
Great Smoky Mountains National Park in the southern section. The Blue Ridge also contains the
Blue Ridge Parkway, a long scenic highway that connects the two parks and is located along the ridge crestlines along the Appalachian Trail.
Geography
Although the term "Blue Ridge" is sometimes applied exclusively to the eastern edge or front range of the Appalachian Mountains, the geological definition of the Blue Ridge province extends westward to the
Ridge and Valley area, encompassing the
Great Smoky Mountains, the Great Balsams, the
Roans, the
Brushy Mountains (a "spur" of the Blue Ridge) and other
mountain ranges.
The Blue Ridge extends as far north into
Pennsylvania as
South Mountain. While South Mountain dwindles to mere hills between
Gettysburg and
Harrisburg, the band of ancient rocks that forms the core of the Blue Ridge continues northeast through the
New Jersey and
Hudson River highlands, eventually reaching
The Berkshires of
Massachusetts and the
Green Mountains of
Vermont.
The Blue Ridge contains the highest mountains in eastern North America. About 125 peaks
exceed in elevation. The highest peak in the Blue Ridge (and in the entire Appalachian chain) is
Mt. Mitchell in
North Carolina at . There are 39 peaks in North Carolina and Tennessee higher than ; by comparison, only
New Hampshire's
Mt. Washington rises above in the northern portion of the Appalachian chain.
The
Blue Ridge Parkway runs 469 miles (750 km) along crests of the Southern Appalachians and links two national parks:
Shenandoah and
Great Smoky Mountains. In many places along the parkway, there are
metamorphic rocks (
gneiss) with folded bands of light-and dark-colored minerals, which sometimes look like the folds and swirls in a marble cake.
Geology
Most of the rocks that form the Blue Ridge Mountains are ancient
granitic charnockites, metamorphosed volcanic formations, and sedimentary limestones. Recent studies completed by Richard Tollo, a professor and geologist at
George Washington University, provide greater insight into the petrologic and geochronologic history of the Blue Ridge basement suites. Modern studies have found that the basement geology of the Blue Ridge is made of compositionally unique
gneisses and
granitoids, including orthopyroxene-bearing charnockites. Analysis of
zircon minerals in the granites completed by John Aleinikoff at the
U.S. Geological Survey has provided more detailed emplacement ages.
Many of the features found in the Blue Ridge and documented by Tollo and others have confirmed that the rocks exhibit many similar features in other North American
Grenville-age terranes. The lack of a calc-alkaline affinity and zircon ages less than 1,200
Ma suggest that the Blue Ridge is distinct from the
Adirondacks,
Green Mountains, and possibly the
New York-New Jersey Highlands. The
petrologic and
geochronologic data suggest that the Blue Ridge basement is a composite orogenic crust that was emplaced during several episodes from a crustal magma source. Field relationships further illustrate that rocks emplaced prior to 1,078-1,064 Ma preserve deformational features. Those emplaced post-1,064 Ma generally have a massive texture and missed the main episode of Mesoproterozoic compression.
The Blue Ridge Mountains began forming during the Silurian Period over 400 million years ago. Approx. 320 mya, North America and Europe collided, pushing the Blue Ridges up higher.
History
The English who settled
Virginia in the early 1600s recorded that the native
Powhatan name for the Blue Ridge was Quirank''.
At the foot of the Blue Ridge, various tribes including the
Sioux Manahoacs, the
Iroquois, and the
Shawnee hunted and fished. As more settlers moved into Virginia, their economic and at times martial competition pushed the native inhabitants west.
Flora and fauna
Musical references
- The song "Stonewall Jackson's Way"
- The song 'Baltimore' by the Virginia based band The Hackensaw Boys features the line "the Blue Ridge Mountains calling me back home".
- Been All Around This World - The Grateful Dead. "Up On The Blue Ridge Mountains, there I'll make my stand."
- The song "Blue Ridge Mountains" by Fleet Foxes contains the lyrics "...I heard that you missed your connecting flight, to the Blue Ridge Mountains over near Tennessee"
- Kristin Hersh's "Houdini Blues," co-written with her father, has the lines: "I been on the other side of the Blue Ridge/Seen the Shenandoah rollin' there."
- Country-folk singer Townes van Zandt sang "My home is in the Blue Ridge Mountains" in the song "Blue Ridge Mountains"
- The song "Spin on a Red Brick Floor" by Nanci Griffith contains the lyrics "Oh the Blue Ridge mountains at the fall of the night; it sure feels good when you cross that line"
See also
