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Geography of the Region:
Nelson Rocks is part of the Valley and Ridge Province of West Virginia characterized by a series of long folded mountains and continuous parallel valleys. This province is part of the Appalachian Ridge and Valley belt which lies between the Blue Ridge Mountains to the east and the Appalachian Plateau to the west. This belt stretches from southeastern New York through Virginia and West Virginia down to northeastern Alabama.
http://en.wikipedia.org/wiki/Ridge-and-Valley_Appalachians
Brief Geologic History of West Virginia:
Ancient Oceans:
Most of the rocks in West Virginia are sedimentary, deposited in the Paleozoic Era (600 to 230 million years ago). These sedimentary deposits tell the story of a marine sea covering most of the state and depositing marine limestones, shales, and sandstones during the Cambrian and Ordovician periods.
Ancient Swamps:
The sea retreated at the end of the Mississippian and during the Pennsylvanian (320-284 million years ago) leaving West Virginia low-lying and swampy. During this time, thousands of feet of non-marine sandstone, shale and coal were deposited.
Ancient Mountains:
There have been multiple mountain building events in the geologic history of West Virginia, but one key event was the Appalachian Orogeny. During the Permian Period (290-230 million years ago), movements of the earth’s tectonic plates caused a massive mountain building event that resulted in the formation of the Appalachian Mountains. The layers of Sedimentary limestones, shales and sandstones were folded, faulted, and thrust upwards as a result of continental collision as landmasses came together to form Pangea- a super continent. The Appalachians were once the centerpiece of Pangea, and rose to Himalayan heights, nearing at least 30,000 feet. It is estimated that 300 million years of erosion may have removed as much as 4 miles of rock off the top of these mountains to reduce them to the ridges and valleys we know today.
“A Geologic Transect of the Central Appalachians in West Virginia and Virginia: Allegheny Plateau to the Blue Ridge” Department of Geosciences, Denison University
http://www.wvgs.wvnet.edu/WWW/GEOLOGY/geology.htm
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Geology Tuscarora Quartzite
Tuscarora Quartzite
The big rock formations of the North Fork Valley of eastern West Virginia, such as Champe Rocks, Seneca Rocks and Nelson Rocks, are formations of Tuscarora Quartzite. This is an extremely hard metamorphic rock, ranging in color from a nearly translucent white, to gray, to pink and orange. Laid down as sediment on a sea floor 440 million years ago, the Tuscarora is about 250 feet thick in West Virginia.
It is the same rock which makes up the famous crags of the Shawangunk range in New York. In the "Gunks", the rock appears in horizontal layers, just as it was laid down on the ancient seabed. Along the hills and ridges east of the North Fork River in West Virginia - the "River Knobs" - it has done something different. Here, the quartzite layer was literally turned on end by enormous geological forces during the formation of the Appalachian Mountains some 230 million years ago. A folding of the Earth's crust forced this layer - and the surrounding strata - into enormous arches, miles wide. The River Knobs trace the western wall of this arch, or "anticline", where the Tuscarora was turned a full 90 degrees from horizontal to vertical.
Over time, erosion stripped away the softer rock covering the arch, and finally the dome of the arch itself. The tough quartzite of the western walls resisted this process, leaving soaring "fins" - narrow vertical plates of exposed rock. These unique formations are visible from Highways 55 and 33 throughout the North Fork Valley. Farther east, along the top of North Fork Mountain, the horizontal strata of the far slope of the Tuscarora anticline are still visible.
Another interesting chapter of this story was recently given to us courtesy of Roy Sites, a geologist with the State of Virginia. Many of quartzite outcroppings seen along the River Knobs may be seen as not one, but two parallel fins. These include Champe and Nelson Rocks.
During the rise of the Appalachians, the same forces which formed the anticline caused the Tuscarora to fault or rupture, with the upper layer sliding over and overlapping the lower. As the top of the arch wore away, two fins were left. Nelson is considered one of the best examples of the faulted Tuscarora. Seneca Rocks is a much thicker, monolithic formation. This is because, at Seneca, the rock did not fault cleanly into two layers but rolled over on itself. From Roy Gap, looking north, this effect is clearly visible in the curving layers of rock surrounding the large cave in the south end of Seneca.
A visit to the Via Ferrata at Nelson Rocks Preserve might be just the thing to supplement and reinforce the science standards covered in the classroom. Check out the geology of Nelson Rocks and see how it relates to concepts such as the minerals that make up different rocks and rock types, plate tectonics, and rock types as clues to ancient environments.
Below are a few standards of learning that could be met with a visit to the Via Ferrata. The possibilities are limited only by the creativity of the teacher!
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Virginia Standards of Learning that may be addressed in conjunction with a Via Ferrata visit
ES.5
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The student will investigate and understand how to identify major rock-forming and ore minerals based on physical and chemical properties. Key concepts include
- a) hardness, color and streak, luster, cleavage, fracture, and unique properties; and
- b) uses of minerals.
ES.6
- The student will investigate and understand the rock cycle as it relates to the origin and transformation of rock types and how to identify common rock types based on mineral composition and textures. Key concepts include
- a) igneous (intrusive and extrusive) rocks;
- b) sedimentary (clastic and chemical) rocks; and
- c) metamorphic (foliated and unfoliated) rocks.
ES.8
- The student will investigate and understand geologic processes including plate tectonics. Key concepts include
- a) how geologic processes are evidenced in the physiographic provinces of Virginia including the Coastal Plain, Piedmont, Blue Ridge, Valley and Ridge, and Appalachian Plateau;
- b) processes (faulting, folding, volcanism, metamorphism, weathering, erosion, deposition, and sedimentation) and their resulting features; and
- c) tectonic processes (subduction, rifting and sea floor spreading, and continental collision).
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West Virginia Science Standards that may be addressed in conjunction with a Via Ferrata visit
Earth Science:
SC.O.ES.2.3
characterize the eras, epochs and periods in relation to earth history and geologic development.
SC.O.ES.2.6
use rock characteristics to predict paleoenvironments or geologic conditions which existed during the formation of a given rock sample.
SC.O.ES.2.9
predict geologic activity associated with specific plate boundaries and interactions.
SC.O.ES.2.11
evaluate current explanations for mechanisms, which drive the motion of plates (convection, slab-pull, plate push).
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