High on the Mountain
So, how is it that Alleghany County is in the mountains anyhow?
Well, it wasn't always that way.
Back in the good old days a billion years, or so, ago Alleghany County was part of a single land mass that included not only modern day North America but also Africa. Hot magma pushed the land mass up, breaking it into two continents. The granite rock we have today comes from the cooling of the magma of that period. Valleys formed during the breakup and sand, shale and limestone filled them, eventually turning into sedimentary rock. The sand became sandstone. The sandstone and shale became quartizite, gneiss and schist. And, the limestone turned into marble.
Alligator Back at Mile Post 242 on the Blue Ridge Parkway is an example of gniess and schist formed about 750 million years ago.
A great deal of pushing and shoving occured over a period of about 500 million years. The movement, generally toward the northwest, thrust the softer sedementary rocks up and over the harder igneous granite. And, that's how Alligator Back got from some ancient valley to the top of The Bluffs.
The wrinkled shape of the Blue Ridge Mountians we see from the air today dates from the end of these movements about 50 million years ago. With an elevation of 4175 feet, Catherine's Knob on the Peach Bottom Mountains (the peak to the extreme left of the view from my WebCam) is the highest peak left by all this activity in Alleghany County.
Now Grandma's old, but she ain't nearly as old as these hills.
Well, it wasn't always that way.
Back in the good old days a billion years, or so, ago Alleghany County was part of a single land mass that included not only modern day North America but also Africa. Hot magma pushed the land mass up, breaking it into two continents. The granite rock we have today comes from the cooling of the magma of that period. Valleys formed during the breakup and sand, shale and limestone filled them, eventually turning into sedimentary rock. The sand became sandstone. The sandstone and shale became quartizite, gneiss and schist. And, the limestone turned into marble.
Alligator Back at Mile Post 242 on the Blue Ridge Parkway is an example of gniess and schist formed about 750 million years ago.
A great deal of pushing and shoving occured over a period of about 500 million years. The movement, generally toward the northwest, thrust the softer sedementary rocks up and over the harder igneous granite. And, that's how Alligator Back got from some ancient valley to the top of The Bluffs.
The wrinkled shape of the Blue Ridge Mountians we see from the air today dates from the end of these movements about 50 million years ago. With an elevation of 4175 feet, Catherine's Knob on the Peach Bottom Mountains (the peak to the extreme left of the view from my WebCam) is the highest peak left by all this activity in Alleghany County.
Now Grandma's old, but she ain't nearly as old as these hills.
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