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| Garrett County History | ||||||
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Background Information |
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For a number of years, scientists had observed that rock formations in
one area resembled rock formations in another area, miles apart.
Similar fossils could be found in these rocks, sometimes separated by hundreds
of miles. As time and observations continued they led to the conclusion that the
rock formations had been composed at the same time. Gradually, these rocks were
given the title sedimentary rocks because they were assumed to have been
formed by sediments deposited in either fresh or salt water seas formed by the
uplifting and depression of land masses to form the seas.
This uplifting and depression of the land masses to form various beds of rock led to a fundamental law of geology called the Law of Superposition. The “Law of Superposition” states that the oldest rock beds are on the bottom of a particular rock formation and the newest rock beds are on the top. Differences in the composition of the material forming the rock beds also led to the theory of erosion of older formations, uplifted hundreds of miles away, and their materials being re-deposited to form new rock beds. (In Garrett County, the “conglomerate sandstone” containing pebbles of older rocks is a good example of the erosion of older rock beds to form new ones.) |
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Continental Drift |
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Similar rock formation containing the same fossils were found on
different continents, and this led to the theory of Continental Drift.
It was put forward by many geologists; foremost among them was Alfred Wegener
in the early 1900’s. Missing from this theory, however, was a reasonable mechanical
explanation of how the “drift” came about. Following WW II, and the development of
electronic measurements, the wedging apart of the continents by ridges built up
in the oceans, led to the idea of plate tectonics and the mechanical
explanation for the Continental Drift.
The wedging apart of the continents also accounted for the great lateral pressures which would bring about folding of the rock strata of the crust of the earth to form mountains. |
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Definitions |
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Garrett County Topography |
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The topography of Garrett County consists of a series of large and small
hills. In some areas, “glade land” stretches out between the hills, forming a
drainage area for small streams feeding into larger ones. In other areas, the
hills slope directly down into a small streams. In general, these changes in
topography are due to a series of geosynclines and geoanticlines which traverse
Garrett County at roughly 30 degrees northeast /
southwest.
Rock beds folding east and west through the County, gradually turn from geosynclines to geoanticlines, and many of the flat glade areas throughout the County sit on top of subterranean geoanticlines. A good example of this folding is the geosyncline which carries the water of the North Branch of the Potomac River. The western outcropping of this rock structure forms cliffs along the western face of Backbone Mountain. The eastern face by contrast, gradually dips toward the Potomac River and rises gently to crest in West Virginia. The eastern face of this geosyncline is the formation generally referred to as Allegheny Front. |
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"The Youghiogheny River follows the axis of another geosyncline." |
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Between the geosynclines which carries these two rivers is a geoanticline, which is
called the “Deer Park Anticline.” On top of this anticline can is found a series of
glades such as the Pleasant Valley area with “Yough Glades”, or “Cherry Glades” found
on top of Meadow Mountain. One oddity of this geoanticline is the fact that it
carries a strata of rock infused with natural gas.
The presence or absence of natural gas along this geoanticline is due to fracturing of the rock strata along its axis. For example, a “fault” in the rock strata accounts for natural gas being found east and west of Accident, Md., but not existing under the town. |
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