Nashville Basin
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The Nashville Basin is a geographic term used to describe the area surrounding Nashville, Tennessee. The term would not be correct in the geologic sense, as geologically this structure is more properly known as the Nashville Dome, as the underlying rock strata all dip downwards away from Nashville. In fact, this contributed to the formation of the area, as the uplift caused the exposure of strata (rock layers) which were softer and more easily erodible. This area is also sometimes referred to as the Central Basin of Tennessee.
It is apparently uphill in any direction out of Nashville, as a visit to any of the taller bulidings in the downtown area will readily make apparent. Nashville itself is located in the northwestern portion of this basin. Travelling north or west out of Nashville one will soon begin the climb up the escarpment that marks the bordering geographic/geologic province, the Highland Rim. The basin extends for approximately forty-five to sixty miles to the east of Nashville, and about eighty miles to the south, near the Tennessee-Alabama line.
The Nashville Basin is underlain primarily by limestone from the Ordovician Period. This area and a similar, but smaller area surrounding Lexington, Kentucky referred to as the "Kentucky Bluegrass" area, are the two primary areas of this sort in the world.
The Inner Basin of the flattest terrain and most limestone-derived soil chemistry is located to the south and east of Nashville, primarily in the counties of Maury, Rutherford, Coffee, and Bedford. Here also are seen the horse farms somewhat reminiscient of the Kentucky Bluegrass region. Supposedly the underlying rock weathers to a soil particularly suited to the growing of the sorts of grasses most favored by horses. Limestone glades, open areas where the flat limestone rock is denuded of overlying soil or nearly so, provide an environment for flora unlike any other in the world.
