Nashville Basin

A false-color satellite image of the Nashville Basin

The Nashville Basin, also known as the Central Basin, is a term often used to describe the area surrounding Nashville, Tennessee. The Central Basin was caused by an uplifting known as the Nashville Dome. The Nashville Dome is evidenced by the underlying rock strata that all dip downwards away from Nashville. The uplifting of the Nashville Dome fractured overlying strata, making it more easily eroded and thus the "dome" resulted in a "basin". Uplifted strata in the center of a geological dome have higher potential erosive energy than the surrounding strata, because they are physically higher. Erosion thus acts on the uplifted area at a greater rate than on the surrounding flat-lying area, creating a low area, i.e. a basin. This area is more correctly 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 buildings in the downtown area will readily make apparent. Nashville itself is located in the northwestern portion of this basin. Traveling 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 state line.

The Central 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 reminiscent 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 (or cedar glades), located to the east of Nashville, primarily in Wilson and Rutherford Counties, are 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.^[1][2]

References

1. ^ "Field Guide to the Limestone Cedar Glades". Center for Cedar Glades Studies at Middle Tennessee State University. Nashville Geology Homepage. 24 September 2007. http://www.nashvillefossils.com/glades/pages/fieldguide.html. Retrieved 16 September 2011. 
2. ^ "Common and Endemic Herbaceous Plants of Cedar Glades by Scientific Name". Bioimages. Vanderbilt University. May 2006. http://www.cas.vanderbilt.edu/bioimages/index/cedar-glade-plants-sci.htm. Retrieved 16 September 2011.