Hartselle sandstone is a common type of Mississippian Period sandstone encountered in northern Alabama. It was laid down when the area laid beneath a shallow sea bed approximately 325 million years ago.
The primary accessible deposits are aligned in a swatch stretching from a point just east of Bessemer and northeast toward Colvin Mountain, which is east of Gadsden in Etowah County. It is the stone which makes up Sand Ridge on the southeastern slope of Red Mountain and is present on the west side of Jones Valley between Bessemer and Vance. It is encountered in the "Rocky Row" between Pinson in Murphree's Valley and the Cahaba River valley near Leeds. Another outcropping forms the hogback ridge that passes through Blount Springs and reappears intermittently in the Sequatchie Valley as far as Guntersville. Additional outcroppings appear in the elevated plateau in western Colbert County and in a thin bed north of Monte Sano.
Hartselle sandstone was quarried to be ground into sand by casting industries in the Birmingham District. One quarry was just north of Red Gap near Irondale and another, operated by the Tennessee Coal, Iron and Railroad Company was located near Vanns, north of Trussville. A prominent exposed bluff was cut through for a railroad a mile east of Odenville.
The thickest beds, as much as 200 feet thick, are found in southern Colbert County. It is estimated to be approximately 100 feet thick at Sand Mountain along the northwest of Shades Valley and in the vicinity of Blount Springs. It is much thinner in its northern reaches, diminishing to about 5 to 10 feet in Monte Sano.
Character and use
The quality of Hartselle sandstone varies greatly. It has a medium grain in the thick beds of Colbert County and the plateau south of the Tennessee Valley, but is found interlaced with shaly layers in many areas, such as alongside the Tuscumbia-Frankfort Road. Near Blount Springs it is a very-hard, fine-grained rock which could be classed as a quartzite. The hard stratum is upturned in the "Rocky Row" near Pinson and stands prominently above adjacent eroded soils. West of Irondale, however, the sandstone is friable and can be crumbled into sand easily.
In some areas, such as near Littleville in Colbert County the sandstone is impregnated with bituminous alphaltum, leading some to explore the possibility that the bed harbors oil reserves, perhaps extending below the Warrior coal fields of Northwest Alabama.
During the rapid growth of Birmingham sandstone from Sand Ridge was quarried in several locations for use in building, landscaping and civil engineering. Notably it is used in Avondale Park, Lane Park and on the tower constructed for Vulcan in the 1930s. Small quarrying operations all along the ridge were undertaken for particular construction projects. The use of sandstone in architecture and landscape was the subject of an exhibit at Vulcan Park during the Summer of 2008.
- "Geology of Alabama" (1926) Special Report No. 14. Birmingham: Geological Survey of Alabama
- Kelley, Barbara T., ed. (2008) Birmingham Rocks: History and Use of Native Sandstone in our Architecture and Landscape. Exhibition catalog. Birmingham: Vulcan Park Foundation.