Tallassee Metaquartzite of Jacksons Gap Group named in Tallapoosa Co., east-central AL. Consists of massive metaquartzite interbedded with graphitic and sandy-schistose units. Age is middle Paleozoic.

Source: GNU records (USGS DDS-6; Reston GNULEX).

Tallassee Metaquartzite of Jacksons Gap Group is composed principally of graphitic sericite(muscovite)-quartz schist and includes sericite-quartz phyllonite. Sericite phyllonite, blastomylonite, porphyroclastic blastomylonite schist, and mylonite quartzite occur principally along margins in south and form most of unit northeast of Jacksons Gap. Includes masses of interbedded grayish-green sericite phyllite and sericite-quartz-chlorite phyllite.

Source: GNU records (USGS DDS-6; Reston GNULEX).

Lithologic units that compose the Jacksons Gap Group do not disappear beneath the Coastal Plain as previously thought, but can be mapped eastward around the hinge zone of the Tallassee synform where along the eastern limb they become the Loachapoka Schist of the Opelika Complex. The Loachapoka continues along the east limb of the synform into GA where it corresponds to the Sandy Springs thrust sheet of Higgins and others (1988). The Saugahatchee quartzite of the Loachapoka Schist, the Tallassee and Devils Backbone quartzites of the Jacksons Gap Group, and the Chattahoochee Palisades Quartzite are correlative. Authors suggest that the name Chattahoochee Palisades Quartzite be applied to these quartzites and further recommend that the schists of the Loachapoka and Jacksons Gap Group be referred to as the Factory Shoals Formation of the Sandy Springs Group.

Source: GNU records (USGS DDS-6; Reston GNULEX).