TALLAHATTA QUARTZITE
Tallahatta Sandstone, also known as Tallahatta quartzite, is a light gray quartz arenite with a distinct snow-flake pattern. The name Tallahatta comes from an Indian term meaning “white rock.” This name is appropriate for the formation, which is light in color where it is exposed at the surface. It was one of the most common lithic materials used by prehistoric peoples in south Alabama.
A quary site in eastern Mississippi
Perhaps the most noted exposures of this formation are the off-white claystones seen in the vertical road cuts west of Meridian, Mississippi, on Interstate 20. Outcrops of erosion-resistant Tallahatta lithologies form a series of ridges and hills known as the Tallahatta cuesta. This cuesta extends from the formation's type locality in the Tallahatta Hills of southern Alabama northwest ward through Lauderdale County, Miss. and into north-central Mississippi. Tallahatta Sandstone is interbedded in some areas with Tallahatta Chert, which is a seam material in some portions of the formation.
The Tallahatta Formation is Middle Eocene in age and consists of silicic claystones, sands, and sedimentary quartzites of marine origin. The quartzites are composed of well-sorted, medium grained quartz sand that is hardened by weakly luminescent phases of opal-CT, chalcedony and some glauconite cemented together by silica. This binds the grains together so strongly that when broken, the fracture cuts through individual grains rather than around them as it would in sandstone. Tallahatta quartzites have a characteristic gray to white sugary texture with scattered dark grains of glauconite. Along a broken surface, fracture surfaces of individual quartz sand grains are slightly inclined to that of the matrix. This gives fracture surfaces a sparkling appearance. The snowflake pattern is caused by patchy distribution of chert cement.
Tallahatta quartzites are unique among coastal plain rocks for their hardness and durability. Tallahatta Sandstone was employed in the region to make a wide variety of stone tools, from the earliest documented settlement during Paleoindian times (circa 15,000 years ago) up until contact with Europeans. Early settlers used these rocks for millstones. While quartzite ledges of a foot or Jess in thickness are common in the Tallahatta Formation, only a few are of the quality needed for knapping tools. These tools have been recovered from sites hundreds of miles from the source. For this reason, the Indians prospected for outcrops or stream beds with the high quality stone. Studies of Alabama quarry sites have shown that Tallahatta Sandstone is the most widely distributed of the three major knappable stone types in south Alabama and has the most identified prehistoric quarries. Sites for this stone were discovered and rediscovered over a period of several thousand years by various Indian groups.