Lithic Sourcing

Archeologists guide to toolstone sources.

Texas Root Beer


Widespread in central Texas including Kimble, Kerr Counties, and several adjacent counties. Color variations occur as far east as Comal County and as far north as the Callahan Divide, just south of Abilene (see Pedernales Pink flint). This flint resemble the color of root beer, dark brown to grayish brown, translucent on thin edges. It occurs in lag deposits (deposits left by ancient rivers and streams) on mesas, divides, and upland plains. It also occurs as outcrops in primary context within limestone bedrock formations, and in secondary context in the gravel beds of streams of the region such as the Llano River. The primary context deposits occur in the Segovia and Fort Terrett geological formation “members” of Lower Cretaceous limestone. It commonly occurs as thin, flat cobbles or “slabs”, often  large, with pieces from 12 to 18 inches in length not at all unusual.  The flint typically has a thin white to orange colored cortex (outer rind).  

Texas Root Beer looks similar to Knife River but lacks the white inclusions.

Ordovician Big Fork Chert, Hot Springs, Arkansas. Interbedded chert and shale are strongly deformed in an irregular style. Photo date 3/81, © J.S. Aber. Do not copy without permission.


Diana Rose Angelo, M.A., R.P.A.


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