Soil Temperature and Obsidian Hydration Dating: A Clarification of Variables Affecting Accuracy

Cultural transmission, copying errors, and the generation of variation in material culture and the archaeological record

“…These points have been well studied because many have been recovered and they represent the transition from atlatl to bow and arrow hunting (e.g., Eerkens, 1997, 1999;Delacorte, 1999;Fenenga, 1953;Lanning, 1963, p. 249;Thomas, 1981;Yohe, 1992). Moreover, most are made out of obsidian, a material which allows for an independent measurement of age of manufacture using hydration techniques (Ericson, 1989;Hall and Jackson, 1989;Hull, 2001;Jones et al, 1997;Meighan, 1983).…”

Obsidian hydration dating by infrared spectroscopy: method and calibration

“…However, this problem is complex, with many interactive variables that include temperature, glass composition, reactivity of the surface, the precipitation and growth rates of secondary phases, and variation in environmental fluid properties [e.g., pH, flow rates, oxygen fugacity] (Stroncik and Schmincke, 2002;Morganstein et al, 1999;Zhang and Xu, 2003). In the subaerial alteration of glass artifacts many of these issues have received considerable attention such as the effects of ground temperature, soil humidity; glass composition, soil pH, and glass dissolution (Anovitz et al, 2004(Anovitz et al, , 2006a(Anovitz et al, ,b, 2008Friedman and Long, 1976;Hull, 2001;Jones et al, 1997;Riddings, 1991;Rogers, 2007Rogers, , 2008Stevenson et al, 1989Stevenson et al, , 1993aStevenson et al, ,b, 1998Wolff-Boenisch et al, 2004).…”

Obsidian hydration dating on the South Coast of Peru

“…In short, the age increases as the square of the hydration rind thickness. Other than time, at least three other factors affect the rate of hydration, including temperature, water vapor pressure, and glass chemistry (Friedman and Smith, 1960;Friedman and Obradovich, 1981;Jones et al, 1997;Michels and Tsong, 1980). These factors are generally expressed as a constant and subsumed into the term D in Eq.…”