Definition        Etymology        Types        Uncertainty        Rock Types        Initiation



Initiation.   How and where tafoni initiate in unknown. I think the tafoni weathering pattern is an emergent pattern in nature, a natural response to energy utilized to denude certain rocky landscapes with ellipsoidal and sometimes nested structures. Lithologic and structural heterogeneity unquestionably influences tafoni development but such variation might not be essential for tafoni to exist. Some workers report on tafoni in homogenous rock with no apparent jointing, bedding, or other structural variations and postulate that tafoni exist stochastically with no preferred orientation, tending to occur at random microscopic points of mineralogical weakness (Calkin & Cailleux, 1962; Dragovich, 1969; Martini, 1978; Mustoe, 1982, 1983; Sancho & Benito, 1990; Mellor, Short, & Kirkby, 1997, Rodriguez-Navarro, Doehne, & Sebastian, 1999; McBride & Picard, 2000).

Some contend complex physical and chemical systems of “dynamic instability and self-organization” govern tafoni development (McBride & Picard, 2000, Turkington & Phillips, 2004). This theory espouses that tafoni develop spontaneously, given certain (and yet unknown) initial conditions that work to maximize rock surface area by increasing the number of rounded cavities. Interestingly, the authors found on the outcrop scale, the rock surface increases in surface area by maximizing the number of cavities, and an individual tafone minimizes surface area by assuming a smooth, rounded shape. Perhaps the tafoni weathering pattern initiates at points of microscopic lithologic weakness (Lee & Parsons, 1995) and in areas of high permeability.