Estimating original assemblage content to adjust for post‐depositional vertical artifact movement

Toward the Identification of Formation Processes

“…In short, refinements of stratigraphic interpretation, including microstratigraphy, are clearly needed (Schiffer 1976:137). For empirical studies of vertical artifact movement in stratified sites, see Matthews (1965), Rowlett and Robbins (1982), and Siirainen (1977).…”

Modeling post-depositional mixing of archaeological deposits

“…The structure of the scenario is meant to be consistent with typical forms of evidence collected in the excavation of archaeological sites, namely three dimensional distribution of archaeological specimens in a stratigraphic section. Drawing on models developed to study sea floor bioturbation and sedimentary diagenesis (e.g., Boudreau, 1997;Meysman et al, 2003; see also Rowlett and Robbins, 1982;Shull, 2001), the components of a discrete mathematical model describing the probabilistic transport of archaeological specimens within a sedimentary profile are presented. Of the formalisms available (see Meysman et al, 2003), discrete transport models are both relatively easy to understand and appropriate for treating distributions of archeological materials in buried contexts.…”

“…doi:10. /j.jaa.2007 a priori assumption that the pre-taphonomic assemblages were completely non-overlapping in their attributes (Albert et al 2003;Karavanic and Smith, 1998;Morin et al, 2005;Rowlett and Robbins, 1982); (2) examination of the distribution of refit stone, bone or ceramic specimens between discrete stratigraphic units (Audouze and Enloe, 1997;Bollong, 1994;Delagnes and Roche, 2005;Hofman, 1986;Kroll, 1994;Morin et al, 2005;Surovell et al, 2005;Villa, 1982); and (3) experimental or observational characterization of the behavior of individual taphonomic agents and the development of criteria to aid in recognizing them in the field (Araujo and Marcelino, 2003;Balek, 2002;Bocek, 1986;Erlandson, 1984;Johnson, 1989;Laville et al, 1980;Morin, 2006;Van Nest, 2002). Using the first set of methods, assemblage overlap-for example, in faunal species representation, ceramic or lithic types-is taken as evidence for the presence of post-depositional mixing, but may also serve as a proxy for the magnitude of the disturbance if the degree of overlap can be established.…”

Identifying the Brazil nut effect in archaeological site formation processes

“…According to her, layers and soil should be considered as fluid, deformable bodies through which archaeological items float, sink, or glide. The main forces behind these movements are routinely described not only in terms of biogenic activity, but also by other instances, such as differential stresses in the Aeolian soil column due to consolidation, or due to the wetting and drying of sediments that may cause vertical descent of artifacts into the soil (e.g., Cahen and Moeyersons 1977;Moeyersons 1978;Wood and Johnson 1978;Rowlett and Robbins 1982;Villa 1982;Villa and Courtin 1983;Erlandson 1984;Hofman 1986;Bocek 1986;1992;Bollong 1994;Leigh 1998;Bueno et al 2013;Araujo 2013). To deal with this vertical mixing of archaeological deposits, a series of mathematical models, based on assigning probabilities to a variety of artifact specimens' movements between discrete stratigraphic layers, have even been developed (Brantingham et al 2007).…”