Atlas of Petroglyph Weathering Forms

Welcome to RASI - Rock Art Stability Index

by the RASI team: Niccole Villa Cerveny, Elyssa Gutbrod, Case Allen, Ronald Dorn, Steve Gordon, David Whitley

This is a dynamic environment used to present the latest information about an entirely new vision for the sustainability of rock art as a cultural resource.

Summary: Existing strategies to characterize the stability of stone require more time, expertise, and cost than normally given to surveys of rock art sites. This field-friendly index includes elements of earth science, engineering, and stone conservation. It has five categories: fissures and rock weaknesses necessary for panel decay; evidence of future detachment; evidence of stone material loss in small increments; evidence of stone material loss in larger increments or chunks; and the role of rock coatings. Initial testing with this scoring system reveals that training of individuals with no prior background in weathering can be conducted within a two-day period and yield reproducible results. RASI's use as a tool of sustainability of cultural resources involves the development of a Geographic Information System to store, display, and analyze rock art.

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The GIS portion of RASI is under development, incorporating the traditional recording of rock art.

Atlas of Petroglyph Weathering Forms
used in the Rock Art Stability Index (RASI)

Site Setting (geological factors)

Fissures independent of stone lithification (pressure release, calcrete wedging)

Fissures dependent on lithification (bedding, foliations)

Changes in sedimentology features (bedding, cementation foliation, banding, striping, concretions)

Hardness of the rock (Moh's test)

Weaknesses of the Rock Art Panel

Fissuresol (future location of flaking or break-offs)

Roots

Plant growth near or on panel

Scaling (larger than flaking)

Splintering (following stone structures and oblique to stone surface)

Undercutting

Weathering-rind development

Other forms (indicating location of future detachment)

Loss of Stone Material

Evidence of Large Erosion events on and below the Panel

Anthropogenic activities

Calcrete/Fissuresol wedging (or dust in fissuresol, or both)

Fire

Undercutting

Other natural causes (wedgework of roots, earthquakes, intersection of fractures, unidentified...)

Evidence of Small Erosion Events on the Panel

Abrasion (from transport of sediment)

Anthropogenic cutting (carving, chiseling, bullet impact, ...)

Aveolization

Crumbly disintegration (in groups of grains and powder)

Flaking (single or multiple)

Weathering rind erosion (important type of flaking)

Granular disintegration

Exfoliation (parallel to surface following stone structure, bedding, banding, foliations)

Lithobiont Pitting of varnish

Lithobiont Erosion releases "dam" of weathered rind

Rock coating (usually incomplete) detachment

Rounding of petroglyph edges

Scaling (larger than flaking)

Sedimentological features erode differentially (clay lenses, cementation differences, nodules)

Splintering (following stone structures and oblique to stone surface)

Other forms of incremental erosion

Rock Coatings on the Panel

Anthropogenic (chalking, graffiti, other)

Rock coatings present

Case Hardening (deposits in rock that harden outer shell)

Efflorescence or subflorescence

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These are details that are not a part of RASI, but could be noted on the form:
Dust Coatings (both atmosphere and runoff)

Efflorescence (salt on surface)

Droppings (phosphate)

Heavy Metal

Iron film

Lithobionts (Biological colonization -lichen, fungi, moss, algae, plants)

Oxalate

Rock varnish

Silica Glaze

Subflorescence (Deposits in the rock that weaken cementation)

The GIS portion of RASI is under development, incorporating the traditional recording of rock art.
Atlas of Petroglyph Weathering Forms used in the Rock Art Stability Index (RASI) Site Setting (geological factors) Fissures independent of stone lithification (pressure release, calcrete wedging) Fissures dependent on lithification (bedding, foliations) Changes in sedimentology features (bedding, cementation foliation, banding, striping, concretions) Hardness of the rock (Moh's test) Weaknesses of the Rock Art Panel Fissuresol (future location of flaking or break-offs) Roots Plant growth near or on panel Scaling (larger than flaking) Splintering (following stone structures and oblique to stone surface) Undercutting Weathering-rind development Other forms (indicating location of future detachment) Loss of Stone Material Evidence of Large Erosion events on and below the Panel Anthropogenic activities Calcrete/Fissuresol wedging (or dust in fissuresol, or both) Fire Undercutting Other natural causes (wedgework of roots, earthquakes, intersection of fractures, unidentified...) Evidence of Small Erosion Events on the Panel Abrasion (from transport of sediment) Anthropogenic cutting (carving, chiseling, bullet impact, ...) Aveolization Crumbly disintegration (in groups of grains and powder) Flaking (single or multiple) Weathering rind erosion (important type of flaking) Granular disintegration Exfoliation (parallel to surface following stone structure, bedding, banding, foliations) Lithobiont Pitting of varnish Lithobiont Erosion releases "dam" of weathered rind Rock coating (usually incomplete) detachment Rounding of petroglyph edges Scaling (larger than flaking) Sedimentological features erode differentially (clay lenses, cementation differences, nodules) Splintering (following stone structures and oblique to stone surface) Other forms of incremental erosion Rock Coatings on the Panel Anthropogenic (chalking, graffiti, other) Rock coatings present Case Hardening (deposits in rock that harden outer shell) Efflorescence or subflorescence - - - - - - - - - - - - - - - - - - - - - - - These are details that are not a part of RASI, but could be noted on the form: Dust Coatings (both atmosphere and runoff) Efflorescence (salt on surface) Droppings (phosphate) Heavy Metal Iron film Lithobionts (Biological colonization -lichen, fungi, moss, algae, plants) Oxalate Rock varnish Silica Glaze Subflorescence (Deposits in the rock that weaken cementation)

original page:
Dorn, R.I. and Cerveny, N.V. (2005) Atlas of Petroglyph Weathering Forms used in the Rock Art Stability Index (RASI). http://alliance.la.asu.edu/rockart/stabilityindex/RASIAtlas.html (originally posted April 1, 2005).

current page:
Cerveny, N.V., Dorn, R.I., Gordon, S.J. and Whitley, D.S. (2007) Atlas of Petroglyph Weathering Forms used in the Rock Art Stability Index (RASI). http://alliance.la.asu.edu/rockart/stabilityindex/RASIAtlas.html (last update March 10, 2007).