Rock Art Management and Landscape Change: Mixed Field Assessment Techniques for Cultural Stone Decay

As tourism continues to grow as one of the world’s most ubiquitous markets, the development and promotion of non-invasive techniques for cultural stone decay analysis and landscape change are vital to establishing conditional base-lines to best aid cultural heritage management (CRM) efficacy. Using rock art as a medium, this dissertation presents three independent case studies employing the Rock Art Stability Index (RASI) and repeat photography to explore the merits of mixed rapid field assessment techniques in relation to CRM and heritage tourism. While rock art is only one example of irreplaceable world heritage resources, examining how they decay and what methods can effectively quantify their change provides valuable data leading to a better understanding of human/environment interaction within the context of tourism and cultural resource management. The first case study examines the applicability of combining the two methods on rock art in the Arkansan Ozark region, showing considerable promise. The second addresses the temporal flexibility of the mixed methods on rapidly changing, and highly impacted, rock art sites on Grenada, West Indies, demonstrating the method pairing’s tremendous monitoring and emergency response potential. The third case study explores adapting RASI to analyze other forms of cultural stone by employing the mixed methods on selected hewn monuments in Petra, Jordan, aptly identifying a critical disparity between appearance and stability. Ultimately, each case study exemplifies different aspects of cultural stone decay and modern challenges: from initial preliminary evaluations to assessing the impact of uninformed conservation efforts, and examining the influences of mass tourism and human interaction at heritage sites. Mixed field techniques effectively highlighted both the need for and benefits of employing such methods for rock art management, cultural stone stability, and global heritage management

Analysis of Environmental Influences on Dressed Stone Decay: a Case Study of Tafoni Development on a Hewn Djinn Block in Petra, Jordan

Petra, Jordan captivates tourists and researchers with its dramatic sandstone cliffs, Nabatean, Roman, Byzantine and Roman architecture, and rich cultural heritage. However, increasing tourism in the valley is exacerbating stone degradation and complicating heritage management. This research analyzed environmental influences on dressed stone decay via tafoni development and evaluating cell evolution on an isolated hewn feature, known as Djinn Block X. Resembling other sandstone blocks found in the area, this irregular sandstone monument exhibits faces ranging in size from 2.5m by 3.5m to 3.9m to 4.2m (29m perimeter). Protruding features, incisions along the top, and a large platform attached to the northern face suggests this monument was ritualistic or unfinished. Over twenty morphometric and micrometeorologic variables were measured for the ten largest and smallest tafoni cells per face. Data were examined and analyzed statistically, photographically, and cartographically. A mirrored-value-aspect matrix was created to reveal statistical relationships between aspect and detailed measurements including cell depth, average diameter, estimated volume, surface temperatures, ambient temperature, and humidity. Results supported field observations displaying greatest decay on the southern and northern faces with r2 values as high as 0.157 at 144˚N for cell volume (total material lost). Moreover, morphometric data exhibited episodic spikes in cell growth, both by depth and diameter, supporting a possible threshold response explanation. These findings challenge steady-rate decay models and represent major implications for rock decay and tafoni research, as well as cultural stone assessment. Furthermore, Geomorphologic research such as this provides policy-makers information necessary to improve conservation efficacy for crucially sensitive heritage sites

Protecting Stone Heritage in the Painted Desert: Employing the Rock Art Stability Index in the Petrified Forest National Park, Arizona

Located in northeastern Arizona (USA), Petrified Forest National Park (PEFO) presents a unique story of both geologic and human history. Though perhaps most well-known for its abundant petrified wood and being part of the Painted Desert, visitors are often surprised when they discover PEFO hosts many ancient petroglyph sites. Over the years, many attempts have been made to record the petroglyph sites, but nothing has been done to assess their geomorphic stability. To address this shortcoming, we employed the Rock Art Stability Index (RASI) to assess geologic stability and (potential) deterioration of rock art sites in PEFO. Used for more than a decade as a triage for researchers assessing which rock art panels/sites are in the most danger of eroding, RASI uses a rank-based system to assess over three-dozen rock decay parameters, resulting in an overall condition analysis of a rock art panel. The findings can then be grouped together by site location to gain a clearer understanding of overall decay processes responsible for (potential) erosion. This study highlights RASI, its use as a low-cost, non-invasive, rapid field assessment technique, and assesses the geomorphic stability of five major petroglyph sites in the Petrified Forest National Park

Protecting Stone Heritage in the Painted Desert: Employing the Rock Art Stability Index in the Petrified Forest National Park, Arizona

Located in northeastern Arizona (USA), Petrified Forest National Park (PEFO) presents a unique story of both geologic and human history. Though perhaps most well-known for its abundant petrified wood and being part of the Painted Desert, visitors are often surprised when they discover PEFO hosts many ancient petroglyph sites. Over the years, many attempts have been made to record the petroglyph sites, but nothing has been done to assess their geomorphic stability. To address this shortcoming, we employed the Rock Art Stability Index (RASI) to assess geologic stability and (potential) deterioration of rock art sites in PEFO. Used for more than a decade as a triage for researchers assessing which rock art panels/sites are in the most danger of eroding, RASI uses a rank-based system to assess over three-dozen rock decay parameters, resulting in an overall condition analysis of a rock art panel. The findings can then be grouped together by site location to gain a clearer understanding of overall decay processes responsible for (potential) erosion. This study highlights RASI, its use as a low-cost, non-invasive, rapid field assessment technique, and assesses the geomorphic stability of five major petroglyph sites in the Petrified Forest National Park

Protecting Stone Heritage in the Painted Desert: Employing the Rock Art Stability Index in the Petrified Forest National Park, Arizona

Located in northeastern Arizona (USA), Petrified Forest National Park (PEFO) presents a unique story of both geologic and human history. Though perhaps most well-known for its abundant petrified wood and being part of the Painted Desert, visitors are often surprised when they discover PEFO hosts many ancient petroglyph sites. Over the years, many attempts have been made to record the petroglyph sites, but nothing has been done to assess their geomorphic stability. To address this shortcoming, we employed the Rock Art Stability Index (RASI) to assess geologic stability and (potential) deterioration of rock art sites in PEFO. Used for more than a decade as a triage for researchers assessing which rock art panels/sites are in the most danger of eroding, RASI uses a rank-based system to assess over three-dozen rock decay parameters, resulting in an overall condition analysis of a rock art panel. The findings can then be grouped together by site location to gain a clearer understanding of overall decay processes responsible for (potential) erosion. This study highlights RASI, its use as a low-cost, non-invasive, rapid field assessment technique, and assesses the geomorphic stability of five major petroglyph sites in the Petrified Forest National Park

The role of fieldwork in rock decay research: Case studies from the fringe

Researchers exploring rock decay hail from chemistry, engineering, geography, geology, paleoclimatology, soil science, and other disciplines and use laboratory, microscopic, theoretical, and field-based strategies. We illustrate here how the tradition of fieldwork forms the core knowledge of rock decay and continues to build on the classic research of Blackwelder, Bryan, Gilbert, Jutson, King, Linton, Twidale, and von Humboldt. While development of nonfield-based investigation has contributed substantially to our understanding of processes, the wide range of environments, stone types, and climatic variability encountered raises issues of temporal and spatial scales too complex to fit into attempts at universal modeling. Although nonfield methods are immensely useful for understanding overarching processes, they can miss subtle differences in factors that ultimately shape rock surfaces. We, therefore, illustrate here how the tradition of fieldwork continues today alongside laboratory and computer-based investigations and contributes to our understanding of rock decay processes. This includes the contribution of fieldwork to the learning process of undergraduates, the calculation of activation energies of plagioclase and olivine dissolution, the high Arctic, the discovery of a new global carbon sink, the influence of plant roots, an analysis of the need for protocols, tafoni development, stone monuments, and rock coatings. These compiled vignettes argue that, despite revolutionary advances in instrumentation, rock decay research must remain firmly footed in the field. © 2012 Elsevier B.V