Stone Monuments Research Articles

Microbiome of seventh-century old Parsurameswara stone monument of India and role of desiccation-tolerant cyanobacterium Lyngbya corticicola on its biodeterioration

The Parsurameswara stone monument, built in the seventh century, is one of the oldest stone monuments in Odisha, India. Metagenomic analysis of the biological crust samples collected from the stone monument revealed 17 phyla in the microbiome, with Proteobacteria being the most dominant phylum, followed by cyanobacteria. Eight cyanobacteria were isolated. Lyngbya corticicola was the dominant cyanobacterium in all crust samples and could tolerate six months of desiccation in vitro. With six months of desiccation, chlorophyll-a decreased; however, carotenoid and cellular carbohydrate contents of this organism increased in the desiccated state. Resistance to desiccation, high carotenoid content, and effective trehalose biosynthesis in this cyanobacterium provide a distinct advantage over other microbiomes. Comparative metabolic profiles of the biological crust and L. corticicola show strongly corrosive organic acids such as dichloroacetic acid, which might be responsible for the biocorrosion of stone monuments.

The contribution of 3D models to the study of stone monuments in the Maya area

The Maya area is known for its numerous monuments sculpted in limestone, which suffered severe erosion over time. The Mayas used soft limestone, which is sensitive to weathering, to carve iconographic motives and inscriptions on stelae, altars and panels. A systematic program of documentation was developed for monuments considered plain—without reliefs visible to the naked eye. Thanks to photogrammetry and various treatments generated from photographic recordings, a series of new data has been revealed, enriching our knowledge of the political history of the Maya cities. This case study is centered on a selection of monuments from the urban Maya center of Naachtun (Classic period, 150-950 CE) and contains useful archaeological, epigraphic and historical data. Our objective is also methodological and aims to report on treatments generated from photographic recording. Diverse and rich, these treatments can be applied on weathered monuments to enhance their relief.

A Machine Learning Approach for Automated Detection and Classification of Cracks in Ancient Monuments using Image Processing Techniques

Stone monuments stand as enduring testaments to human history and cultural heritage, yet they are susceptible to deterioration over time. In this paper, we propose a comprehensive approach for the automated detection and classification of cracks in ancient monuments, integrating machine learning and advanced image processing techniques. Our method addresses the pressing need for efficient and objective assessment of structural integrity in these invaluable artifacts. The proposed algorithm begins with preprocessing steps, including image enhancement using adaptive histogram equalization to improve crack visibility. Subsequently, feature extraction techniques such as Grey Level Co-occurrence Matrix (GLCM) and Local Binary Pattern (LBP) are applied to capture essential characteristics of crack patterns. Central to our approach are the Back Propagation Neural Network (BPNN) and Improved Support Vector Machine (ISVM) classifiers, which are trained on the extracted features to detect and classify cracks with high accuracy. The BPNN learns complex relationships between input features and crack types, while the ISVM leverages a margin-based approach for robust classification. Through extensive experimentation on a diverse dataset of ancient monuments, we demonstrate the effectiveness of our approach in accurately identifying and categorizing cracks. The proposed method offers a scalable and objective solution for monitoring the structural health of ancient monuments, contributing to proactive conservation efforts and the preservation of cultural heritage.

МЕЖДУ ПРОШЛЫМ И БУДУЩИМ: РЕПРЕЗЕНТАЦИЯ ИСТОРИЧЕСКОЙ ПАМЯТИ В РУНИЧЕСКИХ НАДПИСЯХ V-XI ВВ.

The article deals with the representation of the collective historical memory in runic writing. In the 5th – 7th centuries runic inscriptions on stone monuments start to mention public events, such as the death of a chieftain or public sacrifice, preserving thus the historical memory about it. The texts include only ‘keys’ that actualize the memory, a personal name first of all. The emergence of the memorative function changes attitudes to the monuments. They become public value that is protected by spells against anyone who harms the monument. A memorial formula opens with the ‘key’ to the historical memory – the name of the remembered person. In the 9th to 11th centuries the memorial formula is further transformed: it now opens with the names of those who ordered the monument, then follows the statement about its erection, the name of the deceased and his relationship in kinship with the customer(s). The transfer of the emphasis to the customers points to the importance of preserving information on their relationship, probably to confirm their inheritance rights. The glorification of the deceased and making the genealogical information public, however, do not remain events of public concern. The memorative function of runic monuments thus declines, they represent a family and not collective historical memory. Later runic writing loses its memorative function altogether; it becomes the means of communication between individuals.

Megalithic tradition associated with agricultural ritual

The Tiwa community is one of the autochthonous communities of Northeast India. An important aspect of Tiwa culture is the erection of stone monuments during the celebration of Chongkhong Phuja. This ceremony is performed before the commencement of their yearly agricultural cycle which falls in late April and continues to early May. On this occasion, a menhir and table stone are erected by the head priest of the Tiwa village, who then invokes their village guardian deity to call for a better harvest as well as for the wellbeing of the villagers. This elaborate ceremony marks the beginning of the agricultural season for the year, following which the villagers commence their agricultural activities. This paper deals with the performance of Chongkhong Phuja and the associated living megalithic tradition among the Hill Tiwas residing in the Umswai Valley. It also documents the oral traditions associated with the origin of the megalithic tradition in the community. As most of the living megalithic traditions among the ethnic communities of Northeast India are either related to burial practices or commemorating the death of a person or an event, this Chongkhong Phuja represents a unique example of a megalithic tradition related to agricultural practice. Indirect evidence suggests the megalithic structures present at the ceremonial place of the Chongkhong Phuja in the Amsai village of the Umswai Valley have been continuously erected for the last thousand years. The paper also hypothesizes the shifting cultivation in the area to be as old as the practice of the megalithic tradition.

Recolonization dynamics of marble monuments after cleaning treatments: A nine-year follow-up study

The prevention and control of biological patinas on outdoor stone monuments represent a demanding challenge for the conservation of cultural heritage also due to some microorganisms, particularly resistant to treatments, such as black meristematic fungi, an eco-physiological group well known for its tolerance to extreme conditions. Even if several methods and eco-friendly products have been proposed as new alternatives, traditional biocides are still far from being completely replaced. Recolonization is a natural process that occurs sooner or later after cleaning. The time that elapses until its occurrence can vary considerably depending on environmental conditions and the used products; unfortunately, the papers describing the effect of treatments over time are rare. This work aims to shed light on the recolonization process of marble surfaces in the ancient monumental cemetery of Bonaria (Cagliari) after nine years from treatments, evaluating the long-term efficiency of two different cleaning methods, namely dimethyl sulfoxide-based gel (DMSO-based gel) and Biotin T (a didecyldimethylammonium chloride-based product-). In this context, the microflora present before treatments and in the following years was assessed by culture-based methods and identified by molecular techniques, with attention on black meristematic fungi, which were used as reference for the most resistant lithobiontic organisms. Different environmental parameters, such as temperature, exposition, dominant winds, and rainfall, were considered, and infrared thermography, portable light microscopy, and image analysis were used. This research evidenced the influence of water availability and lightning in recolonization processes, the transition from the pioneer fungal community versus more resistant black fungal species after Biotin T treatment, and the long-lasting efficiency of the DMSO-based gel. These findings prove that this low-impact method deserves more attention in the conservation of outdoor marble monuments, emphasizing the importance of long-term studies.

The provenance of the stones in the Menga dolmen reveals one of the greatest engineering feats of the Neolithic

The technical and intellectual capabilities of past societies are reflected in the monuments they were able to build. Tracking the provenance of the stones utilised to build prehistoric megalithic monuments, through geological studies, is of utmost interest for interpreting ancient architectures as well as to contribute to their protection. According to the scarce information available, most stones used in European prehistoric megaliths originate from locations near the construction sites, which would have made transport easier. The Menga dolmen (Antequera, Malaga, Spain), listed in UNESCO World Heritage since July 2016, was designed and built with stones weighting up to nearly 150 tons, thus becoming the most colossal stone monument built in its time in Europe (c. 3800–3600 BC). Our study (based on high-resolution geological mapping as well as petrographic and stratigraphic analyses) reveals key geological and archaeological evidence to establish the precise provenance of the massive stones used in the construction of this monument. These stones are mostly calcarenites, a poorly cemented detrital sedimentary rock comparable to those known as 'soft stones' in modern civil engineering. They were quarried from a rocky outcrop located at a distance of approximately 1 km. In this study, it can be inferred the use of soft stone in Menga reveals the human application of new wood and stone technologies enabling the construction of a monument of unprecedented magnitude and complexity.

Biomineral deposits and coatings on stone monuments as biodeterioration fingerprints

Biominerals deposition processes, also called biomineralisation, are intimately related to biodeterioration on stone surfaces. They include complex processes not always completely well understood. The study of biominerals implies the identification of organisms, their molecular mechanisms, and organism/rock/atmosphere interactions. Sampling restrictions of monument stones difficult the biominerals study and the in situ demonstrating of biodeterioration processes. Multidisciplinary works are required to understand the whole process. Thus, studies in heritage buildings have taken advantage of previous knowledge acquired thanks to laboratory experiments, investigations carried out on rock outcrops and within caves from some years ago. With the extrapolation of such knowledge to heritage buildings and the advances in laboratory techniques, there has been a huge increase of knowledge regarding biomineralisation and biodeterioration processes in stone monuments during the last 20 years. These advances have opened new debates about the implications on conservation interventions, and the organism's role in stone conservation and decay. This is a review of the existing studies of biominerals formation, biodeterioration on laboratory experiments, rocks, caves, and their application to building stones of monuments.

Kuşadası'ndaki Ilıcatepe'nin Kyklopien Duvarları Üzerine Düşünceler

Ilıcatepe, located right on the edge of the Kuşadası-Davutlar modern highway, covers an area of 540x315 meters and consists of limestone bedrock with a height of about 50 meters, and is surrounded by a wall built with Cyclopic stonework, which is understood to have been cut from its own bedrock. This masonry, which is not very common to see in Western Anatolia, attracted the attention of researchers who came to the hill, and some researchers suggested that the wall may belong to the 2nd millennium BC. The strategic importance of this hill, which is located on the slope of Mykale, which is considered by many researchers as Arinnanda, and 4 km away from Kadıkalesi, cannot be ignored. Although the walls built with monumental stones in Western Anatolia are generally approached with suspicion, considering the findings in the researches made in Caria in recent years, similar masonry known to exist in mainland Greece, Crete, Aegean Islands and Central Anatolia can be found in Western Anatolia. It is very natural to come across. Although the walls built with monumental stones in the Archaic Period are known in Western Anatolia, the juxtaposition of the stones, the filling of the gaps between the stones, and the differences in the type and material of the masonry tools used help in the dating of the walls. Historical events in the immediate vicinity of Ilıcatepe increase the strategic importance of the hill. The expedition organised by the Hittite king Murshili II (1322-1298 BC) against the Arzawa Country in Western Anatolia is very important in terms of our knowledge of the geography of the region. In the third year of his reign after becoming the Hittite king, Murshili II marched on Arzawa on the pretext of the non-return of the Hattian refugees who fled from the Hittite lands to the Arzawa Kingdom. At that time, Uhhaziti was at the head of the Arzawa Kingdom. The route of Murshili II during the said campaign started from the land of Hatti and ended in the country of Arzawa and the Aegean coast. The Hittite army under the command of Murshili II followed certain routes and arrived at its final destination, Mount Arinnanda. Based on the king's account of this campaign, it is understood that some of the Arzawans fled to the Aegean islands before the Hittite army arrived. The records indicate that those who did not flee to the Aegean islands ascended Mount Arinnanda, took refuge in Puranda, which is understood to be a fortified centre, and prepared for war there. The passages in which Murshili II describes his struggle with those who fled to Mount Arinnanda are quite remarkable.

A Visual Approach to the Damage Diagnosis of Monoliths from the Monquira Archaeological Park - El Infiernito in Colombia

Natural stones of monuments represent an important part of our world’s cultural heritage but deteriorate by the direct or indirect interaction of mineral and stone weathering. Application of damage indices improves stone damage diagnosis and is very appropriate for the determination of necessary preservation procedures as well as the long-term survey and maintenance of stone monuments. The sandstones used at El Infiernito in Villa de Leyva, Colombia, today show weathering damages of partly extreme intensity. In-situ surveys allowed damage mapping to identify major causes of damage and to understand their relationship with stone and environment characteristics. In this research, the results of describing the state of deterioration of the pre-Hispanic phallic monoliths in the Archaeological Park of Monquirá "El Infiernito", are presented in the form of monument visual posters. On the basis of the visualizing of weathering forms at representative monoliths, the state of deterioration is precisely characterized and evaluated. The monument mapping and photographic documentation method can also be useful for reassessing weather damage in the framework of long-term monitoring and maintenance of monuments. This article presents the methodology of mapping weathering forms of stone monuments by using a visual classification system developed over the years with various applications.

Unraveling the microbiotas and key genetic contexts identified on stone heritage using illumina and nanopore sequencing platforms

The application of metagenomics uncovering stone-dwelling microbiotas and its functional capabilities are of great significance for early warning of stone monuments deterioration and screening of antimicrobial agents. Here, by harnessing the combination of Nanopore and Illumina sequencing, we investigated the microbial community compositions and potential risks resulting from elemental nitrogen (N) and sulfur (S) metabolism and environmental resistomes. Taxonomic profiling showed that lichenized Ascomycota and Actinobacteria dominate the microbial population in the biofilm, followed by Cyanobacteria, Proteobacteria, and Acidobacteria. Certain microbial groups and gene families were responsible for the biogeochemical N/S cycling, probably contributing to the succession and expansion of stone biodeterioration. High abundant and diverse antibacterial biocide and metal resistance genes were retrieved from assembled genome contigs, including those encoding resistance to copper (copR and copS), zinc (znuC/yebM and zraR/hydH), and quaternary ammonium compounds (gale and vcaM). Conversely, antibiotic resistance genes conferring resistance to multiple-antibiotic, aminoglycoside, and glycopeptide accounted for the relatively low percentage of total microbial metagenome. Binned genomes have further confirmed that bacterial species contained diverse antimicrobial resistance genes and mobile genetic elements, implying the possibility of horizontal gene transfer between bacterial lineages. Overall, our findings expand our knowledge of stone-dwelling microbiome and suggest appropriate treatment for stone biodeterioration.

Better, not more, lighting: Policies in urban areas towards environmentally-sound illumination of historical stone buildings that also halts biological colonization

Anthropogenic or Artificial light at night (ALAN) pollution, or more simply light pollution, is an issue of increasing concern to the general public, as well as to scientists and politicians. However, although advances have been made in terms of scientific knowledge, these advances have not been fully transferred to or considered by politicians. In addition, illumination of stone monuments in urban areas is an emerging contribution to ALAN pollution that has scarcely been considered to date. This paper presents a literature review of the topic of light pollution and related policies, including a bibliometric analysis of studies published between 2020 and 2022. The prevailing legislation in Europe regarding the regulation of outdoor lighting, which emphasises the complexity of controlling light pollution, is summarised and the regulation of monumental lighting in Spain is discussed. Findings concerning the impact of ALAN on biodiversity in urban areas, and the promising biostatic effect of ornamental lighting (halting biological colonization on stone monuments, mainly caused by algae and cyanobacteria) are described. Finally, trends in monument illumination and policymaking towards environmentally sustainable management are considered.

Before the Holocene humid period: Life-sized camel engravings and early occupations on the southern edge of the Nefud desert

The Neolithic of northern Arabia is characterised by monumental stone structures, ephemeral ‘hearth sites’ indicative of a highly mobile lifestyle, and a rich rock art heritage with iconic representations of domesticated livestock. However, the character and timing of occupation prior to the spread of pastoralism (ca. 6000 BCE) remains elusive, with only one stratified Epipalaeolithic site and two surface early Neolithic sites so-far known in the Jubbah Oasis. Here we present Sahout, a newly documented rock art site with Neolithic and earlier occupations, on the southern edge of the Nefud desert. The rock art is dominated by life-sized, naturalistic, engravings of camels, which are in some cases superimposed with Neolithic imagery of domesticated sheep. Surveys and test excavations carried out in the vicinity of the rock art revealed a lithic assemblage with similarities to the late Epipalaeolithic and Pre-Pottery Neolithic of the Levant. Radiocarbon ages from two test trenches and two hearths indicate repeated occupation at Sahout between the Terminal Pleistocene and the Middle Holocene, which partly mirror the rock art sequence. Investigations at Sahout indicate that rock art production in northern Arabia may have begun earlier than previously thought. Research also suggests a broader geographical extent to human occupations prior to the Holocene humid period.

Expanding the Microcolonial Black Fungi Aeminiaceae Family: Saxispiralis lemnorum gen. et sp. nov. (Mycosphaerellales), Isolated from Deteriorated Limestone in the Lemos Pantheon, Portugal.

With an impressive ability to survive in harsh environments, black fungi are an ecological group of melanized fungi that are widely recognized as a major contributor to the biodeterioration of stone cultural heritage materials. As part of the ongoing efforts to study the fungal diversity thriving in a deteriorated limestone funerary art piece at the Lemos Pantheon, a national monument located in Águeda, Portugal, two isolates of an unknown microcolonial black fungus were retrieved. These isolates were thoroughly studied through a comprehensive analysis based on a multi-locus phylogeny of a combined dataset of ITS rDNA, LSU, and rpb2, along with morphological, physiological, and ecological characteristics. Based on the data obtained from this integrative analysis, we propose a new genus, Saxispiralis gen. nov., and a new species, Saxispiralis lemnorum sp. nov., in the recently described Aeminiaceae family (order Mycosphaerellales). Prior to this discovery, this family only had one known genus and species, Aeminium ludgeri, also isolated from deteriorated limestone. Additionally, considering the isolation source of the fungus and to better understand its potential contribution to the overall stone monument biodeterioration, its in vitro biodeteriorative potential was also evaluated. This work represents a significant contribution to the understanding of the fungal diversity involved in the biodeterioration of limestone heritage.

Trichocoleus desertorum isolated from Negev desert petroglyphs: Characterization, adaptation and bioerosion potential

The Negev petroglyphs are considered valuable cultural heritage sites, but unfortunately, they are exposed to deterioration processes caused by anthropogenic and natural forces. Despite the many studies that have already pointed to the role of cyanobacteria in biogenic rock weathering, the knowledge involved in the process is still lacking. In this study, a cyanobacterial strain was isolated from the Negev Desert petroglyphs aiming to reveal its involvement in geochemical cycles and in the weathering processes of the rock substrate. The strain was characterized using morphological, molecular, and microscopic studies. The morphological research revealed a green-bluish, bundle-forming filamentous strain characterized by trichomes embedded in a common sheath. A combination of Nanopore and Illumina sequencing technologies facilitated the assembly of a near-complete genome containing 5,458,034 base pairs. A total of 5027 coding sequences were revealed by implementing PROKKA software. Annotation of five replicas of the 16S ribosomal RNA genes revealed that the Negev cyanobacteria isolate is closely (99.73 %) related to Trichocoleus desertorum LSB90_MW403957 isolated from the Sahara Desert, Algeria. The local strain was thus named Trichocoleus desertorum NBK24 CP116619. Several gene sequences that code for possible environmental adaptation mechanisms were found. Our study also identified genes for membrane transporters involved in the exchange of chemical elements, suggesting a possible interaction with rock minerals. Microscopic observations of T. desertorum NBK24 CP116619 infected onto calcareous stone slabs under laboratory conditions demonstrated the effect of the isolated cyanobacteria on stone surface degradation. In conclusion, the findings of this study further our understanding of terrestrial cyanobacterial genomes and functions and highlight the role of T. desertorum NBK24 CP116619 in stone weathering processes. This information may contribute to the creation of efficient restoration strategies for stone monuments affected by cyanobacteria.

The Peculiarities of the Mycobiota Formation on the Saint Petersburg Stone Monuments Based on Metagenomics and Cultural Data

Fungi play an important role in colonization and biodeterioration of stone monuments in the open air. This study significantly complements the data on fungal diversity in lithobiotic communities through the use of metagenomic analysis. It was shown that the mycobiota of tombstones in the historical center of St. Petersburg has a complex structure. There are different complexes of species, which have various origins and ways of getting to the monuments. The complex of dominant fungi in SABs on marble and granite in St. Petersburg is formed by dark-colored micromycetes. At the species level, the absolute dominant in all samples was the Knufia karalitana according to metagenomic data and Aureobasidium pullulans according to cultural data. The use of two methodological approaches indicates the expediency of combining culture-based and molecular genetics methods, which make it possible to obtain the most more complete picture of the formation of lithobiotic communities. The season and the type of biofilm have a key importance for the abundance and diversity of micromycetes on stone surface. It was shown that type of rock has a minimal importance for the fungal diversity on stone monument.

Identification of Bacterial Communities Involved in Bioweathering Crusts on Limestone Sculptures of the Longmen Grottoes

Bioweathering crusts are widely distributed on the limestone sculptures of the Longmen Grottoes, a UNESCO World Heritage Site. However, information on microbial communities in this archaeological site is missing. To fill this gap, we identified bacterial communities involved in the formation of bioweathering crusts. The composition analysis showed that Cyanobacteria, Acidobacteria, Chloroflexi, Actinobacteria, Firmicutes, and Planctomycetota are the major components of the bacterial communities in the crusts. Cyanobacteria might be one of the major contributors to the formation of the crusts. A culture-based analysis indicated the presence of bacterial isolates (e.g., Enterobacter sp. and Bacillus sp.) with a potential role in bioprotection. Moreover, five types of biogenic organic acids were detected in the crusts, implying a consequence of organic acid corrosion. Scanning electron microscopy analysis further confirmed microbial penetration into the stone monuments with a biomechanical attack. Our reports provide a microbiological reference for heritage conservators to treat bioweathering crust.

Water activity in subaerial microbial biofilms on stone monuments

Stone monuments can be difficult environments for life, particularly with respect to liquid water access. Nevertheless, microbial communities are found on them with apparent ubiquity. A variety of strategies for access to liquid water have been proposed. Regardless of their water-retention mechanisms details, though, we argue that water activity (a key indicator for cell viability) is constrained by environmental conditions, largely independently of community structure, and is predicted by the local temperature and relative humidity. However, direct measurement of water activity in SABs, particularly those growing on stone surfaces, is difficult. A method for estimating water activity within SABs is presented that uses a minimally invasive combination of conservative sampling, weather data, confocal imaging, and mathematical modeling. Applying the methodology to measurements from the marble roofs of the Federal Hall National Memorial and of the Thomas Jefferson Memorial, estimations are made for water activity in their subaerial stone communities over the course of an approximately one year period.

Stone as Witness

The depiction of stones that speak has long been used as a literary and philosophical device to reflect upon the limitations of human language (i.e., language as a petrification of thought and action). Jacques Rancière has described stone’s capacity to bear witness as a form of “mute speech,” noting how “any stone can also be language,” as a part of the “testimony that mute things bear to mankind’s activity.” In exploring the character of this form of testimony, and asking how we hear it, this article examines the function of the Stone Guest in the legend of Don Juan, across Molière’s and Pushkin’s theatrical versions, a short film version by Marina Fomenko, and Mozart and Da Ponte’s operatic version, so revered by Kierkegaard and others. The character of the Stone Guest is often seen as casting judgement against the aesthetic mode of life, yet the power of the character lies not in his ghostly humanity or sense of retribution, but in his stoniness – his capacity to bear witness, just as a stone monument bears witness or commemorates a past trauma. In a number of versions of the Don Juan story, the Stone Guest is announced by approaching footsteps or knocking. This acousmatic device mirrors the uncanny separation of sound and source in opera – the way in which music mediates between the conflicting imperatives of language and the corporeal or material aspects of the singing voice, lending opera its vaunted mechanical qualities. Using stones that speak as a heuristic, the article draws together ideas about the limitations of language and the mechanical qualities of opera in order to excavate the auditory affordances of the stone’s form of testimony, in all its inorganic liveliness.

M. K. Kadyrbaev’s Archive as a Source for Studying the Stone Monuments of Kazakhstan

The article describes the unpublished archives collected by M. K. Kadyrbaev from his field work in Central Kazakhstan in 1955–1979. It provides information on eight stone statues and structures. The authors attributed and dated them in line with the contemporary rules of archeology. One of the statues appeared to belong to the Saka period of the Tasmola culture. Another monument had no obvious analogies but, possibly, was part of a Qipcaq sanctuary. The authors also touched upon some challenging or debatable issues raised by M. K. Kadyrbaev and other expedition members, e.g., the validity of correlating statues without sings of sex with images of women; the secret Polovtsian sanctuary, which have to be studied in the context of similar Qipcaq sites, etc.