Towards a diagnostic protocol for the study of monumental terracruda sculpture

Towards a diagnostic protocol for the study of monumental terracruda sculpture Mònica López-Prat 1,2, Domenico Miriello3 , Stephane Chaignepain4, Carla Lancelotti 5, Lea Legan6,7 , Alessandra Pecci 2,8, Marina Reutova9, Barbara Salvadori 1, Caroline Tokarski 4and Emma Cantisani 1 1Consiglio Nazionale delle Ricerche Istituto di Scienze del Patrimonio Culturale (CNR ISPC) 2Institut d’Arqueologia de la Universitat de Barcelona (IAUB) 3Department of Humanistic Studies, Università della Calabria, Via P. Bucci, 87036 Arcavata di Rende (CS) Italy, [email protected] 4Univ. Bordeaux, CNRS, Bordeaux INP, CBMN, UMR 5248, and Bordeaux Proteome, F-33076 Bordeaux, France 5 Universitat Pompeu Fabra - ICREA, Spain 6Institute for the Protection of Cultural Heritage of Slovenia, Poljanska c. 40, SI-1000 Ljubljana Slovenia 7National Museum of Slovenia, Prešernova c. 20, SI-1000 Ljubljana, Slovenia 8 ERAAUB, Department of History and Archaeology, Universitat de Barcelona, INSA-UB MdM Unit of Excellence (Grant CEX2021-001234-M), Spain 9 Samarkand Archaeological Institute, Uzbekistan 2 1. What are Monumental Terracruda Sculptures –Information Sources 2. The Diagnostic Approach –Main results obtained 3. Conclusions PRESENTATION STRUCTURE 1. Section One MONUMENTAL TERRACRUDA SCULPTURES 3 4 Schematic drawing of a Buddhist ‘monumental terracruda sculpture’ with a woodencore López-Prat, M., Pecci, A., Lancelotti, C., & Miriello, D. (2024). Shaping the sacred along the Silk Roads: the millenary artistic tradition of making “monumental terracruda sculptures”. Journal of Archaeological Science: Reports,54, 104454. TERRACRUDA ⍇⍈ TERRACOTTA MONUMENTAL = IMMOVABLE "Monumental Terracuda Sculpture” Human size or bigger unfired clay-based sculpture characteristic of Asian sacred contexts THE SILK ROADS HISTORICAL/ARCHAEOLOGICAL EXAMPLES Great proliferation within Buddhism from 4th century CE onwards First examples: 2nd –1st centuries BCE in Central Asia (Ajina Tepe, Tajikistan) Mogao Caves (Dunhuang, China) Ladakh (India) (Mogao Caves, China) Bamiyan (Afghanistan) Famousexamples 8 Tepe Narenj 6-7th CE (Kabul, Afghanistan) Archaeological examples Kara Tepe 24th CE (Termez, Uzbekistan) Qol e-tut 7-8th CE (Kabul, Afghanistan) Big challenges from conservation point of view –lack of scientific studies to understand the technique Sacred Indian texts linked to Agama literature mentions the ritual of elaborating an image or icon in clay in 7 stages (the oldest text dating back to the 8th century CE) which have a metaphorical correspondence with the seven elements of the human body: Sanskrit Textual Roots: Ritual and Technology in Agama Literature 1. sula (armour) -asthi (bones) 2. astabandha (glue) -medas (fat) 3. rajju (ropes) -sira (veins, arteries, tendons) 4. mrt (soil/clay) - mamsa (flesh, muscles) 5. sarkara-kalka (limestone paste) - sonita (blood) 6. pata (fabric) -tvak (skin) 7. varna (colour) -jiva (life) K. M. Varma, The Indian Technique of Clay Modelling (1970) STRATIFICATION OF MODELLING PASTES •Stratification of the pastes indicating differences in processing depending on their placement: higher proportion of binder in internal layers (clayey) - higher amount of aggregate in external layers (sandier) •Very similar composition of clays of sculptural fragments coming from the same site, indicating acommon quarry Thin section of halo fragment - Tepe Narenj (6th CE, Kabul, Afghanistan) López-Prat et al. 2024. The modeling pastes of the monumental terracruda sculpture of the Silk Roads: Archaeometric study of the Tepe Narenj and Qol‐e‐tut examples, Archaeometry López-Prat et al. 2022, Architectural Terracruda Sculptures of the Silk Roads: New Conservation Insights Through a Diagnostic Approach Based on Non-Destructive X-ray MicroComputed Tomography Studies in Conservation Finger fragment and MC Tomography of finger’s section (Tepe Narenj, Kabul, Afghanistan - 6th CE) Differences in the preparation of the modelling paste depending on the layer Phytoliths and Fibres Analyses To understand the use of the fibrous vegetal matter and try to identify the species employed Added herbaceous matter evidenced in all sculpture samples •Significant differences in quantity and use depending on to the layer and the type of fragment (more straw in internal layers, less in external) López-Prat et al. 2022. The role of plants and fibres in modelling monumental terracruda sculptures of the Silk Roads: archaeobotanical analyses from the Buddhists sites of Tepe-Narenj and Qol-e-tut (Kabul, Afghanistan) Heritage Science 20 •High concentration of bast fibres belonging to nettle/ramie family, especially in those associated with fingers MC Tomography of TN7 finger’s section (Tepe Narenj, Kabul, Afghanistan - 6th CE) UV-OM, FT-IR, GC-MS and “OMICS” To search for organic binders in the modelling pastes Microphotographs in thin section under epifluorescence microscopy: (a) Stucco layer TN1_a (b) Sample TN5 (c) Layers b and c in sample TN2 (d) Clay layer TN1_b López-Prat et al. 2024. The modeling pastes of the monumental terracruda sculpture of the Silk Roads: Archaeometric study of the Tepe Narenj and Qol‐e‐tut examples Archaeometry EPIFLUORESCENCE to evidence the presence of organic binders FT-IR : proteins, polysaccharides, lipids, diterpenoid resin, oxalates López-Prat et al. 2025. The use of organic binders in monumental terracruda sculpture: Integrating Sanskrit texts with spectroscopic and spectrometric data in the study of Tepe Narenj and Qol-e-tut examples (Kabul, Afghanistan, 5th to 11th centuries CE). Journal of Cultural Heritage Transmission FTIR spectra collected on samples. The black and dark grey lines represent the most representative IR spectra before and/or after extractions. 24 GC-MS: Fatty acids detected could indicate the addition of a plant origin product, oil? FA MYRISTIC PALMITIC PALMITOLEI CSTEARIC OLEIC ERUCIC sample amount of individual FA [%] relative to the sum of all identified FA in the samples TN1A 9,1 44,2 14,1 20,9 9,1 2,5 TN1B 14,6 47,3 20,1 9,3 8,8 <LOQ TN2A 7,8 44,7 5,3 11,0 7,1 24,1 TN2B 5,7 38,7 2,6 14,5 9,1 29,3 TN2C 7,2 34,7 <LOQ 12,8 6,2 39,2 TN3 9,1 54,2 <LOQ 22,9 8,7 5,1 TN4 <LOQ 50,2 5,8 26,6 7,8 9,6 TN5 12,0 46,6 18,2 10,3 10,9 1,9 TN6 6,6 45,4 <LOQ 19,6 10,3 18,2 TN7A1 8,2 48,4 <LOQ 20,0 4,8 18,6 TN7A2 12,8 49,3 4,9 25,9 4,5 2,5 TN7B <LOQ 43,8 5,1 13,9 7,6 29,6 QT1 <LOQ 46,3 <LOQ 13,6 7,6 32,5 QT2A 9,6 48,5 4,2 12,8 7,0 17,9 QT2B 7,6 35,0 <LOQ 11,9 6,2 39,3 QT2C 7,3 47,5 5,5 17,7 6,4 15,5 QT3 7,6 49,2 3,4 18,5 6,3 15,1 QT4 8,0 46,4 5,2 12,8 7,6 20,0 López-Prat et al. 2025. The use of organic binders in monumental terracruda sculpture: Integrating Sanskrit texts with spectroscopic and spectrometric data in the study of Tepe Narenj and Qol-e-tut examples (Kabul, Afghanistan, 5th to 11th centuries CE). Journal of Cultural Heritage 25 OMICS approach based on MALDI-TOF analysis developed to identify plant gums MALDI-TOF MS spectra of (A) TN2c sample and (B) to (E) respectively TN1a, TN1b, TN2b and TN6 samples - the reported ions correspond to oligosaccharides with 3-aminoquinoline derivatization. Asterisks are showing the homopolysaccharidic patterns based on hexose residues López-Prat et al. 2025. The use of organic binders in monumental terracruda sculpture: Integrating Sanskrit texts with spectroscopic and spectrometric data in the study of Tepe Narenj and Qol-e-tut examples (Kabul, Afghanistan, 5th to 11th centuries CE). Journal of Cultural Heritage 3. Section Three CONCLUSIONS 32 THE DIAGNOSTIC APPROACH : •Demonstrates that integrating TK and textual analysis with material investigation enhances our understanding of historical fabrication processes and informs the selection of analytical tools 33 •Is giving growing evidence that a precise technical tradition underlies in monumental terracruda sculptures •By identifying such technique, we are formulating more targeted diagnostic questions when approaching historical and archaeological examples •Is changing the historical discourse broadly accepted until today: “the use of terracruda to produce sculpture is due to the shortage of more precious materials or to a high demand and the need to sculpt more quickly” “ Monumental terracruda sculptures are the result of carefully engineered choices grounded in centuries of empirical knowledge. They embody a living tradition that merges earth—terracruda, the primal material from which all things emerge—with the tangible manifestation of the sacred. In this union, the material and the metaphysical converge, revealing a deep understanding of matter as both medium and message Thanks! Any questions? 35 SAMARKAND ARCHAEOLOGICAL INSTITUTE With the contribution of: Funded by: You can find me at [email protected]