ERE5.1

EDI
Global Heritage Stone Resource: The sustainable way forward

Ornamental and dimension stones have been part and parcel of the extinct and evolving civilizations world over. The evolution of civilizations can be easily witnessed through stone built sites which comprises both: grandiose stone built architectural historical monuments and the simple dwellings of a common man reflecting a sync between the extraordinary and the ordinary. In fact, all this forms an integral part of cultural heritage of humankind and reflect close cultural affiliation with varied societies.
Our session deals with Heritage Stones and we promote recognition of natural stones that have contributed to the evolution of human societies across the globe in consonance with the goals of IUGS-HSS and IGCP HerSTONES project (2020-2023). The session is open to discuss the use of heritage stones in different parts of the globe vis-à-vis impact on human culture, architectural heritage, sustainability, historical quarries, conservation, preservation and sustainable restoration of the urban and rural stone built heritage, promoting geotourism (tours to such sites) and familiarising the contemporary generation to the most revered heritage.
Global Heritage Stone Resource designation by IUGS-HSS, will promote public and policy-maker interest in stone built heritage and its upkeep. It will also assist in forming a broader understanding of how the usage of the most traditional building material has evolved over centuries and rekindled the interest of using the same in the contemporary architectural sites.
Selected contributions from our previous EGU sessions are published in high impact factor journals, such as: Geological Society of London Special Publications (SP407: Global Heritage Stone: Towards International Recognition of Building and Ornamental Stones), Episodes Special Issue on Heritage Stones (volume 38-2, June 2015), Geoscience Canada (volume 43(1), March 2016), Geoheritage (2018), Episodes (in process of publication March 2021). Selected contributions of EGU 2021 will be considered for publication in a special issue of a well rated journal.

Convener: Gurmeet Kaur | Co-conveners: Victor Cardenes, Eliane Del Lama, Giovanna Antonella Dino
vPICO presentations
| Wed, 28 Apr, 13:30–14:15 (CEST)

vPICO presentations: Wed, 28 Apr

Chairpersons: Victor Cardenes, Eliane Del Lama, Giovanna Antonella Dino
13:30–13:35
13:35–13:37
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EGU21-12485
Gurmeet Kaur and Victor Cardenes

The initiative of designating the natural stones as Global Heritage Stones Resource by the IUGS is a novel one. The stakeholders are all those countries which record the stone built monuments of cultural significance. The stones used in the monuments with unique geological and architectural attributes and which have been used in the historical past with surviving and/or extinct quarries are being considered for designation of GHSRs. The European nations have been quick in identifying such stones and have proposed many significant stones for designation of GHSR in stark contrast to African, Asian and South American nations which are underrepresented on the world map in terms of designation of GHSR. The need of the hour is to promote the idea to all the nations to come up with the documentation of the stones used in the monuments, the state of preservation of historical quarries, the record and strategy for the upkeep of monuments and the historical quarries. The Project ‘The HERITAGE STONES RECOGNITION: A STEP FORWARD (HerSTONES)’ has been recently granted by IGCP-UNESCO to promote heritage Stones from emerging countries.

How to cite: Kaur, G. and Cardenes, V.: Global Heritage Stones Resource: An IUGS designation, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-12485, https://doi.org/10.5194/egusphere-egu21-12485, 2021.

13:37–13:39
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EGU21-4536
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ECS
David Freire-Lista, Bruno Campos, and Patricia Moreira da Costa

Granite is the most important building stone in the north of Portugal. The importance of the stones in this region is evidenced by the pre-Roman roots Mor (r), Mur (r) and Mour of place names such as Montemuro, Moreiras, Mouçós, and Mourelhe. These roots indicate the existence of building stones used since ancient times in these places.

The quarries of the main building stones of historical buildings were generally in the vicinity of the buildings. Formerly, stonemasons carved mason's marks on ashlars. The mason's marks are lapidary signs to indicate the work carried out by each one. The mason's marks are generally symbolised by the initial of the stonemason's name. They are often found on dressed stones in buildings and in other public structures.

Nossa Senhora de Guadalupe church of Mouçós (possibly 16th century) has typical characteristics from the late Romanesque. It is located in Vila Real (North of Portugal). It is made up of three volumes: a single nave, a lower rectangular apse, and a sacristy attached to the apse. The exterior of this church is preserved almost unaltered in its original state. Each of the granite ashlars that make up this church has a mason's mark in the center of its face.

The mason's marks of the church have been identified; all the ashlars with visible mason's marks have been mapped, and a glyptographic study has been carried out. This has made it possible to calculate the number of stonemasons that worked in the construction of the church and the number of ashlars that were transported in each carriage, and to determine the construction phases of the church.

Eight cubic samples have been cut to calculate the granite’s hydric properties (effective porosity, water absorption and bulk density) according to UNE-EN:1936. Ultrasound wave velocity was measured according to UNE-EN:14579. Furthermore, three thin sections have been made to characterise the granite petrographically under a polarisation microscope Leica DM-4500-P. A mosaic of photomicrographs has been made to evaluate the petrographic properties.

There are six main types of mason's marks in Nossa Senhora de Guadalupe Church. All quarrymen extracted the stones from the same quarry, or from nearby quarries. The mean effective porosity of the building granite is 3.2%±0.3, and the mean water absorption is 1.2%±0.1. Its mean bulk density is 2566 kg/m3±61.0 and its ultrasound P wave velocity is 2920 m/s±98.3.

The mason's marks are preserved because of the excellent petrographic and petrophysical properties of Mouçós granite. Further, Nossa Senhora de Guadalupe church was protected with lime plaster during the past centuries, and the plaster was not removed with the projection of abrasive particles.

The use of analytical techniques such as petrography, ultrasonic P wave velocity and the determination of hydric properties will guarantee the quality and durability of a sustainable restoration.

The historical quarries, forms of traditional stone extraction and uses of Mouçós granite constitute a heritage that must be safeguarded.

Acknowledgements: The Fundação para a Ciência e a Tecnologia (FCT) of Portugal. CEECIND/03568/2017.

How to cite: Freire-Lista, D., Campos, B., and Moreira da Costa, P.: The Heritage Stone of Nossa Senhora de Guadalupe Church, Mouçós, North of Portugal: Characterisation and Glyptography, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-4536, https://doi.org/10.5194/egusphere-egu21-4536, 2021.

13:39–13:41
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EGU21-1408
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ECS
Siham Belhaj and Omaima Essaad Belhaj

Historical monuments represent an archive and a past full of information and emotions transmitted from our ancestors, to preserve this sacred and perilous heritage with universal value, it was necessary to study it and approach it meticulously as a living body that expressing by diseases or pathologies which must be well treated.

From one monument to another, the pathologies found change and differ following several criteria and conditions, in our work we will focus on the bio-calcarinite rock often used in the construction of historical monuments in the Rabat Sala Kenitra’s region because of its availability and its mechanical performances and also by focusing on the criterion of monument’s location opposite the agents of degradation (climate, urbanization, know-how, materials, direction, uses, marine aerosol, etc.) we will identify the various degradations of bio-calcarinites of the Borj Adoumoue monument (Tower of tears) located on the seafront of the city of Sala in Morocco and the Historic monument of Challah in the city of Rabat which was named shared heritage in 2012 and which knows currently a major urbanization project named Rabat capital of lights, the historic monument of Chellah overlooks the Bouregreg river.

And we will therefore compare the impact of the location of the monument on the latter and on the pathologies that manifest themselves on the biocalcarinite of this region.

How to cite: Belhaj, S. and Belhaj, O. E.: Identification and Comparison of Pathologies Encountered at the level of Bio Calcarinites used in the monuments of the city of Sala and Rabat in Morocco., EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-1408, https://doi.org/10.5194/egusphere-egu21-1408, 2021.

13:41–13:43
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EGU21-8531
Eliane Aparecida Del Lama and Antônio Gilberto Costa

Since the establishment of the Heritage Stone Subcommission by the International Union of Geological Sciences (IUGS), in 2011, idealized with the purpose of designating stones of historical significance to compose the Global Heritage Stone Resource (GHSR), 22 of them have been designated. The nationalities of these GHSR are: 3 British, 1 Norwegian, 2 Belgian, 2 Swedish, 1 Slovenian, 3 Italian, 2 Portuguese, 3 Spanish, 1 Maltese, 1 Indian, 2 American and 1 Argentine. So far, no Brazilian stone has been designated as GHSR. We can observe in monuments and buildings in the Brazilian territory the following imported GHSR: Lioz Stone and Estremoz Marble from Portugal, Carrara Marble and Rosa Beta Granite from Italy and Larvikite from Norway. The use of stones from Portugal and Italy is related firstly to the Portuguese colonization and, later, to economic cycles, such as rubber and coffee, with Italian immigration being significant to the coffee cycle. The presence of Lioz is major, however, it is found almost exclusively in some Brazilian coastal capitals, such as Rio de Janeiro, Salvador and Belém. The churches of Salvador are richly decorated with numerous varieties of Lioz. In Belém, it is found in the Basilica of Nossa Senhora de Nazaré, among other churches, and in many tombstones in the Nossa Senhora da Soledade Cemetery. Estremoz Marble is found in commercial buildings and tombstones. In the city of São Paulo, lots of buildings have internal cladding and ornaments made in Carrara Marble, e.g. Municipal Theater, Palace of Justice, Metropolitan Cathedral and Obelisk Mausoleum for the Heroes of 32. In the city of Rio de Janeiro, the tomb of Orville Derby (founder of the Geological Survey of Brazil) at São João Batista Cemetery, among others, is decorated with Carrara Marble, which can also be seen in tomb art of Salvador, Belo Horizonte, Curitiba and São Paulo. Rosa Beta Granite can be seen at Monument to Bartolomeu de Gusmão in the city of Santos, costal area of São Paulo State. The use of Larvikite is contemporary. This stone is mainly present in tombstones, for example, at the Consolação Cemetery in São Paulo, but it also decorates the façades of several commercial buildings, both in capitals and several Brazilian cities. In Brazil, several types of Brazilian stones are found in monuments and religious or administrative buildings. These stones, which have been used since Colonial Brazil, are characteristic of certain regions, such as Augen Gneiss in Rio de Janeiro, Itaquera Granite in São Paulo, beachrock in northeastern Brazil, quartzites and steatite in Minas Gerais, among others. Some of them constitute UNESCO World Heritage Sites, and due to their historical importance to our heritage, these stones may be indicated as GHSR in the future.

How to cite: Del Lama, E. A. and Costa, A. G.: Global Heritage Stone Resource in Brazil, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-8531, https://doi.org/10.5194/egusphere-egu21-8531, 2021.

13:43–13:45
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EGU21-2022
Giuseppe Casula, Silvana Fais, Francesco Cuccuru, Maria Giovanna Bianchi, Paola Ligas, and Alessandro Sitzia

The diagnosis of the conservation state of monumental structures from constraints to the spatial distribution of their physical properties on shallow and inner materials represents one of the key objectives in the application of non-invasive techniques. In situ, CRP and 3D ultrasonic tomography can provide an effective coverage of stone materials in space and time. The intrinsic characteristics of the materials that make up a monumental structure and affect the two properties (i.e., reflectivity, longitudinal velocity) through the above methods substantially differ. Consequently, the content of their information is mainly complementary rather than redundant.

In this study we present the integrated application of different non-destructive techniques i.e., Close Range Photogrammetry (CRP), and low frequency (24 KHz) ultrasonic tomography complemented by petrographycal analysis based essentially on Optical Microscopy (OM). This integrated methodology has been applied to a Carrara marble column of the Basilica of San Saturnino, in Byzantine-Proto-Romanesque style, which is part of the Paleo Christian complex of the V-VI century. This complex also includes the adjacent Christian necropolis in the square of San Cosimo in the city of Cagliari, Sardinia, Italy. The column under study is made of bare material dating back probably to the first century A.D., it was subjected to various traumas due to disassembly and transport to the site, including damage caused by the close blast of a WWII fragmentation bomb.

High resolution 3D modelling of the studied artifact was computed starting from the integration of proximal sensing techniques such as CRP based on Structure from Motion (SfM), with which information about the geometrical anomalies and reflectivity of the investigated marble column surface was obtained. On the other hand, the inner parts of the studied body were successfully inspected in a non-invasive way by computing the velocity pattern of the ultrasonic signal through the investigated materials using 3D ultrasonic tomography. This technique gives information on the elastic properties of the material related with mechanical properties and a number of factors, such as presence of fractures, voids, and flaws. Extracting information on such factors from the elastic wave velocity using 3D tomography provides a non-invasive approach to analyse the property changes of the inner material of the ancient column. The integrated application of in situ CRP and ultrasonic techniques provides a full 3D high resolution model of the investigated artifact. This model enhanced by the knowledge of the petrographic characteristics of the materials, improves the diagnostic process and affords reliable information on the state of conservation of the materials used in the construction processes of the studied monumental structure. The integrated use of the non-destructive techniques described above also provides suitable data for a possible restoration and future preservation.

 

Acknowledgments: This work was partially supported by FIR (Fondi integrativi per la Ricerca) funded by the University of Cagliari (Italy). The authors would also like to thank the Ministero dei Beni e delle Attività Culturali. Polo Museale della Sardegna and Arch. Alessandro Sitzia for their kind permission to work on the San Saturnino Basilica.

How to cite: Casula, G., Fais, S., Cuccuru, F., Bianchi, M. G., Ligas, P., and Sitzia, A.: Decay detection in an ancient column with combined close-range photogrammetry (CRP) and ultrasonic tomography., EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-2022, https://doi.org/10.5194/egusphere-egu21-2022, 2021.

13:45–13:47
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EGU21-9394
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ECS
Sanchit Garg, Pradeep Agarwal, Pushpendra Ranawat, Parminder Kaur, Amritpaul Singh, Jaspreet Saini, Kireet Acharya, Manoj Pandit, and Gurmeet Kaur

Rajnagar Marble, occurring around Rajnagar and Kankroli towns in Rajsamand district of south-central Rajasthan make up the largest marble deposits in India. Rajnagar Marble belongs to late Paleoproterozoic Aravalli Supergroup.  It is mostly white, coarse-grained and compact dolomitic marble. Mining is currently being carried out at several, small to medium-sized, open quarries using both conventional and mechanized operations. Although the Rajnagar Marble has been extensively used in archaeological monuments for centuries, it received recognition since the construction of spectacularly carved embankment (Nau-Chowky) of the Lake Rajsamand built during the period 1662-1676 CE. Its use has been recorded in the 8th century Eklingji Temple and numerous other temples in Udaipur and vicinity. Besides temples, embankments, step-well constructions, Rajnagar Marble was preferred for carving of idols of various Hindu deities, including the famous 12th century Palasma 7-horse drawn chariot Sun idol with nine planets revolving around it. But use of this Dev-Patthar (God's Stone), was avoided for flooring and private dwellings of humans in keeping with the Hindu mythological beliefs. Hence for the residential buildings, Rajnagar Marble was popularly used as a unique ground-in-hand-mill-and-sieved-through-muslin-sieve marble powder-lime paste (~100-micron size) to give the walls, pillars, lanterns, or even floors the "marble-finish". An intangible heritage process typical and unique of the erstwhile Rajputana.  Most palaces and havelies of Mewar area, including the five palaces of Udaipur namely, the City Palace Complex, Jagniwas (now the Taj Lake Palace Hotel), Jag Mandir, Lakshmi Vilas Palace and the Sajjangarh (Monsoon Palace) were all built partly in Rajnagar Marble stone, but mostly with marble powder-lime paste finish on lime-sand-quartzite masonry works.  Numerous architectural sites such as Moti Mahal, embankments of Fateh Sagar Lake and Rajsamand Lake, Eklingji Temple, Jagdish Temple, Saheliyon-ki-Badi, cenotaphs of the Royal family members at Ayad (1620 CE onwards) were built of Rajnagar Marble.

The low water absorption, high bulk density and high compressive, shearing and tensile strength of the Rajnagar Marble, and its ‘blockability’ made it technically suitable for monuments that have sustained for five centuries or more, with no signs of weathering and discoloration. The Rajnagar Marble entered the global market in the later 20th century with its export to various countries including the Middle East and Japan. At present, it is extensively used in building and handicraft industry and is also famous for contemporary artworks. In light of these variety of applications of the Rajnagar Marble, we propose ‘Rajnagar Marble’ for the designation of ‘Global Heritage Stone Resource’.

How to cite: Garg, S., Agarwal, P., Ranawat, P., Kaur, P., Singh, A., Saini, J., Acharya, K., Pandit, M., and Kaur, G.: Rajnagar Marble: a prominent heritage stone from Rajasthan, India, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-9394, https://doi.org/10.5194/egusphere-egu21-9394, 2021.

13:47–13:49
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EGU21-11107
Laura Damas Mollá, Arantza Aranburu, Uriarte Jesus Ángel, Ane Zabaleta, Tomás Morales, and Iñaki Antigüedad

Construction and ornamental stones are important elements of cultural heritage and identity and shape the urban landscape of the territories (Pereira & Cárdenes Van den Eynde, 2019). These stones and their quarries are a part of geoheritage that is gaining interest in the tourism industry (Mateos et al., 2011). Red Ereño is an urgonian limestone (Lower Cretaceous) with abundant rudist fossil shells, which white colours highlight on an intense red micritic matrix. This stone is exploited since Roman times in the north of the Iberian Peninsula (Basque Country, Spain). This lithology is found in many buildings, both heritage and common. Its uniqueness has contributed to its expansion worldwide and, it can be found in such emblematic places as the Colon Theatre in Buenos Aires (Argentina) or St Peter´s basilica in the Vatican (Italy) (Damas Mollá et al., 2021).

The main quarry related to Red Ereño is called Cantera Gorria (meaning Red Quarry) and is located inside the Urdaibai Biosphere Reserve (x: 529,659.29 m; y: 4,800,839.60 m; z: 15 m). It is included in the Geosites Inventory of the Basque Country (LIG nº 15), and is part of the historical heritage of the Biscay province. The last concessionaire of the quarry was Marmolería Bilbaína and it ceased its activity in 1968. At present the quarry is abandoned.  Nevertheless, on its exploitation fronts outstanding geologic features are recognised: stratigraphic (bioconstructions, facies changes), petrologic (diagenesis, mineralisations), tectonic (succession verticality, faults) or geomorphologic (karst). All of them make Cantera Gorria a point of reference for both research and teaching activities. Additionally, it is important to underline the richness related to the mining heritage itself. Numerous buildings from the mining activity are still preserved. Also noteworthy are the signs engraved on the rock showing the progress of exploitation in various stages, from manual to the use of helical steel wire.

In the case of Red Ereño and Cantera Gorria the symbiosis between geoheritage and cultural heritage is significant. This symbiosis, together with all the above mentioned characteristics of the quarry makes Cantera Gorria an interesting space for dissemination of geoheritage as well as for tourism (Damas Mollá, 2011).

References

  • Damas Mollá, L. (2011): Las Calizas rojas de Ereño: facies, paleoambiente, mineralización y diagénesis. Patrimonio geológico-histórico de Bizkaia. PhD Thesis, University of the Basque Country.
  • Damas Mollá L., Uriarte J.A., Zabaleta A., Aranburu A., García Garmilla F., Sagarna M, Bodego A., Clemente J.A., Morales T. & Antigüedad I. (2021). Red Ereño: an ornamental and construction limestone of international significance from Basque Country (northern Spain). Geoheritage 13:2. https://doi.org/10.1007/s12371-020-00529-5
  • Mateos R.M, Durán, J.R & Robledo P.A. (2011). Marès Quarries on the Majorcan Coast (Spain) as Geological Heritage Sites. Geoheritage 3: 41-54. http://doi.org/10.1007/sl12371-010-0026-5
  • Pereira D. & Cárdenes Van den Eynde V. (2019). Heritage Stones and Geoheritage. Geoheritage 11: 1-2. http://doi.org/10.1007/s12371-019-00350-9

How to cite: Damas Mollá, L., Aranburu, A., Jesus Ángel, U., Zabaleta, A., Morales, T., and Antigüedad, I.: Red Ereño and Cantera Gorria: Natural and Cultural Geoheritage (Basque Country, Spain), EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-11107, https://doi.org/10.5194/egusphere-egu21-11107, 2021.

13:49–13:51
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EGU21-9638
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ECS
Jose Diaz-Basteris

Restoration mortars are a designated group of products made to repair damaged masonry. They must be compatible with the former support of stones and bricks, and protect original materials from environmental agents; aesthetical and historic aspects must not be neglected. 

To improve the ecological footprint of the restoration mortars while keeping their efficiency, we have tested several combinations of lime with aggregates and additives. Recycled and natural materials were used as additives such as pinecone resin, semi-milled cones of pine, milled glass waste, brick production residue.

For research purposes different physical properties have been measured in prepared mortars: porosity, density, capillarity absorption, moisture absorption, water vapour permeability. We have also tested the mechanical properties and the P and S waves velocities (from which dynamic Young's modulus and Poisson’s ratio were inferred). The durability of mortars has been estimated by salt crystallization and frost/thaw cycles.

The life cycle analysis (LCA) of such mortars allows us to understand the carbon footprint of each manufacturing process. Considering this we selected the raw materials, from an environmental and commercial point of view, to produce mortars fulfilling sustainability requirements. As a result, the developed mortars are compatible with aged stones, minimize environmental impact, and use minimum natural resources.

 Twenty mortar formulations with three different types of limes (NHL5, NHL3.5, CL90) and two different aggregates (siliceous and calcareous) have been studied using the LCA. Currently, five new formulations are being selected to be tested on Euville limestone. Adhesive strength (James Bond test), and physical properties will be measured on these mortars. 

How to cite: Diaz-Basteris, J.: New sustainable mortars for stone restoration in the context of climate change, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-9638, https://doi.org/10.5194/egusphere-egu21-9638, 2021.

13:51–13:53
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EGU21-12534
Alessandro Cavallo and Giovanna Antonella Dino

The Ossola valley (central Alps, northern Italy) is well known to produce a wide range of dimension stones: granites, gneisses, marbles and soapstones. The calcitic Candoglia marble is well-known because it was used in the cathedral of Milan, whereas the dolomitic Crevoladossola marble is widely spread and appreciated on the market. This work focusses on the varieties of the latter, the Crevoladossola marble: it pertains to the Mesozoic metasedimentary cover that tectonically separates the Monte Leone and Antigorio nappes (lower Penninic Units), with a quite steep structural setting and multiphase folding. The location of the quarry (Lorgino di Crevoladossola) is the same of the historic Pavia quarry of the «Fabbriceria del Duomo di Pavia», at the beginning of the 16th century. At present time there is only one active quarry which produces nine commerciali varieties: among these, Palissandro Bluette, Palissandro Blu Nuvolato, Palissandro Classico and Palissandro Oniciato are the most common ones. The quarry front is terraced and the extraction technology only uses diamond wire technology; the large extracted blocks are then selected based on their dimension, textural and chromatic features. The Crevoladossola marble (dolomite content 75 – 90% wt.)  has fine grain size and variable colour and texture due to the different amount of phlogopite (10 – 25% wt.) which defines the foliation plane, characterized by abundant isoclinal folds; there are also smaller amounts of quartz, anorthite, chlorite, tremolite, and rare disseminated sulphides. The presence of tremolite initially created doubts about the possible presence of asbestiform phases, however in-depth SEM-EDS analytical investigations excluded the presence of fibers, showing only cleavage fragments or prismatic - acicular crystals. With respect to the Candoglia and Ornavasso marbles, the Crevoladossola marble has markedly anisotropic physical and mechanical properties. In the Archaeological Museum of Milano possibly there is the first evidence of the use of this type of marble, represented by a sculpture of a Roman person (T. Labieno). Since 13th and 14th centuries this material was widely utilized in the local architecture of Domodossola, Baceno and Montecrestese, whereas its use was scarce in Lombardy: the main representative buildings are Arco della Pace in Milano with eight monolithic marble columns (10 m height) and the Duomo in Pavia (since 14th century). The marble is now used for internal facing, furnishings and valuable objects: in 1995 a block of Palissandro Classico was worked to produce the significant sculpture «Uovo della Pace» for UNICEF. The overall good quality of the rock mass and a rational exploitation make this quarry an exemplary model of dimension stone extraction; at the present time, efforts are also being made to exploit production waste, from crushed stone up to sawing sludge.

How to cite: Cavallo, A. and Dino, G. A.: The Crevoladossola marble (Piedmont, northern Italy): nine commercial varieties in just one quarry!, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-12534, https://doi.org/10.5194/egusphere-egu21-12534, 2021.

13:53–13:55
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EGU21-13576
Patrick Wyse Jackson, Louise Caulfield, Aidan Forde, Iseult Conlon, Peter Cox, and George Sevastopulo
Valentia Slate from the southwest of Ireland, is herein proposed as a Global Heritage Stone Resource. This Middle Devonian (Givetian) purple to pale green-colouredfine-grained siltstone comprises the Valentia Slate Formation, part of the Old Red Sandstone which extensively crops out in southern Ireland.  The unitwhich developed as an alluvial fan, has a thickness of over 3000m and shows a well developed cleavage and low metamorphic grade imposed during the Variscan which produced its slaty fabric. Although quarried from small surface openings from the late eighteenth century, the commercial value of certain horizons of the Valentia Slate Formation was first recognised by the local landowner The Knight of Kerry who commenced its extraction at Dohilla in 1816 for use as roofing slates.  The operation was expanded from the 1820s by the Hibernian Mining Company and later by the Valentia Slab Company and its successorthe Valentia Slate Companywhich continued to quarry the stone until the late 1870s. Initally stone was extracted from surface workings but since 1840 it has been exclusively obtained from underground workings. From the 1880s the quarry went into decline due to competition from Wales and extraction ceased altogether in 1911 following a large rockfall at the opening to the quarry.  It was revived in the 1980s and recent investment has resulted in being able to provide this quality stone to widespread markets. Although not easily split into thin slates Valentia Slate was first used locally for roofing and general building. Howeveras it could be cut into slabs of a variety of thicknesses and lenghts of up to 3m it was more readily adoptedboth nationally and internationallyfor use in buildings for window cills, steps, domestic fittings in bathrooms and kitchens, and paving both externally and internally as in the Houses of Parliament in London, the Paris Opera House, and for flagging in a number of British railway termini.  The stone was susceptible to and held sharp carving, and it it was also fabricated into headstones, memorials, garden furniture, and shelving. Stone was even exported in the 1870s to Brazil for use as railway sleepers. Craftsmen also fabricated lamps and birdhouses from the material and its most celebrated use was for billiard and snooker tables, a number of which were highly decorative having been enamelled.  During the height of production over 500 men were employed quarrying and working Valentia Slate. The first tramway in an Irish quarry was installed in about 1816 and was used to transport stone and sawn slabs from the quarry to Knightstownsome 4km awaywhere it was further fabricated if required in a dedicated stoneyard prior to exportation from the adjacent slate quay.  Today extraction continues and the stone is used for a variety of restoration, decorative and construction purposes. The longevity of its extraction, its versatility of use, and the extent of the exportation of the Valentia Slate makes it worthy to be proposed as a Global Heritage Stone Resource.

How to cite: Wyse Jackson, P., Caulfield, L., Forde, A., Conlon, I., Cox, P., and Sevastopulo, G.: Valentia Slate, Co. Kerry, Ireland: a Global Heritage Stone Resource proposal, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-13576, https://doi.org/10.5194/egusphere-egu21-13576, 2021.

13:55–13:57
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EGU21-13615
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ECS
Amanda Mozer, Nuria Castro, Kátia Mansur, and Roberto Carlos Ribeiro

Lioz limestone is a well-known Portuguese natural stone, recognised as Global Heritage Stone Resource (GHSR) by the International Union of Geological Sciences (IUGS). This microcrystalline Cretaceous limestone was broadly used in churches and monuments, especially in Lisbon, where it is exploited. It exhibits four varieties of colours: ivory (Lioz), beige (Chainnette), dark pink (Encarnadão), yellow (Amarelo de Negrais), and also many fossils of Rudists, Gastropods and Thalassinoides. This rock was brought to Brazil as ballast in vessels, to stabilise them, and to bring a Portuguese symbol to the "new land". It was mostly used in historical buildings in coastal cities (Belém, Recife, Salvador, São Luis, and Rio de Janeiro) from the 16th to the 20th century, though it can be found in many other of Brazil. The stone that shines in Lisbon, the Royal Stone from Portugal, keeps in Brazilian monuments the memory of the strong relationship between Portugal and Brazil, along this country's history, first as an overseas colony and later as the seat of the United Reign of Brazil, Portugal and the Algarves. The history engraved in these monuments guards that memory, being essential to study the processes of degradation that these rocks suffer. In the central region of Rio de Janeiro, known as “Old Rio”, many heritage buildings present Lioz limestone, usually together with local gneisses, in their construction and ornamentation: in floors, altars in churches, walls, columns and others. Some examples are the Royal Portuguese Cabinet of Reading, the Church of Our Lady of the Candelaria, the Bank of Brazil Cultural Center, the Imperial Palace, the Saint Francis of Paola Church, the Saint Luzia Church, the Master Valentim Fountain, the Holy Cross of the Military Church, the Saint Joseph Church, the Riachuelo Teather, and the Gustavo Capanema Palace. The last one is a symbol of the modernism in Brazil. Some of these buildings are in routes of urban geotourism as a form to disseminate science. These places are relevant in many aspects, such as cultural, historical, architectural, geological and educational. Rio de Janeiro is a coastal city with an average temperature of 23,2ºC, rainfall of 1,278mm per year and relative humidity of 78%. Lioz limestone's alteration gets more accentuated in these conditions, and the deterioration can be even more intense. Another point to observe is that many of these buildings are in high traffic areas, and the pollution emitted by the vehicles is highly prejudicial because of the cycles of dry and wet deposition. The Lioz limestone presents low porosity; however, problems as black crusts and biological colonisation are common and can lead to severe forms of degradation, and the monuments' mischaracterisation. This work aims to elaborate an inventory of the monuments constructed and ornamented with Lioz limestone and the observed decay patterns of this stone in Rio de Janeiro. The inventory and the study of the mechanisms and extension of their degradation over time are crucial for their effective conservation for future generations.

How to cite: Mozer, A., Castro, N., Mansur, K., and Ribeiro, R. C.: Mapping Lioz limestone in monuments at Rio de Janeiro, Brazil, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-13615, https://doi.org/10.5194/egusphere-egu21-13615, 2021.

13:57–13:59
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EGU21-1129
Victor Cardenes Van den Eynde and Gurmeet Kaur

In 2008, during the 33rd IGC in Oslo, a working group on natural stones and heritage built in stone was created. In 2012, the working group was accepted as an IUGS Task Group and in 2016 the network was upgraded to Subcommission: the IUGS Heritage Stones Subcommission (HSS). Since then, HSS has worked on the designation of 22 stones as Global Heritage Stone Resource (GHSR), a figure that distinguishes and protects extraordinary stones that have been used to construct some of the most important monuments and historic buildings, some even designated as UNESCO World Heritage. GHSR is a geological standard approved by the IUGS Executive Committee. The Subcommission continues working on the study, nomination and designation of more GHSR, following a strict and transparent protocol that guarantees that the designated stones are perfectly identified and documented. This process is performed under the review of experts in stone heritage and dimension stone. The results on the heritage stones have been published in different journals, special issues of scientific journals and books. The present work displays the 22 stones designated as GHSRs up to now, showing their locations on the world map, exhibiting the rock specimens, together with a list of the publications considered for the designation of these as GHSRS by the Heritage Stones Subcommission. The map will continuously be updated, plotting the new designated GHSRs as and when approved by the IUGS-EC.

How to cite: Cardenes Van den Eynde, V. and Kaur, G.: The map of the Global Heritage Stones: a resource in development, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-1129, https://doi.org/10.5194/egusphere-egu21-1129, 2021.

13:59–14:15