Piemonte region (Northwestern Italy) shows an extraordinary richness of ornamental stones, whose exploitation strongly influenced during the centuries, and still influences the local culture. Indeed, more than 150 lithotypes, mainly exploited in valleys and mountain areas, are used in the rural, urban and architecture heritage of the region.

The great variety of Piemonte stone materials used since ancient times as ornamental stones  is due to the presence of rocks belonging to very different geological units, ranging from the deep lithospheric mantle to both the continental and oceanic crust, together with successions deposited in different sedimentary basins, as well as many types of metamorphic rocks originating in different geodynamic regimes.

This great variety of rocks represents a historical and cultural heritage worthy of study and scientific dissemination not only among experts of Earth Sciences, but also among a wider public.

Starting from the Interactive Geolithological Map of the ornamental stones of Piemonte, performed by CNR-IGG (Institute of Geosciences and Earth Resources-Turin), in collaboration with ARPA Piemonte and the Department of Earth Sciences of the University of Turin, recently published on the Geoportal of Arpa Piemonte, within the webGIS application GeoPiemonte Map 2021

(https://webgis.arpa.piemonte.it/agportal/apps/webappviewer/index.html?id=6ea1e38603d6469298333c2efbc76c72), some important materials from a geological, economic-commercial and cultural point of view were selected for the enhancement of Piemonte ornamental stones.

Hence the idea of trying to bring to light the relevance and value of some of these stones as proposal for the nomination as ‘’IUGS Global Heritage Stone Resource (GHSR)’’ and some quarry districts as ‘’Global Heritage Stone Province (GHSP)’’.

How to cite: Storta, E., Barale, L., Borghi, A., d'Atri, A., Dino, G. A., and Piana, F.: Enhancement of the Piemonte (NW Italy) stone heritage, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-12818, https://doi.org/10.5194/egusphere-egu23-12818, 2023.

Ançã limestone is one of the most widely used geological formations as building stone throughout history in Portugal, and it can be recognized in many places throughout the country and abroad. The middle Jurassic Ançã Formation was deposited between the Bajocian and the Bathonian at the Lusitanian Basin (central west of Portugal), and it outcrops in Cantanhede municipality, about 25 km northwest of Coimbra. This formation is approximately 250 m thick and it is constituted at the base by layers that reach ≈2 to ≈3 m of greywish micritic limestone, slightly marly, changing to light gray and yellowish to white laterally. It is followed by creamy white to micritic limestones, in layers from ≈0.5 to ≈1 m thick.

Hard limestone types of low porosity and high strength are exploited on three quarry zones located in the Ançã-Portunhos-Outil region, which have many processing and carving workshops. The current annual production of Ançã limestone is ≈8000 m³, which is a distinguishing element of civil construction in the entire area. In addition, the Stone Museum of Cantanhede is a place of learning that promotes activities related to building stones.

The limestone of Ançã Formation is a strong candidate for “Global Heritage Stone”. This stone fits the proposed designation as it has been used since prehistoric times and its greatest use occurs since the 14^th century. It has been widely used in important buildings, tombs and monuments of Coimbra. Some historically remarkable examples include the “Porta Especiosa” in the Old Cathedral, the entrance of Santa Cruz Church and the tomb of the first king of Portugal, D. Afonso Henriques.

The University of Coimbra – Alta and Sofia have been granted UNESCO World Heritage status in 2013, and all associated buildings, monuments and pedestrian streets are constructed from heritage stones. Coimbra University is located on a hill overlooking the city. It has colleges that grew and evolved over more than seven centuries within the old town, with the Ançã limestone as the main building stone. Notable buildings include a number of 16^th-century colleges, the Royal Palace of Alcáçova, which has housed the University since 1537, the Joanine Library (early 17^th century), and the 18^th-century Botanical Garden, as well as the large “University City” created during the 1940s.

The importance of Coimbra’s emblematic heritage makes it necessary to protect Ançã limestone and its historical quarries. Given the ongoing transformation of the dimension stone industry, it is important that urban planners and policymakers responsible for cultural heritage work in tandem with needs of the traditional quarry extraction areas.

As may be deduced from the foregoing, Ançã limestone meets all the requisites for a GHS nomination. Its designation would contribute to raising awareness of its essential importance for regional economic growth, while furthering more efficient use of this dimension stone as a restoration material.

Fundação para a Ciência e a Tecnologia I.P. of Portugal supported this study with the CEECIND/03568/2017, UIDB/00073/2020 and UIDP/00073/2020 projects of I & D unit Geosciences Center (CGEO).

How to cite: Freire-Lista, D. M., Catarino, L., Figueiredo, F., and Henriques, M. H.: The limestone of Ançã Formation: a heritage stone from Portugal, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-3284, https://doi.org/10.5194/egusphere-egu23-3284, 2023.

The earth is a complex planet in permanent modification and the set of its changes includes the degradation of its stony constituents. These degradations result from the interactions of these constituents with an environment that presents conditions different from those where they were formed and in two-time scales: the geological and the time of man and his projects. About the degradations that occurred over geological time and inside the Earth's crust, we can learn about them from the exposure of stony materials close to the surface, due to uplifts and exhumations resulting from tectonic movements. From the interaction of these materials with these new conditions and, through human interference, the speed of transformation is further increased, whether using extraction, processing, and application techniques. As a result, there is inevitable degradation, which in turn will mean deterioration involving, from contemporary buildings to cultural heritage elements. Situations involving these interactions and their different forms of degradation, whether in extraction or application, can be observed around the world, both in constructions and sculptural sets, produced in stone, and in their respective quarries of origin. In this direction, and as an example, we are bringing information about geological interactions of ultramafic rocks, which underwent transformations inside the Earth's crust, generating steatite. Then, and already in the time of man and his projects, we bring information about the results of interactions of this steatite with the environment from which they were extracted and where they were applied, as in the case of the architectural complex of Congonhas, Brazil, which is a cultural heritage of humanity. As a mineralogical association, these steatites are essentially constituted by minerals such as: talc, serpentine, chlorite, and amphiboles. Subordinately, the presence of carbonates and opaque minerals is observed, all with variable contents. In the case of Congonhas, the carbonate is dolomite, pyrite was the sulphide and magnetite the oxide, often altered to hematite and goethite/limonite. These alterations present in the extraction fronts are very similar to those observed in the elements of the cultural heritage of Congonhas. Both in the quarries and in the applications, the forms of degradation result from rock interactions in geological time and application. Of this set of degradations, those involving chromatic variations, loss of parts by differential erosion with elimination of soft components, by mechanical actions and by dissolution, which in this case involve minerals such as carbonates and opaques, are most visible. Presents are other forms, such as patinas, fissures and biological colonizations. Due to lack of adequate information, mainly involving the dissemination of geological knowledge, as well as participatory approaches with local communities, Congonhas’ heritage is at risk of permanent damage. With the publicity about these degradations, which are progressive, it is expected a greater awareness and measures on the part of the agencies responsible for the conservation of this cultural heritage.

How to cite: Costa, A.: The soapstone present in elements of the cultural heritage of humanity in Congonhas - Brazil: interactions from the quarry to the monuments, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-3698, https://doi.org/10.5194/egusphere-egu23-3698, 2023.

The “Beige Bahia” is a unique light beige limestone visually resembling a travertine. It is an uncommon type of natural stone and a vital mineral resource of Ourolândia (State of Bahia), a municipality in the Northeast region of Brazil, where around 25 quarries and 45 looms in several processing plants are reported (Iza et al. 2022).

Member of the Caatinga Formation, Miocene-Pleistocene age, it is, in fact, a secondary, calcrete type, limestone formed by chemical, physical and biogenic alteration of a marine Neoproterozoic limestone of the Salitre Formation. It resembles a brecciated limestone and is characterized by a heterogeneous arrangement of calcareous fragments in a micritic matrix.

The presence of irregular and centimetric cavities is typical, resulting from the dissolution and recrystallization processes. Most of them seem like geodes due to calcite crystals covering their walls. Another relevant characteristic is the sparse occurrence of whitish areas, composed of microcrystalline calcite and minor clay minerals (illite group).

Beige Bahia had its exploration and processing started in the 1960s, although it had already been “discovered in the backlands of Bahia in the 1950s” when the pioneering producers called it “Marta Rocha marble”, in allusion to the famous Miss Brazil 1956 from Bahia, and the stone had immediate acceptance in the yet incipient Brazilian market of marbles and granites (Ribeiro et al. 2002)

Primarily named “Beige Bahia”, it has been commercialized as a travertine to which it does indeed have some similar characteristics and is even called “National Travertine” or “Brazilian Travertine”. Resembling imported travertines, but at a much lower price, this stone is one of the most commercialized all over the country, and exported mainly to USA, for covering floors and walls, indoors (mainly) and outdoors. It is also commonly used on kitchen, bathroom sink tops and other furniture.

Beige Bahia can be found in countless residential and in façades and columns of modern buildings. It is also covering important Brazilian heritage buildings, such as the Planalto Palace and the Federal Supreme Court, in Brasília (the capital of Brazil) (Frascá et al. 2020). In Rio de Janeiro, the heritage building of the Bank of Brazil Cultural Centre has Beige Bahia flooring in the exposition room. Another example is the Beige Bahia veneers at the Legislative Assembly of Minas Gerais building.

All aspects mentioned here demonstrate the geological, historical, and social importance of this rock, whose occurrence must be known and publicized.

References

Frascá, M.H.B.O., Neves, R., Castro, N.F. 2020. The White Marbles of Brasília, a World Heritage site and capital of Brazil. London, Geological Society Special Publications, 486: 217-227. https://doi.org/10.1144/SP486-2018-31.

Ribeiro, A.F., Pereira, C.P., Braz, E., Magalhães, A.C.F., Chiodi Filho, C. 2002. Mármore Bege Bahia em Ourolândia-Mirangaba-Jacobina, Bahia: geologia, potencialidade e desenvolvimento integrado. Salvador, CBPM. (Série Arquivos Abertos; 17). 56p.

Iza, E.R.H.F (org.). 2022. Rochas ornamentais do estado da Bahia. 2^nd ed. Salvador, CPRM. https://rigeo.cprm.gov.br/bitstream/doc/21244/1/irm_rochas_ornamentais_ba.pdf, accessed on 5 Jan. 2023.

How to cite: Frasca, M. H. and Castro, N.: Beige Bahia, the Brazilian travertine-like limestone, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-8696, https://doi.org/10.5194/egusphere-egu23-8696, 2023.

As a climate physicist  - I’m conscious we can use the evidence in the environment around us to help attribute and understand how we adapt to environmental changes. The stones in our vicinities, their use and the geo weathering over long time periods gives us clues to older indigenous societies and the choices made in their cultural epochs.  In this discussion I’ll discuss how society changes over the past 2000 years can be a) assessed using formal methods of signal analysis using paleo and instrumental data record, b) interpreted through the clues provided by stone use/ re-use and weathering evidence and c) known alterations to the climate dynamics in given localities. Examples will be drawn from the localities influenced by long term Pacific and Atlantic climate processes, and the interpretation of how society choices have functioned through their use of stone will be debated.

How to cite: Bruun, J.: A narrative of climate states as represented through cultural use and re-use of stone in local societies, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-15987, https://doi.org/10.5194/egusphere-egu23-15987, 2023.

Pietraforte sandstone is one of the most important stone material used during Renaissance in Historic Center of Florence, a UNESCO World Heritage Site. One of its main uses as building material is rusticated block facades, a peculiar masonry technique typical of many historical Florentine palace (ie. Palazzo Pitti, Palazzo Medici Riccardi, Palazzo Strozzi, etc.). The characteristic color of Pietraforte, ranging from grey to yellow-ochreous, is a distinctive feature of the urban landscape of Florence.

Stone rusticated blocks constitute elements with different overhangs which make them subject to decay phenomena due to weathering that, together with their intrinsic characteristics, can lead to detachment and loss of blocks (even of considerable size).

The study of Pietraforte as a geoheritage with its morphological, mechanical, physical, mineralogical, and petrographic characterization is an important starting point to understand the possible evolution of decay processes.

A multi-analytical characterization of this stone in several study cases allow the comparison of Florentine rusticated blocks used in different architectural registers (rough-hewn, smooth-faced and pillow rusticated), highlighting different behaviors of Pietraforte in distint architectural contexts.

For example, convolute laminations and calcite veins (Pecchioni et al. 2007, Pecchioni et al. 2020), typical macroscopic characteristics of Pietraforte, show different behavior depending on the type of rusticated blocks.

A multi-analytical methodology has been developed including sampling for physical, petrographic and mineralogical characterization and Non Destructive Techniques (NTD), using ultrasonic pulse velocity and sclerometric tests for mechanical behaviors (Salvatici et al. 2020, Centauro et al. 2022, Calandra et al. 2023). The main morphological features of Pietraforte from a geological point of view are investigated pondering each rusticated blocks as a rock mass and applied some methods of rock slope stability analysis.

The study performed in this work aims to protect and preserve geoheritage stones finding a new and sustainable restoration and conservation approach for Pietraforte built Cultural Heritage weaknesses. Furthermore this multi analytical approach allow the diagnosis of the vulnerability of the stone material to detachments of scales, fragments and whole blocks that represent a damage to the monuments and a danger for people.

How to cite: Salvatici, T., Centauro, I., Segabinazzi, E., Calandra, S., Intrieri, E., and Garzonio, C. A.: Multi-analytical methodology to indagate the Pietraforte sandstone risk assessment, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-14744, https://doi.org/10.5194/egusphere-egu23-14744, 2023.

The geological collections, hosted in the Liceo Classico Statale “E. Q. Visconti” in Rome, from the "wonders" of Jesuit Father Athanasius Kircher to the nineteenth-century collections and  the present-day “Wunder Musaeum”, will be presented in this presentation. These collections represent a rich and "hidden" geological jewel preserved in the heart of Rome, made up of thousands of minerals, rocks, fossils and teaching tools, aquired through a long and fascinating story. A historical-scientific heritage that the "Geomuseum" project, developed between the geologists of the University of Roma Tre and teachers of the higher School, has made possible in order to enhance it and make it accessible to the general public and the students, for outreach and teaching purposes.

How to cite: Corrado, S., Adanti, B., Grossi, F., Bosco, V., Vasconi, P., Bollati, A., and Fabbri, M.: The historical geological collections of the "Ennio Quirino Visconti" Higher School at the Roman Collegium: a hidden geological jewel in Rome, from the XVII century to nowadays, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-16959, https://doi.org/10.5194/egusphere-egu23-16959, 2023.