Boletín Geológico y Minero

In Memoriam Luís Lopes (1964-2026)

Noel Moreira — 2026-07-22

Historical Quarries. Global Perspectives and International Research Trends

Enrique Álvarez Areces — 2026-03-30

This monograph integrates research from 12 countries from three continents (Europe, Asia, and America). The publication projects an exceptional international dimension, encompassing studies from Spain, Italy, Greece, Norway, Slovenia, Germany, Portugal, and France in Europe; Qatar, India, and South Korea in Asia; and Brazil in South America. This geographic diversity provides a multidisciplinary perspective from the various research groups that have collaborated on this monograph, documenting the richness of their geodiversity and historical exploitation on a global scale.
The contributions from the different scientific teams underscore the importance of historical quarries as scientific-technical spaces for material traceability. Through the use of advanced methodologies, petrophysical studies, and engineering analysis, these works demonstrate that quarries are not merely exhausted deposits, but authentic laboratories. They allow for the generation of georeferenced inventories and ensure that any restoration intervention respects the petrophysical integrity and originality of the heritage element.
From a heritage perspective, the monograph highlights that the study of these sources is essential for correctly understanding built heritage and its construction history. By linking each building to its territory—as observed in many of the cases presented —the authenticity of the cultural asset is further guaranteed.
The collection of works compiled in this monograph reflects the significance of historical quarries as a key piece in heritage studies and underlines their value as a first-rate scientific-technical space. It is evident that these sites are not only the material origin of our monuments but laboratories where geology, history, and engineering converge to ensure the authenticity and proper conservation of our built memory.

Analysis of the limestone and calcareous rocks exploited in the Vega de Granada from Sierra Gorda and surrounding areas (Granada, Spain) and its archaeological use in the Roman villa of Salar (Granada)

Esther Ontiveros Ortega — 2026-03-30

The province of Granada (Spain) is of great interest for the advance of the research on the use and exploitation of quarries in Roman times. This work shows the first results on the use of local stone varieties from this eastern area of Roman Baetica province. In this respect, a geological and petrographic study of the quarries exploited in the Sierra Gorda sector and surrounding areas is given, taking as reference the archaeological materials documented in the Roman villa of Salar, located at the western edge of the Granada Basin (Spain). Sierra Gorda and the areas around the Vega de Granada were a supply site for stone materials in Roman times in the Roman villa of Salar. Several lithotypes have been identified, most likely coming from this mountain massif. The use of the Dogger calcareous breccia and, probably, the nodular limestones of the Dogger-Malm stands out. However, the use of the micritic Lias limestones remains to be confirmed. In the case of the oolitic limestones (from the Jurassic) there is a high probability that this typology came from other provinces (Málaga or Córdoba), not from Sierra Gorda. The crinoid limestones used (also Jurassic) are most likely from Sierra Elvira. Finally, the exact location from which the Miocene calcarenites (Alhama or Escúzar) were extracted is yet to be determined.

Petrographic, petrophysical and engineering geological properties of stone materials employed in the Late Baroque of Val di Noto UNESCO Heritage sites (Sicily, Italy)

Rosalda Punturo — 2026-03-30

The “late Baroque towns of the Val di Noto” in south-eastern Sicily, Italy, testify an outstanding post-seismic rebuilding architectonic achievement, after that an earthquake destroyed them in 1693. The reconstructed towns, characterised by “distinctive innovations in town planning and urban building” have been added to the UNESCO World Heritage list since 2022. They exhibit architectural features characterised by a close relationship between local stone, geological context and societal development. Indeed, they are characterized by the employment of two lithotypes, i.e., sedimentary (i.e. Hyblean limestones) and magmatic (i.e. Etnean lavas) rocks, resulting in an original bichromy. Nevertheless, once in the city centres, stone materials are exposed to atmospheric agents (e.g., rain, wind, solar radiation, aggressive atmospheric pollutants, freeze-thaw cycles, crystallization of saline solutions, and growth of organisms) that, over time, may trigger weathering process. In this contribution, we focused on two main lithotypes widely used as building stones and, specifically, we carried out a review on its fabric-related petrophysical properties, in terms of petrography, porosity, seismic and geo-engineering behaviour and observed the deterioration forms developed in the buildings. Our review paper aims to provide a basic tool, useful either for conserving monuments of cultural heritage and for their restoration.

The timelessness of Thassos and Naxos heritage ornamental stones

Konstantinos Laskaridis — 2026-06-24

Heritage stones have been used since prehistoric times for a variety of purposes. The beauty of historic stone buildings that have endured over time testifies to the importance of heritage stones to the cultural heritage of societies. The aim of this paper is to study the timelessness of two ornamental stones from the islands of Thassos and Naxos. The marble of Thassos was originally extracted in the 7th century BC from the ancient quarry of Alykes, which produced a grey calcitic marble. This quarry had been in operation for over 1200 years and had become one of the most important sources of marble in ancient times. Today the ancient quarry is no longer in operation. The quarrying and exploitation of another calcitic marble began later, in modern times, in the central part of the island of Thassos. Laboratory tests carried out on this “new” marble have confirmed that its aesthetic and physical-mechanical properties are similar to those of the marble extracted from the ancient Alykes quarry. The white marble of Naxos was widely used even in prehistory and antiquity for religious purposes or for daily life objects and later for architectural purposes, in monuments and sculptures. Naxos quarry is still in operation, and the marble is used for various applications, due to its high quality characteristics. The mineralogical and physical-mechanical properties of these marbles have been determined in the Lithos Laboratory, in order to highlight their importance as heritage stones.

The Intertwined Architectural and Geological Heritage of Ouro Preto, Minas Gerais, Southeastern Brazil

Cláudia dos Santos — 2026-03-30

Ouro Preto, located in the state of Minas Gerais, Brazil, is a city rich in historical, geological, and cultural significance. It was built during the gold rush of the 17th and 18th centuries in the colonial period, and its urban architecture has been remarkably preserved to this day. Ouro Preto is strategically located in the Iron Quadrangle, a globally important mineral province with a complex geological setting spanning from the Archean to the Proterozoic eon. The city is renowned for the exploration of conventional mineral resources such as gold, iron, manganese, uranium, gems, etc., as well as the extraction of ornamental rocks, particularly quartzite, soapstone, marble, and gneisses. These rocks, part of the Qfe stratigraphic framework, were used to construct the architectural heritage in the Baroque and Rococo styles, many of which were crafted by the hands of the artist Aleijadinho (Antônio Francisco Lisboa). Ancient quarries preserved around Ouro Preto, or even within the urban area, are remnants of rock extraction and are an integral part of the city’s historical heritage. They have become a popular tourist attraction and a subject of scientific studies. Knowledge of the conection between the Qfe rocks and the historical monuments in the city of Ouro Preto emphasizes and enriches its legacy as a global geological and architectural heritage, affirming its status as a fundamental human heritage.

Linking 12th century churches and marble quarries in Norway using C, O and Sr isotope ratios

Tom Heldal — 2026-07-17

Archaeological excavations have revealed the existence of a deserted medieval town and trading place named Borgund, near Ålesund, Norway. Borgund, now a greenfield site, boasted three or four churches in its heyday. Worked marble blocks at the excavation site, some with architectural details, and in the last remaining church suggest that some of the churches were built of marble ashlars, probably in the 12th century. The present investigation aims to identify the geological source of the marble ashlars from Borgund and compare the results with marble found in other medieval churches and church ruins in the Sunnmøre district. Samples were collected from 12 marble deposits and six churches/ruins. Since all the relevant marble deposits in the region are mineralogically and texturally similar, provenance sourcing could not be carried out visually or by petrographic examination alone. Moreover, modern quarrying of marble for lime mortar has eradicated traces of medieval marble extraction. Consequently, we studied the provenance of the marble using C, O and Sr isotopic analyses. The isotopic data provided evidence for a major source of marble for the Borgund Churches, most likely the nearest sizeable marble deposit. Other churches in the region displayed different isotopic signatures, indicating that several marble quarries were employed in the 12th century, showing a complex pattern of resource acquisition.

Origins of architectural heritage: the resources and variety of natural stones in Slovenia

Sabina Dolenec — 2026-07-17

The distinct geological variation of Slovene’s territory, which includes all three major types of natural stone (sedimentary, igneous and metamorphic), offers an ample selection of building and art materials to be chosen based on their properties and/or aesthetic appearance. The tectonic diversity of the area caused some difficulties in extracting some of the natural stones, resulting in quarries being abandoned for economic and spatial reasons, but some beautiful examples of the use of lasting value in both construction and art still persist. Examples include the abandoned quarries of Pohorje marble and Podpeč limestone, where extraction has been documented from as early as the Roman times, with the latter also designated as a Global Heritage Stone Resource. The Pohorje mountains are an area of granodiorite as well as green cizlakite, the latter being Slovenian endemic. Furthermore, the Kras (Karst) region is one of the most interesting areas containing natural stone reserves in Slovenia, with a large variety of Cretaceous shallow-water limestones. All of these are abandoned, with the two natural stone quarries still operating being associated with the presence of rudist biostromes and bioherms, which are responsible for the aesthetic appearance of these natural stones. It is also characteristic of Slovenia to use a variety of local rocks, such as sandstone, conglomerate, breccia, shale and tuff, to give character to vernacular architecture. Some of the quarries are designated and protected as valuable natural features or natural monument, while several buildings decorated with Slovene natural stones are declared as cultural monuments of local or national importance or included in the UNESCO World Heritage List. This paper presents the most significant Slovene quarries of natural stones that have been used in architectural heritage, the mineralogical and physical-mechanical characteristics of these stones, as well as examples of their use in monuments.

Stone monuments and abandoned quarries –ways of restoration in Germany through times

Angela Ehling — 2026-07-17

Numerous buildings and monuments in the cultural heritage in Germany are made of stone. Increasingly, quarries are closing and the original stone is no longer available as a substitute material. Various ways of dealing with this situation in the past are presented here using 6 examples: Cologne Cathedral, Freiburg Münster, the Stone Bridge in Regensburg, Kaiser-Wilhelm-Monument at Porta Westphalica, Old National Gallery in Berlin and the Picture Gallery of Sanssouci Palace in Potsdam. It is shown how the replacement stones were selected at different times and under different economic and political conditions when the original rock was no longer available. In two cases, old quarries were (temporarily) reactivated. For the other buildings, other, available stones were used for restoration or reconstruction. In one example, this replacement was reversed after the original material became available again. The ways of decision-making, advantages and disadvantages as well as experiences are presented and discussed in this contribution.

The Historical Quarries of Jabal Fuwairit (North Qatar): Preliminary Studies for its Enhancement, Conservation, and Musealisation

David Martín Freire-Lista — 2026-07-17

The historical quarries of Jabal Fuwairit are in the north of Qatar. Approximately 1 km NW of the archaeological site of Fuwairit (N 26° 2’ 28.457’’ E 51° 21’ 57.418’’). Jabal Fuwairit fossil dunes are pseudo-parallel to the coastline and have an NW-SE orientation. They are approximately 1.3 km long and 0.2 km wide at their widest. Throughout the hills, there are numerous vestiges of historic stonework. Traditionally quarried building stone at Jabal Fuwairit is an ooidal limestone characterised by medium-scale crossbedding and a vuggy fabric with ophiomorpha burrows and cemented roots. Ooid grains are well sorted and medium- to coarse-grained, with sparse fossil debris. The quarrying was facilitated by the cross-bedded strata set in pseudo-horizontal planes, along with the desiccation cracks filled with muddy material (pseudo-vertical planes), which made possible the extraction of individual blocks in the historical quarry. The homogeneity of the grain size and high porosity of this stone allows it to be easily carved. Jabal Fuwairit historical quarries are in a privileged geological environment. They have numerous engravings, especially cup-marks, and possibly a ground-plan of a house with an inscription, attesting to the place where the stone was extracted for the building of a shaikhly residence around 1900 by the headman of Fuwairit, Nasr bin Shahin Al Tuwar. Jabal Fuwairit historical quarries can be reused generating economic profitability with cultural actions. They have numerous geological and archaeological elements to become an open-air museum.

Ancient Quarries on the Estremoz Anticline (Ossa Morena Zone, Portugal): Exploitation, Use and Dispersion of Estremoz Marbles during Roman times

Luís Lopes — 2026-07-17

The use of crystalline marbles from Estremoz Anticline, Alentejo (Southern Portugal), and their historical exploitation are documented since the Roman period. While most of the ancient quarries in the area were originally discovered due to the intense mining activity of the 20th century, the remains that still preserved in situ are very scarce, as this recent exploitation has often erased the existing evidence. However, in several of the cases here documented, recent quarrying operations have contrastingly provided and helped preserve these traces of earlier extractive activity. The analysis of aerial photographs, confirmed by a field visit to the area, identifies almost five hundred marble quarrying and exploration sites in the Estremoz Anticline, most of which were opened in the 70s and 90s of the 20th century, while official records show that in the late 80s there were 187 quarries operating simultaneously around the villages of Estremoz, Vila Viçosa and Borba.

Today, for various reasons (including the globalisation of the economic market, the ageing of the population, recurring economic crises, the recent tightening of safety regulations, etc.), only around 40 quarries are still active, some of which are over 150 metres deep. Nevertheless, the analysis and conservation of the archaeological evidence of exploration remains a significant challenge. This paper presents a summary and characterisation of the identified ancient quarries and remains in terms of their location, geological setting and marble type, but also of the ancient exploitation methods observed. It also explains the current challenges for the conservation of the relevant geodiversity found and some resulting geoconservation measures, defined according to the site, which could be implemented on a larger scale to conserve and display the unique architectural and cultural heritage of these sites. This study assumes a particular relevance so that both landowners and industry continue to support and preserve this historical and cultural, tangible and intangible heritage of undeniable and differentiating value for this raw material.

Ancient and modern quarries of building stones in North-East France: main limestone deposits and rock types

Gilles Fronteau — 2026-07-17

The north-east of France is mainly occupied by the Paris Basin, which has provided a significant quantity of building stone, particularly limestones used as dimension stone. A series of famous quarries have left their mark on the local area, from the Jurassic (Dom, Euville, Savonnières) to the Cenozoic layers (Hermonville, Courville), while others have been forgotten. These building stones are sometimes used on their own or mixed with more local materials that are less valued or with other properties. Some of these quarry areas have stones which were exported, competing with stone from Belgium, Burgundy and the Paris region. By comparing old maps and archives with quarries and stones that are still accessible, it is possible to draw up a number of assessments of the geological signatures of each limestone (facies, microfacies, petrophysical features). This allows us to gain a deeper insight into the utilisation of these building stones and to attempt to refine the restoration of cultural heritage.

Selected historical quarries of India: an account

Gurmeet Kaur — 2026-07-17

Diverse stones and rocks have played a crucial role in shaping the monumental architectural heritage of India. Sourced from historical quarries scattered across the Indian subcontinent, these rocks have served as a vital link to our rich past cultures and traditions. Each stone narrates a story, reflecting the craftsmanship and creativity of previous eras. Acknowledging the significance of these stones and the quarries is essential for celebrating and preserving our cultural legacy. By recognizing these stones and qaurries, we ultimately nurture a deeper appreciation for the cultural identity that has evolved over centuries. Indian subcontinent is well endowed with rocks like marble, basalt, sandstone, charnockite, granite, limestone, laterite, to name a few. Some of these stones are inherent part of well-known UNESCO World Heritage Sites, such as the Taj Mahal (Makrana Marble), Jaisalmer Fort (Jaisalmer Limestone), Elephanta, Ajanta and Elora caves (Deccan Basalt), the Qutb Minar complex (Alwar Quartzite), Group of monuments at Hampi (Closepet granite) and Konark Sun temple (Khondalite), Mamallapuram Shore Temple (Indian Charnockite), Basilica of Bom Jesus (Western Ghats Laterite) so on and so forth. Recently, seven stones from India viz. the Makrana Marble, the Jaisalmer Limestone, the Deccan Basalt, the Alwar Quartzite, the Himachal Slate, the Indian Charnockite and the Western Ghats Laterite have been recognised as ‘IUGS Heritage Stones’. This paper will focus on a few noteworthy stones and the ancient quarries that produced them.The significant architectural heritage crafted in these stones have experienced some deterioration as a result of anthropogenic and natural factors. As a result, it is crucial to retrieve stones from the historical quarries of these significant rocks for restoration work and to understand how quarrying practices have changed through time. It is important to conserve and preserve the historical quarries for posterity.

Iksan Granite and Stone Monuments in Sabi Period of Baekje Kingdom, Korea

Myoungju Choie — 2026-07-17

The Iksan granite was included in the mid-western part of the Korean peninsula during the Jurassic Daebo orogeny. This granitic batholith has many historical quarries dating back to the 6th century until today. It is called one of the top 3 quarry sites in South Korea because this area is accessible to stone with a huge reserve in the hill region. Many stone monuments are well-known in the Sabi period (538–660 CE), belonging to the late Baekje Dynasty, which ruled in the Iksan area, in the heyday and was the essence of Baekje culture. Many researchers have reported continuously that Iksan granite is medium- to coarse-grained and K-feldspar porphyritic granite with a very homogeneous texture and geochemical composition over the twenty years. Paradoxically, this ‘homogeneity’ of Iksan granite has limited previous studies in finding specific historical quarries. The whole-rock geochemical analysis results do not explain the discrimination for each quarry site. This review compares the geochemical composition of the granites from quarry sites and stone monuments. It summarizes interpretation results concerning historical quarries of the late Sabi period of Baekje from the literature. Additionally, new geochemical analysis methods are suggested for tracing historical quarries on the condition that the whole-rock geochemical compositions of stone are homogeneous in the study area. The results on the geological characteristics and tracing historical quarries in the Iksan area show the long-term value of the Iksan granite as a natural resource for more than 1,500 years.