Cadernos do Laboratorio Xeolóxico de Laxe. Revista de Xeoloxía Galega e do Hercínico Peninsular
Cadernos do Laboratorio Xeolóxico de Laxe is a publication of Instituto Universitario de Xeoloxía Isidro Parga Pondal of the University of A Coruna (Spain). It is a journal that has been published continuously since 1980. In its origins, it was dedicated to the geology of Galicia and the Hercynian. Nowadays, it includes many other topics related to Earth Sciences: geomorphology, geochemistry, petrology, hydrology, palaeontology, edaphology, geoarchaeology, geological heritage, geotourism, etc. It accepts original research, revision or synthesis papers in Spanish, Galician, Portuguese or English, which will be submitted for peer review. ISSN: 2173-6936 (electrónico), 0213-4497 (impreso) || https://doi.org/10.17979/cadlaxe
Universidade da Coruña, Servizo de Publicacións
Los trabajos publicados en esta revista están bajo una licencia Creative Commons Reconocimiento-CompartirIgual 4.0 Internacional. Los autores ceden el derecho de la primera publicación a Cadernos do Laboratorio Xeolóxico de Laxe, que podrá publicar en cualquier lengua y soporte, divulgar y distribuir su contenido total o parcial por todos los medios tecnológicamente disponibles y a través de repositorios. Se permite y anima a los autores a difundir los artículos aceptados para su publicación en los sitios web personales o institucionales, antes y después de su publicación, siempre que se indique claramente que el trabajo pertenece a esta revista y se proporcionen los datos bibliográficos completos junto con el acceso al documento.
Reinaldo Costas Vázquez (1956 - 2025): a tribute
Copyright (c) 2025 Marcos Vaqueiro Rodríguez https://creativecommons.org/licenses/by-sa/4.0
Georeferenced digital models for the study of caves and their microforms
The study of caves requires strategies that allow for the analysis of their geometry and structural patterns at a three-dimensional level. The proper construction of their digital models allows us to treat them as structured data models, to which we can associate and georeference records related to geomorphodiversity, biodiversity, cultural heritage, environmental impact, and the environment. This allows us to analyze all this information, also considering its geospatial component.
Copyright (c) 2025 Marcos Vaqueiro Rodríguez, Reinaldo Costas Vázquez https://creativecommons.org/licenses/by-sa/4.0
The Roman mine of As Borreas: Description and approach to its geology
The Roman mine of As Borreas de Caldesiños (Viana do Bolo, Ourense) is a Roman gold exploitation from the 1st and 2nd centuries. The erosion of the surrounding Variscan materials (slates, schists, quartzites and two-mica granites) provided the gold-bearing sediments deposited during the Miocene. Mining activity using hydraulic means allowed the extraction of gold and generated a very striking landscape similar to that of the Médulas de Carucedo (León). In this study, the boundary between Paleozoic materials and Tertiary sediments is defined, and, on the other hand, an attempt is made to identify the origin of the sedimentary materials by measuring the orientation of imbricated clasts, with the trouble that these sediments are tilted towards the east by alpine tectonics. These measurements indicate that the sediments were deposited by water currents coming from the south-southwest. Likewise, the existing anthropic deposits in the lower part of the exploitation are mapped and granulometrically described, which are the materials expelled through the mine washing channels and, accordingly, they are not tectonized and are deposited over fluvial terraces of the river Camba.
Copyright (c) 2025 Víctor Barrientos, Roberto Matías Rodríguez, Eduardo González Clavijo https://creativecommons.org/licenses/by-sa/4.0
Regional mapping of climate variables in Galicia from point samples
Galicia's (NW Spain) diverse climate, driven by various factors, exhibits significant spatial and temporal variability, directly affecting the region's economy and society. Taking this into account, it is of great importance to have climate observation networks that cover most of the territory, and in the case of not having them, to have tools that allow the estimation of climate parameters. The main tools used for the estimation of parameters in unmeasured locations are climate database and the interpolation of data from climate stations, with kriging being one of the most widely used interpolation methods. The evaluation of climatic database is very important to establish how well they estimate the parameters and to ensure that they result in a homogeneous data series. For this purpose, in the present study a comparison was made of point data from the MeteoGalicia weather station network with data extracted from the SIMPA, AEMET and ERA5 databases and with data resulting from interpolation using regression kriging methods. The climatic parameters for which data were used for the study are: mean temperature, precipitation and reference potential evapotranspiration (Eto). To extract the data from SIMPA, ERA5 and AEMET and to interpolate point data from MeteoGalicia, we worked with the statistical programming environment R. After extracting the data or interpolating them, they were compared with the data measured in the MeteoGalicia network of climatological stations using the Nash-Sutcliffe index. The results of this study seek to conclude which method is more effective for estimating each of the parameters studied. In general, the predictions based on interpolation (AEMET and regression kriging) presented the best goodness of fit, while SIMPA also presented good results for some parameters. In general, the parameters with the best estimation results were mean temperature, followed by precipitation and finally potential evapotranspiration.
Copyright (c) 2024 Jorge Dafonte, Samira Hernández https://creativecommons.org/licenses/by-sa/4.0
A note on Dodgson’s Rock platform, Elkington quarry, and the origin of bornhardts on north-western Eyre Peninsula, South Australia
The excavation of what was Dodgson‘s Rock, now Elkington quarry, exposed a domical bedrock form that can be construed as a stage in the development of incipient bornhardts. It confirmed the earlier interpretation of the domical inselberg known as Ucontitchie Hill as a structural feature initiated by the differential etching in the shallow subsurface of compartments of granitic rock of contrasted fracture density and exposed by the erosional lowering of the densely fractured and weathered surrounds. Stages in the excavation provided evidence concerning the nature of sheet fractures and structures as well as the origin of breached arches or A-tents. Other bornhardts in the district (Mt Wudinna, Polda Rock, Little Wudinna Hill) as well as sundry additional inselbergs, turrets, and elevated platforms may be of a similar origin.
Copyright (c) 2024 Author https://creativecommons.org/licenses/by-sa/4.0
Statistical variability of general properties and microelements along a transect of a soil under wineyard
Soil properties may exhibit an important spatial variability between neighboring samples. In agricultural soils, there is a need to assess the presence of potential limiting factors and their variability. The aim of this work was to evaluate the statistical variability of the main soil general properties and micronutrients of a vineyard soil from samples collected along a small transect. On this transect, which was located on a field from the Ribeiro Origin Determination, 65 soil samples were taken at a between-sample distance of 0.8 m. The general soil properties studied were texture, pH, organic matter content and exchange complex attributes. In additions, total concentrations and available concentrations extracted by Mehlich 3 and DTPA solutions of four micronutrients, namely Fe, Mn, Cu and Zn, were also determined. The soil texture ranged from loamy to sandy loam. Mean soil pH was 5.30, mean organic matter content was 2.31% and mean cationic exchange capacity was 7.56 cmol(+)kg-1 of soil. The coefficients of variation of sand, silt and clay fractions, pH, organic matter and cation exchange capacity were smaller than 10% and were classified as low, however the remaining soil properties showed CVs ranging from 10% to 20% and were classified as medium. The concentrations of total micronutrients and available micronutrients extracted with Mehlich 3 ranked as: Fe > Mn > Cu > Zn, while concentrations extracted with DTPA ranked as: Fe > Cu > Mn > Zn. Cooper accumulation was found to be the main limiting factor for wine production. Moreover, an imbalance of the Mg/K ratio in segments of the transect was evidenced. The pH and organic matter content showed relatively low values and therefore liming and increasing use of organic manures are recommended. Summarizing, the used experimental design allowed to evaluate soil quality state and to recognize the soil properties that act as production limiting factors.
Copyright (c) 2024 Irene Varela Vila, Antonio Paz González, Marcos Lado Liñares, Eva Vidal Vázquez, Gabriela Cristina Sarti https://creativecommons.org/licenses/by-sa/4.0
Evaluation of different gels and poultices to chemically remove graffiti from a Lioz limestone (Lisbon, Portugal)
In recent decades, graffiti paintings have become an artistic manifestation under the label of «Street Art». However, there are still many cases where its application is carried out with vandalic purposes. If we consider historical buildings, they cause an aesthetic alteration and jeopardise the long-term preservation of the stone used. This is why their removal is seen as necessary. In doing so, multiple factors must be considered, such as the stone substrate properties, the composition of the paint, and the cleaning method selected as all of them will determine the effectiveness of the graffiti removal. For this purpose, a study was carried out based on the removal of graffiti paint from a Lioz limestone. This is a stone widely used in the architectural heritage of Lisbon (Portugal). In this article, the effectiveness on the removal of two kinds of spray paints (silver and black), commonly used in this type of vandalism, was evaluated. Different gels and poultices used in heritage conservation were compared as cleaning agents. The aim was to evaluate their effectiveness in terms of graffiti removal, leaving the minimum amount of residues on the surface of the stone. Regardless of the paint, the greatest cleaning level was achieved with gels, mainly with Nevek®. However, further research must be conducted to avoid remains of the cleaning vehicles and chemical contamination.
Copyright (c) 2024 Daniel Jiménez Desmond, José Santiago Pozo-Antonio https://creativecommons.org/licenses/by-sa/4.0
First insights into the diet of the Atlas brown bear: evidence from Ifri Oussaïd Cave (Middle Atlas, Morocco)
This study presents the first isotopic evidence of the palaeodiet of the extinct Atlas bear, based on remains recovered from Ifri Oussaïd cave in the Middle Atlas Mountains of Morocco. Comparative isotopic analysis with Holocene brown bears from Europe suggests an omnivorous diet with a notable intake of animal protein, in contrast to more herbivorous populations such as Holocene Cantabrian bears, although these conclusions should be taken with caution, as there is no local baseline with which to compare. This bear likely inhabited a closed, humid forest environment, with C3 plants at the base of the trophic chain. The calibrated radiocarbon dating places this individual shortly after the 8.2 kyr BP cooling event, during a period characterised by slightly warmer temperatures and greater arboreal vegetation compared to present-day conditions in the area.
Copyright (c) 2024 Ana García-Vázquez, Aïcha Oujaa, Shaymae Iken, Aurora Grandal d'Anglade https://creativecommons.org/licenses/by-sa/4.0
Geostatistical analysis of macroelements, microelements and heavy metals extracted with Mehlich-3 on a vineyard microplot
A geostatistical analysis of macroelements (P, K, Ca, Mg), microelements (Fe, Mn, Cu, Zn) and heavy metals (Cd, Cr, Ni, Pb) extracted with the solution Mehlich-3 was carried out at the microplot scale in a vineyard of the Ribeiro area, Ourense, Spain. The data set studied consisted of 80 samples collected along five transects, with 16 points per transect and a distance between neighbouring points of 0.8 m. The elements extracted with Mehlich-3 presented a spatial dependency, which was described by means of spherical models, except for Mn that fitted an exponential model. The adjusted semivariograms showed a strong spatial dependency, except for Zn and Pb, which exhibit moderate spatial dependency. Therefore, it was verified that the elements extracted with Mehlich-3 can present an important spatial variability even at small distances. The kriging maps showed important differences regarding the spatial distribution, between the zones of the microplot and between the elements studied. It has to be emphasized that the spatial distribution of cationic macronutrients (K, Ca and Mg) turned out to be highly dependent upon the position of the rows and the streets of the vineyard; in this way these three elements showed lower concentration in the surroundings of the row, which may be attributed to the withdrawal of such elements by the plant.
The origin, age, and conservation, of an ‘elevated platform’, Yarwondutta Rock, north-western Eyre Peninsula, South Australia
Yarwondutta Rock is a dimpled platform that was shaped at ground level by soil moisture but subsequently elevated, not because of local tectonism, but by the erosional lowering of the surrounding pedimented plains. Concave or flared slopes fashioned in the erstwhile piedmont were revealed during this erosional phase which took place in the earlier Pleistocene. The elevated platform is now buttressed against dissection by the calcreted surrounding pediments. It is concluded that in technical terms, Yarwondutta Rock appropriately can be referred to as an ‘elevated platform’. ‘Criticism and testing are the essence of our work.’ Remark by Herman Bondi on the occasion of Karl Popper’s 90th birthday anniversary (But with a reminder that a ‘criticism’ is an assessment or evaluation, and is neither implicitly, nor of necessity, adverse. C.R.T.).
Galician research on the application of laser technology in the cleaning of material cultural heritage: past and future strategies
The cleaning of cultural heritage elements is essential to ensure the durability and transmission of our cultural and artistic legacy. In Galicia, the importance of our stone-built heritage reflects the skill of our masters and artisans and is a symbol of our strength as a community. The difficulty involved in cleaning polymineralic stones such as granites, schists, etc. used on these artworks justifies the need to carry out detailed research on the effectiveness of different cleaning methods, considering both the degree of extraction of the undesirable substance (crust, graffiti, biological colonization, etc.) and the side effects that such cleaning may cause, such as mineral extraction, chromatic changes, etc. For this reason, a group of researchers from the University of Vigo and the University of A Coruña have been working together for 13 years to optimize the application of laser technology as a cleaning tool for these stones. This physical method allows cleaning to be achieved in a selective, gradual, and respectful way with the environment and the workers’ health. A sustainable cleaning method is therefore possible. In addition to the innovative use of lasers to clean heritage polymineralic stones, this Galician research group made progress in this area with the simultaneous application of wavelengths (infrared-1064 nm and ultraviolet-355 nm) and the sequential combination of laser with chemical and mechanical cleaning procedures. These strategies have made it possible to reach high levels of extraction and reduce side effects thanks to the reduction of applied fluence levels.
Characterization of joint mortars and pavements from the Roman site of A Ciadella (NW Spain)
The results of the mineralogical and textural characterization of joint mortars and pavement samples collected at the Roman site of A Ciadella are presented. The results indicate that these are earth mortars whose most likely origin could be sub-surface horizons from nearby soils, considering the mineralogical similarity between the inherited minerals detected in the mortars and the mineralogy of the rocks in the area. No lime has been detected in any mortar. The textural analysis confirms a poor pre-treatment of the soil samples used as raw material. In the pavement samples analysed, the existence of a kaolinite-rich surface layer, probably applied deliberately on the surface, stands out.
Lithostratigraphy of the “Schist-Greywacke Domain” in Portugal: a reappraisal
A synthesis of the knowledge of the Schist-Greywacke Domain (SGD) in Portugal is here presented. Until recently, this sequence assumed the designation of Dúrico-Beirão Supergroup composed by the Douro Group (DG) and the Beiras Group (BG). The DG is considered of Neoproterozoic – Cambrian age and the BG is of Neoproterozoic age. The identification and mapping in the BG of an unconformity as the Cadomian unconformity identified in Spain, which splits the Neoproterozoic in “lower Alcudian” and “upper Alcudian”, is a turning point for the understanding and establishment of consistent stratigraphic sequences that now compose the Fróia and the Lousã groups assembled in the Beiras Supergroup. These new groups are correlated with the Neoproterozoic sequences currently recognized in Spain: the Lousã group is equivalent to the Ibor Group (upper Alcudian) and the Fróia Group is equivalent pro parte, to the Domo Extremeño Supergroup.
Periglacial features in Las Ubiñas Massif (Cantabrian Mountains)
Currently there are two active periglacial belts in Las Ubiñas Massif: the nivoperiglacial, located between 1750-1800 and 2100-2200 meters a.s.l.; and the cryonival, located above 2100-2200 meters a.s.l. to the top of the massif at 2417 meters a.s.l. (Fontán Sur). The nivoperiglacial belt, where the processes are more attenuated and the snow determines the geomorphological activity, is characterized by stable snow sheets between six and eight months per year, frequently triggering snow avalanches, as well as debris flows and landslides, Solifluction, streams and nival karst processes are also present. On the other hand, few freeze-thaw cycles have been observed in this belt. For its part, in the cryonival belt an intensification of the aforementioned processes can be seen, with the exception of snow avalanches, due to lower temperatures, around 1 ºC and 3 ºC on average per year, and a greater presence and duration of the snow and permanent snow patches. At these levels, cryoturbation generates patterned ground features such as stone stripes and stone-sorted circles.
Transporting Vitriol in the 19th Century: The Transatlantic Voyage of 4 Rhenish Stoneware Vessels
The results of the study carried out on four 19th-century Rhenish Stoneware vessels that, being recovered in Cuba, have probably been made in Germany by order of the British Crown, filled with vitriol in Germany or England, and then transported by ship to America. The study includes a formal analysis, based on the concept of chaîne opératoire, and analytical (CAT, DRX, FRX, SEM-EDX). The synthesis of both approaches allows us to reconstruct in detail the biography of the vessels.
Use of stable and radioactive cosmogenics for dating in Spain
Historically, the greatest difficulty in geomorphology work has been the absolute dating of geomorphological surfaces, which reaches its maximum when the surface lacks any type of coating. It is then that the only criterion is either the creative imagination or the use of stable cosmogenic isotopes and, failing that, of radioactive ones, since as long as the stability of a surface can be guaranteed, the method will give an absolute age for the surface. Dating has different precision depending on which isotope is used. In the case of stable cosmogenics there is no age limitation, although in others (radioactive cosmogenics) it would be limited by the half-life of the isotope used. The detailed analysis of the geological and geomorphological history of the analyzed surface should never be neglected, more than in any other type of dating.
Tourmalines in the Namacotche Li-Cs-Ta granitic pegmatite group, Mozambique: crystal chemistry and origin
The field work, backscattered electron images and detailed microanalyses of three generations of tourmaline from the Namacotche LCT pegmatites allows de distinction between the compositional magmatic and hydrothermal tourmalines. The generation 1 occurs in the outer intermediate zone of the pegmatite. It consists of zoned crystals with an oscillatory inner core of foitite and schorl, an outer core of schorl and an Fe-rich fluor-elbaite rim. Unzoned Fe-rich fluor-elbaite crystals occur in the inner intermediate zone of the pegmatite. All the crystals are derived by fractionation of a (Al, Li, B)-rich pegmatite melt. However, the rim of zoned crystals and some compositions of unzoned crystals show evidence of hydrothermal fluids, as they plot outside the fractionation trends. The zoned fluor-elbaite crystals of the generation 2 are from the inner intermediate zone of the pegmatite. They have a pink core and a green rim. The rim has higher YFe2+, Na, F contents YFe2+/(YFe2++Licalc.) value and lower Si, YAl, Licalc. and X-site vacancy contents, X-vacancy/(Na+X-vacancy) value than the core. Both zones are hydrothermal. The rim is an overgrowth. The fluor-elbaite gemmy crystals of the generation 3 occur in sheared breccia blasts and clasts with a cookeite matrix. They depend mainly on the fluid-rich hydrothermal environment of low temperatures (280-150ºC). Some from the cycle a may result from the dissolution of magmatic tourmaline crystals of the generation 1 from the sheared outer and inner intermediate zones of the pegmatite due to reaction with late fluids in chemical disequilibrium, followed by growth of tourmaline with low temperature hydrothermal fluids. The evolution from the cycle a to the cycle b and to the cycle c of the generation 3 implies that the hydrothermal reacting fluids were undergoing fractionation and becoming richer in Li and poorer in Fe2+ during the late hydrothermal crystallization of the pegmatites.
Late-Pleistocene chronology of coastal fluvial deposits at the mouth of the Ulla River in the Ría de Arousa (Galicia, NW Spain) by OSL dating
This work establishes the age of an outcrop of fluvial deposits located at the current mouth of the Ulla River in the Ría de Arousa (Galicia, NW Spain), at +40 m and +30 m above present sea level. The deposits are formed by braided siliciclastic materials. Although they have been known for a long time their age had never been determined, being considered successively from Upper-Tertiary to Quaternary and even Holocene undifferentiated material. Using the optically stimulated luminescence (OSL) technique, a burial age has been calculated for the quartz grains included in the sediment of 180 ky for the lower level and between 70 ky and 60 ky for the upper levels. The chronology established here is consistent with that obtained for other fluvial deposits studied on the Galician and northern Portuguese coast.
Glacial evolution and periglacial morphodynamics in the Asturian area of Puerto de Ventana (Cantabrian Mountains)
Despite the recent advances in glacial and periglacial studies in the Cantabrian Mountains, the focus of research has been on the highest altitude areas, while areas such as the central-western sector of the Asturian mountain have received less attention. In this sector, Puerto de Ventana constitutes a paradigmatic area due to its altimetric and lithostratigraphic characteristics. In this study, both glacial and periglacial morphologies of the Puerto de Ventana have been identified and mapped, subsequently turning the information into a GIS and proceeding to the paleoglacial reconstruction and to the calculation of paleoELAs. The results show the existence of three stages in the glacial evolution of the area: Maximum Ice Extension Stage (MEH), Internal Stage and Cirque Stage. Through these phases the altitude of the paleoELAs goes from 1400-1557 in the MEH to 1515-1649 and 1650-1838 m in the following stages (depending on the method used). Likewise, from an initial glacial surface of 491.3 ha and an ice volume of 510.7 hm3 in the MEH, the second and third stages show a reduction of 90.25% and 96.28% in volume, respectively. Moreover, the study of periglacial morphodynamics allowed to identify both relict morphologies whose genesis is highly conditioned by the existing lithology in the area, and functional morphologies showing a weak geomorphological activity and a marked seasonal character compared to other areas of the Cantabrian Mountains.
Karst features in Las Ubiñas Massif (Cantabrian Mountains)
Las Ubiñas is one of the most outstanding limestone massifs in the Cantabrian Mountains. Its altitude and its climatic conditions (with heavy winter snowfalls in the highest sectors), favor karstification, but there are no specific studies to date. This research, based on field work and geomorphological mapping, examines the spatial distribution of karst features and processes, their altitudinal gradation, as well as their interferences with other landforms (especially with glacial and periglacial landforms). The results suggest that the karst has evolved through a succession of three stages (preglacial, glacial and postglacial), in which both climatic conditions and the main geomorphological processes have changed. At present, we differentiate three karstic areas according to the altitudinal gradient: low-altitude karst (below 1,700 m); karstic desert, and the nival karst area (above 1,700 m). The Massif is home to a great profusion of exokarstic landforms and an extensive endokarstic system network, evidencing an important influence and interdependence between karst features and processes, and Quaternary glaciers and the present-day periglacial and nival morphodynamics.
Remote sensing and geophysical survey in Veladiez. A new sector of the Roman town of Segisamo (Sasamón, Burgos).
The authors have paid special attention to the study of the Roman city of Segisamo (Sasamón) within the framework of the project that analyses the archaeological landscapes in the transition between the Iron Age and the Roman period in the Odra-Pisuerga region (Burgos). In 2019, some aerial photographs allowed the detection and documentation of archaeological structures in the city's northwest sector. Further UAV-derived aerial (RGB and NIR) and geophysics surveys have taken place since then. This non-destructive approach has made it possible to recover an unknown sector of the Roman city of Segisamo and put forward new hypotheses about the city's limits in ancient times.
The power of moisture: under and over ‘weathering’ and the ‘umbrella effect’
Water is the supreme agent of weathering and even small amounts of moisture, can have far-reaching impacts.
Application of a Nd:YAG laser to remove graffiti from Lioz limestone: influence of laser parameters (wavelength, fluence and number of pulses) and graffiti composition
Recently laser ablation as a tool for cleaning heritage stones has experienced important improvements due to the mechanical contactless, the absence of residues, its gradualness and its selectivity. Once a laser equipment has been selected, optimization of the laser parameters (i.e. wavelength, fluence and number of pulses) has to be carried out. In this work, the influence of these parameters on the extraction of two compositionally different graffiti paints from the Portuguese limestone Lioz using a nanosecond Nd: YAG laser was evaluated. Unpainted and painted surfaces were treated with different wavelengths (infrared at 1064nm or ultraviolet at 355nm), fluences and number of pulses. Initially, the damage threshold was identified, and then, the most suitable conditions for the extraction of an alkyd blue graffiti and a polyethylene silver paint were detected. The resulting surfaces were evaluated by means of stereomicroscopy, spectrophotometry, roughness measurement and scanning electron microscopy. As a general result, after the optimization of the removal, differences were not identified for the results obtained by both wavelengths. However, the most influential factor in the efficacy was the graffiti paint composition. The silver paint was the most difficult graffiti to clean since after the laser application with the subsequent extraction of the aluminum sheets (inorganic pigment in this paint), a C-rich translucent layer was found on the surface. Although damage thresholds were established at 0.4 and 0.8 J.cm-2 for 355 and 1064 nm respectively, the fluences that allowed better results in terms of graffiti extraction were higher than these thresholds. The optimal fluences were different depending on the composition of paint: i) for blue paint, ultraviolet radiation (at 355 nm) achieved a satisfactory cleaning with 0.5 J.cm-2 and 10 pulses and infrared radiation (at 1064 nm) achieved it with 1.3 J.cm-2 and 25 pulses, and ii) for the silver paint, although the total extraction of the C-rich translucent layer was not achieved, the best efficiency levels were identified with 0.5 J.cm-2 and 5 pulses for 355 nm and 0.9 J.cm-2 and 5 pulses for 1064 nm. Therefore, the cleaning efficacy was influenced by the stone-graffiti interaction.
Geophysical survey by electric tomography in Sopeña rockshelter (Asturias, Northern Spain)
A geophysical survey analysis is carried out using electrical resistivity tomography (ERT) in the Sopeña shelter (Asturias) and its immediate area. The shelter contains an interesting Upper Middle Palaeolithic and Early Upper Palaeolithic site, revealed in an archaeological test pit up to 3 metres deep without having reached the bedrock. Its current entrance is protected by large blocks fallen from the ledge, covered by thick stalagmitic flows. This arrangement possibly testifies to an original position of the innermost human occupation zone, inside a larger cave. Through this analysis we have located several possible sedimentary fills at a certain depth on the outside of the shelter. This opens up the possibility of sampling these fills in the future, in search of possible older occupation levels.
First data on testate amoebae in speleothems of caves in igneous rocks
The testate amoebae form part of the habitual troglobios in caves developed in igneous rocks (plutonic and volcanic) where the little light, the persistence of humidity, the availability of silica and organic matter allow these protozoa to develop their biological cycle. This work presents a first inventory of species of amoebae testate identified in caves in igneous rocks from different parts of the World.
Geological sketch and the non-karstic caves of the Bakony Mountains in Hungary
The about 4000 km2 Bakony Mountains form the most extensive region of the Trans-Danubien Mountains between Lake Balaton and Marcal River. They have a typical medium relief, including plateaux of various heights, and denudated fault blocks interspersed with inter mountain basins. In the southern and western areas of the mountains, basalt cones and basaltic sheets are frequently found. In the central area, the variously sloping landscape is inclined towards the blocks. Limestone and dolomite predominate, and there are extensive karst regions and numerous karst caves. Of course, from the point of view of the non-karstic caves, these regions are insignificant. Significantly smaller is the occurrence of quartziferous (sandstone and conglomerate) and basalt rocks, however 147 non-karstic cave are known in these rocks and, in addition, 35 artificial cavities, considered as caves, are listed. The authors describe the geology, the geomorphology and the non-karstic cave development of the Bakony Mountains. Furthermore, typical examples of the caves have been selected and presented according to the different rock formations and development types.
New data on the lithostratigraphy of Beiras Group (Schist Greywacke Complex) in the region of Góis- Arganil-Pampilhosa da Serra (Central Portugal)
In the course of geological surveys conducted in the region of Góis (Central Portugal) a new unit was recognized at the top of Boque-Serpins Formation, characterized by the presence of levels of quartzites interlayered with shales, now called by Colmeal Formation. Its formal characterization is now presented and their regional geological implications are discussed in the context of the Neoproterozoic metasedimentary sequence of Beiras Group (Dúrico-Beirão Supergroup or “Schist-Greywacke Complex”). The geological surveys in progress confirm that the sequence, from the base to the top, of the Caneiro, Boque-Serpins and Colmeal Formations, feature the same structural and deformation pattern, common to the three units. It is noted that these units, defined in sector south of Coimbra – Lousã - Góis, have wide regional cartographic representation, as they have already been mapped and recognizable from Arganil until Sertã, to the south. To the west, they shall extend to the limit with Ossa-Morena Zone metasediments established by Porto-Tomar dextral wrench fault.
Assessing the soil physical characteristics of the gallery woods area at the hydrographic Mariana sub-catchment for environmental conservation
The objective of this work was to characterize soil physical properties of the gallery woods area at the hydrographic Mariana sub-catchment. The physical attributes evaluated were: bulk density, gravimetric humidity, soil porosity and mechanical resistance to penetration. The field work was carried out at Alta Floresta-MT, Brazil. Nine plots of 20 m x 50 m in surface were marked along the upper and middle river course areas in such a way that they were representative of all the subcatchment extension. The experimental design was completely randomized. Soil density of the gallery woods area was higher than that of the native forest, so that development of the root system of the trees even could be restricted. Gravimetric humidity was found to be homogeneous when different areas or different depths were compared. Soil porosity was found to be adequate for native gallery woods. Mean penetration resistance at the 0-0.25 m depth was classified as moderate, bout hint the upper and middle river course areas.
TL estimation of ages of pottery fragments recovered from granite caves in the NW coast of Spain
Granite caves and cavities are geomorphological environments associated with underground water flows with a strong turbulent regime linked to seasonality. Though not much studied, they have a great sedimentary and geomorphological interest but sometimes also archaeological because remains of human activity (mainly lithic industry and pottery). Pottery remains appear either exposed or buried and may be characterised mineralogically and dated by thermoluminescence (TL). Water dynamics justifies erosion and fragmentation of ceramic remains which appear broken and spread inside the cavities. This fact hinders their dating due to the small size of the fragments and the disappearance of the original sedimentary context, which does not allow the calculation of part of the received annual radiation dose. In this work, the results from the dating and the estimation of ages of different ceramic fragments of several granite caves of Galicia are presented. The obtained ages go from Medieval (1 ka BP) to Roman or pre-Roman (2 ka BP), Chalcolithic (6 ka BP) and even the beginning of the Neolithic (7 ka BP).
Loess caves account for a negligible amount of Austria's caves only – despite the fact that the areas covered by loess and loess-loam comprise several thousand square kilometres. Loess can be found in the northern and eastern foreland of the Alpine Mountain Range as well as in the Styrian Basin south of the Alps. Only a handful of caves have been mapped so far, concentrated at a few spots. This eye-catching fact documents a certain lack of exploration rather than a general lack of loess caves. According to Striebel (2005) and others most loess caves are formed by piping and gully erosion, initiated by inhomogeneities like disintegrating roots and animal burrows where the infiltrating water causes fast-growing pipe structures, subsequently enlarging to caves that can be entered by cavers. The rate of cave evolution is tremendous. In several cases – so far investigated – the earliest onset of cave formation lies within the early 20th Century. This can be dated as the required gradient was man-made at that time. On the other hand distinctive alterations of the caves took place within 30 years. This can be documented strikingly by comparing old and new cave maps. The crucial points – from a quantitative point of view – for the formation of loess caves are still under fundamental discussion as there are severe differences in local climatic parameters – some of the areas belong to the driest in Austria – lithologies, gradients and human interventions. Furthermore, the role of dissolution of calcitic components enhancing the subsequent erosion remains ambiguous.