Cave Morphology Research Articles

Delimiting morphological and volumetric elements of cave surveys as analogues for paleokarst reservoir modelling – A case study from the Maaras cave system, northern Greece

Active karst systems can offer good analogues for paleokarst reservoir modelling as they can provide links between present karst system geometries and the final reservoir architecture. Although clastic sediments are a characteristic and commonly conspicuous component of modern karst systems, their impact on the surveyed cave morphology has received limited attention. Here we address this topic by investigating the spatial and volumetric distribution of clastic sediments in a large karst cave hosting an active fluvial channel in northern Greece and discretize these in a geocellular framework. Mapping of cave floor sediment-types was supplemented by local stratigraphic logging of relict sediment terraces and electrical resistivity tomography in parts of the cave. Four resistivity groups were identified and interpreted as low- and high-porosity siliciclastic sediments, interbedded marble clasts, and host rock (marble). Sediment infill thickness ranges from 25 m to >45 m at the time of measurement; corresponding to a minimum of 64–95% of the cross-sectional area of the karst cavity in the surveyed part. These observations demonstrate that under certain circumstances, allochthonous siliciclastic sediments can form a significant volumetric component in karst systems and, by extension, in paleokarst reservoirs originating from similar karstic systems. This highlights the importance of understanding the context, organization and development of the initial karst system when characterizing paleokarst reservoirs. Mapping of sediment thickness is not usually carried out during cave surveys, which primarily focus on recording open cavities accessible to man. This implies that survey data concerning the shape and volume of cave systems and statistics compiled and derived from them should be handled with care when applied to paleokarst reservoir modelling.

Cave and Speleothem Science: From Local to Planetary Scales

Caves occur everywhere on our planet, from the tropics to the high latitudes and from below sea level to alpine settings. Cave morphologies provide clues to their formation mechanisms, and their iconic mineralogical features—stalagmites and stalactites—carry a wealth of paleoenvironmental information encoded in their geochemistry and mineralogy. Recent work demonstrates a striking improvement in our ability to decode these paleoenvironmental proxies, and dramatic geochronological advances enable higher resolution records that extend further back in geologic time. Cave research addresses an ever-increasing range of geoscience problems, from establishing the timing and mechanisms of climate change to uncovering detailed records of geomagnetic field behavior.

Microclimates in Fumarole Ice Caves on Volcanic Edifices—Mount Rainier, Washington, USA

AbstractThe fumarole ice caves of Mount Rainier in the Cascade Volcanic Arc in Washington, USA, provide unique insight into the dynamic equilibrium between thermal flux of fumaroles on volcanic edifices and snow accumulation on summit glaciers. More than 3.5 km of surveyed cave passage nearly circumnavigate the East Crater, reaching within 19 m of the 4,392 m summit and extending to 144 m depth along the glacier‐crater boundary. The large circum‐crater passage connects entrances on the crater rim to steep transverse passages, and cave morphology is maintained by fumarole gas convection and advection. A melt‐ and condensate‐formed lake, Lake Adélie, occupies a portion of the circum‐crater passage. Hourly data were collected between August 2016 and August 2017 and included the measured temperatures at three fumaroles, the cave air temperature and pressure, the lake water temperature and depth, and the outside temperature and snow depth at Paradise Visitors Center. Time‐series analyses of these data reveal complex associations between synoptic to seasonal weather, fumarole activity, and lake level. On seasonal and longer scales, fumarole temperatures follow independent pathways connected to spatial and temporal changes in volcanic heat flux and the circulation of glacial melt. Major snowfall seals the cave entrances, increasing cave air temperature and pressure from fumarole output and causing rising lake levels from increased melt until entrances reopen. Repeating freeze‐thaw cycles observed in the cave monitoring data are a primary cause of crater mass wasting. Despite these transient variations, the scale and morphology of the caves is preserved over decadal or longer scales.

Late Miocene Elevated Horizontal Caves on the Highest Planation and its Significance for Karst Landform Evolution in Southern China

In Southern China, the development of the planations and cave levels are closely related to the evolution of the drainage systems and regional tectonics. The downcutting of this topographic surface represents the beginning of the modern regional river system, but researches on its age and development process have been minimal. A series of karst planations and large horizontal caves at the upstream area of the Three Gorges gives the opportunity to clarify the changes and chronology to the drainage system and the formation of these planations. A comprehensive study including cave morphology, cave infills, sediment provenance, and chronology has been carried out on the top phreatic caves located at planation surface near 2100m asl.The cave morphology features large horizontal trunk passage with maze-like branch conduits and small lower horizontal cave passages connected by shafts, the changes of cave morphology being related to the changes in the location of surface rivers. The cave deposits include fluvial gravel, thick clay, and speleothems have been analyses and dated. The lithological analysis of the cemented gravel deposits indicates that they came from the strata in Late Triassic-Early Permian. The results of 5.7 Ma and 3.8 Ma in cemented gravels were obtained by using cosmogenic burial dating, which constrained the minimum age of the top cave level and the planation .The widespread thick clay deposited in caves represent the rapid denudation of the Silurian clastic strata based on its U-Pb clastic zircon age analysis, and the age of loose clay is 810-600 ka using ESR method. Thick clay sediments transportation and cave enlargement generally resulted from large river development in humid climate. Subsequently speleothems are widely deposited in caves during the period 600-90ka (analyses by U-Th dating). Strangely the fluvial sediment deposition suddenly terminates, indicating the onset of rapid fluvial downcutting.This paper suggest that the timing of this planation is before late Miocene and tectonics played a key role in overlapped clastic caprocks denudation on it, while climate acted as the main forcing for cave enlargement and sediment during stable crustal periods after late Miocene. The adjustment of cave sediments and morphology is the response to the evolution of the hydrosystem caused by the decline of the water table through the cut-through of the Three Gorges and catchment disintegration in middle Pleistocene.

An comparative analysis of airborne and terrestrial fungi in show caves Novoafonskaya (Caucasus) and Ali-Sadr (Iran)

Caves are considered as ecosystems isolated from the surface in varying degrees. Hypogean habitats are mostly A study of cultivated species of microfungi in two show caves Novoafonskaya (Caucasus) and Ali-Sadr (Iran) was carried out. The species composition of fungi has been analyzed in the air and cave sediments along the excursion route. Species identification was performed using standard approaches and cultivation methods. Jaccard index was applied to estimate similarity of communities of different biotopes. The species diversity of microfungi was higher in the Novoafonskaya cave where 50 species of microfungi were identified. Only 38 species were isolated from the Ali-Sadr cave. Representatives of Ascomycota predominated in fungal communities. The greatest species diversity was noted in the genera Alternaria, Aspergillus, Fusarium, Penicillium, and Trichoderma. Species Alternaria alternata, Cladosporium cladosporioides, Cladosporium herbarum, Pseudogymnoascus pannorum, Oidiodendron tenuissimum and Penicillium chrysogenum were identified in all biotopes of both caves. Comparison of two biotopes of the caves using the Jaccard index revealed a high similarity in the species composition in the soil and air of the Novoafonskaya cave (KJ = 0.64). On the contrary, the species composition of fungi was different in Ali-Sadr cave (KJ = 0.22), which may be explained by intensive propagules input from the surface due to the cave morphology features and the arrangement of excursion route.

Benthic foraminifera and brachiopods from a marine cave in Spain: environmental significance

Sediment samples from a marine cave in the Murcia region (eastern Spain) were analysed for grain size, total benthic foraminiferaand dead brachiopoda to obtain environmental information through physical and ecological data in order to understandthe benthic communities of cave environments and their ecological significance. A total of 100 foraminiferal and 7 brachiopodspecies were classified, highlighting the first occurrence in the western Mediterranean of Gwynia capsula (Jeffreys, 1859). Statistical analysis applied to foraminiferal data allowed the identification of three assemblages characterised by decreasing species diversity along the cave. This corresponded to a similar separation recognisable through changes in brachiopod species abundance and well-correlated with cave morphology. The relative abundance of epifaunal clinging-attached foraminifera as well as the rate of cave and sciaphilic/coralligenous Brachiopoda, thought to be representative of the degree of separation from marine conditions,were found to be highly correlated, increasing towards the inner cave. Our hypothesis was that despite the different lifestyles ofthese two groups, the strict correlation of environmental factors (i.e. light, nutrients, sediment texture, water parameters) changingalong the length of the cave determines a comprehensive environmental gradient, causing an increase in environmental stress that has similar effects on the different taxonomic groups.

Surveying and High-Resolution Topography of the Ochtiná Aragonite Cave Based on TLS and Digital Photogrammetry

The Ochtiná Aragonite Cave (Slovakia, Central Europe) is a world-famous karst phenomenon of significant geological, geomorphological, and mineralogical values. Its specific origin is determined by particular lithological and hydrogeological conditions of the Ochtiná karst formed in lenses of Paleozoic crystalline limestones, partly metasomatically altered to ankerite and siderite. Although the cave is only 300 m long, it represents a combined labyrinth consisting in parallel tectonically controlled halls and passages, that are largely interconnected through transverse conduits of phreatic and epiphreatic morphology with many medium- and small-scale forms originated in slowly moving or standing water (flat solution ceilings, wall inward-inclined facets, water table notches, convectional cupolas, and spongework-like hollows). The highly dissected and irregular morphologies of the cave were surveyed with terrestrial laser scanning and digital photogrammetry. Both used surveying technologies proved to be suitable for quick and accurate mapping of the complicated cave pattern. While terrestrial laser scanning can provide a rapid survey of larger and more complex areas with results delivered directly in the field, digital photogrammetry is able to generate very high-resolution models with quality photo-texture for mapping of small-scale morphologies. Several data on cave morphometry were generated from terrestrial laser scanning (e.g., the area of cave ground plan, the peripheral surface of underground spaces, and their volume). The new detailed map, sections, and 3D model create an innovation platform for a more detailed study on the morphology and genesis of this unusual cave also for its environmental protection and use in tourism.

Acoustic analysis of the glacier caves in Svalbard

Glacier caves are unique and spectacular wonders of nature that can be found in very few places in the world. They have different shapes, capacity or wall structures that most often form anew every winter season. The article explores an interesting aspect of glacier cave acoustics as these spaces have never been investigated in that respect. The paper shows the methods and results of spatial impulse measurements in four different glacier caves of the Svalbard archipelago located near the city of Longyearbyen. The basic room acoustic parameters together with Sound Pressure Levels have been measured or calculated together with parametric statistical analysis. The results show the diversity of acoustical climates inside the glacier caves that strongly depends on the morphology and dimensions of the caves. The analysis of measurement locations (within particular caves) shows the strong influence on sound absorption by the snow located at the entrance of the caves. The conducted research shows the potential of acoustical measurements in the process of monitoring the cave morphology and therefore climate changes as well.

Flank Margin Caves and the Position of Mid- to Late Pleistocene Sea Level in the Bahamas

Mylroie, J.; Lace, M.; Albury, N., and Mylroie, J., 2020. Flank margin caves and the position of mid- to late Pleistocene sea level in the Bahamas. Journal of Coastal Research, 36(2), 249–260. Coconut Creek (Florida), ISSN 0749-0208.The Bahamian Archipelago has abundant fossil coral reefs and related subtidal deposits as evidence of the last interglacial (marine isotope stage [MIS] 5e) sea-level highstand; evidence of earlier highstands from the mid-Pleistocene is limited and controversial (excepting Mayaguana Island). Data from flank margin cave elevations, used as a sea-level proxy, were initially interpreted to demonstrate an MIS 5e origin derived from ∼60 mapped caves across the archipelago. A new analysis of cave morphologies and distribution has now produced 363 maps of flank margin caves, demonstrating for the first time that 26 caves with associated elevations between +8 and +24 m above modern sea level are found spanning the northwest to the southeast boundaries of the archipelago. Flank margin caves are the primary remaining evidence of past sea-level position, because almost all mid-Pleistocene subtidal deposits, and related sea-level indicators such as subtidal facies, sea caves, and bioerosion notches, have been removed by karst denudation. Cave elevations up to 24 m (above sea level) indicate that prior assumptions as to the rate of subsidence of the Bahama Banks at 1–2 m per 100 ka may not be correct. The activity of MIS 5e was recent enough, and its subtidal deposits voluminous enough, to survive to the present, along with the majority of flank margin caves formed at that time. Karst denudation may have created sufficient mass loss that isostatic subsidence stopped, or was possibly reversed, as has been demonstrated for the Florida peninsula. If true, then mid-Pleistocene flank margin caves may not represent eustatic sea-level position at the time of speleogenesis.

Cave morphology, microclimate and abundance of five cave predators from the Monte Albo (Sardinia, Italy).

BackgroundSystematic data collection on species and their exploited environments is of key importance for conservation studies. Within the less-known environments, the subterranean ones are neither easy to be studied, nor to be explored. Subterranean environments house a wide number of specialised organisms, many of which show high sensitivity to habitat alteration. Despite the undeniable importance to monitor the status of the subterranean biodiversity, standardised methodologies to record biotic and abiotic data in these environments are still not fully adopted, impeding therefore the creation of comparable datasets useful for monitoring the ecological condition in the subterranean environments and for conservation assessment of related species.New informationIn this work we describe a methodology allowing the collection of standardised abiotic and biotic data in subterranean environments. To show this, we created a large dataset including information on environmental features (morphology and microclimate) and abundance of five predators (one salamander, three spiders and one snail) occurring in seven caves of the Monte Albo (Sardinia, Italy), an important biodiversity hotspot. We performed 77 surveys on 5,748 m2 of subterranean environments througout a year, recording 1,695 observations of the five cave predators. The fine-scale data collection adopted in our methodology allowed us to record detailed information related to both morphology and microclimate of the cave inner environment. Furthermore, this method allows us to account for species-imperfect detection when recording presence/abundance data.

Quaternary environmental evolution in the South Carpathians reconstructed from glaciokarst geomorphology and sedimentary archives

The Carpathian island-type glaciokarst has a great potential of preserving signals of past environments, archived in cave deposits like speleothems and clastic infills. We present here the geomorphology and structural control of several relict alpine caves and the surrounding glaciated marble karst in the Făgăraș Mountains. Four truncated and partially unroofed caves remained on the ridge-top of Mușeteica Mountain, above the glacial cirque, while a ponor cave that developed on the cirque bottom could be related to the Last Glacial Period. Structural measurements and cave morphology showed that the conduits formed at the intersection of foliation planes and tectonic fractures on the NE-SW and NW-SE directions. Cave development reflects three speleogenetic stages: 1) texture- and fabric-controlled dissolution and distension; 2) structurally-controlled breakdown; and 3) truncation, unroofing, and cave infilling with sediments. Slow diffuse dissolution was typical for the ridge-top caves, whereas M1 Cave developed by pressure flow.Further, we report the first UTh speleothem ages, related to the evolution of alpine caves and island glaciokarst in the South Carpathians during the Middle and Late Pleistocene. Dating results show a minimum estimated age of ~560 ka for the ridge-top caves, and that speleothem deposition met optimal conditions only during warmer periods, largely corresponding to interglacials. Stable carbon isotope values in speleothems range between −9.96‰ and −4.11‰, indicating the presence of plant and soil organic activity at the time of deposition. In total, five speleothem growth phases were distinguished during the last ~560 ka.We excavated the sediment infill of a ridge-top doline down to a 2-m depth. Radiocarbon dating revealed that it was deposited during the Late Holocene, and preliminary pollen analysis identified a plant assemblage dominated by grasses.Using the relationships between karst development, glaciation, and cave sedimentary archives, we present a time slice chronology of alpine landscape evolution at >560 ka, ~400 ka, ~330 ka, the Last Glacial Period (70–12 ka), and the Late Holocene. Our geomorphological, isotopic, and geochronological results also support the existing hypothesis that the South Carpathians may have experienced at least two glacial phases during the Pleistocene. Glacial erosion rate during the Last Glacial Period, and most likely during the penultimate glaciation, averages around 0.6 mm yr−1.

Reconstruction and Measurement of Irregular Karst Caves Using BLST along the Shield Metro Line

This study investigated the application of the borehole laser scanning technology (BLST) method in the detection of both dry and water-filled karst caves. In order to solve the problem of excessive laser attenuation during the detection, we designed a test for the characteristics of multiwavelength laser attenuation in water-filled karst caves and studied the influence exerted by various factors, including different wavelengths, different laser power levels, different suspended media, and effect of turbidity on the attenuation coefficient. During the test, we discovered the existence of a “blue-green window” with low turbidity and a “near infrared window” with high turbidity in karst cave water environments. Based on the general survey results of drilling and comprehensive geophysical prospecting, a quantitative method using targeted drilling was proposed to detect the spatial morphology of karst caves in complex environments. We also investigated the effects of complex environmental factors such as suspended media and high turbidity on the laser detection distance and accuracy in karst caves, and established a quantitative matching model of laser wavelengths, laser power, and complex environmental parameters. Based on this, we obtained the best acquisition mode for detecting lasers in different karst development environments. A high-precision, three-dimensional visualized model of a real karst cave was established to quantitatively obtain the characteristic parameters, such as accurate position, three-dimensional shape, space volume, and cave filling type, which was applied to the detection of karst caves along the Jinan subway line.

Insights into the speleogenesis of Ejulve cave (Iberian Range, NE Spain): quaternary hydrothermal karstification?

We provide first insights into the speleogenesis of Ejulve cave (Teruel province, Iberian Range, NE Spain) by studying cave morphologies and cave deposits, combined with regional geomorphological and hydrothermal observations. Three main hydrogeomorphic evolutionary stages can be distinguised to explain the origin and evolution of the Ejulve endokarstic system. Cave pattern and cave solutional features (calcite vein fillings, tubes with rising ceiling cupolas, pendants and cusps, spongework and micro-corrosion features) suggest that the cave generated in a phreatic environment by ascending water. Cave morphologies and regional hydrothermal springs in this region suggest, but not prove, the involvement of thermal waters and related convection and condensation-corrosion mechanisms in the origin of the cave. Subsequently, the cave underwent a change to epigenic conditions driven by denudation, as a result of regional uplift. Once the karstic system was exhumated, carbonate speleothems formed in a vadose environment. Mineralogical, petrographic, isotopic and chronological (U-series dating) analyses of carbonate speleothems (i.e. stalagmites, flowstones, botryoids, spars, acicular crystals and farmed carbonate) are provided. Calcite, high-Mg calcite and aragonite are the most common minerals, whereas columnar, dendritic, micrite, mosaics and fans are the main fabrics. Mean δ18O values of − 7.3‰ and δ13C values of − 9.1‰ indicate carbonate precipitation from meteoric waters without a hydrothermal origin. Carbonate deposits formed at least since 650 ka BP. Our study suggests that hydrothermal fluid flow may explain, although the evidences are not fully conclusive, the speleogenesis of this cave.

Reconstruction of Sea Level Change in Indonesia: Preliminary Evidence From Maratua-Kakaban Complex

This research was conducted in Maratua-Kakaban Islands, East Kalimantan, Indonesia. This location was chosen because of its stable tectonic activity and its geographical setting as the front most island in Indonesia. This location is also known as its tourism destination and beautiful scenery. A small island like in Indonesia is prone to climate change, especially sea level changes. This research is needed to formulate adaptation and mitigation of sea level change in Indonesia. This research also important to understanding the global sea change. This research also important from national sovereignty and coastal resources management point of view. This research aims to: (1) identify water level changes evidence by marine terraces analysis, cave morphology and speleothem; (2) define the highest and lowest water level in Maratua Island, and (3) reconstruct the sea water level fluctuation during Holocene. Sea level fluctuation data were interpreted using marine terrace data, marine notch, and cave morphology. The data were collected by field survey using profiling method to find surface topography and measuring sea floor profile using echo sounder. Based on the field measurement, there are major and minor marine terraces found in the ocean floor in 82 and 180 m depth (major), 155 and 205 m depth (minor). Marine terrace also found in +6 m above present sea level. Below, marine notch was found covered with sediment.

PHOTOGRAMMETRIC SURVEY WITH FISHEYE LENS FOR THE CHARACTERIZATION OF THE LA SASSA CAVE

Abstract. The survey of ancient cave can generally be performed by traditional topographic methods that allow also its georeferencing in a global reference frame; some difficulties may arise when there are narrow tunnels that do not consent the use of a total station or a terrestrial laser scanner. In such cases a visual-based approach can be used to produce, both the followed path and the 3D model of the hypogeal environment. A prompt photogrammetric survey has been used to reconstruct the morphology of the La Sassa Cave, situated in the municipality of Sonnino (Latina), in the lower Lazio region. In this cave, a very large quantity of Pleistocene animal bones was found, together with several fragments of Copper Age human bones and Bronze Age impasto potsherds. The survey was carried out using a DSLR full frame camera Nikon D800E with a Nikkor 16 mm fisheye lens pre-calibrated. During the acquisition, several targets were measured in order to contain the deformations model. The photogrammetric model has been georeferenced using 3 GCPs positioned outside the cave entrance where a double frequency GNSS receiver has acquired data in static session mode.

Sulfuric acid caves in Calabria (South Italy): Cave morphology and sulfate deposits

Research on karst in the Calabria region recognized three different hypogenic cave systems, all related to sulfidic thermal springs. Cave morphology, the depositional setting and isotopic characteristics of gypsum deposits reveal that the main process for cave formation was the oxidation of H2S to sulfuric acid. This process, known as sulfuric acid speleogenesis, was induced by thermal water rising towards the oxidizing zone in tectonic windows where dolomitic or limestone rocks outcrop. The δ34S values of most gypsum deposits prove they originated from sulfuric acid produced by H2S oxidation in the cave atmospheres. Most gypsum deposits in the Calabrian caves, in fact, exhibit δ34S values very similar to those of H2S, not to those of sulfate in the groundwater. On the contrary, the barite and part of the gypsum in the Terme Luigiane have δ34S values similar to those for sulfate in the water, implying that the sulfate minerals precipitated in a subaqueous environment. A large-scale deposition of replacement gypsum occurred only in the water table caves of Cassano, where subaerial corrosion greatly influenced cave morphology and the typical passage cross-sections. In the Terme Luigiane and Mount Sellaro cave systems, these subaerial processes caused only minor changes in inclined passages that had evolved mainly in subaqueous conditions.

The origin and morphology of Al-Tar caves, West Karbala, Iraq

This study aims to interpret the origin and morphology of Al-Tar caves based on comprehensive analysis of fractures. The current research highlights the significant impacts of the geological system (especially jointing and lithology) in forming and developing caves in the study area. Around 50 caves and 100 joints planes have been recognised. Field measurements were transformed into three dimensions in geometric form. A location map, stratigraphic column, and survey data map of caves have been produced in order to resolve the bond of Al-Tar caves with joints in the study area. Caves and joints systems are linked with the nearly horizontal beds in the stable shelf of Iraq. Caves created by two sets of joints. Joints form two main systems; each system comprises two orthogonal sets of vertical or nearly vertical joints. A three-dimension model was used dependent on field measurements, and the model predicted where caves occurred and how they formed. Presuming autonomy, the way of alignment of caves was acquired, which was related to the direction of joints. Joints and passages orientations are consistent with regionally expected directions. After examining the anatomy and organisational position of these caves, it was demonstrated that they have large spaces or corridors, which have circular or steep entrances, most importantly where the dip angles of rock layers are sub-horizontal.

Presence of the Middle Pleistocene cave bears in China confirmed – Evidence from Zhoukoudian area

For a long time, it is controversial whether cave bears have ever lived in China during the Pleistocene. Here we checked the published and unpublished bear fossils from Zhoukoudian (North China) housed in Institute of Vertebrate Paleontology and Palaeoanthropology, CAS and Zhoukoudian Site Museum, and compared them with contemporary cave bears and brown bears. Our observation confirms the existence of cave bears only in Loc. 1 of Zhoukoudian. The general morphology of cave bears in China is similar to that of the early Middle Pleistocene cave bears in Europe and this bear can be assigned to Ursus deningeri. The metacarpals of U. deningeri from Loc. 1 of Zhoukoudian are much plumper than those of the approximately contemporary U. deningeri from Hundsheim (Austria) and are similar to those of the Late Pleistocene U. spelaeus/ingressus, presumably with a good digging ability. In contrast to Europe and Caucasus, cave bears from China are much less abundant than brown bears during the Middle Pleistocene.

Geological values of lava caves in Krongno Volcano Geopark, Dak Nong, Vietnam

The paper presents the initial results of the study of volcanic cave system and its typical formations in Krongno Volcano Geopark (KVG), Dak Nong, Vietnam. The volcanic caves have been discovered since 2007, under UNESCO sponsored the scientific project, are seen as unique geological heritages. The collaborative surveys and studies between Vietnamese geologists and the members of the Non-Profit Organization, Vulcanospeleological Society of Japan have discovered and surveyed 45 caves, and detailed mapping 20 caves. Using a complex of adequate methods, especially Remote Sensing image interpretation method, Surveying and mapping lava cave method, K/Ar dating isotopic analytical method and Current methodology, the studies aim to affirm endogenous origin of the lava cave system, the formation mechanism, as well as the typical formations of the caves. Up to date, the lava caves and interior formation in lava caves in KVG have been examined and evaluated in term of geological nature and recognized as pillar geological heritages of the Geopark.References Allred K., AllredC., 1997. Development and morphology of Kazumura Cave, Hawaii. Journal of Cave and Karst Studies, 59(2), 67-80.Allred K., Allred C., 1997. Tubular lava stalactites and other related segregations. Journal of Cave and Karst Studies, 60(3), 131-140.Barnabás Korbély, 2014. Diverse volcanic features as dominant landscape elements and pillars of geotourism in the Bakony-Balaton Geopark, Hungary. Abstract Book Workshop “Geoparks in volcanic areas: sustainable development strategies”, October 29th to November 1st, 2014. Terceira and Graciosa Islands, Azores Global Geopark, 35-38.Bird Deanne K., et al., 2014. Southern Iceland: Volcanoes, Tourism and Volcanic Risk Reduction.In Volcanic Tourist Destinations. Springer, Editors: Erfurt-Cooper, Patricia (Ed.). ISBN: 978-3-642-16190-2, 35-46. Cooper Malcolm J.M., 2014. Volcanic National Parks in Japan.In Volcanic Tourist Destinations. Springer, Editors: Erfurt-Cooper, Patricia (Ed.). ISBN: 978-3-642-16190-2, 231-246.Dave Bunnell, 2014. The virtual lava cave Created: August 4, 2000.Last update: December 16, 2014. Reviewed by Kevin & Carlene Allred. Available at:<http://www.goodearthgraphics.com/virtual_tube/virtube.html). Date accessed: 02 May 2018.Gadányi P., 2010. Formation, types and morphology of basalt lava caves. PhD. thesises. University of Pécs Faculty of Natural Sciences Doctoral School of Earth Sciences, Hungary, 1-19.Gaki-Papanastassiou, Kalliopi, et al., 2014. Volcano Tourism in Greece: Two Case Studies of Volcanic Islands.In Volcanic Tourist Destinations. Springer, Editors: Erfurt-Cooper, Patricia (Ed.). ISBN: 978-3-642-16190-2, 69-87.Honda T., Tachihara H., 2015. Vietnam Volcanic Cave Survey. e-NEWSLETTER, UIS Commission on Volcanic caves, 69, 11-12. Honda T., Tinsley J.C., 2016. Classification of lava tubes from Hydrodynamic models for active lava tube, filled lava tube and drained lava tube. 17th International Vulcanospeleology symposium in Hawaii, USA. Sponsored by the Commission on volcanic caves of the International Union of Speleology.Larson C.V., 1991. Nomenclatures of lava tube features. 6th International Symposium on Vulcanospeleology in Hawaii. Published by the National Speleological Society, 231-248.Laumanns M., 2013. Important Lava Tube Caves found in Dong Nai Province Southern Vietnam. e-NEWSLETTER, UIS Commission on Volcanic caves, 67, 13. Machado M., Lima E., 2014. Geotourism and sustainable development partnerships in the Azores Geopark. Abstract Book Workshop “Geoparks in volcanic areas: sustainable development strategies”, October 29th to November 1st. Terceira and Graciosa Islands, Azores Global Geopark, 45-48.Moreira Jasmine Cardozo, et al., 2014.Tourism and Volcanism in the Canary Islands, Spain. In Volcanic Tourist Destinations.Springer, Editors: Erfurt-Cooper, Patricia (Ed.). ISBN: 978-3-642-16190-2, 47-55.Nelson S.A., 2017. Volcanoes and Volcanic Eruptions.EENS 1110. Physical Geology.Tulane University. New Orleans, USA.Nguyen Duc Thang (Ed.), 1989. Geology and Mineral Resources of Ben Khe - Dong Nai sheet at scale 1:200,000. General Department of Geology and Minerals of Vietnam. Hanoi. Nunes, João Caros., 2014. The Azores Archipelago: Islands of Geodiversity.In Volcanic Tourist Destinations. Springer, Editors: Erfurt-Cooper, Patricia (Ed.). ISBN: 978-3-642-16190-2, 57-67.Nunes João Caros., 2014. Azores Geopark volcanoes and volcanic landforms. Valuating the Azorean geodiversity and geosites through the geotourism. Abstract Book Workshop “Geoparks in volcanic areas: sustainable development strategies”, October 29th to November 1st. Terceira and Graciosa Islands, Azores Global Geopark, 41-43.Ogawa T., 1993. On lava caves in Japan and vicinity.Proceedings of the Third International Symposium on Vulcanospeleology, 56- 73.Patricia Erfurt-Cooper, 2014. Volcanic Geo-heritage.Sustainable Tourism Development in Volcanic Regions: Geoparks, National Parks and World Heritage Sites. Abstract Book Workshop “Geoparks in volcanic areas: sustainable development strategies”, October 29th to November 1st. Terceira and Graciosa Islands, Azores Global Geopark, 23-25.Peterson D.W., Holcomb R.T., Tilling R.I., Christiansen R.L., 1994. Development of lava tubes in the light of observations at Mauna Ulu, Kilauea Volcano, Hawaii. Bulletin of Volcanology, 56, 343-360.

Cranial and mandibular morphology of Middle Pleistocene cave bears (Ursus deningeri): implications for diet and evolution

ABSTRACTDeninger’s bears (Ursus deningeri) have been studied less frequently than Ursus spelaeus s.l. Our objective is to present, for the first time, an analysis of the skull shape of U. deningeri.Bear crania and mandibles were digitised with a Microscribe or CT-scanned and the surface models subsequently landmarked. The landmarks were chosen based on a compromise between functional morphology and sample size.Results show that U. deningeri and U. spelaeus mandibles display very similar morphologies and allometric trajectories, both to each other and to Ailuropoda melanoleuca. It is inferred that masticatory adaptations to a herbivorous diet were already present in the Middle Pleistocene. U. deningeri displays a cranial morphology that is similar to that of U. spelaeus when comparing all species, but U. deningeri has a relatively narrower and dorsoventrally lower zygomatic arch than U. spelaeus, although the masticatory signal is less strong in the skull.We observe intraspecific differences between different populations of U. deningeri, which could parallel the genetic diversity found in U. spelaeus. The intraspecific differences found within U. deningeri may be temporal and/or geographical in nature and could be related to the evolution of the Late Pleistocene cave bear, but this hypothesis remains to be tested.