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El Niño–Southern Oscillation dynamics affect global weather patterns, with regionally diverse hydrological responses posing critical societal challenges. The lack of seasonally resolved hydrological proxy reconstructions beyond the observational era limits our understanding of boundary conditions that drive and/or adjust El Niño–Southern Oscillation variability. Detailed reconstructions of past El Niño–Southern Oscillation dynamics can help modelling efforts, highlight impacts on disparate ecosystems and link to extreme events that affect populations from the tropics to high latitudes. Here, mid‐Holocene El Niño–Southern Oscillation and hydrological changes are reconstructed in the south‐west Pacific using a stalagmite from Niue Island, which represents the period 6.4–5.4 ka BP. Stable oxygen and carbon isotope ratios, trace elements and greyscale data from a U/Th‐dated and layer counted stalagmite profile are combined to infer changes in local hydrology at sub‐annual to multi‐decadal timescales. Principal component analysis reveals seasonal‐scale hydrological changes expressed as variations in stalagmite growth patterns and geochemical characteristics. Higher levels of host rock‐derived elements (Sr/Ca and U/Ca) and higher δ18O and δ13C values are observed in dark, dense calcite laminae deposited during the dry season, whereas during the wet season, higher concentrations of soil‐derived elements (Zn/Ca and Mn/Ca) and lower δ18O and δ13C values are recorded in pale, porous calcite laminae. The multi‐proxy record from Niue shows seasonal cycles associated with hydrological changes controlled by the positioning and strength of the South Pacific Convergence Zone. Wavelet analysis of the greyscale record reveals that El Niño–Southern Oscillation was continuously active during the mid‐Holocene, with two weaker intervals at 6–5.9 and 5.6–5.5 ka BP. El Niño–Southern Oscillation especially affects dry season rainfall dynamics, with increased cyclone activity that reduces hydrological seasonality during El Niño years. [ABSTRACT FROM AUTHOR]

The engineering construction of karst city is often affected by karst geological hazards. Guilin City is a typical representative of karst city; therefore, we should consider the influence of karst hazards when analyzing the suitability for engineering construction in planned urban areas of Guilin. In this study, we established a method for evaluating the construction suitability based on the analytic hierarchy process (AHP) on the geographic information system (GIS) platform. Firstly, the landform of planned urban areas in Guilin is mainly composed of peak-cluster depression, peak-forest valley, peak-forest plain, isolated peak plain, karst-ridge valley, karst-hill plain, low mountain with steep hillslope, hill, hill with gentle slope, and undulating hills. The areas intensely developed with karst are mainly located along the banks of the Lijiang River and in the Lingui district. The areas with karst development at a medium level are located in the middle and southwestern parts of Guilin City and on the periphery of the Lijiang River banks. The areas with weak karst development are mainly located at the Yanshan district, Dingjiang town, and southwestern Lingui district. The groundwater types of the study area are mainly composed of carbonate karst water, impure carbonate cave-fissure water, and clastic bedrock fissure water. For the suitability evaluation of engineering construction in planned urban areas of Guilin, the topographic slope, geomorphic unit, bearing capacity of soil foundation, bearing capacity of rock foundation, special soil distribution, soil thickness, soil structure, groundwater depth, surface water system, karst influence, and fault factors are selected as evaluation indexes, all of which have passed the consistency test of judgment matrix. The weight of these eleven evaluation indexes was calculated by AHP. Then, the engineering construction suitability index (P) was computed from multi hierarchy evaluation with AHP. The P values can be classified as P≥5.00, 2.50≤P<5.00, 1.00≤P<2.50, and P<1.00, which may respectively fall into the category of suitable area, relatively suitable area, poorly suitable area, and unsuitable area for engineering construction. The zoning of planned unban areas in Guilin was visualized based on the suitability for engineering construction on the GIS spatial platform. Finally, in terms of the zoning based on suitability for engineering construction, six sites were chosen and were verified that the zoning by AHP method is consistent with that by field engineering drilling surveys. The consistency may indicate the reliability of APH method with GIS platform. Main conclusions can be drawn as follows,(1) The impact indexes of suitability for engineering construction of the study area include topography (slope degree and geomorphic unit), engineering geological conditions (bearing capacity of soil foundation, bearing capacity of rock foundation, special soil distribution, soil thickness and soil structure), hydrological conditions (groundwater depth and surface water system), and unfavorable geological condition (karst influence and fault factors). (2) Planned urban areas in Guilin are generally suitable for engineering construction, because suitable and relatively suitable areas account for 3.1% and 48.3% of the total area respectively, which can meet the land use needs of recent urban development planning and major infrastructure projects. However, the poorly suitable areas account for 11.4%, which are unsuitable for large-scale engineering construction and require necessary engineering treatment in practical construction. Unsuitable areas account for 37.2%, mostly located at medium-sized mountain, peak-cluster, and isolated peak. The site selection of major construction should be avoided in the unsuitable area. (3) If the major construction site is selected in a poorly suitable area, measures should be taken to prevent and control the existing and induced geological disasters and uneven settlement of foundations. The unsuitable area is proposed to be planned as the ecological land, which can serve as the ecological barrier for Guilin. [ABSTRACT FROM AUTHOR]

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Drip fertigation provides enormous opportunities for the effective utilization and distribution of water and nutrients in sustainable management of orchard. Under various drip irrigation and fertigation schedules, the analysis of NO3−-N and NH4+-N distribution within the soil has been found to be efficacious to enhance the crop growth. Over the 2-year period of study (2019 and 2020), the response of NPK fertilization and irrigation in nutrient and soil moisture distribution under high-density apple plantation in the NW Himalayan region was investigated. In the present study, under drip irrigation, the wetting front extended up to 45 cm horizontally from the emitter; however, the maximum increase in soil moisture content remained confined near the emitting point. The soil moisture content decreased consistently with the increasing horizontal distance from the emitter. Drip irrigation recorded a higher soil moisture content at the surface soil depth of 0–15 cm compared to conventional surface irrigation, where the sub-surface soil depths of 15–30 cm registered a higher moisture content. The distribution of NO3−-N and NH4+-N content under drip fertigation nearly followed the soil moisture distribution pattern. The NO3−-N and NH4+-N content was maximum below the emitter and decreased thereafter with the increasing lateral distance from the emitter as nutrient mobility in soil is primarily governed by water movement. The decreasing trend of NO3−-N and NH4+-N with the increasing lateral distances is in accordance with the water distribution pattern under drip irrigation. The nutrient mobility is proved to be well pronounced under the drip fertigation system, and nutrients carried along with the water movement get concentrated near the outer periphery of the wetting zone. [ABSTRACT FROM AUTHOR]

This paper addresses the conservation problems of the cave of Altamira, a UNESCO World Heritage Site in Santillana del Mar, Cantabria, Spain, due to the effects of moisture and water inside the cave. The study focuses on the description of methods for estimating the trajectory and zones of humidity from the external environment to its eventual dripping on valuable cave paintings. To achieve this objective, several multisensor remote sensing techniques, both aerial and terrestrial, such as 3D laser scanning, a 2D ground penetrating radar, photogrammetry with unmanned aerial vehicles, and high-resolution terrestrial techniques are employed. These tools allow a detailed spatial analysis of the moisture and water in the cave. The paper highlights the importance of the dolomitic layer in the cave and how it influences the preservation of the ceiling, which varies according to its position, whether it is sealed with calcium carbonate, actively dripping, or not dripping. In addition, the crucial role of the central fracture and the areas of direct water infiltration in this process is examined. This research aids in understanding and conserving the site. It offers a novel approach to water-induced deterioration in rock art for professionals and researchers. [ABSTRACT FROM AUTHOR]

The Badami Caves are a significant example of ancient Indian rock-cut architecture, dating back to the 6th century. These caves are situated in the Malaprabha River valley and are part of the candidate UNESCO World Heritage Site known as the "Evolution of Temple Architecture—Aihole-Badami-Pattadakal", which is considered to be the cradle of temple architecture in India. Our study aimed to investigate the diversity, distribution, and biodeterioration phenomena of the fungal communities present on the cave surfaces. The study also conducted a comprehensive analysis of fungal biodeterioration on the cave carvings. Utilizing specialized techniques, the dissolution of calcite, alterations in pH levels, and biomineralization capabilities of isolated fungal strains were monitored. Additionally, this study analyzed fungal acid production using high-performance liquid chromatography (HPLC). Our findings revealed that the major genera of fungi found on the cave surfaces included Acremonium, Curvularia, Cladosporium, Penicillium, and Aspergillus. These isolated fungi were observed to produce acids, leading to the dissolution of calcium carbonate and subsequent decrease in pH values. Notably, the dominant genus responsible for acid production and the promotion of biomineralization was Aspergillus. These discoveries provide valuable insight into the ecology and functions of fungi inhabiting stone surfaces, contributing to our understanding of how to preserve and protect sculptures from biodeterioration. [ABSTRACT FROM AUTHOR]

The oldest known wolf appears 800,000 years ago (Marine Isotope Stage 21) in Eurasia with the unspecialized short‐legged old Mammoth steppe wolf Canis lupus bohemica nov. spec. From this species, about 600,000–420,000 years ago (MIS 15‐11), the interglacial Canis lupus mosbachensis (Soergel, 1925) short‐legged Mosbach grey wolf subspecies roamed Eurasia. In the late Middle Pleistocene, there are two lineages, the southern interglacial grey and northern glacial White wolves in Eurasia. Since 320,000 (MIS 8), the short‐legged White wolf Canis lupus spelaeus (Goldfuss, 1823) was the glacial Mammoth steppe‐adapted wolf. Parallel to the "cave wolf" (found in the German Zoolithen Cave), the warm climate grey wolf Canis lupus brevis Kuzmina and Sablin, 1994 existed. C. l. spelaeus relates to the Holocene (MIS 1) extant Holarctic Greenland Canis lupus arctos and Siberian Canis lupus albus (Kerr, 1792). The Late Palaeolithic (MIS 2) "Gravettian Goyet dogs" fall into the DNA pool of C. l. spelaeus and are identified herein as pathological bite trauma individuals, which braincase shortened during the healing process. European prehistoric Neolithic dogs seem to have been imported from Central Asia with the Bandkeramik people (approx. 7000 BP) first, which have the stepped frontals originating from grey wolves. [ABSTRACT FROM AUTHOR]

Clumped isotope measurements of carbonates and stable isotope analyses of water trapped in fluid inclusions are both promising techniques to determine carbonate formation temperatures. Cave-hosted carbonate deposits (speleothems) are excellent targets for such studies, but kinetic fractionations and diagenetic influences frequently deteriorate the temperature data obtained from these methods. However, subaqueous carbonate deposits may provide reliable data, as kinetic fractionations are less significant in underwater environments. In this study, subaqueous speleothems, whose formation temperatures were directly measured in the water, were investigated. Additionally, temperatures calculated from the oxygen isotope fractionations between calcite and fluid inclusion-hosted water were compared with clumped isotope temperatures obtained for subaqueous carbonate formations in cave-hosted lakes. The clumped isotope temperatures fit the measured and calculated fluid inclusion temperatures within the analytical precisions. Carbonate deposits formed at elevated temperatures (~50°C or above) may undergo post-formational calcite-water oxygen isotope exchange, altering the composition of the inclusion-hosted water. In contrast, subaqueous speleothems formed at about 20-25°C appear to preserve the primary isotopic compositions. Our study shows that subaqueous carbonate speleothems are useful targets for clumped isotope and inclusion water analyses, making them valuable paleotemperature archives. [ABSTRACT FROM AUTHOR]

The study of modern cave deposits forming under near isotopic equilibrium conditions can potentially help disentangle the processes influencing the oxygen isotope system and suitability of stalagmites as archives of past hydrological or thermal changes. We used cave monitoring to evaluate the impact of kinetic isotope fractionation and assess the conditions under which modern cave carbonates form in the Caumont cave and quarry system, located in Normandy, northwest France. Over 20 months, we collected climatological data, dripwater, and modern carbonate samples at 2–4-week intervals at three different stations inside the Caumont cave and quarry system. We find highly stable (10.4 ± 0.3°C – 11.3 ± 0.1°C) temperature in the deeper sections of the Caumont cave and quarry system. The temporal dynamics of δ18Odrip indicates that the drip water composition in Caumont reflects the original (though subdued) signal of precipitation, rather than the impact the seasonal to inter-annual cave air temperature has on isotopic fractionation. The monitoring reveals that δ13C of modern carbonate is influenced by prior carbonate precipitation that occurs during the summer season when evapotranspiration can minimize effective infiltration. Comparison of δ18O from dripwater and modern calcite, precipitated on glass plates and collected every two to four weeks, reveals that modern calcite forms near oxygen isotope equilibrium. A Hendy test on modern carbonate deposited on a stalagmite-shaped glass flask over 20 months confirms this finding because neither does δ13C increase with distance from the apex, nor are δ13C and δ18O positively correlated. We conclude that the δ13C signal in speleothems reflect summer (and longer-term) prior carbonate precipitation in response to effective infiltration dynamics, and that the δ18O signal likely reflects annual to multi-annual changes in the composition of precipitation above the cave. [ABSTRACT FROM AUTHOR]

The present paper is aimed at studying hydrophilic and hydrophobic interactions via the modeling behavior of carbonate-clayey soil in a laboratory experiment. The typical aspects of human impact on the biogeochemical processes of natural soils such as decompression, disintegration, hydration and introducing easily oxidized organic matter were simulated (Bronick and Lal in Geoderma 124:3–22, 2005). The experimental settings were adjusted regarding common field conditions for the clay near-surface layers in the temperate zone. The model system consisted of a carbonate-clayey soil, filtering water, and a psychrophilic microbial community desorbed from cave calcite formations (speleothems). The carbonate-clayey soil was collected from eluvium on red clay bedrock deposits of the Permian system along the right bank of the Volga River in the Republic of Tatarstan. The microbial community was stimulated with a modified R2A growth medium and inoculated into the clay using ceramic carrier discs. To explain the results of the experiment auxiliary materials presented simplified systems of the carbonate clay components were used. Soil properties such as the size distribution of mechanically strong particles and microaggregates, mineral composition, organic matter content, water wettability, and the chemical composition of filtered water were determined. The experiment being carried out during six months showed the appearance of new hydrophobic contacts between soil particles, crystalline cement deposition and the high sensitivity of these processes to microbial activity. The results of the study may help in understanding the processes that occur when foundations for constructions or underground facilities contact microbially produced substances, as well as predicting soil weathering. [ABSTRACT FROM AUTHOR]

Globally, caves provide important refugia for bats. The Grand Canyon, more than 400 km (250 mi) long, consists of steep-sided, rocky formations with hundreds to thousands of natural caves. Two of these, Double Bopper and Leandras Caves, are remarkable because of the presence of desiccated bat carcasses, ranging in condition from skeletal to well-preserved animals identifiable to species. Both caves are complex but differ in length and structure. Double Bopper Cave, >60 km (37 mi) long, is variable with narrow passages. Leandras Cave, 24 km (15 mi) long, has wide, open passages. We surveyed both caves, collecting information for 482 specimens. We initially hypothesized that a single catastrophic event caused the deaths of many individuals or that bats died of various causes over a long period. We expected bat communities to differ between caves, since different cave structures would favor different species based on flight maneuverability. Radiocarbon dating of 67 samples found ages ranged from modern to >45,800 cal BP, spanning the Last Glacial Maximum. The dominant bat species in each cave differed, with Townsend's big-eared bat (Corynorhinus townsendii), a cave obligate, dominant in Double Bopper Cave and silver-haired bat (Lasionycteris noctivagans) dominant in Leandras Cave. Bats continue to use these caves today, as evidenced by the presence of fresh guano. The remarkable evidence of long-term continuous use of these caves by bats illustrates the importance of protection and conservation to provide habitat for them. The caves also provide an unprecedented time machine to study bat communities from the past, understand long-term patterns of habitat use, and prepare for climate change. [ABSTRACT FROM AUTHOR]

Subterranean karst caves are windows into the terrestrial subsurface to deconstruct the dimensions of mycobiome fingerprints. However, impeded by the constraints of remote locations, the inaccessibility of specimens and technical limitations, the mycobiome of subterranean karst caves has remained largely unknown. Weathered rock and sediment samples were collected from Luohandu cave (Guilin, Southern China) and subjected to Illumina Hiseq sequencing of ITS1 genes. A total of 267 known genera and 90 known orders in 15 phyla were revealed in the mycobiomes. Ascomycota dominated all samples, followed by Basidiomycota and Mortierellomycota. The sediments possessed the relatively highest alpha diversity and were significantly different from weathered rocks according to the diversity indices and richness metrics. Fifteen families and eight genera with significant differences were detected in the sediment samples. The Ca/Mg ratio appeared to significantly affect the structure of the mycobiome communities. Ascomycota appeared to exert a controlling influence on the mycobiome co-occurrence network of the sediments, while Ascomycota and Basidiomycota were found to be the main phyla in the mycobiome co-occurrence network of weathered rocks. Our results provide a more comprehensive dimension to the mycobiome fingerprints of Luohandu cave and a new window into the mycobiome communities and the ecology of subterranean karst cave ecosystems. [ABSTRACT FROM AUTHOR]

Changes in rainfall patterns are a direct consequence of the current climate change. Climate projections indicate an intensification of extreme rainfall events, which will directly affect social, ecological, and economic systems. One of the greatest challenges of climate science is to understand, model, and predict the variability of floods. The uncertainties in projected rainfall are still high, and even higher in Mediterranean areas where the climate is characterized by extreme and sudden rainfall events. The instrumental record is too short to correctly estimate flood return periods. Thus, geological records are required to better understand the long term variability, at millennial to decadal scales, of natural extreme flood events. MODKARST is a MSCA-GF project awarded by the European Union, to develop a quantitative flood database for the Western Mediterranean realm based on speleothems. The action plans to infer past flood events from the last 18 ka based on detrital layers recorded in stalagmites from 5 different caves in the north of Spain, in combination with karst hydraulic models and water-level monitoring. MODKARST will help to better disentangle the relation between flood recurrence and climate changes, and will shed light on how to better predict the variability of floods in the context of present-day global warming.

The Slovenian climate has undergone significant fluctuations, and an understanding of the past climate is necessary to improve models and recognise long-term patterns. The cryosphere environment, such as ice core samples, provides valuable palaeoclimate data. Palynology and dendroclimatology are also effective ways to study long-term changes in vegetation and reconstruct past climates using pollen and tree proxies. Sediment cores from various locations in Slovenia have been studied to understand past environmental changes. Borehole temperature profiles as well as historical records were also used to reconstruct past climate conditions. Studies have shown specific periods when climatic changes likely played a major role, but a complete timeline of the Slovenian climate throughout the Holocene has not yet been fully developed.

Abstract High‐resolution records from past interglacial climates help constrain future responses to global warming, yet are rare. Here, we produce seasonally resolved climate records from subarctic‐Canada using micron‐scale measurements of oxygen isotopes (δ18O) in speleothems with apparent annual growth bands from three interglacial periods—Marine Isotope Stages (MIS) 11, 9, and 5e. We find 3‰ lower δ18O values during MIS 11 than MIS 5e, despite MIS 11 likely being warmer. We explore controls on high‐latitude speleothem δ18O and suggest low MIS 11 δ18O values reflect greater contribution of cold‐season precipitation to dripwater from longer annual ground thaw durations. Other potential influences include changes in precipitation source and/or increased fraction of cold‐season precipitation from diminished sea ice in MIS 11. Our study highlights the potential for high‐latitude speleothems to yield detailed isotopic records of Northern Hemisphere interglacial climates beyond the reach of Greenland ice cores and offers a framework for interpreting them.

This document is a collection of articles that highlight the significant roles that microbes play in caves. The articles cover various topics such as the presence of fungi in caves, the microbial communities in quartz-rich rocks, the variation of microbial communities in cave rocks, the potential for microbial-induced calcite precipitation, the formation of biospeleothems in caves, fungal infections in amphibians, the gut microbiota of cave-dwelling insects, and the effects of electrical lighting on cave-dwelling cyanobacteria. These articles offer insights into the diverse biogeochemical processes that occur in caves and the ways in which microbes adapt to cave environments. [Extracted from the article]

The reasons for covariations of speleothem δ13C and δ18O remain controversial, primarily due to the limited high‐resolution stalagmite records that can be compared with meteorological data. This study presents δ13C and δ18O records of two coeval, annually laminated stalagmites (TS9701 and TS9501) spanning the past ∼2000 years from Shihua cave, Beijing, northern China. The low correlation between stalagmite TS9701 records, with annual resolution, and local annual precipitation as well as mean annual temperature on interannual to decadal scales indicates that the positive covariations of δ18O and δ13C in TS9701 are partly attributed to kinetic isotope effects caused by rapid CO2 degassing. Isotopic disequilibrium between HCO3−(aq) and drip water, induced by prior calcite precipitation on cave ceiling and stalactite surface, is another potential contributing factor. δ18O and δ13C exhibits distinct patterns on multidecadal to millennial timescales. δ18O records show notable centennial variability, aligning with El Niño‐Southern Oscillation cycles. In contrast, δ13C profiles reveal a decreasing trend during the first ∼750 years, followed by an increasing trend. Prior to 1588 AD, variations in δ13C broadly correspond to changes in warm season temperature and/or moisture on centennial scale. Both δ13C records show an abrupt enrichment between 1588 and 1654 AD. Historical documents indicate that this anomaly is likely attributed to coal mining and resultant deforestation around Shihua cave during late‐Ming and early‐Qing Dynasties. In summary, while isotopic disequilibrium can cause high‐frequency covariations of speleothem δ18O and δ13C, it does not erase the imprints of climate changes and human activities on multidecadal to millennial timescales. Plain Language Summary: This study examines the relationship between δ13C and δ18O of stalagmites from Beijing, northern China. We analyzed two stalagmites, TS9701 and TS9501, which grew over the past ∼2000 years. We found that the covariations in δ13C and δ18O on interannual to decadal scales do not directly correspond to local annual rainfall or temperature changes. Instead, these variations are partly caused by isotopic disequilibrium due to prior calcite precipitation on the cave ceiling and stalactite surface as well as rapid CO2 degassing during stalagmite grew. However, δ18O and δ13C exhibit distinct patterns on multidecadal to millennial timescales. δ18O records show significant centennial variability, linked to El Niño‐Southern Oscillation cycles. δ13C records reveal a decreasing trend during the first ∼750 years, followed by an increasing trend. Before 1588 AD, variations in δ13C broadly matched changes in warm season temperature and/or moisture on centennial scale. Between 1588 and 1654 AD, δ13C records show a sudden increase, likely due to coal mining and the resulting deforestation around the cave during late‐Ming and early‐Qing Dynasties. In summary, while isotopic disequilibrium can cause high‐frequency variations in stalagmite isotopes, it does not erase the effects of climate changes and human activities over longer timescales. Key Points: Correlation between δ18O and δ13C in a laminated stalagmite from northern China varies across multi‐timescalesInterannual to decadal covariations of stalagmite δ18O and δ13C partly result from isotopic disequilibrium as prior loss of 12C16O2Isotopic disequilibrium does not alter multidecadal to millennial isotopic variations in response to climate changes and human activities [ABSTRACT FROM AUTHOR]

The fossil fauna of small mammals from the Imanay cave deposits (53°02′ N, 56°26′ E), Southern Urals, Russia, was studied. Species of open habitats prevailed, the narrow-headed vole (Microtus (Stenocranius) gregalis) being dominant. Two types of fauna were identified that characterize its composition and structure at the end of the Late Pleistocene and, presumably, in the Early Holocene. A codominant species of the first type of fauna (lower and middle cave deposits) was the steppe lemming (Lagurus lagurus). This type was characterized by a sharp predominance (83.0–92.2%) of steppe species and a low proportion (1.5–3.9%) of forest mammal species. Open landscapes must have dominated and been common in the Late Glacial in the southern part of the Ural Mountains. The pika (Ochotona sp.) co-dominated in the fauna of the second type (upper cave deposits), with relatively high proportions of forest species (14.3–21.4%) indicating the appearance of forest formations in the Late Glacial or Early Holocene in this area. Samples of the first lower molars of narrow-headed voles were characterized by a high proportion of teeth (>50%) with simple variants of the structure of the anteroconid cap ("gregaloid" morphotype). High proportions (up to 51.6%) of the "transiens" morphotype were recorded among the first lower molars of the steppe lemming. Among the teeth in the lower half of the cave deposits, rootless cemented first lower molars (m1) and third upper molars (M3) were found with wide merging triangles T4–T5 (m1) and T2–T (M3). This structure of the chewing surface of the molars was typical of the ancient voles Microtus (Stenocranius) gregaloides and M. (Terricola) arvalidens from the fauna of the first half of the Early Pleistocene and the second half of the Middle Pleistocene. [ABSTRACT FROM AUTHOR]

The locality Janoch (ETE-south) situated nearby the Temelín nuclear power plant (Czech Republic, South Bohemian Region) was chosen out of nine possible localities as a suitable deep radioactive waste depository. Based on further geological, geochemical, geophysical and hydrological studies a suitable area for a potential radioactive waste depository was defined. Furthermore, in this area two homogeneous blocks (eastern block and western block) representing the insulation part of the depository were defined. Both homogeneous blocks are located in the Varied unit of the Moldanubian domain composed of metamorphic rocks (up to Precambrian in age) intruded by Variscan igneous rocks. The only inhomogeneity are intercalations of calc-silicates, marbles and quartzites and also some brittle structures related to the presence of the intercalations. New geological and geophysical mapping helped to improve on the existing results and defined dip and dip direction of the intercalations, their thickness and orientation as well as their range in depth. Petrological, geochemical and hydrological research focused at karstification features related to the presence of isolated lenses of marbles and calc-silicates. Marbles are alternating with calc-silicates, but also with non-karst rocks. They vary in colour, grain size and often contain high proportion of insoluble minerals. In the Moldanubian domain, typical surface karst features as sinkholes, surface stream sinking or springs of karst water are rare and the role of mechanical erosion by ground water on cavity formation and growth is very limited. The origin of the karst features here is mostly related to corrosion. Corrosion is either controlled by the rain water or more commonly by chemically aggressive water from the non-karst host rock that accumulates easily in the more permeable marbles. Dissolution occurs mostly near cracks, joints, faults and fault zones. Some cavities can develop along contacts between marbles and non-karst rocks, which are often related to the presence of brittle structures. The back-reaction of calcium carbonate precipitation is not important here and results only in formation of secondary surface features as for example travertine filling of cavities in non-karst rocks. Besides that, on the locality of ETE-south (Janoch), one of the marble intercalations developed a small karst system with several small caves with speleothems, karst spring and calcareous tufa deposit. The largest cave was around 15 m long and was almost completely destroyed by marble mining activities in the early 1950s. [ABSTRACT FROM AUTHOR]

The caves and karst forests of southern Sierra Madre are a unique and understudied habitat that is home to a high number of endemic and globally threatened species. These habitats provide essential resources for the local terrestrial vertebrate fauna, although increasing anthropogenic disturbances pose a serious threat to existing wildlife populations. Here, we provide an inventory of terrestrial vertebrate fauna of caves and limestone forests of three ecotourism areas within the southern Sierra Madre in CALABARZON Region, Philippines. A combination of various field survey methods (i.e. line transect surveys, mist netting, opportunistic catching, cage trapping) was conducted from 2021-2023 to determine the diversity of amphibians, reptiles, non-volant mammals, bats, and birds in the three sites. A total of 160 species (13 amphibians, 23 reptiles, 98 birds, four non-volant mammals, and 22 bats) were recorded in this study. Endemicity was high at 46% with 56 Philippine endemics, including 21 species endemic to the Greater Luzon Island. In addition, we recorded 18 locally and globally threatened species based on the IUCN Red List and DENR-DAO 2019-09. The high species richness and presence of threatened species underline the high conservation value of the study areas. However, unmanaged growth of tourism and habitat fragmentation threaten their biodiversity. The data generated will be used to guide the classification, proper management, and conservation of these karst areas, caves, and their resources by the national government and local government units. [ABSTRACT FROM AUTHOR]

The physical and chemical characteristics of the bedrock, along with the geological and hydrological conditions of karst caves may influence the taxonomic and functional diversity of prokaryotes. Most studies so far have focused on microbial communities of caves including only a few samples and have ignored the chemical heterogeneity of different habitat types such as sampling sites, dripping water, carbonate precipitates, cave walls, cave sediment and surface soils connected to the caves. The aim of the present study was to compare the morphology, the composition and physiology of the microbiota in caves with similar environmental parameters (temperature, host rock, elemental and mineral composition of speleothems) but located in different epigenic karst systems. Csodabogyós Cave and Baradla Cave (Hungary) were selected for the analysis of bacterial and archaeal communities using electron microscopy, amplicon sequencing, X-ray diffraction, and mass spectroscopic techniques. The microbial communities belonged to the phyla Pseudomonadota, Acidobacteriota, Nitrospirota and Nitrososphaerota, and they showed site-specific variation in composition and diversity. The results indicate that morphological and physiological adaptations provide survival for microorganisms according to the environment. In epigenic karst caves, prokaryotes are prone to increase their adsorption surface, cooperate in biofilms, and implement chemolithoautotrophic growth with different electron-donors and acceptors available in the microhabitats. [ABSTRACT FROM AUTHOR]

Speleothems are unique archives of information on climate, geomagnetism, and environmental conditions of the past, and have been successfully used for paleoclimatic and paleomagnetic studies in the last two decades. The uniqueness of these geological objects lies in the peculiarities of their formation and preservation of a wide range of geochemical, geological and geophysical proxies, and, most importantly, in the ability to obtain time series of the corresponding characteristics in an unprecedentedly accurate resolution using isotope-geochronological dating methods and incremental chronology. This paper presents the first results of dating the Vor speleothem from the Vorontsovskaya Cave (Krasnodar region), which preserved a record of the geomagnetic excursion, obtained by 230Th/U α-spectrometry, 14C dating, and incremental chronology. Such studies have been carried out in Russia for the first time. Despite the limitations of using the methods of isotope geochronology, it was possible to obtain an upper limit on the age of the excursion, which probably occurred no earlier than 5500–6000 years ago. By the method of incremental chronology, the duration of the main phase of the excursion Vor – 871 ± 16 years – was determined with great accuracy. [ABSTRACT FROM AUTHOR]

Cave-dwelling species are of special interest in evolutionary biology, because (i) many share particular traits associated with the cave habitat (troglomorphic traits), and (ii) some represent relict lineages that may conserve ancestral traits or possibly transitional traits, which may provide insights into the evolution of other highly derived species. However, these different kinds of characters are hard to assess thoroughly in troglobionts belonging to little known terrestrial arthropod groups. We describe a new species of centipedes from the Areias System caves, Brazil, namely, Plutogeophilus jurupariquibaba gen.n. sp.n., which adds to the few putative troglobionts known among Chilopoda Geophilomorpha. We analyzed a suite of characters in the light of a phylogenetic analysis and by direct comparison with epigean relatives, controlling for interindividual variation and its confounding sources. We found that: (i) troglomorphic traits of P. jurupariquibaba may include large body, elongate antennae, elongate legs and claws, and possibly also elongate setae and large coxal pores; (ii) the cave-dwelling Plutogeophilus is the sister lineage of the soil-dwelling Macronicophilus, whose morphology is highly derived and whose phylogenetic position remained unclear; (iii) compared with other extant geophilids, symplesiomorphic traits and apparently intermediate traits found in Plutogeophilus provide insights on the origin of the morphology of Macronicophilus, suggesting a stepwise modification of labrum, forcipular apparatus and ultimate legs, and the derivation of the unique rounded and spiny tip of the second maxillae from a pointed claw. [ABSTRACT FROM AUTHOR]

Caves are among the most important roosts of hundreds of bat species worldwide. However, caves can be formed in different lithologies. Cave structure and characteristics, which are shaped by lithology, can, in turn, influence roost preferences for different bat species. Therefore, cave lithology and characteristics can help us to better understand why some bat species may be rare in some caves and common in others. Brazil is a continental country, rich in bat species (181 spp.), lithologies and caves (>23 000). However, only a small fraction of the known caves has been sampled for bats so far, with no emphasis on the role lithology may have. Based on a literature review and using data on bat occurrence, in this study, we investigated the influence of lithology on bat species richness and rarity in Brazilian caves. We evaluated 117 studies, including data from 552 caves, and updated the number of bat species occurring in Brazilian caves to 81. Species richness differed between lithologies: carbonate caves had higher species richness, whereas iron caves had lower species richness. Richness was positively related to carbonate caves and with cave size: the bigger the cave, the more species‐rich it tends to be. Overall, caves in the Cerrado had the highest species richness, followed by Atlantic Forest, Caatinga caves and Amazonian caves. Thirteen species can be considered as primarily cave‐dwelling species, recorded in 10%–20% of the caves. Rarity was common among primarily cave‐dwelling species. Nearly 22% of the sampled caves harboured endangered species, reaching 53% of the species‐richest caves. Our analysis provides a comprehensive baseline for bat fauna in different types of caves in Brazil. Even so, we strongly recommend the establishment of long‐term monitoring of population trends for bats in Brazilian caves, which is necessary information but almost non‐existing for the country. [ABSTRACT FROM AUTHOR]

In recent decades geoarchaeological techniques have increasingly been used to document archaeological remains in terrestrial and underwater sites. However, the archaeological record in submerged caves lacks systematic documentation techniques, due to difficulties of the environment and time limitations. These methodological constraints may result in incomplete documentation of an archaeological site and its artifacts. In the present work, we aim to combine geoarchaeological techniques, photogrammetry, topography, and manual surveying to geolocate archaeological remains dated to the Roman period of Mallorca (30 BCE [Before Common Era] and 70 Common Era (CE), in one of the most important submerged sites in Europe, the Font of Ses Aiguades cave in Alcúdia (Mallorca). An innovative methodological protocol based on non-intrusive surveying was applied to improve the historical, topographical, and archaeological knowledge of the cave. Here we propose a fast, rigorous, and economic documentation protocol for the generation of a georeferenced database of submerged archaeological remains. We also demonstrate the superior cost/benefit balance of generating a georeferenced photogrammetric three-dimensional model of a site versus manually calculating the geopositions of underwater archaeological artifacts. This study also corroborates the efficacy and accuracy of photogrammetry versus manual measurement. [ABSTRACT FROM AUTHOR]

The carbon isotopic signature inherited from soil and epikarst processes may be modified by degassing and prior calcite precipitation (PCP) before its imprint on speleothem calcite. Despite laboratory demonstration of PCP effects on carbon isotopes and increasingly sophisticated models of the governing processes, to date, there has been limited effort to deconvolve the dual PCP and soil–epikarst components in measured speleothem isotopic time series. In this contribution, we explore the feasibility, advantages, and disadvantages of using trace element ratios and δ44 Ca to remove the overprinting effect of PCP on measured δ13 C to infer the temporal variations in the initial δ13 C of drip water prior to degassing and PCP. In nine examined stalagmites, the most widely utilized PCP indicators Mg/Ca and δ44 Ca covary as expected. However, Sr / Ca does not show consistent relationships with δ44 Ca so PCP is not the dominant control on Sr / Ca. From δ44 Ca and Mg/Ca , our calculation of PCP as fCa , the fraction of initial Ca remaining in solution at the time the stalagmite layer is deposited, yields multiple viable solutions depending on the assumed δ44 Ca fractionation factor and inferred variation in DMg. Uncertainty in the effective fractionation of δ13 C during degassing and precipitation contributes to uncertainty in the absolute value of estimated initial δ13 C. Nonetheless, the trends in initial δ13 C are less sensitive to these uncertainties. In coeval stalagmites from the same cave spanning the 94 to 82 ka interval, trends in calculated initial δ13 C are more similar than those in measured δ13 C and reveal a common positive-anomaly initial δ13 C during a stadial cooling event. During deglaciations, calculated initial δ13 C implies a trend of greater respiration rates and higher soil CO 2 , although the higher interglacial drip water saturation favors more extensive PCP. Initial δ13 C can be estimated for active and fossil speleothems from a range of settings, wherever there is confidence that Mg/Ca and/or δ44 Ca provides a quantitative indication of past changes in PCP. Further study of Mg partitioning in speleothems will improve the robustness of Mg/Ca as a PCP proxy. [ABSTRACT FROM AUTHOR]

Response of gerbera var. Arka Nesara was studied under different soil-less production systems with the aim to improve quality, productivity and water use efficiency, in completely randomized design with eight treatments viz., deep flow technique (DFT), nutrient film technique (NFT), aggregate wick system (AWS) with pots on NFT bench, AWS with pots on ground, AWS with grow bags on ground, AWS on soil bed, aeroponics and conventional soil-based drip system, which were replicated five times. Results revealed that AWS with pots on ground recorded maximum plant height (31.66 cm), leaf length (21.31 cm), leaf breadth (9.96 cm) and stalk diameter near neck (4.75 mm), minimum stem deviation (1.27 cm) and stem deflection (2.2°), prolonged vase life (9.2 days), greater water use efficiency (92 mL/plant/day) and water saving (83.46%). Hence, cultivation of gerbera var. Arka Nesara under aggregate wick system with pots on ground could be the superior alternative for traditional soil cultivation. [ABSTRACT FROM AUTHOR]

The 8.2 ka event is the most significant global climate anomaly of the Holocene epoch, but a lack of records from Mainland Southeast Asia (MSEA) currently limits our understanding of the spatial and temporal extent of the climate response. A newly developed speleothem record from Tham Doun Mai Cave, Northern Laos provides the first high‐resolution record of this event in MSEA. Our multiproxy record (δ18O, δ13C, Mg/Ca, Sr/Ca, and petrographic data), anchored in time by 9 U‐Th ages, reveals a significant reduction in local rainfall amount and weakening of the monsoon at the event onset at ∼8.29 ± 0.03 ka BP. This response lasts for a minimum of ∼170 years, similar to event length estimates from other speleothem δ18O monsoon records. Interestingly, however, our δ13C and Mg/Ca data, proxies for local hydrology, show that abrupt changes to local rainfall amounts began decades earlier (∼70 years) than registered in the δ18O. Moreover, the δ13C and Mg/Ca also show that reductions in rainfall continued for at least ∼200 years longer than the weakening of the monsoon inferred from the δ18O. Our interpretations suggest that drier conditions brought on by the 8.2 ka event in MSEA were felt beyond the temporal boundaries defined by δ18O‐inferred monsoon intensity, and an initial wet period (or precursor event) may have preceded the local drying. Most existing Asian Monsoon proxy records of the 8.2 ka event may lack the resolution and/or multiproxy information necessary to establish local and regional hydrological sensitivity to abrupt climate change. Plain Language Summary: The most significant global climate event in the last ∼11,000 years occurred ∼8,200 years ago (the "8.2 ka event"). Many globally distributed records of past climate (paleoclimate) document significant changes during the event, but there are few from Mainland Southeast Asia available to reconstruct the climate impacts in this region. We present a new speleothem (cave sample) record from Tham Doun Mai Cave, Northern Laos that uses multiple geochemical and physical signals (proxies) to document local and regional climate effects of the 8.2 ka event at a high resolution. Using oxygen isotopes, we find that the 8.2 ka event weakened regional monsoon intensity for at least ∼170 years, which resembles findings from other studies. However, other proxies suggest local rainfall changed abruptly decades before the signal of monsoon weakening. Additionally, local drying may have lasted much longer than current estimates of 8.2 ka event responses. Most proxy records of the 8.2 ka event in monsoon regions lack similar multiproxy information and/or do not have high enough resolution to fully capture the climatic response. Additional records like ours from monsoon regions may assist in establishing how sensitive local and regional rainfall is to abrupt climate change. Key Points: High‐resolution speleothem record of the 8.2 ka event in northern Laos shows weakened monsoon intensity and reduced local rainfall amountsMultiproxy data suggest the disruption to local rainfall amounts started decades before the weakened monsoon intensity inferred from δ18OPrevious monsoon records of the event lack the resolution and/or multiproxy dimensions needed to reconstruct local hydrologic changes [ABSTRACT FROM AUTHOR]

Understanding the formation mechanism of bed separation in coal seam mining under a karst landform is needed for the prevention and control of roof-separated water damage in such areas. This research used a mine in the northern Guizhou coalfield, China, as a case study, and applied theoretical analysis, numerical simulation, and on-site measurement to develop a circular cave structure model in a key stratum. The dynamic evolution of a separation bed was analyzed from several aspects, including the formation mechanism, development location, the mechanical condition of local karst caves, fracture evolution, and fractal rules. Verification using in situ measurements is presented for the case study mine, and a quantitative evaluation method for water inrush from bed separation and improved fusion weighting is proposed based on a cloud model. The research results indicate the following: (1) Tensile cracks are prone to occur above and below a karst cave, which produce an impact of connectivity on the separated space. (2) When the working face advances to 270 m in coal mining, longitudinal tensile cracks below the karst cave gradually increase and the width of the bed separation crack shrinks to 68.2 m, with a maximum separation layer height of 3.01 m. (3) Based on the cloud model and the improved weighted fusion method, the risk of water inrush in bed separation is judged as "high". The En of the cloud digital features is 0.0622 and the He is 0.0307, achieving a quantitative evaluation of water inrush in the separation layer that is consistent with on-site practice, and is highly stable and reliable. This study improves the understanding of the development pattern of bed separation and water inrush risk assessment in coal seam mining under a karst cave landform. [ABSTRACT FROM AUTHOR]

With the rapid development of cities, people are paying increasing attention to urban ground subsidence and underground space. As a means to directly explore the structure of subsurface media, geophysical methods are increasingly being applied to solve the geophysical and geological problems on shallow surface in urban areas. Due to the various electromagnetic interference produced by the human noise and industrial production in cities, the application of traditional geophysical survey methods (gravity, magnetism, electricity and earthquake) is greatly limited in densely populated urban areas, but the human noise provides an effective source for the method of passive surface wave. The method of passive surface wave has developed rapidly due to its strong anti-interference capacity and little influence by site conditions. Specifically, this method has been used in karst collapse detection, prediction of overburden thickness, detection of velocity structure of underground shear wave, site effect evaluation, geothermal resource exploration, active fault detection, urban geological survey and other fields. Since the study area is located in an urban residential area whose ground had subsided, it is urgent to find out the geological structure of the underground medium. The authors adopt the method of passive surface wave for exploration and application research. The core of this method lies in the extraction of the dispersion curve. There are two most commonly used methods at present. One is the method of frequency-wave number domain (F-K method), and the other is the method of spatial autocorrelation (SPAC method). In this study, the authors mainly adopt the latter, while for irregular arrays, the method of extended spatial autocorrelation (ESPAC) is used. The main exposed strata in this study area lies successively as follows: the overlying clay in light yellow and brick red and gravel in Quaternary Holocene Guiping Formation (Qhg), and the underlying bedrock composed of thick limestone in light gray and gray-white in the upper segment of Devonian Upper Rongxian Formation (D3r3). There is no fault structure developed in the area. The overburden is characterized by low velocity. The complete limestone shows characteristics of obviously high velocity. When there are fissures or even water-filled caves in the limestone, the high velocity will be significantly weakened, which is the geophysical premise for the application of this method. Due to the narrow space and the criss-crossing buildings in the area, the method of linear passive surface wave was adopted in actual data collection. The SUMMIT seismograph of the German DMT company was adopted as the instrument to collect data, and a vertical geophone of 4.5 Hz was used to receive data. One-time layout at intervals of 2 m was completed, and the whole survey line was received at the same time. Each survey line collected 20 or more records, and the sampling time of each record was 32,768 ms with the sampling frequency of 500 Hz. Before indoor processing, the original data were extracted in an orderly manner according to the spread length of 11 traces. The specific processing flow included preprocessing, extraction of dispersion curve, calculation of apparent shear wave velocity and drawing of apparent S-wave velocity profiles. The apparent shear wave velocity Vx is a physical parameter of surface wave different from the phase velocity Vr and the shear wave velocity Vs. It has a velocity dimension. Because it avoids the influence of human factors such as setting the initial model and selecting the inversion results during the inversion process, the apparent shear wave velocity was chosen. In this study, the characteristics of apparent shear wave velocity in the backfilling area for the original subsidence were firstly interpreted and analyzed, and then the characteristics of other survey lines were interpreted. The profiles and the slice diagrams at different depths of the apparent shear wave velocity show that: (1) The thickness of overburden layer in this area ranges from several meters to more than ten meters, and the thickness varies greatly at or near the sudden change in velocity. According to the comparison with the backfill area of original subsidence, the obvious abnormal features indicate that the upper soil layer is disturbed and developed in the solution groove, and karst caves are developed in the deep part, resulting in soil leakage and then ground subsidence. (2) Survey lines reveal that the karst in the bedrock is mostly developed within 30 m, mainly composed of Zone I--a strong karst development zone. Zone I is mainly distributed under and around Building 10 in a residential area, with a wide range and a certain extension direction. It is speculated to be a strong runoff zone with the main trend of north-south direction. (3) The statistical results of apparent shear wave velocity of multiple survey lines show that the apparent shear wave velocity range of the overburden in this study area is 220-380 m½s-1, and the intact limestone is 580-920 m½s-1. However, due to the development of fissures in broken limestone, its range is 390-510 m½s-1, and the apparent shear wave velocity of water-filled cave is relatively lower at the range of 340--430 m½s-1. [ABSTRACT FROM AUTHOR]

If the tunnel construction work is done in the karst area, the tunnel shall keep a certain distance from the karst cave to ensure the stability of the surrounding rock and support. If the distance between the tunnel and the filled karst cave with high water pressure is short, it is easy to cause the instability and damage of tunnel face or the circumferential surrounding rock, thus resulting in karst water inrush, mud inrush, collapse and other disasters. Especially, the karst cave concealing around the tunnel is often difficult to be accurately predicted. Therefore, the study of the critical safety distance between the karst cave and the tunnel plays a vital role in the evaluation and prevention of disasters caused by concealing filled karst cave. Studies on the critical safety distance between tunnel and karst cave can be divided into qualitative research, semi-quantitative research and quantitative research. Qualitative research, such as judging the influence degree of karst cave on tunnel through numerical analysis, is generally conducted to comprehensively analyze the factors affecting the stability of structure for water burst prevention and obtain the empirical critical safety value. Semi-quantitative research mainly focuses on theoretical calculation, which can be roughly sub-divided into three types: simplified beam slab model based on strength theory, catastrophe theory model and the model of crack tension-compression shear based on fracture mechanics. Mainly focusing on numerical simulation, quantitative research is conducted to set up multiple groups of numerical tests for calculation, and to obtain the calculation model of safety distance through linear regression. The safety distance between the tunnel and the filled karst cave can be explored by theoretical calculation and numerical simulation test. Based on the bending and shear strength theory, the mechanical calculation models of the filled karst cave at the top, bottom and side of the tunnel are established by using the fixed beam model at both ends. Meanwhile, the self-weight of the internal filler and the pore water pressure are taken into account. Given the influence of the surrounding rock pressure above the karst cave on the waterproof rock stratum, the critical safety distance between the tunnel and the karst cave can be explored, and the calculation formula of the distance in different circumferential positions can be deduced. However, this formula does not consider the excavation effect of the tunnel and the process of support, nor can it reflect the changes of the displacement, stress and plastic zone of the surrounding rock. Therefore, it is difficult to obtain a universal formula to express relationship. It is necessary to supplement the predicted safety distance with the help of numerical simulation. In this study, the numerical model of the critical safety distance between the filled karst cave and the tunnel at different circumferential positions was established by FLAC 3D software. Based on the method of orthogonal experimental design (a total of 48 numerical test schemes), the stability of surrounding rock has been evaluated by the distribution range of plastic zone of surrounding rock caused by tunnel excavation. If the plastic zone connects the tunnel with the karst cave, the distance between these two indicates that the surrounding rock is unstable, and thereby the critical safety distance can be calculated. The results of critical safety distance under different working conditions were also analyzed by range analysis and variance analysis. Besides, the law and significance of three influencing factors--the level of surrounding rock, the water pressure in karst cave and the karst cave size--on the critical safety distance were explored. Through the nonlinear multiple regression analysis of the orthogonal test results, the prediction formula of the critical safety distance between the filled karst cave and the tunnel at different circumferential positions was established respectively. The results show that the critical safety distance increases with the increase of surrounding rock level, pressure of karst cave water and the karst cave size. The comprehensive influence degree of the three factors can be ranked from the strongest to the weakest as follows: the surrounding rock level, the pressure of karst cave water and karst cave size. Finally, the research results were applied to Yangzong tunnel project to verify the rationality and applicability of the prediction model of critical safety distance. The results show that the safety distance predicted based on the strength theory is relatively conservative, and the predicted results based on the numerical test are close to the reserved distance. The predicted results have a certain reference for the project of karst tunnel with water abundance. [ABSTRACT FROM AUTHOR]

In China, approximately 346.3 x 104 km² of the karst rocks are distributed, accounting for about one-third of the country's land area. Karst groundwater channels are common geological phenomena in concealed karst areas. Various karst caves and underground channels widely developed cause the complex groundwater system dominated by pipe flow, which promotes the transport of groundwater, soil, and rocks, resulting in complex geological issues for urban underground space development and utilization in karst areas. In these areas, ground collapse disasters occur from time to time. In geothermal areas, karst groundwater channels are often accompanied by frequent heat exchange, directly affecting the quality of geothermal development. Therefore, conducting exploration of karst underground channels is of great significance for the development of urban underground space and the prevention of geological disasters in karst areas. Due to the high degree of spatial variability of karst channels, it is a challenge for conventional two-dimensional detection methods to complete the geophysical imaging, which in turn results in the difficulty of conventional karst detection. Geophysical exploration is widely used due to its wide applicability, large detection depth, and accuracy. However, different geophysical methods have different advantages in terms of detection depth, resolution and practicality. The Ground Penetrating Radar has the characteristics of high efficiency and high resolution, but it is mainly applied to the exposed and shallow-covered karst due to factors such as limited penetration depth, irregular terrain, and clay content. Electromagnetic and seismic exploration can generate better results in the exploration of buried karst. In addition, microgravity exploration can be used to detect shallow karst caves and fill-type karst caves. Electrical resistivity tomography (ERT) is the most commonly used geophysical method for karst exploration, and has been applied to various karst geological environments, such as cave exploration, the exploration of water-filled karst groundwater channel, the detection of urban underground cavity, and engineering surveys. In this study, 3D ERT was used for fine detection of concealed karst underground channels in the urban area. Combining with geophysical numerical simulation and application examples, the effectiveness of 3D on karst underground channels with different filling types was analyzed. The research results show that 3D ERT has a significant improvement in data volume and resolution compared to 2D ERT. 3D ERT can more intuitively characterize the three-dimensional electrical structure characteristics of the target body and has advantages in imaging karst groundwater channels. Through the three-dimensional electrical imaging of the karst groundwater channel in Yuanquan village, Wuhan City, the groundwater migration characteristics of the low-temperature hot spring are revealed. The analyses of geophysical prospecting and drilling show that two low-temperature hydrothermal vent groups in this area are directly connected by karst underground channels and connected with north-west fault structures, reflecting a hydrodynamic process. In this process, deep hot water firstly circulates along the fault fracture zone to shallow karst channels, and after its horizontal migration at a certain distance, deep hot water exposes at the surface in the form of spring near the fracture zone, and the contact zone of carbonate rock and schist. In this study, the three-dimensional electrical structure imaging of karst groundwater channel near the hot spring point has been jointly realized by geophysical exploration and drilling, and the trends of fractured fault zone and karst channel have been displayed. Study results show that the low-temperature hydrothermal spring is connected to the karst groundwater system through deep faults. In view of this, it is proposed to carry out systematic geothermal explorationin the area to find out the hydrogeological conditions of hydrothermal spring, the groundwater circulation and heat interaction processes. In addition, the study results may provide support for the temperature increase of the hydrothermal spring and for the development of urban geothermal energy. [ABSTRACT FROM AUTHOR]

The Yellow River Plain (YRP), being regarded as the cradle of Chinese civilization, is traditionally thought to be the locale of the Great Flood, a hazardous flood (or floods) tamed by Yu who started China's first "dynasty", Xia, in ~ 2000 BC. However, by integrating published archaeological data, we propose that the Great Flood in fact impacted the Jianghan Plain (JHP) along the middle course of the Yangtze River. The arguments include: (1) around the era of the Great Flood, the most civilized and populated society in East Asia, named the Jianghan society, was located around the JHP (at that time, the habitation on the YRP remained limited); (2) the Jianghan society lived on river resources (shipping and rice growing) and was thus subject to flood risks (but not for the people inhabiting the YRP); (3) the people in the Jianghan society were experienced in dredging moats/ditches for shipping and irrigation; (4) unlike the floods on the YRP that were characterized by dynamic sedimentation and channel avulsion, those on the JHP typically occurred with slow-moving water manageable to ancient people; (5) the JHP has been associated with lake/wetland systems serving as detention basins during floods. Here, the recorded method for controlling the Great Flood, dredging channels to divert flood water to a "sea", was feasible. Known speleothem paleo-rainfall data from multiple sites show that the climate of the JHP had been wet since the middle Holocene (earlier than the era of the Great Flood) and significantly turned dry after ~ 1850 BC (~ 150 years later than the Great Flood). Thus, the uniqueness of the Great Flood was likely to reflect an increase in land use on the JHP with the expansion of the Jianghan society, and the success in taming this flood was mainly due to the efforts of the society, not by luck. Key points: Floods on the Jianghan Plain were predictable and manageable in ancient times. The most populated society in East Asia was located around the Jianghan Plain. The people in the Jianghan society were experienced in dredging moats/ditches. [ABSTRACT FROM AUTHOR]

Investigations of the unconsolidated Upper Pleistocene – Holocene cave deposits of the Northern Urals resulted in detailed biostratigraphical and palaeoenvironmental data. The article summarizes data from important stratigraphical levels exposed in 19 cave localities, most part of which represent several layers dated to different periods. These data cover the period from the beginning of the Upper Pleistocene (MIS 5-4) to the end of the Upper Holocene. At the beginning of Marine Isotope Stage 3 (MIS 3), open woodlands were distributed, which at the end of MIS 3 were replaced by Forest–steppe landscapes. At the beginning of MIS 2 (LGM), Periglacial steppe landscape was distributed. At the end of MIS 2 and at the beginning of the Holocene (MIS 1), semi-open landscapes were common. At the beginning of the Middle Holocene, they were replaced by taiga landscapes. Fish were present in the fauna of the Northern Urals in the Upper Pleistocene and Holocene. Amphibians in the Upper Pleistocene as part of the fauna of the region appear only at its beginning (MIS 5-4) and end (Bølling – Allerød period). Since the beginning of the Holocene (MIS 1), they have been constantly present in the fauna of the Northern Urals. Reptiles appear in the fauna of the region only in the Middle Holocene. During the Upper Pleistocene, the avifauna and fauna of small mammals were dominated by species of open landscapes, and the fauna of large mammals was dominated by species of open and semi-open landscapes. At the beginning of the Holocene, the avifauna and theriofauna increased the number of species associated with tree and shrub vegetation and near-aquatic species. Since the beginning of the Middle Holocene, the avifauna and theriofauna have been dominated by species of taiga landscapes. Palynological data and data on the fauna of small and large mammals allow us to separate the deposits of the Upper Pleistocene and Holocene. These data also allow us to separate the deposits of the beginning (MIS 5-4), middle (MIS 3), end (MIS 2)) of the Upper Pleistocene, Lower, Middle and Upper Holocene (MIS 1). [ABSTRACT FROM AUTHOR]

Speleothems are secondary mineral structures typically found in karstic caves and usually composed of calcite or aragonite. Despite being naturally white, some might exhibit unusual colors, such as blue, black, red, yellow or green. The causes of these exceptional colorations are poorly understood, especially for green speleothems, which are barely reported. Here we describe the occurrence of the green Ni-bearing serpentine nepouite in green aragonite and calcite speleothems, in the Aven du Marcou (Hérault, France). Nepouite is mainly found as flat lamellar crystals in the outer rim of green speleothems and crystallized alongside radially grown aragonite crystals. This supports nepouite beginning to crystallize recently, due to a change in the chemical composition of the water. Nepouite also exhibits extensive substitution between Ni, Mg and Zn. The various elements responsible for nepouite precipitation are thought to come from the weathering of pyrite crystals in the overlying rocks, which is consistent with the pH conditions of the cave and the Al-free composition of nepouite. This study explains the crystallization mechanisms and stability conditions of silicate minerals in colored caves. [ABSTRACT FROM AUTHOR]

Integrating geomatics remote sensing technologies, including 3D terrestrial laser scanning, unmanned aerial vehicles, and ground penetrating radar enables the generation of comprehensive 2D, 2.5D, and 3D documentation for caves and their surroundings. This study focuses on the Altamira Cave's karst system in Spain, resulting in a thorough 3D mapping encompassing both cave interior and exterior topography along with significant discontinuities and karst features in the vicinity. Crucially, GPR mapping confirms that primary vertical discontinuities extend from the near-surface (Upper Layer) to the base of the Polychrome layer housing prehistoric paintings. This discovery signifies direct interconnections helping with fluid exchange between the cave's interior and exterior, a groundbreaking revelation. Such fluid movement has profound implications for site conservation. The utilization of various GPR antennas corroborates the initial hypothesis regarding fluid exchanges and provides concrete proof of their occurrence. This study underscores the indispensability of integrated 3D mapping and GPR techniques for monitoring fluid dynamics within the cave. These tools are vital for safeguarding Altamira, a site of exceptional significance due to its invaluable prehistoric cave paintings. [ABSTRACT FROM AUTHOR]

Reconstructing the geologic history of a karst area can advance understanding of the system's present-day hydrogeologic functioning and help predict the location of unexplored conduits. This study tests competing hypotheses describing past conditions controlling cave formation in an alpine karst catchment, by comparing an ensemble of modeled networks to the observed network map. The catchment, the Gottesacker karst system (Germany and Austria), is drained by three major springs and a paleo-spring and includes the partially explored Hölloch cave, which consists of an active section whose formation is well-understood and an inactive section whose formation is the subject of debate. Two hypotheses for the formation of the inactive section are the following: (1) glaciation obscured the three present-day springs, leaving only the paleo-spring, or (2) the lowest of the three major springs (Sägebach) is comparatively young, so its subcatchment previously drained to the paleo-spring. These hypotheses were tested using the pyKasso Python library (built on anisotropic fast-marching methods) to generate two ensembles of networks, one representing each scenario. Each ensemble was then compared to the known cave map. The simulated networks generated under hypothesis 2 match the observed cave map more closely than those generated under hypothesis 1. This supports the conclusion that the Sägebach spring is young, and it suggests that the cave likely continues southwards. Finally, this study extends the applicability of model ensemble methods from situations where the geologic setting is known but the network is unknown to situations where the network is known but the geologic evolution is not. [ABSTRACT FROM AUTHOR]

Tsumeb Aragonite Categories Most aragonite occurrences at Tsumeb fall into one of the following five categories: "pure" aragonite, I nicholsonite, tarnowitzite, i aragonite flowstone, and pseudomorphs. Aragonite Flowstone The seepage of groundwater through the dolostone host rocks at Tsumeb commonly resulted in the precipitation of sheets of aragonite resembling frozen waterfalls with gently mammilated surfaces on the walls of the underground mine workings. The Kabwe mine aragonite is currently represented by one large preserved specimen consisting of aragonite on vanadinite (Southwood, Cairncross, and Rumsey [26]) (fig. 52). Aprevious Connoisseur's Choice column (Pohwat [22]) featured aragonite from Western Europe (part 1) and beyond (part 2), the latter making brief mention of specimens from Morocco, and Namibia, South Africa. [Extracted from the article]

Moonmilk is a cave deposit that was used for medical and cosmetic purposes and has lately raised interest for its antimicrobial potential. We studied five moonmilk samples from four caves with different microclimatic conditions, two temperate in north-western and northern Romania (Ferice, Fața Apei, and Izvorul Tăușoarelor caves) and one tropical in Minas Gerais, Brazil (Nestor Cave). The physicochemical and mineralogical analyses confirmed the presence of calcite and dolomite as the main phase in the moonmilk. A 16S rRNA gene-based metabarcoding approach showed the most abundant bacteria phyla Proteobacteria, GAL15, Actinobacteriota, and Acidobacteriota. The investigated caves differed in the dominant orders of bacteria, with the highest distance between the Romanian and Nestor Cave samples. Climate and, implicitly, the soil microbiome can be responsible for some differences we found between all the samples. However, other factors can be involved in shaping the moonmilk microbiome, as differences were found between samples in the same cave (Ferice). In our five moonmilk samples, 1 phylum, 70 orders (~ 36%), and 252 genera (~ 47%) were unclassified, which hints at the great potential of cave microorganisms for future uses. [ABSTRACT FROM AUTHOR]

Drip tape layout and flow rate are crucial variables that impact the effects of drip fertigation. To investigate the influence of drip tape layout and flow rate on the soil water and nitrogen transport in summer maize in sandy tidal soil, field experiments were conducted for two years. Two drip tape layouts were set: one tape serving for two crop rows (N) and one tape serving for each crop row (E), with two levels of drip flow rate, i.e., high (2 L/h; H) and low (1.3 L/h; L). The results show that under the same drip tape layout, the lower the drip emitter flow rate, the more upright the shape of wetted soil volume. The maximum vertical and horizontal water transport distance under NL treatment was higher than that under NH, EH, and EL treatments. After surface drip fertigation, nitrate nitrogen accumulated near and at the edge of the wetted soil volume. In 2020, under NL treatment, nitrate nitrogen transported to a 55 cm soil layer, which was 22.22%, 71.42%, and 57.14% deeper than that under NH, EH, and EL treatments, respectively. In 2021, nitrate nitrogen could transport to a 60 cm soil layer in both NL and NH treatments. The maximum concentration of ammonium nitrogen was nearby the emitter. Under NL treatment, ammonium nitrogen was transported to 48 and 60 cm soil layers below the emitter in 2020 and 2021, respectively, which was deeper than that observed under NH, EH, and EL treatments. The soil inorganic nitrogen residue of the NL was lower than that of the NH, EH, and EL treatments. Compared with NH, EH, and EL treatments, the two-year maize yield under NL treatment increased by 11.09%, 13.47%, and 8.66% on average, respectively. NL treatment exhibited the highest water use efficiency and nitrogen fertilizer productivity. Therefore, NL treatment (one drip tape serving for two rows with 1.3 L/h flow rate) could promote the absorption of water and nutrients, reduce inorganic nitrogen residue, and to obtain high maize yield in sandy tidal soil. [ABSTRACT FROM AUTHOR]

Understanding supra-regional climate variability such as the changes in the North Atlantic realm is important to identify the drivers of the climate system. In this study maar lake sediments from the Eifel (western Germany) were analysed with a multi-proxy approach and compared to central and western European speleothem growth phases. C org (chlorins) and the pollen assemblage were analysed from two sediment cores of the Hoher List infilled maar lake. To generate C org (chlorins) and pollen records covering the entire last 130,000 yr b2k (years before year 2000 CE), the data from this study were stacked with published data from other Eifel maar lake sediment cores (Sirocko et al., 2013, 2021, 2022). The sediment cores from Hoher List infilled maar lake were dated by marker tephra layers giving chronological anchor points and the precise dating of the sediment cores was performed by the tuning of the C org (chlorins) records to the NGRIP δ18O record (Rasmussen et al., 2014). The speleothems, whose growth phases are compared to the lake sediment proxy records, were compiled from the literature as well as speleothems from Dechencave (western Germany) dated by the 230Th/U-method in this study. The C org (chlorins) variability shows the bioproductivity in the maar lake, which is related to water temperature and corresponds to the Greenland Interstadials (GIs) in the NGRIP δ18O record indicates its dependence on supra-regional climate variations in the North Atlantic. The pollen record shows three periods of forest with temperate forest species, during the Eemian, early Marine Isotope Stage (MIS) 3, and the Holocene. Speleothem growth in four caves in central and western Europe (Dechencave, Spannagel Cave, Hölloch Cave, Villars Cave) is predominantly sensitive to cold periods with glaciers and/or permafrost conditions above the caves inhibiting speleothem growth. The forested phases and phases of high bioproductivity in the Eifel correspond well with phases of speleothem growth indicating three warm phases in central Europe during the last glacial cycle. [ABSTRACT FROM AUTHOR]

In recent years, pyroarchaeology has expanded rapidly and included experimental approaches. However, analyses of the combustion products carried by smoke (mainly soot and microcharcoal) and the study of fixing, recording, and preserving processes of this material on parietal surfaces remain limited. We therefore launched the ExTraS (Experiments on Traces of Soot) program, which aims to document the processes of fixation, recording, and preservation of combustion products in speleothems. We focused on various parameters, including the influence of wall surfaces, meteorological and seasonal conditions, and the nature of the fuel. Here, we present results acquired over several years (2015–2023) that combine macroscopic, microscopic, and colorimetric observations, as well as Raman microspectroscopy characterization. Our findings improve our understanding of the formation process of sooty speleothems observed at archaeological sites in rock shelters and caves. [ABSTRACT FROM AUTHOR]

Nitrate (NO3−) pollution in karst areas has been widely discussed, which affects human health and the ecological environment. To investigate nitrate sources and their perturbations on cave hydrogeochemistry in karst cave systems, this study was conducted in Mahuang Cave, a karst cave in Southwest China, to assess the impact of human activities on the karst carbon cycle and the environment. The results show that (1) the variations of the water-soluble ions in Mahuang Cave are mainly controlled by carbonate weathering, and the cave water chemistry is characterized as the HCO3–Ca–Mg and HCO3–SO4–Ca–Mg types. (2) The dual isotopes and stable isotope Bayesian mixing model (SIAR) show that chemical fertilizers (41.5%) and soil nitrogen (33.75%) are the main nitrate sources in the cave water bodies, followed by manure and sewage (17.25%) and atmospheric precipitation (7.5%). (3) The significant enrichment of dissolved inorganic carbon isotope (δ13CDIC) in Mahuang Cave reveals that nitric acid produced by nitrification accelerates carbonate weathering in Mahuang Cave, and the carbon source effect of the carbon cycle in the cave is enhanced. Consequently, the response of cave drips and sediments to external environments is disturbed. [ABSTRACT FROM AUTHOR]

Meta menardi (Latreille, 1804) and M. bourneti Simon, 1922 (Araneae: Tetragnathidae) are ubiquitous inhabitants of the twilight zone of most hypogean sites across Europe. Recent observations in volcanic caves pointed out the presence of both species in Sicily, with M. menardi occurring in a small number of caves. On the basis of field investigations conducted in 2017-2021, we analyzed the distribution and the habitat frequency of the two species along the altitudinal gradient of Mount Etna. Our results demonstrate a significant effect of climate and altitude on the segregation of the two species, with M. menardi occurring exclusively above 1200 meters in caves opening in areas characterized by low temperatures (mean ± SD = 10.1 ± 0.688C) and high precipitations (682 ± 19 mm). Conversely, M. bourneti preferably occurred in areas with higher temperatures (14.5 ± 2.18C) and lower precipitations (606 ± 46 mm). Substrate age was not affecting the distribution of the two species, as both occurred in volcanic caves of ancient and recent formation (from 350 to .1,000 years). In light of the ongoing global warming, a possible increase in temperature could favor the upshift of M. menardi towards upper areas on the volcano subjected to high volcanic disturbance and thus unsuitable for hosting stable populations through time. In this regard, investigations on the response of Meta spiders to increases in temperature on the Etna volcano would be an asset to establish an appropriate management plan for the conservation of the newly discovered population of M. menardi in Sicily. [ABSTRACT FROM AUTHOR]

The drip emitter type used influences the dissolved oxygen concentration (DOC) distribution in a drip irrigation system. Understanding the spatial and temporal DOC distribution in the irrigation system and its change pattern and determining the optimal irrigation emitter and aeration concentration threshold are important to reasonably apply aerated irrigation. Here, we designed three common drip irrigation emitter treatments under a drip irrigation system, i.e., an inserted in-line labyrinth emitter with a flow rate of 1.0 L h−1 (T1) and 2.2 L h−1 (T2), respectively, and a pressure-compensating emitter with a flow rate of 2.0 L h−1 (T3). Each irrigation emitter was associated with five initial DOC treatments, i.e., 3–5 mg L−1 (CK), 10 mg L−1 (C1), 15 mg L−1 (C2), 20 mg L−1 (C3), and 25 mg L−1 (C4). The results showed that the DOC values gradually increased in nonaerated water (CK) but gradually decreased in aerated water with standing time. Each emitter type significantly increased the DOC values after nonaerated water (CK) passed through different drip irrigation systems, and the highest increase (73.7%) was observed in the T1CK treatment. However, the DOC values significantly decreased after the aerated water passed through the drip irrigation systems, especially in the T2 treatment (33.2%). In addition, the reduction (or increase) in DOC in aerated water (or nonaerated water) in the first 10 m of the capillary pipe was smaller than that in the last 10 m for all treatments except T1C1. Furthermore, the T3 treatment had the most stable attenuation at different initial DOC treatments, with a maximum laying length of 20 m. More importantly, aeration can significantly increase DOC in the soil water (DOS), and the maximum value occurred when the initial DOC was 19.8 mg L−1. Hence, for practical application, the recommended initial DOC range for aerated irrigation is 15 ~ 20 mg L−1 combined with a pressure-compensating emitter at a flow rate of 2.0 L h−1 (T3). This study provides technical support for the optimal design and rational application of aerated drip irrigation systems. [ABSTRACT FROM AUTHOR]

Cave ice can contain a wealth of paleo-climatic and geochemical information that is rapidly being lost with the melting of the temperate zone cryosphere. The karst areas of Slovenia host over 260 ice caves. We collected samples for stable water isotope, major ion, and nutrient analyses from two Slovenian ice caves. Samples included two shallow ice cores in Snežna Cave, collected »5 m apart, and an ice face profile in Ivačičeva Cave. All ice isotopic ratios reflected modern precipitation that could be described by high-elevation meteoric water lines. An offset suggested that fractionation and mixing processes of melted ice affected the isotopic signals. Cation concentrations of ice in both caves showed Ca » Mg>Na>K. The high Ca2+ and Mg2+ contents and elevated HCO3- concentrations indicate that CaCO3 dissolution within the local karst landscape is a primary control on ice chemistry. Low concentrations and inconsistent profile patterns of other major ions and nutrients suggest atmospheric deposition and vadose zone leaching were also primary sources of ions to the ice. Differences in Cl- and SO4 2- profile concentrations at similar depths in Snežna Cave imply that ice melting, water mixing, and re-freezing processes can affect the primary climatic signal stored in the ice. While temperate ice caves can be repositories of climatic information, secondary diagenetic processes that affect ice chemical composition alter the original signal. In addition to chemical analysis, physical processes within the caves must be studied at a small spatial scale to understand and interpret ice chemistry. [ABSTRACT FROM AUTHOR]

The EPICA (European Project for Ice Coring in Antarctica) Dome C (EDC) ice core drilling in East Antarctica reaches a depth of 3260 m. The reference EDC chronology, the AICC2012 (Antarctic Ice Core Chronology 2012), provides an age vs. depth relationship covering the last 800 kyr (thousands of years), with an absolute uncertainty rising up to 8000 years at the bottom of the ice core. The origins of this relatively large uncertainty are twofold: (1) the δ18 O atm , δO2/N2 and total air content (TAC) records are poorly resolved and show large gaps over the last 800 kyr, and (2) large uncertainties are associated with their orbital targets. Here, we present new highly resolved δ18 O atm , δO2/N2 and δ15 N measurements for the EDC ice core covering the last five glacial–interglacial transitions; a new low-resolution TAC record over the period 440–800 ka BP (ka: 1000 years before 1950); and novel absolute 81 Kr ages. We have compiled chronological and glaciological information including novel orbital age markers from new data on the EDC ice core as well as accurate firn modeling estimates in a Bayesian dating tool to construct the new AICC2023 chronology. For the first time, three orbital tools are used simultaneously. Hence, it is possible to observe that they are consistent with each other and with the other age markers over most of the last 800 kyr (70 %). This, in turn, gives us confidence in the new AICC2023 chronology. The average uncertainty in the ice chronology is reduced from 1700 to 900 years in AICC2023 over the last 800 kyr (1σ). The new timescale diverges from AICC2012 and suggests age shifts reaching 3800 years towards older ages over marine isotope stages (MISs) 5, 11 and 19. But the coherency between the new AICC2023 timescale and independent chronologies of other archives (Italian Lacustrine succession from Sulmona Basin, Dome Fuji ice core and northern Alpine speleothems) is improved by 1000 to 2000 years over these time intervals. [ABSTRACT FROM AUTHOR]

Several studies have analyzed the ice margin behavior of the Quelccaya Ice Cap (QIC), Earth's largest tropical ice cap, through the Holocene. However, continuous integration of new information to produce a more cohesive history of the QIC is necessary. Here, the radiocarbon dates of 33 rooted plant specimens collected in situ along the western ice margin between 2002 and 2018 reveal the timing of its past extent as it advanced during the mid‐Holocene. The most recent evaluation of collected specimens indicates that the QIC margin advanced ∼350 m down the Challpacocha Valley between 7.1 and 4.5 ka BP. Past studies of documented ice extent on the western side of the QIC based on a variety of techniques are compiled to create a more comprehensive history of the QIC's behavior throughout the Holocene. Records of documented ice extent, as well as other proxy records, indicate a climate transition ∼5–7 ka BP that created the proper environmental conditions for the expansion of the QIC. Evidence from nearby valleys indicates that the QIC behaved similarly to the documented ice extent in the Challpacocha Valley in response to Holocene climatic fluctuations. The ability to collect the plant specimens and recent analysis of satellite imagery reveals rapid retreat rates of the western outlet glaciers from 1985 to 2020, leaving the western margin of the QIC at its smallest extent since the mid‐Holocene. Plain Language Summary: The area around the Quelccaya Ice Cap (QIC) is unique as wetland plant samples have been found preserved in their growth positions, buried by past advancing ice, whereas the ice typically removes vegetation and soil in its advance down a valley. Using the 14C dates of these plants, we map a 350‐m advance of the ice margin between 7.1 and 4.5 ka BP. Combined with a variety of previous studies involving different methods and records from ice and lacustrine sediment cores, a larger picture of the QIC's behavior comes into view. A largely accepted global climate shift between ∼7 and 5 ka BP occurred in tandem with the QIC's advance. Although the QIC has fluctuated before, at no time has the western margin receded to the current extent since the mid‐Holocene. This is indicated by the exposure of the plants and current margin retreat rates calculated from satellite imagery (1985–2020). Key Points: Mid‐Holocene advance of the Quelccaya Ice Cap (QIC) is documented using 14C dating of in situ vegetation exposed during the recent retreatPlant ages of ∼4.5 to ∼7.1 ka BP provide evidence of a mid‐Holocene climate transition and the QIC ice‐margin expansionAnalysis of satellite imagery from 1985 to 2020 documents a recent rapid retreat (∼20 m/yr) of the QIC margin [ABSTRACT FROM AUTHOR]