2024 |
Johnston VE, Frisia S, Borsato A, Woodhead JD, McDermott F, 'The incorporation of chlorine and cosmogenic
Cave carbonate mineral deposits (speleothems) contain trace elements that are intensively investigated for their significance as palaeoclimate and environmental proxies. However, ... [more]
Cave carbonate mineral deposits (speleothems) contain trace elements that are intensively investigated for their significance as palaeoclimate and environmental proxies. However, chlorine, which is abundant in marine and meteoric waters, has been overlooked as a potential palaeo-proxy, while cosmogenic 36Cl could, in principle, provide a solar irradiance proxy. Here, total Cl concentrations analysed from various speleothems were low (3¿14 mg/kg), with variations linked to crystal fabrics. High-resolution synchrotron radiation micro X-ray fluorescence (µ-XRF) trace element mapping showed Cl often associated with Na, Si, and Al. We propose that speleothems incorporate Cl in two fractions: (1) water soluble (e.g., fluid inclusions) and (2) water insoluble and strongly bound (e.g., associated with detrital particulates). However, disparities indicated that alternate unidentified mechanisms for Cl incorporation were present, raising important questions regarding incorporation of many trace elements into speleothems. Our first measurements of 36Cl/Cl ratios in speleothems required large samples due to low Cl concentrations, limiting the potential of 36Cl as a solar irradiance proxy. Critically, our findings highlight a knowledge gap into how Cl and other trace elements are incorporated into speleothems, how the incorporation mechanisms and final elemental concentrations are related to speleothem fabrics, and the significance this may have for how trace elements in speleothems are interpreted as palaeoclimate proxies.
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Nova |
2024 |
Borsato A, Samadelli M, Martimucci V, Manzi G, 'Temperature fluctuations and ventilation dynamics induced by atmospheric pressure variations in Lamalunga Cave (Apulia, Italy) and their influences on speleothem growth', Quaternary Research (United States), 118 100-115 (2024) [C1]
Lamalunga Cave (Altamura, Southern Italy) is renowned for the discovery in 1993 of an excellently preserved Neanderthal skeleton. Given the importance of the findings and the pote... [more]
Lamalunga Cave (Altamura, Southern Italy) is renowned for the discovery in 1993 of an excellently preserved Neanderthal skeleton. Given the importance of the findings and the potential use of Lamalunga speleothems for paleoclimate reconstructions, a detailed monitoring program was undertaken to investigate the connections between microclimate parameters and speleothem growth. The cave air temperature is characterized by annual sinusoidal cycles with increasing phase shift and decreasing thermal amplitude from ± 2.1°C to ± 0.04°C as a function of increasing rock overburden, and daily to sub-daily cycles induced by surface air pressure (SAP) variations characterized by strong 24-hour and 12-hour solar harmonic frequencies, with thermal amplitude decreasing from 0.0054°C to 0.0021°C in the deeper parts of the cave. The ventilation regime is mainly controlled by SAP fluctuations. Fast SAP rises can trigger ¿emptying events¿ during which most of the cave air is replaced and the CO2 concentration falls towards near-atmospheric values. The steady and gentle ventilation created by SAP fluctuations also influences the growth and morphology of calcite coralloids, with larger popcorn assemblages concentrated in the northern galleries and delicate branching morphologies prevailing along the South Gallery where stable temperature and relative humidity conditions occur. The study is a seminal example of how high-precision measurements of cave air temperature can provide a wealth of information on cave ventilation and thermal regime and provide valuable support for robust paleoclimate reconstruction from speleothems.
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Nova |
2024 |
Faraji M, Borsato A, Frisia S, Hartland A, Hellstrom JC, Greig A, 'High-resolution reconstruction of infiltration in the Southern Cook Islands based on trace elements in speleothems', QUATERNARY RESEARCH, [C1]
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Nova |
2023 |
Wood CT, Johnson KR, Lewis LE, Wright K, Wang JK, Borsato A, et al., 'High-Resolution, Multiproxy Speleothem Record of the 8.2 ka Event From Mainland Southeast Asia', Paleoceanography and Paleoclimatology, 38 (2023) [C1]
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... [more]
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 (d18O, d13C, 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 d18O monsoon records. Interestingly, however, our d13C 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 d18O. Moreover, the d13C 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 d18O. Our interpretations suggest that drier conditions brought on by the 8.2¿ka event in MSEA were felt beyond the temporal boundaries defined by d18O-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.
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Nova |
2023 |
Faraji M, Frisia S, Hua Q, Borsato A, Markowska M, 'Accurate chronological construction for two young stalagmites from the tropical South Pacific', Quaternary Geochronology, 74 (2023) [C1]
Modern to Holocene tropical Pacific stalagmites are commonly difficult to date with the U-series, the most commonly used dating method for speleothems. When U-series does not prov... [more]
Modern to Holocene tropical Pacific stalagmites are commonly difficult to date with the U-series, the most commonly used dating method for speleothems. When U-series does not provide robust age models, due to multiple sources of 230Th or little U, radiocarbon is, potentially, the best alternative. The 14C content of two stalagmites (Pu17 and Nu16) collected from Pouatea and Nurau caves in the Cook Island Archipelago of the South Pacific were measured to obtain accurate chronology for their most modern parts. The bomb-pulse soil continuum modelling indicates that bomb radiocarbon in Pu17 onsets in 1956 and reaches its maximum in 1966 CE, suggesting a fast transfer of atmospheric carbon to the stalagmite of <1 year. The modelling for Pu17 suggests a 20% contribution from C1 - an instantaneous carbon source, which renders possible an immediate transfer of atmospheric signal into the cave. Nu16 shows a slower transfer of atmospheric carbon to the stalagmite than Pu17, with bomb radiocarbon onsetting in 1957 CE and peaking in 1972 CE. The less negative d13C values in Nu16 than Pu17, and also the modelling corroborated this, which points out no contribution from the instantaneous carbon source. The radiocarbon age models and laminae counting age models were then spliced to achieve a single master chronology for the top part of each stalagmite. This study is an example of 14C age modelling combined with visible physical and chemical laminae counting and how it can improve the accuracy and precision of dating for otherwise hard-to-date tropical Pacific speleothems. Such accurate and precise age models pave the way to obtain sub-annually resolved paleoclimate records by further improving the calibration of climate proxy data with the current and instrumental weather parameters.
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Nova |
2023 |
Borsato A, Fairchild IJ, Frisia S, Wynn PM, Fohlmeister J, 'The Ernesto Cave, northern Italy, as a candidate auxiliary reference section for the definition of the Anthropocene series', Anthropocene Review, (2023) [C1]
Annually laminated stalagmites ER77 and ER78 from Grotta di Ernesto provide an accurate annual record of environmental and anthropogenic signals for the last ~200 years. Two major... [more]
Annually laminated stalagmites ER77 and ER78 from Grotta di Ernesto provide an accurate annual record of environmental and anthropogenic signals for the last ~200 years. Two major transitions are recorded in the stalagmites. The first coincides with the year 1840 CE, when a change from porous and impurity-rich-laminae to clean, translucent laminae occurs. This is accompanied by a steady increase in the growth rate, a decrease in fluorescence and a sharp increase in d13C values. These changes concur with the end of the Little Ice Age. The second transition takes place around the year 1960 CE and corresponds with an increase in both annual growth rate and sulfur concentration in stalagmite ER78 at 4.2 mm from the top, and with the deflection point in the 14C activity curve in stalagmite ER77 at 4.8 mm from the top. This latter is the stratigraphic signal proposed as the primary guide for the definition of the Anthropocene series. The following shift toward depleted d34S¿SO4 in stalagmite ER78 suggests that industrial pollution is a major source of sulfur. The interpretation of atmospheric signals (S, d34S, 14C) in the stalagmites is affected by attenuation and time lags and the environmental signals are influenced by soil and ecosystem processes, while other anthropogenic signals (d15N, 239Pu) are not recorded. For these reasons, the stalagmite record is here proposed as an auxiliary (reference) section rather than a global standard. In summary, Grotta di Ernesto contains one of the best stalagmite records documenting the Anthropocene, and one of only two stalagmite records where the S peak has been measured at high resolution.
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Nova |
2023 |
Profico A, Buzi C, Di Vincenzo F, Boggioni M, Borsato A, Boschian G, et al., 'Virtual excavation and analysis of the early Neanderthal cranium from Altamura (Italy).', Commun Biol, 6 316 (2023) [C1]
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Nova |
2022 |
Treble PC, Baker A, Abram NJ, Hellstrom JC, Crawford J, Gagan MK, et al., 'Ubiquitous karst hydrological control on speleothem oxygen isotope variability in a global study', COMMUNICATIONS EARTH & ENVIRONMENT, 3 (2022) [C1]
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Nova |
2022 |
Faraji M, Borsato A, Frisia S, Mattey DP, Drysdale RN, Verdon-Kidd DC, et al., 'Controls on rainfall variability in the tropical South Pacific for the last 350 years reconstructed from oxygen isotopes in stalagmites from the Cook Islands', QUATERNARY SCIENCE REVIEWS, 289 (2022) [C1]
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Nova |
2022 |
Frisia S, Borsato A, Hartland A, Faraji M, Demeny A, Drysdale RN, Marjo CE, 'Crystallization pathways, fabrics and the capture of climate proxies in speleothems: Examples from the tropics', Quaternary Science Reviews, 297 (2022) [C1]
The quality of climate proxy data from speleothem archives depends to varying degrees on crystallization processes, which result in diverse fabrics. Here, we document shifts in ca... [more]
The quality of climate proxy data from speleothem archives depends to varying degrees on crystallization processes, which result in diverse fabrics. Here, we document shifts in calcite growth mechanisms, from ion-by-ion to nanoparticle/nanocrystal attachment, in stalagmites from the tropical island of Atiu (South Pacific). Changes in solution stoichiometry and organic matter content result in the development of two columnar fabrics that are common elsewhere in settings characterized by seasonal contrast. A porous columnar fabric, characterized by intracrystalline micro and nanoporosity grows via a non-classical pathway through amorphous calcium carbonate (ACC) nanoparticles (~2¿4 nm in diameter) and calcite nanocrystal attachment. Despite subsequent transformation of nanoparticles/crystals into a large calcite crystal, the porous columnar fabric appears to preserve a d18O signal that faithfully reflects that of the parent fluid via quasi-equilibrium fractionation. Furthermore, the porous fabric shows random and fuzzy lateral distributions of Sr, another hydrological proxy, yet this element's incorporation follows equilibrium partitioning. The chemical properties of compact columnar fabrics, which appear to grow by classical ion-by-ion attachment, may not directly reflect those of the original depositional environment because of degassing, the presence of growth inhibitors (such as Na) and very early diagenetic modifications. Columnar porous calcite fabrics that formed through non-classical pathways in other settings may faithfully record the original properties of the parent drip water, whereas compact fabrics that formed through classical pathways elsewhere may not. It is concluded that the study of fabrics at the nano-scale is a necessary complement to speleothem research to identify the influence of crystallization pathways on the accuracy of proxy data.
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2022 |
McDonough LK, Treble PC, Baker A, Borsato A, Frisia S, Nagra G, et al., 'Past fires and post-fire impacts reconstructed from a southwest Australian stalagmite', Geochimica et Cosmochimica Acta, 325 258-277 (2022) [C1]
Speleothem records of past environmental change provide an important opportunity to explore fire frequency and intensity in the past, and the antecedent climatic conditions leadin... [more]
Speleothem records of past environmental change provide an important opportunity to explore fire frequency and intensity in the past, and the antecedent climatic conditions leading to fire events. Here, fire sensitive geochemical signals in a stalagmite from Yonderup Cave, a shallow cave in Western Australia, are compared to well-documented wildfire events that occurred in recent decades. The results are extended to identify wildfires during the growth interval of the speleothem (1760 CE¿2005 CE). Principal component analysis of the stalagmite time-series revealed distinct peaks in a combination of phosphorus and metal (aluminium, zinc, copper and lead) concentrations in response to known fire events, which are interpreted to have come from ash. Varying responses in the geochemical signal in the pre- and post-European colonisation period are likely linked to changes in land management, fire frequency and fire intensities. Of note is what we infer to be a particularly intense fire event concluded to have occurred in 1897 ± 5 CE, which climate sensitive proxies (d18O and bedrock-derived elements) indicate was preceded by a multi-decadal dry period that began in the late 1860s. The intensity of the deduced fire event is supported by a peak in P that is 6.3 times higher than elsewhere in the speleothem, accompanied by a peak in Zn. It was also inferred that changes to the surface-cave hydrology occurred as a result of this event, indicated by increased input of colloidal organic material onto the stalagmite that was interpreted to be caused by shallow karst bedrock fracturing from the heat-induced deformation that is observed after intense fires. These findings show the potential for speleothems to provide dated records of fire intensity and recurrence intervals. Further development could lead to a better understanding of the climate-fire relationship and the effects of land-management practices on wildfire frequency and intensity.
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2021 |
Baker A, Mariethoz G, Comas-Bru L, Hartmann A, Frisia S, Borsato A, et al., 'The Properties of Annually Laminated Stalagmites-A Global Synthesis', Reviews of Geophysics, 59 (2021) [C1]
Annually laminated speleothems have the potential to provide information on high-frequency climate variability and, simultaneously, provide good chronological constraints. However... [more]
Annually laminated speleothems have the potential to provide information on high-frequency climate variability and, simultaneously, provide good chronological constraints. However, there are distinct types of speleothem annual laminae, from physical to chemical, and a common mechanism that links their formation has yet to be found. Here, we analyzed annually laminated stalagmites from 23 caves and 6 continents with the aim to find if there are common mechanisms underlying their development. Annually laminated stalagmites are least common in arid and semiarid climates, and most common in regions with a seasonality of precipitation. At a global scale, we observe faster growth rates with increasing mean annual temperature and decreasing latitude. Changepoints in average growth rates are infrequent and age-depth relationships demonstrate that growth rates can be approximated to be constant. In general, annually laminated stalagmites are characterized by centennial-scale stability in calcite precipitation due to a sufficiently large and well-mixed water source, a time series spectrum showing first-order autoregression due to mixing of stored water and annual recharged water, and an inter-annual flickering of growth acceleration, bringing growth rates back to the long-term mean. Climate forcing of growth rate variations is observed where a multi-year climate signal is strong enough to be the dominant control on calcite growth rate variability, such that it retains a climate imprint after smoothing of this signal by mixing of stored water. In contrast, long-term constant growth rate of laminated stalagmites adds further robustness to their unparalleled capacity to improve accuracy of chronology building.
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2021 |
Sauro F, Fellin MG, Columbu A, Haeuselmann P, Borsato A, Carbone C, De Waele J, 'Hints on the Late Miocene Evolution of the Tonale-Adamello-Brenta Region (Alps, Italy) Based on Allochtonous Sediments From Raponzolo Cave', FRONTIERS IN EARTH SCIENCE, 9 (2021) [C1]
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2021 |
Faraji M, Borsato A, Frisia S, Hellstrom JC, Lorrey A, Hartland A, et al., 'Accurate dating of stalagmites from low seasonal contrast tropical Pacific climate using Sr 2D maps, fabrics and annual hydrological cycles', Scientific Reports, 11 (2021) [C1]
Tropical Pacific stalagmites are commonly affected by dating uncertainties because of their low U concentration and/or elevated initial 230Th content. This poses problems in estab... [more]
Tropical Pacific stalagmites are commonly affected by dating uncertainties because of their low U concentration and/or elevated initial 230Th content. This poses problems in establishing reliable trends and periodicities for droughts and pluvial episodes in a region vulnerable to climate change. Here we constrain the chronology of a Cook Islands stalagmite using synchrotron µXRF two-dimensional mapping of Sr concentrations coupled with growth laminae optical imaging constrained by in situ monitoring. Unidimensional LA-ICP-MS-generated Mg, Sr, Ba and Na variability series were anchored to the 2D Sr and optical maps. The annual hydrological significance of Mg, Sr, Ba and Na was tested by principal component analysis, which revealed that Mg and Na are related to dry-season, wind-transported marine aerosols, similar to the host-rock derived Sr and Ba signatures. Trace element annual banding was then used to generate a calendar-year master chronology with a dating uncertainty maximum of ± 15 years over 336 years. Our approach demonstrates that accurate chronologies and coupled hydroclimate proxies can be obtained from speleothems formed in tropical settings where low seasonality and problematic U¿Th dating would discourage the use of high-resolution climate proxies datasets.
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Nova |
2021 |
Borsato A, Frisia S, Howard D, Greig A, 'A guide to synchrotron hard X-ray fluorescence mapping of annually laminated stalagmites: Sample preparation, analysis and evaluation', SPECTROCHIMICA ACTA PART B-ATOMIC SPECTROSCOPY, 185 (2021) [C1]
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Nova |
2021 |
Johnston VE, Borsato A, Frisia S, Spötl C, Hellstrom JC, Cheng H, Edwards RL, 'Last interglacial hydroclimate in the Italian Prealps reconstructed from speleothem multi-proxy records (Bigonda Cave, NE Italy)', Quaternary Science Reviews, 272 (2021) [C1]
Past climate archives show the Last Interglacial (LIG) period as similar to slightly warmer than current temperatures. However, there is a lack of LIG proxy evidence regarding var... [more]
Past climate archives show the Last Interglacial (LIG) period as similar to slightly warmer than current temperatures. However, there is a lack of LIG proxy evidence regarding variations of the climate across large topographic features and how this manifests at different altitudes. Here, we analysed two flowstones from Bigonda Cave, northeast Italy, to reconstruct LIG climate conditions in a region where precipitation is strongly influenced by the presence of the Alps. Stable isotope ratios, trace element concentrations and speleothem petrography from 133 ka to 105 ka allowed the detection of various hydroclimate and environmental conditions. Composite speleothem d18O records from northeast Italy were found to closely follow the Northern Hemisphere summer insolation curve, attesting to the influence of solar isolation on Earth's hydroclimate. Our reconstructions indicate a northward shift of the Intertropical Convergence Zone during the LIG maximum, permitting Atlantic-derived moisture to travel further east across North Africa than at present, before being directed north towards the Alps. The latter part of the LIG exhibited frequent, extreme precipitation events in the SE Prealps due to orographic lifting of moisture from both the Atlantic and Mediterranean seas. Socio-economic planning must prepare for extreme autumnal flooding events and serious summer droughts, particularly important in vulnerable mountainous regions.
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2020 |
Frisia S, Borsato A, Della Porta G, 'Continental carbonates growth pathways, fabrics and diagenesis (2020)
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2020 |
Comas-Bru L, Rehfeld K, Roesch C, Amirnezhad-Mozhdehi S, Harrison SP, Atsawawaranunt K, et al., 'SISALv2: a comprehensive speleothem isotope database with multiple age-depth models', EARTH SYSTEM SCIENCE DATA, 12 2579-2606 (2020)
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2019 |
Comas-Bru L, Harrison SP, Werner M, Rehfeld K, Scroxton N, Veiga-Pires C, et al., 'Evaluating model outputs using integrated global speleothem records of climate change since the last glacial', CLIMATE OF THE PAST, 15 1557-1579 (2019) [C1]
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Nova |
2019 |
Vanghi V, Borsato A, Frisia S, Howard DL, Gloy G, Hellstrom J, Bajo P, 'High-resolution synchrotron X-ray fluorescence investigation of calcite coralloid speleothems: Elemental incorporation and their potential as environmental archives', Sedimentology, 66 2661-2685 (2019) [C1]
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Nova |
2019 |
Wang J, Johnson K, Borsato A, Amaya D, Griffiths M, Henderson G, Frisia S, 'Hydroclimatic Variability in Southeast Asia over the past two millennia', Earth and Planetary Science Letters, 525 (2019) [C1]
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Nova |
2018 |
Vanghi V, Borsato A, Frisia S, Drysdale R, Hellstrom J, Bajo P, 'Climate variability on the Adriatic seaboard during the last glacial inception and MIS 5c from Frasassi Cave stalagmite record', Quaternary Science Reviews, 201 349-361 (2018) [C1]
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Nova |
2018 |
Atsawawaranunt K, Comas-Bru L, Amirnezhad Mozhdehi S, Deininger M, Harrison SP, Baker A, et al., 'The SISAL database: A global resource to document oxygen and carbon isotope records from speleothems', Earth System Science Data, 10 1687-1713 (2018) [C1]
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Nova |
2018 |
Wynn PM, Fairchild IJ, Borsato A, Spötl C, Hartland A, Baker A, et al., 'Sulphate partitioning into calcite: Experimental verification of pH control and application to seasonality in speleothems', Geochimica et Cosmochimica Acta, 226 69-83 (2018) [C1]
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Nova |
2018 |
Frisia S, Borsato A, Hellstrom J, 'High spatial resolution investigation of nucleation, growth and early diagenesis in speleothems as exemplar for sedimentary carbonates', Earth-Science Reviews, 178 68-91 (2018) [C1]
Investigation by high resolution Transmission Electron Microscopy (HR-TEM) and Synchrotron-Radiation based micro X-ray fluorescence (SR-µXRF) of diagenesis in carbonates imposes u... [more]
Investigation by high resolution Transmission Electron Microscopy (HR-TEM) and Synchrotron-Radiation based micro X-ray fluorescence (SR-µXRF) of diagenesis in carbonates imposes uncertainties on the boundary between stages of crystal growth and post-depositional processes. Speleothems and dolomite are exemplars of the entire range of processes that result in solid materials consisting of crystals. HR-TEM investigation of speleothems suggests that there are many possible pathways of crystallization comprising classical ion-mediated, particle-mediated and formation of metastable phases. Diverse pathways influence the potential of a primary carbonate to undergo post-depositional transformation, with consequences on the accuracy of the preservation of original chemical and physical properties. The capability to date speleothems with U-series techniques is unique amongst other archives of Earth's history. It has been observed that U mobilization, which results in age inversions and uncertainties, is dependent on both crystallization and diagenetic pathways. Here, it is also proposed that the presence of organic colloids, mostly consisting of humic substances (HS), influences the extent to which U may be mobilized, as well as the capacity of original speleothem fabric to undergo dissolution and re-precipitation. Our hypothesis that colloidal HS protect the initial products of crystallization from subsequent diagenesis could explain the existence of primary dolomite preserved in Triassic sabkha facies influenced by fluvial input of siliciclastics. Primary dolomite nanocrystal aggregates coexist with single crystals, highlighting that multiple formation mechanisms were possible, which explains the variety of micro and nanostructures observed by conventional TEM investigations in dolomites. Similarly, we observed calcite nanocrystal aggregates and single crystals preserved in Triassic shallow marine facies, which are famous for their preservation of original aragonite, influenced by continental siliciclastic input. Our new data on the Triassic carbonates suggest that when HS colloids are abundant, nanocrystal aggregates are commonly preserved, possibly because of a protective coating by organic substances. These hinder both the transformation of the aggregates into larger crystals and multiple-steps diagenetic transformation that obliterate primary environmental signals. As opposed to textbook assumptions, it is here proposed that the existence of multiple crystallization pathways for carbonates within the same depositional environment, such as a cave setting or a sabkha, have repercussion on the early diagenetic processes and the extent to which diagenesis significantly resets the original chemical and physical signals. By using speleothems as paradigm for carbonates formed in natural environments where organic compounds are ubiquitous, the present review corroborates the notion that most mechanisms of carbonate crystallization, when the carbonate is not a biomineral, follow inorganic pathways. However, the role of organic substances, as inhibitors of growth and diagenesis, has profound influences on preservation of initial states of crystal formation.
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Nova |
2018 |
Johnston VE, Borsato A, Frisia S, Spoetl C, Dublyansky Y, Toechterle P, et al., 'Evidence of thermophilisation and elevation-dependent warming during the Last Interglacial in the Italian Alps', SCIENTIFIC REPORTS, 8 (2018) [C1]
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Nova |
2017 |
Belli R, Borsato A, Frisia S, Drysdale R, Maas R, Greig A, 'Investigating the hydrological significance of stalagmite geochemistry (Mg, Sr) using Sr isotope and particulate element records across the Late Glacial-to-Holocene transition', GEOCHIMICA ET COSMOCHIMICA ACTA, 199 247-263 (2017) [C1]
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Nova |
2017 |
Treble PC, Baker A, Ayliffe LK, Cohen TJ, Hellstrom JC, Gagan MK, et al., 'Hydroclimate of the Last Glacial Maximum and deglaciation in southern Australia's arid margin interpreted from speleothem records (23-15 ka)', CLIMATE OF THE PAST, 13 667-687 (2017) [C1]
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Nova |
2017 |
Bajo P, Borsato A, Drysdale R, Hua Q, Frisia S, Zanchetta G, et al., 'Stalagmite carbon isotopes and dead carbon proportion (DCP) in a near-closed-system situation: An interplay between sulphuric and carbonic acid dissolution', GEOCHIMICA ET COSMOCHIMICA ACTA, 210 208-227 (2017) [C1]
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Nova |
2017 |
Frisia S, Weyrich LS, Hellstrom J, Borsato A, Golledge NR, Anesio AM, et al., 'The influence of Antarctic subglacial volcanism on the global iron cycle during the Last Glacial Maximum', NATURE COMMUNICATIONS, 8 (2017) [C1]
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Nova |
2017 |
Vanghi V, Frisia S, Borsato A, 'Genesis and microstratigraphy of calcite coralloids analysed by high resolution imaging and petrography', Sedimentary Geology, 359 16-28 (2017) [C1]
The genesis of calcite coralloid speleothems from Lamalunga cave (Southern Italy) is here investigated from a purely petrographic perspective, which constitutes the basis for any ... [more]
The genesis of calcite coralloid speleothems from Lamalunga cave (Southern Italy) is here investigated from a purely petrographic perspective, which constitutes the basis for any subsequent chemical investigation. Lamalunga cave coralloids formed on bones and debris on the floor of the cave. They consist of elongated columnar crystals whose elongation progressively increases from the flanks to the tips of the coralloid, forming a succession of lens-shaped layers, which may be separated by micrite or impurity-rich layers. Organic molecules are preferentially concentrated toward the centre of convex lenses as highlighted by epifluorescence. Their occurrence on cave floor, lens-shaped morphology and concentration of impurities toward the apex of the convex lenses supports the hypothesis that their water supply was hydroaerosol, generated by the fragmentation of cave drips. Evaporation and degassing preferentially occurred on tips, enhancing the digitated morphology and trapping the organic molecules and impurities, carried by the hydroaerosol, between the growing crystals which became more elongated. Micrite layers, that cap some coralloid lenses, likely identify periods when decreasing in hydroaerosol resulted in stronger evaporation and higher supersaturation with respect to calcite of the parent film of fluid. This interpretation of coralloid formation implies that these speleothems can be used to extract hydroclimate information.
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Nova |
2017 |
Blyth AJ, Hua Q, Smith A, Frisia S, Borsato A, Hellstrom J, 'Exploring the dating of "dirty" speleothems and cave sinters using radiocarbon dating of preserved organic matter', QUATERNARY GEOCHRONOLOGY, 39 92-98 (2017) [C1]
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Nova |
2016 |
Borsato A, Johnston VE, Frisia S, Miorandi R, Corradini F, 'Temperature and altitudinal influence on karst dripwater chemistry: Implications for regional-scale palaeoclimate reconstructions from speleothems', Geochimica et Cosmochimica Acta, 177 275-297 (2016) [C1]
The reconstruction of robust past climate records from speleothems requires a prior understanding of the environmental and hydrological conditions that lead to speleothem formatio... [more]
The reconstruction of robust past climate records from speleothems requires a prior understanding of the environmental and hydrological conditions that lead to speleothem formation and the chemical signals encoded within them. On regional-scales, there has been little quantification of the dependency of cave dripwater geochemistry on meteorology (net infiltration, temperature), environmental and geographical factors (elevation, latitude, soil activity, vegetation cover, atmospheric aerosol composition) and geological properties of the aquifer (lithology, porosity and thickness). In the present study, we analysed over 200 karst waters collected in 11 caves of the Trentino region (NE Italy). The caves span sub-humid Mediterranean to cold-humid temperate climates and infiltration elevations (Zinf) ranging from 355 to 2400 m a.s.l., corresponding to infiltration mean annual temperatures (MATinf) between 12 and 0 °C. Since all the caves developed in pure carbonate rocks, soil pCO2 is found to be the main factor controlling the carbonate dissolution. For this reason, the parameters controlling the carbonate-carbonic acid system and calcite saturation state (SICC) are directly correlated with the MATinf, which influences the vegetation zones and eventually the production of CO2 in the soil. SICC linearly depends on MATinf (SICC = 0.09 MATinf - 0.4) and SICC = 0 is reached at Zinf = 1.66 km a.s.l., corresponding to a MATinf = 4.4 °C. This point identifies the "speleothem limit" defined here as the elevation (or corresponding MATinf) above which no sparitic speleothem precipitation usually occurs. We demonstrate that due to temperature-forced changes in the soil and vegetation and subsequently SICC, the speleothem limit shifts to higher altitudes during maximum interglacial conditions. Speleothems from high altitude caves (1.5-2.5 km a.s.l.) thus can identify optimum interglacial periods. By contrast, speleothems formed at lower altitudes are better suited as archives of hydrological proxies. At altitudes below 1.2 km a.s.l., prior calcite precipitation (PCP) modifies percolating waters, particularly during periods of reduced infiltration. We introduce the use of the SiO2/Ca and SO4/Ca ratios in cave waters to complement Mg/Ca and Sr/Ca ratios as markers of PCP. SO4 and SiO2 are derived from atmospheric deposition and siliciclastic minerals in the soil zone, rather than carbonate host rocks (as in the case of Mg and Sr). By combing shifts to higher Mg/Ca, SiO2/Ca and SO4/Ca ratios along their characteristics PCP lines, we improve the robustness of the interpretation that this resulted from increasing PCP, rather than incongruent calcite dissolution (ICD). Our method permits the quantification of PCP between 0% and 40% for low elevation cave waters. This novel approach has important implications for speleothem-based paleoclimate studies where the distinction between PCP and ICD can be ambiguous and, in combination with Mg/Ca and Sr/Ca ratios, permits the quantification of net infiltration and/or rainfall amount from speleothem records.
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Nova |
2016 |
Treble PC, Baker A, Ayliffe LK, Cohen TC, Hellstrom JC, Gagan MK, et al., 'Supplementary material to "Hydroclimate of the Last Glacial Maximum and deglaciation in southern Australia s arid margin interpreted from speleothem records (23 15 ka)" (2016)
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2016 |
Phillips BL, Zhang Z, Kubista L, Frisia S, Borsato A, 'NMR spectroscopic study of organic phosphate esters coprecipitated with calcite', GEOCHIMICA ET COSMOCHIMICA ACTA, 183 46-62 (2016) [C1]
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Nova |
2016 |
Bajo P, Hellstrom J, Frisia S, Drysdale R, Black J, Woodhead J, et al., ' Cryptic diagenesis and its implications for speleothem geochronologies', Quaternary Science Reviews, 148 17-28 (2016) [C1]
Speleothems are usually considered as one of the most amenable palaeoclimate archives for U-series dating. A number of studies in recent years, however, report cases of diagenetic... [more]
Speleothems are usually considered as one of the most amenable palaeoclimate archives for U-series dating. A number of studies in recent years, however, report cases of diagenetic alteration which compromises the use of U-series systematics in speleothems, resulting in inaccurate U-Th ages. Here we present the results of a high-resolution U-Th dating study of a stalagmite (CC26) from Corchia Cave in Italy where we document a number of departures from an otherwise well-defined age-depth model, and explore potential causes for these outliers. Unlike examples illustrated in previous studies, CC26 contains no visible evidence of neomorphism, and appears, at least superficially, ideally suited to dating. Good reproducibility obtained between multi-aliquot U-Th analyses removes any possibility of analytical issues contributing to these outliers. Furthermore, replicate analyses of samples from the same stratigraphic layer yielded ages in stratigraphic sequence, implying very localized open-system behavior. Uranium loss is suggested as a causative mechanism on account of the fact that all the outliers are older than their assumed true age. A limited number of micro-voids were observed under micro-CT analyses, and it is proposed that these were pathways for U loss. Uranium-loss modelling allows us to constrain the possible timing of diagenetic alteration and indicates that the precursor for the outlier with the largest age discrepancy (309%) must have been aragonite. This study indicates that visibly unaltered speleothems may still contain small domains that have experienced post-depositional alteration. Such ¿cryptic¿ diagenesis, as recorded in this stalagmite, has implications for the constancy of accuracy of the U-series dating technique, and suggests a need for careful examination of speleothems prior to dating, particularly in low-resolution U-Th studies.
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Nova |
2015 |
Borsato A, Frisia S, Miorandi R, 'Carbon dioxide concentration in temperate climate caves and parent soils over an altitudinal gradient and its influence on speleothem growth and fabrics', EARTH SURFACE PROCESSES AND LANDFORMS, 40 1158-1170 (2015) [C1]
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Nova |
2015 |
Borsato A, Frisia S, Wynn PM, Fairchild IJ, Miorandi R, 'Sulphate concentration in cave dripwater and speleothems: Long-term trends and overview of its significance as proxy for environmental processes and climate changes', Quaternary Science Reviews, (2015) [C1]
Sulphate concentrations in speleothems identify major volcanic eruptions, provide useful information on soil and aquifer dynamics and, in similar fashion to the <sup>14</... [more]
Sulphate concentrations in speleothems identify major volcanic eruptions, provide useful information on soil and aquifer dynamics and, in similar fashion to the <sup>14</sup>C bomb peak, its Anthropocene peak can be used to date recent cave formations. However, the transmission of S from the atmosphere to cave dripwater and its incorporation in speleothems is subjected to biogeochemical cycling and accurate studies of each cave site are needed in order to assess how the S atmospheric signal is modified and eventually encoded in speleothems. This study investigates the role of biogeochemical cycling and aquifer hydrology by utilising published and new dripwater and speleothem data from Grotta di Ernesto (ER) in northern Italy. Here we provide the first long-term record of sulphate concentration in cave dripwater based on over 20 years of measurements. Fast drip site st-ER1 is characterised by a continuous decrease in SO<inf>4</inf> concentration from a high of 7.5±0.8mg/l in 1993-1994 to a low of 2.2±0.2mg/l in 2013-2014, and replicates with a delay of ~15 years the decline in the atmospheric SO<inf>2</inf> emissions. The S-series of slow flow ER78 site is further delayed by ~4.5 years in relation to the S retention in the aquifer matrix. The dripwater data are used to extend the previously published S record (1810-1998 AD) of stalagmite ER78 and reconstruct the anthropogenic S-peak: this displays a delay of ~20 years with respect to the atmospheric S emission peak due to biogeochemical cycling and aquifer storage. However, sulphur recycling above the cave did not operate with the same degree of efficiency through time, which resulted in a variable time delay between S deposition and incorporation into the stalagmite. In the pre-Anthropocene era, and in particular during the cold Little Ice Age, biogeochemical cycling was far less efficient than today, and the fast transmission of the atmospheric signal allowed capture of S released during major volcanic eruptions by stalagmites.
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Nova |
2014 |
Moreno A, Svensson A, Brooks SJ, Connor S, Engels S, Fletcher W, et al., 'A compilation of Western European terrestrial records 60-8kaBP: Towards an understanding of latitudinal climatic gradients', Quaternary Science Reviews, 106 167-185 (2014) [O1]
Terrestrial records of past climatic conditions, such as lake sediments and speleothems, provide data of great importance for understanding environmental changes. However, unlike ... [more]
Terrestrial records of past climatic conditions, such as lake sediments and speleothems, provide data of great importance for understanding environmental changes. However, unlike marine and ice core records, terrestrial palaeodata are often not available in databases or in a format that is easily accessible to the non-specialist. As a consequence, many excellent terrestrial records are unknown to the broader palaeoclimate community and are not included in compilations, comparisons, or modelling exercises. Here we present a compilation of Western European terrestrial palaeo-records covering, entirely or partially, the 60-8-ka INTIMATE time period. The compilation contains 56 natural archives, including lake records, speleothems, ice cores, and terrestrial proxies in marine records. The compilation is limited to include records of high temporal resolution and/or records that provide climate proxies or quantitative reconstructions of environmental parameters, such as temperature or precipitation, and that are of relevance and interest to a broader community. We briefly review the different types of terrestrial archives, their respective proxies, their interpretation and their application for palaeoclimatic reconstructions. We also discuss the importance of independent chronologies and the issue of record synchronization. The aim of this exercise is to provide the wider palaeo-community with a consistent compilation of high-quality terrestrial records, to facilitate model-data comparisons, and to identify key areas of interest for future investigations. We use the compilation to investigate Western European latitudinal climate gradients during the deglacial period and, despite of poorly constrained chronologies for the older records, we summarize the main results obtained from NW and SW European terrestrial records before the LGM.
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2014 |
Badertscher S, Borsato A, Frisia S, Cheng H, Edwards RL, Tüysüz O, Fleitmann D, 'Speleothems as sensitive recorders of volcanic eruptions - the Bronze Age Minoan eruption recorded in a stalagmite from Turkey', Earth and Planetary Science Letters, 392 58-66 (2014) [C1]
Mounting evidence exists that variations in sulphur content in stalagmites are closely linked to changes in volcanic or anthropogenic atmospheric sulphur. The strong dependency of... [more]
Mounting evidence exists that variations in sulphur content in stalagmites are closely linked to changes in volcanic or anthropogenic atmospheric sulphur. The strong dependency of sulphur on soil pH and ecosystem storage, however, can result in a delay of several years to decades in the registration of volcanic eruptions and anthropogenic emissions by stalagmites. Here we present synchrotron-radiation based trace element analysis performed on a precisely-dated section of a stalagmite from Sofular Cave in Northern Turkey. As this section covers the time interval of the intensively studied Minoan volcanic eruption between 1600 and 1650 BC, we can test whether this vigorous eruption can be traced in a stalagmite. Of all measured trace elements, only bromine shows a clear short-lived peak at 1621 ± 25 BC, whereas sulphur and molybdenum show peaks later at 1617 ± 25 and 1589 ± 25 respectively. We suggest that all trace element peaks are related to the Minoan eruption, whereas the observed phasing of bromine, molybdenum and sulphur is related to differences in their retention rates in the soil above Sofular Cave. For the first time, we can show that bromine appears to be an ideal volcanic tracer in stalagmites, as it is a prominent volatile component in volcanic eruptions, can be easily leached in soils and rapidly transferred from the atmosphere through the soil and bedrock into the cave and stalagmite respectively. Highly resolved oxygen and carbon isotope profiles indicate that the Minoan eruption had no detectable climatic and environmental impact in Northern Turkey. © 2014 Elsevier B.V.
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Nova |
2014 |
Cantonati M, Guella G, Spitale D, Angeli N, Borsato A, Lencioni V, Filippi ML, 'The contribution of lake benthic algae to the sediment record in a carbonate mountain lake influenced by marked natural water-level fluctuations', Freshwater Science, 33 499-512 (2014)
Lake Tovel is an oligotrophic, meromictic, mountain lake of the Dolomites that undergoes marked seasonal water-level fluctuations (WLFs). We used neo- and paleolimnological data c... [more]
Lake Tovel is an oligotrophic, meromictic, mountain lake of the Dolomites that undergoes marked seasonal water-level fluctuations (WLFs). We used neo- and paleolimnological data collected since 1999 to test the utility of algal and cyanobacterial pigments and diatom and chironomid biodiversity as proxies for WLF and to highlight the contribution of benthic algae to the sediment record. We found that detailed knowledge of presentday spatiotemporal patterns of WLF is essential for a complete and correct interpretation of paleolimnological data. Scytonemin, a cyanobacteria-specific photoprotective pigment, was produced by epilithic cyanobacteria in the depth zone affected by WLF and should be considered a proxy for the extent of WLF. The phytobenthos was as important as phytoplankton as a source of sedimentary pigments. We used information gained on the detailed distribution of diatoms at different depths and on different substrata in the 2 basins to show the probable location in the lake from which taxa in sediment cores originated to aid in interpretation of the sediment archive (including identification of periods of active hydrology). We sampled present-day chironomids in springs and streams feeding the lake and along a depth transect in the main basin. The taxa found were all rheophilic, crenophilous, or typical of the littoral zone of oligotrophic lakes. We interpreted sections of the cores containing large numbers of Orthocladiinae and Diamesinae head capsules as indicative of periods of active hydrology (including sudden and marked WLF) because the littoral taxa found in the cores must have been derived from the littoral zone by sediment focusing or slumps. Thus, we identified useful proxies of WLF in mountain, carbonate lakes. © 2014 by The Society for Freshwater Science.
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2014 |
Lari M, Di Vincenzo F, Borsato A, Ghirotto S, Micheli M, Balsamo C, et al., 'The Neanderthal in the karst: First dating, morphometric, and paleogenetic data on the fossil skeleton from Altamura (Italy)', Journal of Human Evolution, (2014) [C1]
In 1993, a fossil hominin skeleton was discovered in the karst caves of Lamalunga, near Altamura, in southern Italy. Despite the fact that this specimen represents one of the most... [more]
In 1993, a fossil hominin skeleton was discovered in the karst caves of Lamalunga, near Altamura, in southern Italy. Despite the fact that this specimen represents one of the most extraordinary hominin specimens ever found in Europe, for the last two decades our knowledge of it has been based purely on the documented on-site observations. Recently, the retrieval from the cave of a fragment of bone (part of the right scapula) allowed the first dating of the individual, the quantitative analysis of a diagnostic morphological feature, and a preliminary paleogenetic characterization of this hominin skeleton from Altamura. Overall, the results concur in indicating that it belongs to the hypodigm of Homo neanderthalensis, with some phenetic peculiarities that appear consistent with a chronology ranging from 172±15ka to 130.1±1.9ka. Thus, the skeleton from Altamura represents the most ancient Neanderthal from which endogenous DNA has ever been extracted.
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Nova |
2013 |
Borsato A, 'About Non-Noticeability in Perception. A phenomenological Analysis of the Point of View of analytical Philosophy on the Subject "Attention"', HUSSERL STUDIES, 29 113-141 (2013)
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2013 |
Wynn PM, Borsato A, Baker A, Frisia S, Miorandi R, Fairchild IJ, 'Biogeochemical cycling of sulphur in karst and transfer into speleothem archives at Grotta di Ernesto, Italy', BIOGEOCHEMISTRY, 114 255-267 (2013) [C1]
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Nova |
2013 |
Belli R, Frisia S, Borsato A, Drysdale R, Hellstrom J, Zhao J-X, Spoetl C, 'Regional climate variability and ecosystem responses to the last deglaciation in the northern hemisphere from stable isotope data and calcite fabrics in two northern Adriatic stalagmites', QUATERNARY SCIENCE REVIEWS, 72 146-158 (2013) [C1]
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Nova |
2013 |
Johnston VE, Borsato A, Spoetl C, Frisia S, Miorandi R, 'Stable isotopes in caves over altitudinal gradients: fractionation behaviour and inferences for speleothem sensitivity to climate change', CLIMATE OF THE PAST, 9 99-118 (2013) [C1]
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Nova |
2012 |
Hartland A, Fairchild IJ, Lead JR, Borsato A, Baker A, Frisia S, Baalousha M, 'From soil to cave: Transport of trace metals by natural organic matter in karst dripwaters', Chemical Geology, 304-305 68-82 (2012) [C1]
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Nova |
2012 |
Wackerbarth A, Langebroek PM, Werner M, Lohmann G, Riechelmann S, Borsato A, Mangini A, 'Simulated oxygen isotopes in cave drip water and speleothem calcite in European caves', CLIMATE OF THE PAST, 8 1781-1799 (2012) [C1]
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2012 |
Scholz D, Frisia S, Borsato A, Spotl C, Fohlmeister J, Mudelsee M, et al., 'Holocene climate variability in north-eastern Italy: Potential influence of the NAO and solar activity recorded by speleothem data', Climate of the Past, 8 1367-1383 (2012) [C1]
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Nova |
2012 |
Frisia S, Borsato A, Drysdale RN, Paul B, Greig A, Cotte M, 'A re-evaluation of the palaeoclimatic significance of phosphorus variability in speleothems revealed by high-resolution synchrotron micro XRF mapping', Climate of the Past, 8 2039-2051 (2012) [C1]
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Nova |
2011 |
Frisia S, Fairchild IJ, Fohlmeister J, Miorandi R, Spotl C, Borsato A, 'Carbon mass-balance modelling and carbon isotope exchange processes in dynamic caves', Geochimica et Cosmochimica Acta, 75 380-400 (2011) [C1]
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Nova |
2010 |
Wynn PM, Fairchild IJ, Frisia S, Spotl C, Baker A, Borsato A, Eimf, 'High-resolution sulphur isotope analysis of speleothem carbonate by secondary ionisation mass spectrometry', Chemical Geology, 271 101-107 (2010) [C1]
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Nova |
2010 |
Frisia S, Borsato A, 'Chapter 6 Karst', Developments in Sedimentology, 61 269-318 (2010) [C3]
Karst environments are regions where sparingly soluble rocks outcrop and efficient acid hydrolysis creates spectacular dissolution landforms. The release of CO 2 from karst waters... [more]
Karst environments are regions where sparingly soluble rocks outcrop and efficient acid hydrolysis creates spectacular dissolution landforms. The release of CO 2 from karst waters to the atmosphere causes precipitation of calcium-carbonate deposits, which, in caves, are collectively known as speleothems. Karst carbonate deposits capture climate and environmental signals in their macro- and micro-morphological characteristics, their mineral composition, and their chemical properties. They can be precisely dated with radiometric techniques and, thus, constitute an archive of climate change for millions of years. Karst carbonate formation is a product of both inorganic and organic processes. The influence of bacteria appears to be particularly important in the formation of calcareous tufa, deposits which commonly dam flowing water at both surface and subsurface. Bacteria also play a role in favouring the growth of mineral fibres in cave moonmilk, a plastic and powdery deposit consisting mostly of water and calcite. The most typical products of deposition in the subsurface karst environment are speleothems consisting of a rigid and relatively fragile arrangement in successive layers of calcium-carbonate crystals, which are here referred to as sparitic speleothems. Stalagmites, stalactites and flowstones mostly consist of calcite, and less commonly of aragonite or other minerals, which reflect events that occurred at the surface in their fabrics, trace-element composition, stable-isotope ratio and organic chemistry. The focus of this chapter is on issues related to the formation of karst deposits and their significance as palaeoclimate archives. © 2010 Elsevier B.V. All rights reserved.
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2010 |
Miorandi R, Borsato A, Frisia S, Fairchild IJ, Richter DK, 'Epikarst hydrology and implications for stalagmite capture of climate changes at Grotta di Ernesto (NE Italy): Results from long-term monitoring', Hydrological Processes, 24 3101-3114 (2010) [C1]
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Nova |
2010 |
Obertegger U, Borsato A, Flaim G, 'Rotifer-crustacean interactions in a pseudokarstic lake: influence of hydrology', AQUATIC ECOLOGY, 44 121-130 (2010) [C1]
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2009 |
Smith CL, Fairchild IJ, Spotl C, Frisia S, Borsato A, Moreton SG, Wynn PM, 'Chronology building using objective identification of annual signals in trace element profiles of stalagmites', Quaternary Geochronology, 4 11-21 (2009) [C1]
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Nova |
2009 |
Fairchild IJ, Loader NJ, Wynn PM, Frisia S, Thomas PA, Lageard JGA, et al., 'Sulfur fixation in wood mapped by synchrotron X-ray studies: Implications for environmental archives', Environmental Science & Technology, 43 1310-1315 (2009) [C1]
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Nova |
2009 |
Belli R, Frisia S, Drysdale RN, Borsato A, 'A multidisciplinary approach to the study of an archaeological site: The case of Riparo Dalmeri (Trentino, Italy)', Quaternary Australasia, 26 2-7 (2009) [C1]
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Nova |
2008 |
Frisia S, Badertscher S, Borsato A, Susini J, Gokturk OM, Cheng H, et al., 'The use of stalagmite geochemistry to detect past volcanic eruptions and their environmental impacts', PAGES News, 16 25-26 (2008) [C2]
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Nova |
2008 |
Frisia S, Susini J, Borsato A, 'Synchrotron radiation applications to past volcanism archived in speleothems: An overview', Journal of Vulcanology and Geothermal Research, 177 96-100 (2008) [C1]
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Nova |
2007 |
Obertegger U, Flaim G, Braioni MG, Sommaruga R, Corradini F, Borsato A, 'Water residence time as a driving force of zooplankton structure and succession', AQUATIC SCIENCES, 69 575-583 (2007)
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2007 |
Borsato A, Frisia S, Fairchild IJ, Somogyi A, Susini J, 'Trace element distribution in annual stalagmite laminae mapped by micrometer-resolution X-ray fluorescence: Implications for incorporation of environmentally significant species', GEOCHIMICA ET COSMOCHIMICA ACTA, 71 1494-1512 (2007) [C1]
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2006 |
Frisia S, Borsato A, Mangini A, Spoetl C, Madonia G, Sauro U, 'Holocene climate variability in Sicily from a discontinuous stalagmite record and the Mesolithic to Neolithic transition', QUATERNARY RESEARCH, 66 388-400 (2006) [C1]
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2006 |
Frisia S, Borsato A, Mangini A, Spötl C, Madonia G, Sauro U, 'Holocene record of climate changes and land use in Sicily reconstructed from a stalagmite', Quaternary Research, 66 388-400 (2006) [C1]
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2006 |
Smith CL, Baker A, Fairchild IJ, Frisia S, Borsato A, 'Reconstructing hemispheric-scale climates from multiple stalagmite records', INTERNATIONAL JOURNAL OF CLIMATOLOGY, 26 1417-1424 (2006) [C1]
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2005 |
Frisia S, Borsato A, Susini J, Somogyi A, 'Climate forcings and their influence on Alpine history as reconstructed through the application of synchrotron-based X-ray microfluorescence on layered stalagmites', ARCHAEOMETRY, 47 209-219 (2005) [C1]
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2005 |
Frisia S, Borsato A, Fairchild IJ, Susini J, 'Variations in atmospheric sulphate recorded in stalagmites by synchrotron micro-XU and XANES analyses', EARTH AND PLANETARY SCIENCE LETTERS, 235 729-740 (2005) [C1]
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2005 |
McMillan EA, Fairchild IJ, Frisia S, Borsato A, McDermott F, 'Annual trace element cycles in calcite-aragonite speleothems: evidence of drought in the western Mediterranean 1200-1100 yr BP', JOURNAL OF QUATERNARY SCIENCE, 20 423-433 (2005) [C1]
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2005 |
Frisia S, Borsato A, Spotl C, Villa IM, Cucchi F, 'Climate variability in the SE Alps of Italy over the past 17 000 years reconstructed from a stalagmite record', BOREAS, 34 445-455 (2005) [C1]
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2004 |
Bini A, Borsato A, Carraro F, Carton A, Corbari D, Cucato M, et al., 'Definition of some terms used in the cartography of alpine continental Quaternary deposits', Alpine and Mediterranean Quaternary, 17 75-82 (2004)
In the past decade a new approach to cartography and mapping of Quaternary continental deposits allowed the abandonment of the now obsolete "classical model" by Penck &a... [more]
In the past decade a new approach to cartography and mapping of Quaternary continental deposits allowed the abandonment of the now obsolete "classical model" by Penck & Brückner (1909), which was based on four major glaciations. The new approach utilizes stratigraphic units, which are bounded by discontinuities and defined by following glacial and/or hydrographic basins, framed within a relative chronological scale (Allostratigraphic Units and Unconformity-bounded stratigraphic units). The present paper, which synthesizes different approaches to Quaternary continental stratigraphy, proposes a definition of the terminology used in the Alpine area, in order to make clear the significance of each term, and assess its proper use. The terms Last Glacial Maximum (LGM), post-glacial, and Pre-LGM are here discussed in detail. The term LGM indicates the last local glacial maximum, without any reference to stratigraphic and chronostratigraphic units. The term post-glacial is used to indicate the events which followed the last local glacial expansion. The term Pre-LGM indicates the events that preceded the last local glacial maximum. Furthermore, we here discuss some of the problems of classification that arise following the use of the new terminology, and suggest possible cartographic solutions.
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2004 |
Majone B, Bellin A, Borsato A, 'Runoff generation in karst catchments: multifractal analysis', JOURNAL OF HYDROLOGY, 294 176-195 (2004)
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2003 |
Frisia S, Borsato A, Preto N, McDermott F, 'Late Holocene annual growth in three Alpine stalagmites records the influence of solar activity and the North Atlantic Oscillation on winter climate', EARTH AND PLANETARY SCIENCE LETTERS, 216 411-424 (2003) [C1]
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2002 |
Frisia S, Borsato A, Mackenzie FT, Tomasoni R, 'Dissolution experiments and natural weathering of carbonates.', GEOCHIMICA ET COSMOCHIMICA ACTA, 66 A247-A247 (2002)
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2002 |
Frisia S, Borsato A, Fairchild IJ, McDermott F, Selmo EM, 'Aragonite-calcite relationships in speleothems (Grotte de Clamouse, France): Environment, fabrics, and carbonate geochemistry', JOURNAL OF SEDIMENTARY RESEARCH, 72 687-699 (2002) [C1]
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2002 |
Majone B, Bellin A, Borsato A, 'Fractal and multi-fractal analysis of the hydraulic property variations of karst aquifers', Acta Universitatis Carolinae, Geologica, 46 172-175 (2002)
We present the multifractal analysis of several signals recorded at the valclusian karstic spring of Prese val, located in the Dolomities area NW of Trento (Italy). The data analy... [more]
We present the multifractal analysis of several signals recorded at the valclusian karstic spring of Prese val, located in the Dolomities area NW of Trento (Italy). The data analysed include water discharge, temperature and electric conductivity. Both electric conductivity and temperature, which mimic the spatial variability of hydraulic conductivity, show the signature of multifractality with increments distributed as a Lévy stable probability distribution. This is not the case for the water discharge. We conclude that accurately recorded signals of electric conductivity and temperature of spring water can be used for characterization of karst systems.
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2001 |
Huang HM, Fairchild IJ, Borsato A, Frisia S, Cassidy NJ, McDermott F, Hawkesworth CJ, 'Seasonal variations in Sr, Mg and P in modern speleothems (Grotta di Ernesto, Italy)', CHEMICAL GEOLOGY, 175 429-448 (2001)
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2001 |
Fairchild IJ, Baker A, Borsato A, Frisia S, Hinton RW, McDermott F, Tooth AF, 'Annual to sub-annual resolution of multiple trace-element trends in speleothems', JOURNAL OF THE GEOLOGICAL SOCIETY, 158 831-841 (2001)
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2000 |
Fairchild IJ, Borsato A, Tooth AF, Frisia S, Hawkesworth CJ, Huang YM, et al., 'Controls on trace element (Sr-Mg) compositions of carbonate cave waters: implications for speleothem climatic records', CHEMICAL GEOLOGY, 166 255-269 (2000)
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2000 |
Borsato A, Frisia S, Jones B, Van der Borg K, 'Calcite moonmilk: Crystal morphology and environment of formation in caves in the Italian Alps', JOURNAL OF SEDIMENTARY RESEARCH, 70 1171-1182 (2000)
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2000 |
Frisia S, Borsato A, Fairchild IJ, McDermott F, 'Calcite fabrics, growth mechanisms, and environments of formation in speleothems from the Italian Alps and southwestern Ireland', JOURNAL OF SEDIMENTARY RESEARCH, 70 1183-1196 (2000)
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2000 |
Borsato A, Frisia S, Jones B, Van Klaas Borg DER, 'Calcite moonmilk: crystal morphology and environment of formation in caves in the Italian ALPS', Journal of Sedimentary Research, 70 1179-1182 (2000)
Calcite moonmilk, which is a cave deposit formed of calcite crystals and water, is found in many caves in the Italian Alps. These modern and ancient deposits are formed of fiber c... [more]
Calcite moonmilk, which is a cave deposit formed of calcite crystals and water, is found in many caves in the Italian Alps. These modern and ancient deposits are formed of fiber calcite crystals, 50-500 nm wide and 1 to > 10 µm long, and pol) crystalline chains that have few crystal defects. Radiocarbon dating indicates that most moonmilk deposits in these caves are fossil and that for most precipitation ceased ~ 6400 cal years BP, at the end of the mid-Holocene Hypsithermal. In the caves of the Italian Alps, the optimal conditions for formation of calcite moonmilk are: (1) a temperature range of 3.5-5.5°C, (2) low discharge volumes of seepage waters that are slightly supersaturated (SICAL = 0.0 to ~ 0.2), and (3) relative humidity that is at or close to 100%. Microbial activity apparently did not play an active role in the formation of the calcite moonmilk. Conditions for moonmilk formation are typically found in caves that are located beneath land surfaces, which are soil covered and support a conifer forest. Precipitation of the fiber calcite crystals apparently involved very slow flow of slightly supersaturated fluids. The fact that moonmilk appears to form under a narrow range of environmental conditions means that this cave deposit has potential as a paleodimatic indicator in high alpine karst areas. Copyright ©2000, SEPM (Society for Sedimentary Geology).
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2000 |
Borsato A, Frisia S, Jones B, Van Der Borg K, 'Calcite moonmilk: Crystal morphology and environment of formation in caves in the Italian Alps', Journal of Sedimentary Research, Section A: Sedimentary Petrology and Processes, 70 1179-1182 (2000)
Calcite moonmilk, which is a cave deposit formed of calcite crystals and water, is found in many caves in the Italian Alps. These modern and ancient deposits are formed of fiber c... [more]
Calcite moonmilk, which is a cave deposit formed of calcite crystals and water, is found in many caves in the Italian Alps. These modern and ancient deposits are formed of fiber calcite crystals, 50-500 nm wide and 1 to > 10 µm long, and polycrystalline chains that have few crystal defects. Radiocarbon dating indicates that most moonmilk deposits in these caves are fossil and that for most precipitation ceased ~ 6400 cal years BP, at the end of the mid-Holocene Hypsithermal. In the caves of the Italian Alps, the optimal conditions for formation of calcite moonmilk are: (1) a temperature range of 3.5-5.5°C, (2) low discharge volumes of seepage waters that are slightly supersaturated (SICAL= 0.0 to ~ 0.2), and (3) relative humidity that is at or close to 100%. Microbial activity apparently did not play an active role in the formation of the calcite moonmilk. Conditions for moonmilk formation are typically found in caves that are located beneath land surfaces, which are soil covered and support a conifer forest. Precipitation of the fiber calcite crystals apparently involved very slow flow of slightly supersaturated fluids. The fact that moonmilk appears to form under a narrow range of environmental conditions means that this cave deposit has potential as a paleoclimatic indicator in high alpine karst areas. Copyright © 2000, SEPM (Society for Sedimentary Geology).
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1999 |
McDermott F, Frisia S, Huang YM, Longinelli A, Spiro B, Heaton THE, et al., 'Holocene climate variability in Europe: Evidence from delta O-18, textural and extension-rate variations in three speleothems', QUATERNARY SCIENCE REVIEWS, 18 1021-1038 (1999)
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1996 |
Borsato A, 'Late-glacial to Holocene biogenic moonmilk and calcareous tufa deposits from caves in Trentino (NE Italy): Environment of precipitation and paleoclimatic significance', Alpine and Mediterranean Quaternary, 9 473-480 (1996)
Flowstones and coatings consisting of biogenic moonmilk and calcareous tufa are commonly associated with macrocrystalline speleothems in several caves of the Trento Province. Biog... [more]
Flowstones and coatings consisting of biogenic moonmilk and calcareous tufa are commonly associated with macrocrystalline speleothems in several caves of the Trento Province. Biogenic moonmilk is most common in caves located at middle to high elevation, from 1400 m a.s.l.up to the timberline (1900-2000 m), whereas calcareous tufa flowstones occur in caves set at low and middle elevation, from the valley bottom up to the upper limit of the deciduous forest (1400-1500 m). Most of these flowstones are fossil and exhibit evidences of erosion. 14C dating on both moonmilk and calcareous tufa, and U/Th dating on associated macrocrystalline stalagmites, allowed for the recognition of three depositional phases which can be correlated with the following environmental and climatic events at the surface: (1) - Between 12,000 and 9,000 year B.P., macrocrystalline and calcareous tufa speleothems started to form in caves at low elevation. (2) - Between 9,000 and 5,000 year B.P., the maximum deposition of moonmilk flowstones and, probably, of calcareous tufa flowstones, occurred. This time span corresponds to the Holocene climatic optimum, i.e. to an increase in both temperature and precipitation that promoted intense pedogenesis and the consequent increase in carbonate dissolution above the cave and speleothem precipitation within the caves. (3) - At about 5,000 B.P. moonmilk deposition stopped in caves located at high-altitude. This event corresponds to a dramatic drop in calcareous tufa deposition in low-altitude caves and is probably related to an abrupt climatic deterioration and strong soil erosion at the surface.
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