Apatite fission track and (U-Th)/He thermochronology of the Rochovce granite (Slovakia) – implications for the thermal evolution of the Western Carpathian-Pannonian region     

Martin Danišík  Milan Kohút  István Dunkl  L’ubomír Hraško  Wolfgang Frisch 《Swiss Journal of Geoscience》2008,101(1):225-233

The thermal evolution of the only known Alpine (Cretaceous) granite in the Western Carpathians (Rochovce granite) is studied by low-temperature thermochronological methods. Our apatite fission track and apatite (U-Th)/He ages range from 17.5 ± 1.1 to 12.9 ± 0.9 Ma, and 12.9 ± 1.8 to 11.3 ± 0.8 Ma, respectively. The data thus show that the Rochovce granite records a thermal event in the Middle to early Late Miocene, which was likely related to mantle upwelling, volcanic activity, and increased heat flow. During the thermal maximum between ~17 and 8 Ma, the granite was heated to temperatures ? 60 °C. Increase of cooling rates at ~12 Ma recorded by the apatic fission track and (U-Th)/He data is primarily related to the cessation of the heating event and relaxation of the isotherms associated with the termination of the Neogene volcanic activity. This contradicts the accepted concept, which stipulates that the internal parts of the Western Carpathians were not thermally affected during the Cenozoic period. The Miocene thermal event was not restricted to the investigated part of the Western Carpathians, but had regional character and affected several basement areas in the Western Carpathians, the Pannonian basin and the margin of the Eastern Alps.  相似文献   

Analysis of karst hydrodynamics through comparison of dissolved and suspended solids' transport     

Danièle Valdes  Jean-Paul Dupont  Nicolas Massei  Benoît Laignel  Joël Rodet 《Comptes Rendus Geoscience》2005,337(15):1365-1374

In karst systems, rain events often result in a decrease of the conductivity (a tracer of dissolved phase transport) and an increase in turbidity (a tracer of suspended solids transport) at wells and springs. This study shows that the comparison of suspended solids and solute transport by the coupled approach of $T\text{–}C$ curves (Turbidity–Conductivity) and autocorrelations gives evidence of the transport processes in the karst network and allows understanding the karst hydrodynamics. To cite this article: D. Valdes et al., C. R. Geoscience 337 (2005).  相似文献   

A multi‐system geochronology in the Ad‐3 borehole,Pannonian Basin (Hungary) with implications for dating volcanic rocks by low‐temperature thermochronology and for interpretation of (U–Th)/He data          下载免费PDF全文

Martin Danišík  László Fodor  István Dunkl  Axel Gerdes  János Csizmeg  Mária Hámor‐Vidó  Noreen J. Evans 《地学学报》2015,27(4):258-269

Independent geochronological and thermal modelling approaches are applied to a biostratigraphically exceptionally well‐controlled borehole, Alcsútdoboz‐3 (Ad‐3), in order to constrain the age of Cenozoic geodynamic events in the western Pannonian Basin and to test the efficacy of the methods for dating volcanic rocks. Apatite fission track and zircon U–Pb data show two volcanic phases of Middle Eocene (43.4–39.0 Ma) and Early Oligocene (32.72 ± 0.15 Ma) age respectively. Apatite (U–Th)/He ages (23.8–14.8 Ma) and independent thermal and subsidence history models reveal a brief period of heating to 55–70 °C at ~17 Ma caused by an increased heat‐flow related to crustal thinning and mantle upwelling. Our results demonstrate that, contrary to common perception, the apatite (U–Th)/He method is likely to record ‘apparent’ or ‘mixed’ ages resulting from subsequent thermal events rather than ‘cooling’ or ‘eruption’ ages directly related to distinct geological events. It follows that a direct conversion of ‘apparent’ or ‘mixed’ (U‐Th)/He ages into cooling, exhumation or erosion rates is incorrect.  相似文献   

Landslide susceptibility of volcanic landforms in the Río El Estado watershed,Pico de Orizaba volcano,Mexico     

Gabriel Legorreta Paulín  Marcus I. Bursik  José Juan Zamorano Orózco  José Ernesto Figueroa García 《Natural Hazards》2015,77(2):559-574

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Tracing metamorphism,exhumation and topographic evolution in orogenic belts by multiple thermochronology: a case study from the Nízke Tatry Mts., Western Carpathians     

Martin Danišík  Jaroslav Kadlec  Christoph Glotzbach  Anett Weisheit  István Dunkl  Milan Kohút  Noreen J. Evans  Monika Orvošová  Brad J. McDonald 《Swiss Journal of Geoscience》2011,104(2):285-298

A combination of four thermochronometers [zircon fission track (ZFT), zircon (U–Th)/He (ZHe), apatite fission track (AFT) and apatite (U–Th–[Sm])/He (AHe) dating methods] applied to a valley to ridge transect is used to resolve the issues of metamorphic, exhumation and topographic evolution of the Nízke Tatry Mts. in the Western Carpathians. The ZFT ages of 132.1 ± 8.3, 155.1 ± 12.9, 146.8 ± 8.6 and 144.9 ± 11.0 Ma show that Variscan crystalline basement of the Nízke Tatry Mts. was heated to temperatures >210°C during the Mesozoic and experienced a low-grade Alpine metamorphic overprint. ZHe and AFT ages, clustering at ~55–40 and ~45–40 Ma, respectively, revealed a rapid Eocene cooling event, documenting erosional and/or tectonic exhumation related to the collapse of the Carpathian orogenic wedge. This is the first evidence that exhumation of crystalline cores in the Western Carpathians took place in the Eocene and not in the Cretaceous as traditionally believed. Bimodal AFT length distributions, Early Miocene AHe ages and thermal modelling results suggest that the samples were heated to temperatures of ~55–90°C during Oligocene–Miocene times. This thermal event may be related either to the Oligocene/Miocene sedimentary burial, or Miocene magmatic activity and increased heat flow. This finding supports the concept of thermal instability of the Carpathian crystalline bodies during the post-Eocene period.  相似文献   

How do early successional patterns in man-made wetlands differ between cold temperate and Mediterranean regions?     

Albert Ruhí  Jan Herrmann  Stéphanie Gascón  Jordi Sala  Dani Boix 《Limnologica》2012,42(4):328-339

The early stages of succession in newly created wetlands should be impacted by the region in which the wetland is located, since climate may have filtered the dominant biological strategies of the taxa leading this process and may condition their dynamics. We studied the early successional patterns of macroinvertebrates within man made ponds, located in cold temperate (Scandinavian Peninsula) and Mediterranean regions (Iberian Peninsula), during the first three years following their creation. We predicted (1) non random subsets of the regional species pool (deterministic assembly) guiding the successional process in cold temperate wetlands, and random (stochastic) assembly in the Mediterranean region; (2) higher successional rates in Mediterranean ponds than in the cold temperate ponds, with contrary episodes of highest and lowest change throughout the year; and (3) a significant difference in the composition of biological traits between regions, due to the dominance of traits adapted to hydrological variability in the Mediterranean region. Hypotheses on community structure (1) and the composition of dominant biological traits (3) were mostly supported – deterministic assembly mechanisms in the cold temperate ponds and stochastic assembly in the Mediterranean ponds; and a dominance of different biological traits between regions, explained by the need to overcome hydrological disturbances in the Mediterranean ponds. The dynamics of succession (2) were explained by climatic factors in the cold temperate region but not in the Mediterranean ponds. We suggest that the intrinsic hydrological variability of Mediterranean lentic systems may be a major factor driving community changes in man-made wetlands in this region. In order to generalize the observed patterns, we performed a meta-analysis of the temporal trends of taxonomic distinctness parameters of other successional studies across a latitudinal gradient in Europe, which supported the differences we had observed between latitudinal extremes.  相似文献   

Assessing volcanic origins within detrital zircon populations——A case study from the Mesozoic non-volcanic margin of southern Australia     

Milo Barham  Christopher L.Kirkland  Martin Danisík 《地学前缘(英文版)》2019,10(4):1371-1381

Detrital zircon U/Pb geochronology is a common tool used to resolve stratigraphic questions,inform basin evolution and constrain regional geological histories.In favourable circumstances,detrital zircon populations can contain a concomitant volcanic contribution that provides constraints on the age of deposition.However,for non-volcanic settings,proving isolated detrital zircon grains are from contemporaneous and potentially remote volcanism is challenging.Here we use same grain(U-Th)/He thermochronology coupled with U/Pb geochronology to identify detrital zircon grains of contemporary volcanic origin.(U-Th)/He ages from Cretaceous zircon grains in southern Australia define a single population with a weighted mean age of 104±6.1 Ma.indistinguishable from zircon U/Pb geochronology and palynology(～104.0-107.5 Ma).Detrital zircon trace-element geochemistry is consistent with a continental signature for parent rocks and coupled with detrital grain ages,supports derivation from a2000 km distant early-to mid-Cretaceous Whitsunday Volcanic Province in eastern Australia.Thus,integration of biostratigraphy,single-grain zircon double-dating(geochronology and thermochronology)and grain geochemistry enhances fingerprinting of zircon source region and transport history.A distal volcanic source and rapid continental-scale transport to southern Australia is supported here.  相似文献   

Effect of water on the fluorine and chlorine partitioning behavior between olivine and silicate melt     

Bastian?JoachimEmail authorView author&#;s OrcID profile  André?Stechern  Thomas?Ludwig  Jürgen?Konzett  Alison?Pawley  Lorraine?Ruzié-Hamilton  Patricia?L.?Clay  Ray?Burgess  Christopher?J.?Ballentine 《Contributions to Mineralogy and Petrology》2017,172(4):15

Halogens show a range from moderate (F) to highly (Cl, Br, I) volatile and incompatible behavior, which makes them excellent tracers for volatile transport processes in the Earth’s mantle. Experimentally determined fluorine and chlorine partitioning data between mantle minerals and silicate melt enable us to estimate Mid Ocean Ridge Basalt (MORB) and Ocean Island Basalt (OIB) source region concentrations for these elements. This study investigates the effect of varying small amounts of water on the fluorine and chlorine partitioning behavior at 1280?°C and 0.3 GPa between olivine and silicate melt in the Fe-free CMAS+F–Cl–Br–I–H₂O model system. Results show that, within the uncertainty of the analyses, water has no effect on the chlorine partitioning behavior for bulk water contents ranging from 0.03 (2) wt% H₂O (D_Cl ^ol/melt = 1.6?±?0.9 × 10^?4) to 0.33 (6) wt% H₂O (D_Cl ^ol/melt = 2.2?±?1.1 × 10^?4). Consequently, with the effect of pressure being negligible in the uppermost mantle (Joachim et al. Chem Geol 416:65–78, 2015), temperature is the only parameter that needs to be considered for the determination of chlorine partition coefficients between olivine and melt at least in the simplified iron-free CMAS+F–Cl–Br–I–H₂O system. In contrast, the fluorine partition coefficient increases linearly in this range and may be described at 1280?°C and 0.3 GPa with (R ²?=?0.99): \(D_{F}^{\text{ol/melt}}\ =\ 3.6\pm 0.4\ \times \ {{10}^{-3}}\ \times \ {{X}_{{{\text{H}}_{\text{2}}}\text{O}}}\left( \text{wt }\!\!\%\!\!\text{ } \right)\ +\ 6\ \pm \ 0.4\times \,{{10}^{-4}}\). The observed fluorine partitioning behavior supports the theory suggested by Crépisson et al. (Earth Planet Sci Lett 390:287–295, 2014) that fluorine and water are incorporated as clumped OH/F defects in the olivine structure. Results of this study further suggest that fluorine concentration estimates in OIB source regions are at least 10% lower than previously expected (Joachim et al. Chem Geol 416:65–78, 2015), implying that consideration of the effect of water on the fluorine partitioning behavior between Earth’s mantle minerals and silicate melt is vital for a correct estimation of fluorine abundances in OIB source regions. Estimates for MORB source fluorine concentrations as well as chlorine abundances in both mantle source regions are within uncertainty not affected by the presence of water.  相似文献   

Long-term thermo-mechanical behavior of energy pile in dry sand     

Van?Tri?Nguyen  Anh?Minh?TangEmail authorView author&#;s OrcID profile  Jean-Michel?Pereira 《Acta Geotechnica》2017,12(4):729-737

A small-scale pile has been developed in the laboratory to investigate the thermo-mechanical behavior of energy piles subjected to a significant number of thermal cycles. The pile (20 mm external diameter), installed in dry sand, was initially loaded at its head to 0, 20, 40 and 60% of its ultimate bearing capacity (500 N). At the end of each loading step, 30 heating/cooling cycles were applied. The long-term behavior of the pile was observed in terms of head settlement, axial force profile, soil and pile temperature, and stress in soil. The results evidence the irreversible settlement of the pile head induced by thermal cycles under constant load head. In addition, the incremental irreversible settlement that accumulates after each thermal cycle decreases when the number of cycles increases. The evolution of irreversible pile head settlement versus number of cycles can be reasonably predicted by an asymptotic equation.  相似文献   

Thermotectonic evolution of the Ukrainian Donbas Foldbelt revisited: new constraints from zircon and apatite fission track data     

M. Danišík  R. F. Sachsenhofer  W. Frisch  V. A. Privalov  E. A. Panova  C. Spiegel 《Basin Research》2010,22(5):681-698

The Donbas Foldbelt (DF) is the compressionally deformed segment of a large Late Palaeozoic rift cross‐cutting the southern part of the East European Craton and is traditionally described as a classic example of an inverted intracratonic rift basin. Proposed formational models are often controversial and numerous issues are still a matter of speculation, primarily due to the lack of absolute time constraints and insufficient knowledge of the thermal evolution. We investigate the low‐temperature thermal history of the DF by means of zircon fission track and apatite fission track (AFT) thermochronology applied to Upper Carboniferous sediments. In all samples, the AFT chronometer was reset shortly after deposition in the Early Permian (～275 Ma). Samples contained kinetically variable apatites that are sensitive to different temperatures and using statistic‐based component analysis incorporating annealing characteristics of individual grains assessed by D_par , we identified several distinct age populations, ranging from the Late Permian (～265 Ma) to the Late Cretaceous (～70 Ma). We could thus constrain the thermal history of the DF during a ～200 Myr long period following the thermal maximum. We found that earliest cooling of Permian and Permo‐Triassic age is recorded on the basin margins whereas the central parts were residing in or slowly cooling through the apatite partial annealing zone during Jurassic and most of Cretaceous times, and then finally cooled to near‐surface conditions latest around the Cretaceous/Palaeogene boundary. Our data show that Permian erosion was less significant and Mesozoic erosion more significant than generally assumed. Inversion and pop‐up of the DF occurred in the Cretaceous and not in the Permian as previously thought. This is indicated by overall Cretaceous AFT ages in the central parts of the basin.  相似文献