The study of hydrodynamic behaviour of a complex karst system under low-flow conditions using natural and artificial tracers (the catchment of the Unica River,SW Slovenia)   总被引：2，自引：1，他引：1  

Nataša Ravbar  Juan Antonio Barberá  Metka Petrič  Janja Kogovšek  Bartolomé Andreo 《Environmental Earth Sciences》2012,65(8):2259-2272

In this study a multi-tracer test with fluorescent tracers was combined with time series analyses of natural tracers to characterize the dynamics of the solute transport through different recharge pathways and to study hydraulic behaviour of a binary karst system under low-flow conditions. Fluorescent tracer testing included the introduction of uranine, amidorhodamine G, or naphthionate at three injection points. Sampling and monitoring took place at two karst springs (Malenščica, Unica) and at two underground rivers (Pivka, Rak) recharging the Unica River at the Polje of Planina, SW Slovenia. Other monitored parameters included precipitation, spring or underground river discharge, water temperature, and electrical conductivity. Water samples were collected and analyzed for total organic carbon, Mg²⁺, SO₄ ²⁻, and NO₃ ⁻ in the laboratory. In the study area, results of the tracer test suggest that contaminant transport in karst may be retarded for several weeks during low-flow conditions followed by increases in contaminant concentrations after subsequent rainfall events. Based on interpretation of tracer concentration breakthrough curves, low apparent dominant flow velocities (i.e., between 5.8 and 22.8 m/h through the well developed karst conduits, and 3.6 m/h through the prevailing vadose zone with a dominant influence of a diffuse recharge) were obtained. Together with analyses of hydro-chemographs the artificial tracing identified different origins of water recharging the studied aquifer. During prolonged low-water conditions the Malenščica spring is mainly recharged from the karst aquifer and the Unica spring by the sinking Pivka River. After more intensive rainfall events allogenic recharge from Cerknica prevails in the Malenščica spring, while the Unica spring drains mainly the allogenic water from the Pivka Valley. These findings of alternating hydraulic connections and drainage areas due to respective hydrological conditions are important and should be considered when monitoring water quality, implementing groundwater protection measures, and optimizing future water exploitation.  相似文献   

Performance of the acousto-optical spectral line receivers at the metsahovi 14 m radio telescope     

L. Malkamäki  K. Mattila  A. Räisänen  A. Lehto  J. Peltonen 《Experimental Astronomy》1991,2(3):149-161

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Re-Mo-Cu-Os sulphide from the Ekojoki Ni-Cu deposit,SW Finland   总被引：1，自引：0，他引：1  

P. Peltonen  L. Pakkanen  B. Johanson 《Mineralogy and Petrology》1995,52(3-4):257-264

Summary This short communication reports the discovery and composition of the first Os-bearing rhenium sulphide. It occurs as a single euhedral crystal in the early Proterozoic Ekojoki Ni-Cu deposit in Finland, being enclosed by interstitial magmatic Fe-Ni sulphides. Electron microprobe analyses are most consistent with a general formula of Cu(Re,Os,Mo)₅S₉. The Re-Os model age calculations indicate that approximately 2/3 osmium is "common" Os that was accommodated by the sulphide at the time of crystallisation, 1/3 being produced via post-crystallisation decay of¹⁸⁷,Re to^{18 7}Os. We propose that this sulphide crystallised from an immiscible sulphide liquid that was unusually rich in rhenium due to extensive assimilation of black schist sulphides by the magma.With 2 Figures  相似文献   

Identifying the characteristics of groundwater flow in the Classical Karst area (Slovenia/Italy) by means of tracer tests     

Metka Petrič  Janja Kogovšek 《Environmental Earth Sciences》2016,75(22):1446

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Age determination of Baltic herring from whole otoliths and from neutral red stained otolith cross sections   总被引：2，自引：1，他引：2  

Peltonen  Heikki; Raitaniemi  Jari; Parmanne  Raimo; Eklund  Jan; Nyberg  Kari; Halling  Folke 《ICES Journal of Marine Science》2002,59(2):323-332

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The role of technical measures in European fisheries management and how to make them work better     

Suuronen  Petri; Sarda  Francesc 《ICES Journal of Marine Science》2007,64(4):751-756

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Thermal and mechanical behaviour of the orogenic middle crust during the syn‐ to late‐orogenic evolution of the Variscan root zone,Bohemian Massif     

B. Petri  P. Štípská  E. Skrzypek  K. Schulmann  M. Corsini  J. Franěk 《Journal of Metamorphic Geology》2014,32(6):599-626

We combine structural observations, petrological data and ⁴⁰Ar–³⁹Ar ages for a stack of amphibolite facies metasedimentary units that rims high‐P (HP) granulite facies felsic bodies exposed in the southern Bohemian Massif. The partly migmatitic Varied and Monotonous units, and the underlying Kaplice unit, show a continuity of structures that are also observed in the adjacent Blanský les HP granulite body. They all exhibit an earlier NE?SW striking and steeply NW‐dipping foliation (S3), which is transposed into a moderately NW‐dipping foliation (S4). In both the Varied and Monotonous units, the S3 and S4 foliations are characterized by a Sil–Bt–Pl–Kfs–Qtz–Ilm±Grt assemblage, with occurrences of post‐D4 andalusite, cordierite and muscovite. In the Monotonous unit, minute inclusions of garnet, kyanite, sillimanite and biotite are additionally found in plagioclase from a probable leucosome parallel to S3. The Kaplice unit shows rare staurolite and kyanite relicts, a Sil–Ms–Bt–Pl–Qtz±Grt assemblage associated with S3, retrogressed garnet?staurolite aggregates during the development of S4, and post‐D4 andalusite, cordierite and secondary muscovite. Mineral equilibria modelling for representative samples indicates that the Varied unit records conditions higher than ~7 kbar at 725 °C during the transition from S3 to S4, followed by a P?T decrease from ~5.5 kbar/750 °C to ~4.5 kbar/700 °C. The Monotonous unit shows evidence of partial melting in the S3 fabric at P?T above ~8 kbar at 740–830 °C and a subsequent P?T decrease to 4.5–5 kbar/700 °C. The Kaplice unit preserves an initial medium‐P prograde path associated with the development of S3 reaching peak P?T of ~6.5 kbar/640 °C. The subsequent retrograde path records 4.5 kbar/660 °C during the development of S4. ⁴⁰Ar–³⁹Ar geochronology shows that amphibole and biotite ages cluster at c. 340 Ma close to the HP granulite, whereas adjacent metasedimentary rocks preserve c. 340 Ma amphibole ages, but biotite and muscovite ages range between c. 318 and c. 300 Ma. The P?T conditions associated with S3 imply an overturned section of the orogenic middle crust. The shared structural evolution indicates that all mid‐crustal units are involved in the large‐scale folding cored by HP granulites. The retrograde P–T paths associated with S4 are interpreted as a result of a ductile thinning of the orogenic crust at a mid‐crustal level. The ⁴⁰Ar–³⁹Ar ages overlap with U–Pb zircon ages in and around the HP granulite bodies, suggesting a short duration for the ductile thinning event. The post‐ductile thinning late‐orogenic emplacement of the South Bohemian plutonic complex is responsible for a re‐heating of the stacked units, reopening of argon system in mica and a tilting of the S4 foliation to its present‐day orientation.  相似文献   

New chondrichthyans from the Irati Formation (Early Permian,Paraná Basin), Brazil: origin,paleoenvironmental and paleogeographical considerations     

Artur Chahud  Setembrino Petri 《Proceedings of the Geologists' Association. Geologists' Association》2014

Three genera, known by dorsal finspine, are reported from conglomeratic sandstone at the base of the Lower Permian (Kungurian) Irati Formation (Paraná Basin) near Rio Claro, São Paulo State, Brazil, noteworthy for the great richness of vertebrate fossils. The fossils include: (1) the previously known Sphenacanthus with the species Sphenacanthus sanpauloensis and an indeterminate species; (2) the Permian – Carboniferous genus Amelacanthus; (3) a new indeterminate Chondrichthyes. These fossils are found together with: continental, fresh-water and salt-water vertebrates. The analysis of this assemblage allows inference about the origin of Paraná Basin Chondrichthyes as well as reconstruction of the paleoenvironment and the possible geographic isolation of these fishes during the Permian in Brazil.  相似文献   

Ejections of Magnetic Structures Above a Spherical Wedge Driven by a Convective Dynamo with Differential Rotation     

J?rn Warnecke  Petri J. K?pyl?  Maarit J. Mantere  Axel Brandenburg 《Solar physics》2012,280(2):299-319

We combine a convectively driven dynamo in a spherical shell with a nearly isothermal density-stratified cooling layer that mimics some aspects of a stellar corona to study the emergence and ejections of magnetic field structures. This approach is an extension of earlier models, where forced turbulence simulations were employed to generate magnetic fields. A spherical wedge is used which consists of a convection zone and an extended coronal region to ???1.5 times the radius of the sphere. The wedge contains a quarter of the azimuthal extent of the sphere and 150^° in latitude. The magnetic field is self-consistently generated by the turbulent motions due to convection beneath the surface. Magnetic fields are found to emerge at the surface and are ejected to the coronal part of the domain. These ejections occur at irregular intervals and are weaker than in earlier work. We tentatively associate these events with coronal mass ejections on the Sun, even though our model of the solar atmosphere is rather simplistic.  相似文献   

U–Pb geochronology of the Sondalo gabbroic complex (Central Alps) and its position within the Permian post-Variscan extension     

Petri  B.  Mohn  G.  Skrzypek  E.  Mateeva  T.  Galster  F.  Manatschal  G. 《International Journal of Earth Sciences》2017,106(8):2873-2893

International Journal of Earth Sciences - The end of an orogenic cycle is commonly associated with a general extensional regime, widespread magmatism and complex metamorphic overprints. The...  相似文献