Klein–Nishina effects in the spectra of non-thermal sources immersed in external radiation fields     

Rafa&#; Moderski  Marek Sikora  Paolo S. Coppi  Felix Aharonian 《Monthly notices of the Royal Astronomical Society》2005,363(3):954-966

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Book reviews     

A. Mészáros  Marek Wolf  J. Kleczek  R. Hudec 《Astrophysics and Space Science》1990,167(2):347-349

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New data on the Neoproterozoic – Cambrian geotectonic setting of the Teplá-Barrandian volcano-sedimentary successions: geochemistry,U-Pb zircon ages,and provenance (Bohemian Massif,Czech Republic)     

Kerstin?DrostEmail author  Ulf?Linnemann  Neal?McNaughton  Old?ich?Fatka  Petr?Kraft  Michael?Gehmlich  Christian?Tonk  Jaroslav?Marek 《International Journal of Earth Sciences》2004,93(5):742-757

The Teplá-Barrandian unit (TBU) of the Bohemian Massif was a part of the Avalonian-Cadomian belt at the northern margin of Gondwana during Neoproterozoic and Early Cambrian times. New detrital zircon ages and geochemical compositions of Late Neoproterozoic siliciclastic sediments confirm a deposition of the volcano-sedimentary successions of the TBU in a back-arc basin. A change in the geotectonic regime from convergence to transtension was completed by the time of the Precambrian-Cambrian boundary. The accumulation of around 2,500 m Lower Cambrian continental siliciclastics in a Basin-and-Range-type setting was accompanied by magmatism, which shows within-plate features in a few cases, but is predominantly derived from anatectic melts displaying the inherited island arc signature of their Cadomian source rocks. The geochemistry of clastic sediments suggests a deposition in a rift or strike-slip-related basin, respectively. A marine transgression during Middle Cambrian times indicates markedly thinned crust after the Cadomian orogeny. Upper Cambrian magmatism is represented by 1,500 m of subaerial andesites and rhyolites demonstrating several geochemical characteristics of an intra-plate setting. Zircons from a rhyolite give a U-Pb-SHRIMP age of 499±4 Ma. The Cambrian sedimentary and magmatic succession of the TBU records the beginning of an important rifting event at the northern margin of Gondwana.

Kerstin DrostEmail:

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Ongoing tectonic reactivation of the Outer Carpathians and its impact on the foreland: Results of borehole breakout measurements in Poland   总被引：1，自引：0，他引：1  

Marek Jarosi&#x  ski 《Tectonophysics》2005,410(1-4):189-216

The direction of present-day maximum horizontal compression (= S_Hmax = tectonic stress) was interpreted for 62 wells in Poland, using the method of borehole breakout analysis of 4-arm and 6-arm dipmeter logs. The study area covers complex tectonic junction of the Carpathian orogen and its foreland, which comprises the East European Craton (EEC) divided by the Teisseyre–Tornquist zone (TTZ) from the Palaeozoic platform of western Poland. For this area, frequent deviation of the S_Hmax direction from NW–SE characteristic for the Atlantic ridge push has been interpreted in terms of the ALCAPA tectonic push. In the Upper Silesian segment of the Polish Outer Carpathians (POC), NNE–SSW-oriented S_Hmax in the accretionary wedge differs significantly from NNW–SSE S_Hmax in the autochthonous basement. The above discrepancy points to uncoupled type of the suture in this segment of the POC. In this scenario the ALCAPA push involves the nappes and is compensated in the top of the basement, which is expressed by systematic S_Hmax rotations. In the accretionary wedge of the eastern Małopolska segment, S_Hmax follows the trend perpendicular to the strike of nappes. It is in general agreement with NNE–SSW-oriented S_Hmax in the autochthonous basement that also parallels the ALCAPA push direction. Similarity in stress orientation between these structural levels implies coupled suture zone in this segment of the POC. Further to the north, ALCAPA push is transmitted into the foreland plate where it causes N–S orientation of S_Hmax, as determined for sedimentary cover of the EEC. Within the Baltic portion of the EEC, further S_Hmax rotation towards the intermediate NNW–SSE position suggests balance between the ALCAPA push and the ridge push components. Within the TTZ, common S_Hmax rotations from N–S to NW–SE indicate structurally controlled accommodation of the ALCAPA push. In the Palaeozoic platform of western Poland, Mesozoic complex of the Fore-Sudetic Monocline reveals NNE–SSW-directed S_Hmax that differs from NW–SE-oriented S_Hmax in the Variscan accretionary wedge. Here, mechanical decoupling along Zechstein evaporates is likely.

Presented set of breakout data from Poland shows that recent compressive reactivation of the Carpathians exerts strong impact on the stress field of the foreland plate at a distance of 700 km from the suture. Due to this effect, the Fore-Carpathian stress domain within the North European stress province can be discriminated.  相似文献   

Crustal structure of northern Spitsbergen along the deep seismic transect between the Molloy Deep and Nordaustlandet   总被引：1，自引：0，他引：1  

Wojciech Czuba  Oliver Ritzmann  Yuichi Nishimura  Marek Grad  Rolf Mjelde  Aleksander Guterch  Wilfried Jokat 《Geophysical Journal International》2005,161(2):347-364

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Comment on “Point of zero charge of a corundum-water interface probed with optical second harmonic generation (SHG) and atomic force microscopy (AFM): new approaches to oxide surface charge” by A. G. Stack, S. R. Higgins, and C. M. Eggleston     

Marek Kosmulski 《Geochimica et cosmochimica acta》2003,67(2):319-320

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Three-dimensional seismic modelling of crustal structure in the TESZ region based on POLONAISE''97 data     

Piotr roda  Wojciech Czuba  Marek Grad  Aleksander Guterch  Edward Gaczy ski  POLONAISE Working Group 《Tectonophysics》2002,360(1-4):169-185

This paper reports the results of 3-D tomographic modelling of crustal structure in the Trans European Suture Zone region (TESZ) of Poland, eastern Germany and Lithuania. The data are the product of a large-scale seismic experiment POLONAISE'97, which was carried out in 1997. This experiment was designed to provide some 3-D coverage. The TESZ forms the boundary between the Precambrian crustal terranes of the East European Craton (EEC) and the younger Phanerozoic terranes to the southwest. The 3-D results generally confirm the earth models derived by earlier 2-D analyses, but also add some important details as well as a 3-D perspective on the structure. The velocity model obtained shows substantial horizontal variations of crustal structure across the study area. Seismic modelling shows low (<6.1 km/s) velocities suggesting the presence of sedimentary rocks down to a depth of about 20 km in the Polish basin. The shape of the basin in the vicinity of the profile P4 shows significant asymmetry. Three-dimensional modelling also allowed tracing of horizontal irregularities of the basin shape as well as variations of the Moho depth not only along profiles, but also between them. The slice between P2 and P4 profiles shows about 10-km variations of the Moho over a 100-km interval. The crustal thickness varies from about 30 km in SW, beneath the Palaeozoic platform, to about 42 km beneath East European Craton in NE. High seismic velocities of about 6.6 km/s were found in the depth range 2–10 km, which coincides with K trzyn anorthosite massif. The results of this 3-D seismic modelling of the POLONAISE'97 data will ultimately be supplemented by inversion of seismic data from previous experiments.  相似文献   

Quantifying volume transports during SKAGEX with the Norwegian Ecological Model system     

Morten D. Skogen  Einar Svendsen  Marek Ostrowski 《Continental Shelf Research》1997,17(15):1817-1837

A coupled 3-dimensional physical, chemical and biological model system, NORWECOM (the NORWegian ECOlogical Model system), is validated and used to identify and quantify the short-term variability of the different water masses being transported into and out of Skagerrak. The model system is a nesting between a coarse grid model set up for an extended North Sea, and a fine grid defined in the Skagerrak/Kattegat area.Originating from the extensive SKAGEX (SKAGerrak EXperiment) database, several interesting events have been identified and become the focus of the modeling. Through interactive use of the SKAGEX data set and NORWECOM, it is possible to gain a new insight into a very complex hydrodynamic system, an insight that is hard to achieve based on measurements only.  相似文献   

Two Periods of 1999 HF₁—Another Binary NEA Candidate     

Petr PravecLenka Šarounová  Michael D. HicksDavid L. Rabinowitz  Marek WolfPeter Scheirich  Yurij N. Krugly 《Icarus》2002,158(1):276-280

Photometric observations of 1999 HF₁ reveal that its lightcurve has two components of low amplitudes (0.10-0.12 mag) and different periods (2.3191 and 14.02 h). It is likely another binary near-Earth asteroid; its lower limit on the secondary-to-primary-diameter ratio is ≈0.2, the radius of the mutual orbit is (2.0±0.3)× the effective primary diameter, the primary's bulk density is >2.0 g/cm³, and it belongs to the E/M/P taxonomic class.  相似文献   

Long‐distance fluid migration defines the diagenetic history of unique Ediacaran sediments in the East European Craton     

Arkadiusz Derkowski  Jan rodo&#x;  Magdalena Goryl  Leszek Marynowski  Marek Szczerba  Stanis&#x;aw Mazur 《Basin Research》2021,33(1):570-593

The diagenetic history of the Ediacaran sedimentary rocks in the East European Craton (EEC) over the area extending from Arkhangelsk (Russia) in the north to Podolia (Ukraine) in the south was revealed by means of the XRD characterization and K–Ar dating of clay fractions, mudstone porosity measurements and organic geochemistry investigations. Mudstone porosity measurements produced direct evidence of shallow maximum burial of the Ediacaran sediments on the craton (Russia, Lithuania, Belarus, Volyn), not exceeding 1.5 km, and much deeper burial at the cratonic margin, in Podolia and Poland. In general, illitization of smectite and biomarker indices indicates more advanced diagenesis at the cratonic margin. K–Ar dating of authigenic illite–smectite and aluminoceladonite revealed the Palaeozoic age of mineral diagenesis (ca. 450–300 Ma) both on the craton and its margin, with older ages generally observed in the north. When the maximum palaeotemperatures were evaluated from illite–smectite and biomarkers, based on the calibrations from the conventional burial diagenetic sections, a major mismatch was detected for the cratonic area: 100°C–130°C from illite––smectite and tens of ^oC lower from the lipid biomarkers. This diagenetic pattern was interpreted as the result of short‐lasting (in ky scale) pulses of potassium‐bearing hot fluids migrating from the Caledonian and Variscan orogens deep in the craton interior, effectively promoting illitization in porous rocks without altering the organic matter. Analogous short pulses of fluids were responsible for numerous diagenetic phenomena, including Mississippi Valley‐Type ore deposits, in the American Midwest, in front of the Appalachians. K–Ar dating indicates that the entire Proterozoic sedimentary cover of the Great Unconformity on the EEC remained untouched by measureable post‐sedimentary changes until the early Palaeozoic, thus for over 1000 My, which is an unprecedented finding.  相似文献