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    Stanislaw Mazur

    Abstract The Andean foreland basin formed throughout the Cenozoic in a retro-arc setting in front of the advancing orogen. A 2500 km (1553 mi) long segment of this basin system passes through eastern Peru and Bolivia and comprises, from... more
    Abstract The Andean foreland basin formed throughout the Cenozoic in a retro-arc setting in front of the advancing orogen. A 2500 km (1553 mi) long segment of this basin system passes through eastern Peru and Bolivia and comprises, from north to south, the Maranon, Ucayali, Madre de Dios, Beni, and Chaco Basins. The Andean foreland basin contains substantially thick units of Cenozoic sediments, which overlie Mesozoic and Paleozoic successions and Precambrian crystalline basement. In the deeper parts of the foreland basin, no wells have penetrated the full, pre-Andean sedimentary section and the sheer thickness of the sediments makes it difficult to seismically image crystalline basement in some areas. Thus, the thickness of the pre-Andean sediments and the existence of basins that pre-date the Andean orogeny are partly obscured. Areally extensive gravity and magnetic data sets have been used to build a structural and tectonic framework for the area. Gravity and magnetic 2-D forward modeling and 3-D inverse gravity modeling, constrained by seismic interpretation and well data, enabled base Cretaceous and top crystalline basement horizons to be derived. This approach allowed lateral extrapolation of the detailed but localized seismic interpretation into areas without seismic coverage, and it also extended this interpretation by including the depth to top crystalline basement. The results of this analysis indicate the presence of large pre-Cretaceous depocenters underlying the Andean foreland basin. These include a major depocenter extending from the central Maranon Basin north-northeastward across the Iquitos Arch, two depocenters underlying the Madre de Dios Basin and four depocenters beneath the Beni/Chaco Basins.
    <p>We performed reinterpretation of the DEKORP-BASIN’96 offshore deep reflection seismic profiles PQ-002 and PQ-004-005 running ENE-WSW in the South Baltic area through the transition zone between the East... more
    <p>We performed reinterpretation of the DEKORP-BASIN’96 offshore deep reflection seismic profiles PQ-002 and PQ-004-005 running ENE-WSW in the South Baltic area through the transition zone between the East European Craton (EEC) in the NE and the Palaeozoic Platform in the SW. These profiles intersect the Teisseyre-Tornquist Zone (TTZ) and the Sorgenfrei-Tornquist Zone (STZ) to the south and north of the Bornholm Island, respectively. While the STZ is considered to be an intra-cratonic structure within the EEC, the TTZ is often believed to represent the actual edge of the Precambrian craton. Regardless of their origin and tectonic position, both zones are characterized by intense compressional deformations associated with the Alpine inversion of the Permian-Mesozoic basins at the transition from the Cretaceous to Paleogene.</p> <p>Our research aimed to explain the structure of the transition zone between the EEC and the Palaeozoic Platform and check whether its structure differs north and south of Bornholm. We also aimed at documenting the nature of the Late Cretaceous deformations and their relationship to the STZ and TTZ, as well as the marginal zone of the EEC.</p> <p>Both PQ profiles show a continuation of the EEC crust toward the WSW beyond the STZ and TTZ. The cratonic crust has a considerable thickness and is characterized by a deep Moho position along the entire length of the profiles. The depth of Moho is in our interpretation much greater than that postulated in previous interpretations. Consequently, numerous reflections once interpreted as upper mantle reflections occur within the lower crust in our opinion.</p> <p>The most spectacular feature of both PQ profiles is related to the zones of thick-skinned compressional deformation associated with the Alpine inversion along the STZ and TTZ. Crustal-scale, ENE-vergent thrusts have been traced from the top of the Cretaceous down to the Moho in terms of the detachment faults through the entire crust. They are accompanied by back thrusts with vergence toward the WSW, which also reach the Moho. The Late Cretaceous deformation resulted in the uplift of a block of cratonic crust as a pop-up structure, bounded by thrusts and back thrusts, and displacement of the Moho within the STZ and TTZ. It also led to the formation of the Late Cretaceous syn-inversion troughs on both sides of the uplifted wedge providing evidence for the age of deformation.</p> <p>The STZ and TTZ, imaged by the PQ profiles, appear as zones of the localised Late Cretaceous thick-skinned deformation that is superimposed on the EEC crust and its sedimentary cover. Within these zones, the Moho is faulted in several places and a large block of the basement is uplifted as a crustal-scale pop-up structure. A similar crustal architecture characterises the Dnieper-Dontes Paleorift, which was also inverted in the Late Cretaceous. A special position is occupied by the island of Bornholm, located in the middle of the pop-up structure, which owes its formation to the Late Cretaceous inversion of the sedimentary basin in this place.</p> <p>This study was funded by the Polish National Science Centre grant no UMO-2017/27/B/ST10/02316.</p>
    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... more
    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.
    DEFORMATION AND METAMORPHISM OF ROCK SERIES EAST OF THE SOWIE GORY BLOCK - NEW DATA AND INTERPRETATIONS Summary An important NNE-SSW - trending tectonic boundary, located between the Gory Sowie Gneiss Block to the west and the Strzelin... more
    DEFORMATION AND METAMORPHISM OF ROCK SERIES EAST OF THE SOWIE GORY BLOCK - NEW DATA AND INTERPRETATIONS Summary An important NNE-SSW - trending tectonic boundary, located between the Gory Sowie Gneiss Block to the west and the Strzelin Crystalline Unit to the east (Fig. 1), separates the structures of the West and East Sudetes in the area of the Fore-Sudetic Block. The West Sudetes have been traditionally included into the Saxothuringian and the East Sudetes into the Moravo-Silesian major facies-structural zones of the European Variscan belt. The boundary between the two zones continues further southwestward along the SE margin of the Bohemian Massif into the Moldanubian thrust [45] which separates Moldanubian and Moravian nappe piles. The ductile, NNE-directed, synmetamorphic displacements with a significant dextral, strike-slip component have been documented in this area throughout the entire length of the SE margin of the Bohemian Massif [26, 42, 21]. In contrast, the mylonites of the Niemcza Zone, located immediately to the west of the Western/ Eastern Sudetes boundary (Fig. 1), recorded effects of sinistral strike-slip displacements [28]. Metamorphic rocks cropping out to the east of the Gory Sowie Block are subdivided into three regional units. From west to east these are: the Niemcza Shear Zone, the Niemcza-Kamieniec Metamorphic Unit and the Doboszowice Metamorphic Unit (Fig. 1). The orientation of foliations and lineations in these units are shown in Figures 3, 4 and 7. On the basis of our field data, we established a tentative sequence of three tectonic events in the rock sequences of the study area (Fig. 8). The DJ event was related to E-directed tectonic transport under amphibolite facies conditions. The DJ fabric is preserved in paragneisses comprising the eastern part of the Doboszowice Metamorphic Unit (Fig. 6). The western part of this unit is composed of orthogneiss body (Fig. 6) representing a syntectonic granite intrusion emplaced during the D2 event. The D2 structures, well developed in this orthogneiss body and in coarse-grained mica schists exposed near to Kamieniec Ząbkowicki (Fig. 5) recorded a top-to-NE shearing under amphibolites fades conditions. The D3 event involved sinistral, strike-slip displacement in the Niemcza Shear Zone (Fig. 2) and a top-to-SW shearing in the Niemcza-Kamieniec Unit. The Niemcza Zone (Fig. 2), extending along the eastern edge of the Gory Sowie Block, consists of mylonites derived from the Gory Sowie gneisses during the D3. The mylonites occur as high- and low-temperature varieties produced under the amphibolite and greenschists facies conditions, respectively. The D2 event corresponds to synmetamorphic NNE-directed thrusting recognized along the entire SE margin of the Bohemian Massif. The displacements towards NNE were preceded by a separate stage of E-directed tectonic transport. The sinistral sense of shear in the Niemcza Zone is related to the subsequent D3. It seems to be comparable with late-orogenic, sinistral shearing localized in several NNE-SSW shear zones and ductile to brittle faults in the S and SE part of the Bohemian Massif [10].
    Abstract The Paleoproterozoic suture between Sarmatia and Fennoscandia (SFS), two major components of the East European Craton, extends SW-ward from Russia through Belarus to SE Poland. The exact character of this suture remains... more
    Abstract The Paleoproterozoic suture between Sarmatia and Fennoscandia (SFS), two major components of the East European Craton, extends SW-ward from Russia through Belarus to SE Poland. The exact character of this suture remains speculative, despite the results of the wide-angle reflection and refraction (WARR) soundings. Here, we show results of newly reprocessed deep reflection seismic data of the PolandSPAN™ survey, portraying the whole crust and uppermost mantle in SE Poland. Their interpretation is supported by the unsupervised clustering of seismic reflectivity patterns. From the integration of PolandSPAN™ data with both magnetic and WARR data, we conclude that the SFS cannot be interpreted as a localised lithospheric discontinuity coincident with the Minsk Fault. Instead, we observe a so-called diffuse cryptic suture zone, c. 150 km wide, where materials from two colliding plates are mixed over large distances to form a unified continental crust. The suture-related reflections are interpreted as a thrust-wedge rooted at the lower-middle crust interface underneath the Ivanowo-Borisov zone. We support Bogdanova et al. (2015) view that the Okolowo-Holeszow Belt and Belarus-Podlasie Granulite Belt have affinities to the NW margin of Sarmatia. We interpret both units as belonging to the diffuse SFS.
    The Southern Alps are the retro-vergent belt of the European Alps that developed from Late Cretaceous subduction to Neogene times. The most prominent Alpine thrusts and folds, nowadays sealed off by the Adamello intrusion, were already... more
    The Southern Alps are the retro-vergent belt of the European Alps that developed from Late Cretaceous subduction to Neogene times. The most prominent Alpine thrusts and folds, nowadays sealed off by the Adamello intrusion, were already developed before the continental collision and clasts derived from the eroded pre-collisional wedge can be found in the Cretaceous foredeep sequences. In contrast, the thermal state attained by the Southern Alps during the long-lasting Alpine evolution is still unknown. This contribution provides evidence for Alpine metamorphism in the northern part of the central Southern Alps. Metamorphic conditions are determined for the alkaline Edolo diabase dykes that emplaced in the exhumed Variscan basement rocks before being deformed during the Alpine convergence (D3). The Alpine foliation in the Edolo diabase dykes is marked by actinolite, biotite, chlorite, epidote, albite, and titanite and it developed under greenschist facies conditions at temperature of ...
    <p>Defining a transition zone between the Precambrian East European Craton (EEC) and the Palaeozoic West European Platform (WEP) is still a matter of discussion despite a large body of geophysical and geological... more
    <p>Defining a transition zone between the Precambrian East European Craton (EEC) and the Palaeozoic West European Platform (WEP) is still a matter of discussion despite a large body of geophysical and geological data. The main tectonic feature of the transition zone is the Teisseyre-Tornquist Zone (TTZ), which has been variously interpreted over the past decades mainly because of a thick (c. 10 km) Palaeozoic and Mesozoic sedimentary cover masking its crustal architecture.  We investigated the crustal structure of the TTZ using a 270-km long wide-angle reflection/refraction profile (WARR) measured along 15 ocean-bottom seismometers and 2 land stations during the course of the RV MARIA S. MERIAN expedition ‘MSM52’. This NE to SW profile is oriented nearly parallel to the Polish coast, located ~ 48 km south of the Danish island of Bornholm. We prepared a two-dimensional gravity and magnetic forward model along this profile, using the Geosoft GM-SYS software with layers of infinite length. The basis for the potential field modelling is a seismic velocity model that has been prepared through trial-and-error forward modelling.</p><p>The seismic velocity model shows a continuity of the lower and middle crust of the EEC towards the basement of the WEP. The synthetic magnetic profile is smooth and indicates that the seismic data accurately revealed the geometry and depth of the magnetic (crystalline) basement. However, the model was unable to replicate short-wavelength, high-amplitude magnetic anomalies in the ENE section of the profile, probably representing iron oxide mineralisation in the crystalline basement of the EEC. The gravity model shows 3 areas of misfit between the synthetic and observed gravity profile. The most prominent misfit coincides with the NE boundary of the TTZ. To remedy the misfit, we produced two alternative gravity models that deviate from the seismic velocity model in the problematic area. One model postulates a crustal keel underneath the NE section of the TTZ and the other suggests the presence of a middle crust magmatic intrusion. Both models equally and adequately reduce the misfit of the gravity model.</p><p>Our models suggest a SW-ward continuation of the Baltica middle and lower crust through the TTZ and seem to preclude the coincidence of the Caledonian Thor suture with the TTZ. An important perturbation of the upper crust and sedimentary cover within the latter is mostly associated with the superimposed effects of Devonian-Carboniferous and Permian-Mesozoic extension. The only conspicuous compressional event confirmed by our data is the Late Cretaceous-Paleogene inversion of the Permian-Mesozoic basin. Due to limited resolution, our models did not reveal the effects of Caledonian nor Variscan shortening, including the Caledonian Deformation Front.<br><br><span>This study was funded by the Polish National Science Centre grant no UMO-2017/27/B/ST10/02316.</span></p>
    <p>Cambrian age volcanic arc-related rocks crop-out in high-grade metamorphic complexes marking the principal Devonian age suture zone in the Bohemian Massif. The age and tectonic setting of these rocks are... more
    <p>Cambrian age volcanic arc-related rocks crop-out in high-grade metamorphic complexes marking the principal Devonian age suture zone in the Bohemian Massif. The age and tectonic setting of these rocks are established from whole-rock geochemical and isotopic data from basic-intermediate rocks transformed to eclogite and granulite, and U-Pb and Lu-Hf isotopic data of detrital zircon in associated meta-sediments. Recent works have established that these rocks can be correlated on the basis of their age and tectonic setting as well as their Variscan metamorphic evolution with allochthonous complexes in NW Iberia, and potentially, the whole European Variscan Belt (Martínez Catalán et al., 2020). Detrital zircon spectra from the high-grade metasediments associated with the Cambrian volcanic arc are superficially similar to the classically interpreted ‘West African signature’ with Neoarchean, Paleoproterozoic and late Neoproterozoic maxima. Nonetheless, limited Cryogenian input and shifting of the late Neoproterozoic maxima into the early Cambrian is in contrast to Variscan autochthonous complexes. Moreover, Lu-Hf isotopic data show important contrasts in the source of the Paleoproterozoic detritus. The Variscan autochthon is charecterised by Paleoproterozoic detritus with negative ɛHf<sub>i</sub> values indicating reworking of an Archean crust. However, the Paleoproterozoic detritus in the Cambrian arc terrane exhibits mostly positive ɛHf<sub>i</sub> values indicating a juvenile Paleoproterozoic source.</p><p>In fact, the data from the Cambrian arc terrane show remarkable similarity to detrital zircon data from early Cambrian sediments on the southern margin of the East European Craton (Paszkowski et al., 2021). These sediments incorporate significant juvenile late Neoproterozoic-early Cambrian detritus from an as yet unidentified volcanic arc and their whole-rock geochemical composition is consistent with immature sediments sourced from intermediate igneous rocks. If true, this correlation suggests that the Cambrian arc terrane is a peri-East European Craton assemblage and necessitates a re-evaluation of the role of the East European Craton within the Variscan Orogeny.</p><p>Catalán, J. R. M., Collett, S., Schulmann, K., Aleksandrowski, P., and Mazur, S., 2020. Correlation of allochthonous terranes and major tectonostratigraphic domains between NW Iberia and the Bohemian Massif, European Variscan belt. International Journal of Earth Sciences, 109, 1105-1131.</p><p>Paszkowski, M., Budzyń, B., Mazur, S., Sláma, J., Środoń, J., Millar, I.L., Shumlyanskyy, L., Kędzior, A. and Liivamägi, S., 2021. Detrital zircon U-Pb and Hf constraints on provenance and timing of deposition of the Mesoproterozoic to Cambrian sedimentary cover of the East European Craton, part II: Ukraine. Precambrian Research, 362, 106282.</p>
    A tephra-rich cherty-clayey Famennian succession within the major Brzeźnica olistostrome in the Bardo Mountains, Central Sudetes, SW Poland, preserves a record of the lost ocean later incorporated into the Variscan orogenic belt.... more
    A tephra-rich cherty-clayey Famennian succession within the major Brzeźnica olistostrome in the Bardo Mountains, Central Sudetes, SW Poland, preserves a record of the lost ocean later incorporated into the Variscan orogenic belt. Fluctuating but mostly oligotrophic regimes and low primary production levels were influenced by weak up-welling below the perennial oxygen minimum zone, which controlled the interplay between biosiliceous and siliciclastic deposition in the oceanic basin, with episodic oxygen deficiency. The Hangenberg Black Shale has been identified in this oceanic setting based on its characteristics described worldwide (including mercury enrichments). A tectonic uplift of the sediment source area near the Devonian-Carboniferous boundary, recorded in the distinguishing provenance signal of old continental crust, was paired with a global transgression, anoxia, and volcanic episode in an interglacial interval. Assuming paleogeographic affinity with the Bavarian facies of t...
    On the new tectonic solutions in Geological Atlas of Poland. A b s t r a c t. Authorial comprehensive comments and explanations are given to some of the interpretations applied in the tectonic part of the newly published Geological Atlas... more
    On the new tectonic solutions in Geological Atlas of Poland. A b s t r a c t. Authorial comprehensive comments and explanations are given to some of the interpretations applied in the tectonic part of the newly published Geological Atlas of Poland (Nawrocki, Becker, 2017) that considerably change the hitherto generally accepted concepts. It should be, however, admitted that most of those “new solutions were already proposed in the past by other workers as hypotheses that could not have been tested in the then state of knowledge on Poland’s deep geology and scientific tools at hand. This has now changed with abundant new data obtained with modern seismic techniques and advanced methods of potential field modelling. Using those data, we justify the reasons for, among others, a significant eastward shifting the front of the Variscan Orogen in Poland and for the accompanying change in position of the division line between the Precambrian and Palaeozoic platforms. We also show the ration...
    Od blisko roku Polska jest czlonkiem Miedzynarodowego Programu Naukowych Wiercen Kontynentalnych (ICDP). W niniejszym artykule dokonujemy przeglądu biezących problemow naukowych, ktore moglyby byc rozwiązane za pomocą wiercen badawczych.... more
    Od blisko roku Polska jest czlonkiem Miedzynarodowego Programu Naukowych Wiercen Kontynentalnych (ICDP). W niniejszym artykule dokonujemy przeglądu biezących problemow naukowych, ktore moglyby byc rozwiązane za pomocą wiercen badawczych. Rozumiejąc wazkośc wielu innych, nie wymienionych tutaj zagadnien, koncentrujemy sie raczej na tych, ktore moglyby wywolac szersze zainteresowanie w skali miedzynarodowej. Specjalny nacisk kladziemy zatem na potencjalnie wazkie naukowo wiercenia w Karpatach Zachodnich w bezpośrednim sąsiedztwie pieninskiego pasa skalowego, by nastepnie przedyskutowac znaczenie wiercenia badawczego poprzez strefe szwu skorupowego, spajającą masywy śląski i malopolski na odcinku pomiedzy Krakowem a Lublincem. Proponujemy takze wiercenie badawcze w strefie Koszalin–Chojnice, ktorego celem bylby pas faldowy tzw. kaledonidow pomorskich. Dokonujemy takze skrotowego przeglądu innych problemow, ktore mogą byc celem wiercen badawczych, takze w aspekcie poszukiwawczym. Nalezą...
    The Intra-Sudetic Basin, a ~ 12 km deep Variscan intramontane basin, has the best preserved post-orogenic sedimentary record available at the NE margin of the Bohemian Massif. Apatite fission track (AFT) analyses have been performed on 16... more
    The Intra-Sudetic Basin, a ~ 12 km deep Variscan intramontane basin, has the best preserved post-orogenic sedimentary record available at the NE margin of the Bohemian Massif. Apatite fission track (AFT) analyses have been performed on 16 sedimentary and volcanic samples of Carboniferous to Cretaceous age from the Intra-Sudetic Basin to improve understanding of the post-Variscan thermal evolution. AFT central ages range from 50.1 ± 8.8 to 89.1 ± 7.1 Ma (Early Eocene to Coniacian), with 13 of them being Late Cretaceous. The mean track length values range from 12.5 ± 0.4 to 13.8 ± 0.5 (except for one sample 14.4 ± 0.2) µm. This relatively short mean track length together with the unimodal track length distributions and rather low standard deviation (0.8 to 1.7 µm) in most samples indicate a long stay in the partial annealing zone during slow cooling. However, in the northern part of the Intra-Sudetic Basin, samples show a wider track length distribution (standard deviation of 1.8 to 2...
    The low‐temperature thermal history of the Holy Cross Mountains (HCM) is investigated by apatite fission track and apatite and zircon (U–Th)/He thermochronology. Our results provide constraints on the deformation history of Palaeozoic... more
    The low‐temperature thermal history of the Holy Cross Mountains (HCM) is investigated by apatite fission track and apatite and zircon (U–Th)/He thermochronology. Our results provide constraints on the deformation history of Palaeozoic basement rocks in the transition area from Precambrian to Palaeozoic Europe that are exposed from beneath Permian–Mesozoic sediments within the HCM. Late to post‐Variscan cooling of the Palaeozoic strata from maximum temperatures is shown to be a major feature of the HCM. This cooling likely followed a heating event related to burial and/or hot fluid circulation along the Holy Cross Fault in the late Carboniferous. The central part of the HCM shows a rapid cooling event caused by tectonic inversion, which started in the Late Cretaceous. However, this event was less pronounced in the western margin of the HCM, where slow cooling continued throughout the Mesozoic with only minor acceleration of the cooling rate since the latest Cretaceous.
    The Caledonian foreland basin of Poland onlaps the SW slope of the East European Craton and is elongated in a NW–SW direction along the margin of the Baltica palaeocontinent. The base of the synorogenic clastic wedge rises in age from... more
    The Caledonian foreland basin of Poland onlaps the SW slope of the East European Craton and is elongated in a NW–SW direction along the margin of the Baltica palaeocontinent. The base of the synorogenic clastic wedge rises in age from Llandovery to Ludlow between NW and SE Poland, respectively. As the initial influx of orogen‐derived detritus can be unequivocally identified, this diachronism documents a southeastward migration of the basin depocentre, parallel to the present‐day Caledonian Deformation Front. Our best‐fit plate model shows an oblique collision of Baltica and Avalonia, the latter initially indenting the Baltica margin in the NW. Afterwards, Baltica was progressively underthrust beneath Avalonia towards the SE in response to the oblique soft‐mode closure of the Tornquist Ocean. The final deformation event within the Caledonian foreland took place in the earliest Devonian as a far‐field effect of sinistral orogen‐parallel displacements along the Iapetus suture.

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