Malopolska Block Research Articles

Zastosowanie skanera rdzeni wiertniczych do wstępnych badań petrograficznych na przykładzie skał magmowych z profili trzech wierceń w bloku małopolskim

Use of a core scanner for preliminary petrographic studies exemplified by magmatic rocks from three borehole sections in the Malopolska Block. A b s t r a c t. Scanning of fragments of drill cores from the Myszkow–Mrzyg³od area was performed using the DM CoreScan V3 tool. Rocks for further investigations have been selected on the basis of both the scanned images obtained and the archive data. Granitoids were analyzed, the main components of which are quartz, feldspars and mica, well distinguished in the scans. Further detailed mineralogical-petrological analyses were performed in thin and/or double-sided polished sections. That was an introduction to the geochronological research on biotite and/or zircon.

Microphytoplankton from middle palaeolatitudes of the Southern Hemisphere – a record from climate change strata of Baltica’s O/S boundary

In the present study, data on the diversity of acritarch and prasinophyte microphytoplankton were collected from Ordovician–Silurian transitional strata at three different geological localities in Poland: southern part of the Holy Cross Mountains (Malopolska Block, southern Poland), East European Platform (Baltica), and Koszalin–Chojnice Zone (NW Poland). The material represents the mucronata (trilobite) to vesiculosus (graptolite) biozones. The Ordovician microphytoplankton assemblages are characterized by low frequency and low diversity: up to 110 specimens and 12 genera per slide, in contrast to Silurian ones that are more frequent and more diverse – >3000 specimens and 16 genera per slide (diversity at the species level is also higher). Throughout the Ordovician part of the succession, typical Ordovician genera occur, such as Acanthodiacrodium , Ordovicidium , Orthosphaeridium and large Baltisphaeridium , together with isolated occurrences of typical Silurian genera, especially in the upper part of the Hirnantian (e.g., Diexallophasis ). The Silurian assemblages are typified by high frequency of prasinophytes followed by typical Silurian acritarchs: Tylotopalla , Ammonidium , Domasia and Oppilatala . The palynological material from Poland is compared with material known from other localities: the Rapla and Valga boreholes (Estonia) and Anticosti Island (Canada), as well as others placed in different palaeocontinents and different bathymetric zones. Palynological assemblages obtained from Polish material confirm that bathymetry played the key role in taxonomic diversification of the microphytoplankton assemblage. This supports the existing models of distribution: dominance of prasinophytes (leiospheres) and cryptospores is characteristic for shallow-water environments. In deeper water, dominance of acanthomorphs is observed. In the deepest-water zones – mixed assemblages occur. For the Holy Cross Mountains, microphytoplankton frequency is compared with a TOC curve in the same interval.

Geological setting and Ediacaran–Palaeozoic evolution of the western slope of the East European Craton and adjacent regions

A set of geological maps and geological cross-sections was prepared to document the geological setting of sedimentary basins developed on the western slope of the EEC and adjacent areas to the west. On the basis of these data and literature on the subject, the evolution of the sedimentary basins in the study area was reviewed, with special emphasis on the Ediacaran–Lower Palaeozoic basin. The basin originated during late Ediacaran rifting, related to the latest stages of breakup of the Precambrian super-continent Rodinia/Pannotia, associated with large-scale igneous activity. The rifting ultimately led to the formation of the Tornquist Ocean and subsequently, during the latest Ediacaran to Middle Ordovician, the SW margin of the newly formed Baltica became a passive continental margin. The upper Cambrian depocentre in the Bilgoraj-Narol Zone and the Łysogory Block tentatively is interpreted as a small, narrow foredeep, related to the docking of the Malopolska Block to the western margin of Baltica. From the Late Ordovician through the Silurian, a gradual change to a collisional tectonic setting is observed across the entire SW margin of Baltica, as well as in the zones adjacent to it from the west, which together became the site of development of the extensive Caledonian foredeep basin, related to the convergence and collision of Avalonia and Baltica. The oblique character of the collision resulted in a prominent diachronism in the development of the foredeep basin. This refers to the initiation of basin subsidence, the starved basin phase, the main phase of rapid subsidence and supply of detritus from the west, and the termination of basin development. The Early Mississippian (Bretonian) phase of uplift and erosion and, to a lesser degree, also the Late Pennsylvanian one significantly affected the structure of the western EEC. During the Mississippian, extensive magmatic activity took place at the SW margin of East European Craton, in the region referred to here as the Baltic-Lublin Igneous Province.

Reconstruction of an early Pennsylvanian fluvial system based on geometry of sandstone bodies and coal seams: the Zabrze Beds of the Upper Silesia Coal Basin, Poland

The Zabrze Beds (Kinderscoutian), together with the underlying Jejkowice Beds (late Chokerian– Alportian) of local extent, are the oldest deposits of the fully terrestrial phase of sedimentation in the Upper Silesia Coal Basin. The maximum thickness zone of Zabrze Beds is trending SSW–NNE and reflects the migrating narrow zone of basin-floor main subsidence. The westward erosional termination of Zabrze Beds is due to the tectonic thrusting of the Devonian to Mississippian rocks of the Variscan Moravo-Silesian orogen, whereas their eastward thinning and pinch-out towards the craton of Malopolska Block is due to the related forebulge growth. The present-day tectonic structure of the basin, with the east-trending Main Anticline near Zabrze, is due to the Cenozoic northward thrusting of the Carpathian orogenic front. The deposition of Zabrze Beds occurred in a north-trending alluvial valley formed and filled in by a bedload-dominated, sandy river system. In the southern part of the basin, the alluvial deposits are characterized by numerous thick, multistorey, sheet-like channel-belt sandstone bodies with sparse overbank and phytogenic deposits, indicating a braided river system. This alluvial architecture passes northwards – in the basin’s area of Main Anticline – into an architecture composed of smaller, isolated sandstone bodies of single-storey channel belts with a much higher relative proportion of overbank and phytogenic deposits, indicating a meandering river system. The down-valley transformation of the fluvial system from braided into meandering is attributed to such factors as a spatially differential sediment supply to the system and a non-uniform axial valley gradient.

PILOTAŻOWE BADANIA PIERWIASTKÓW ZIEM RZADKICH W STREFIE KONTAKTU BLOKU MAŁOPOLSKIEGO Z BLOKIEM GÓRNOŚLĄSKIM

PILOT STUDIES OF RARE EARTHS IN THE CONTACT ZONE OF THE MAŁOPOLSKA BLOCK WITH THE UPPER SILESIA BLOCK Abstract. The paper presents the results of a pilot prospecting study on archived drill cores from boreholes in the contact zone of the Malopolska Block with the Upper Silesia Block, with a use of a Portable XRF spectrometer Delta 50 Premium (Olympus). A few hundred measurements of concentrations of La, Ce and other trace elements were made in selected boreholes from the prospective zones for the occurrence of Mo Cu–W ore mineralization. The maximum content for La (400 ppm) and Ce (600 ppm) measured by the Portable spectrometer has been found in the Ko-4 borehole (depth interval 450–550 m). In the depth interval of ca. 400–1300 in the other boreholes (Pz-36, RK-2 and Cianowice-2), the maximum La and Ce contents were approximately twice lower than in the Ko-4. The study also shows an interdependence of the occurrence of LREE with Sr, Y or Th. The most interesting samples were additionally analyzed by ICP-MS and electron microprobe (CAMECA SX-100). The sum of REE (ICP-MS) in four samples that reveal the highest contents of these elements varied from ca. 0.02 to 0.1%. Total REE contents for samples normalized to the upper continental crust are low (1–10). The highest REE concentrations in samples of hydrothermal breccia were found in the Ko-4 borehole (depth ca. 500 m). They reach for the Ce (305.1 ppm), Nd (266.9 ppm), La (258 ppm) and Sm (31.3 ppm). Other REE occur at low concentrations. This is clearly visible on the standard logarithmic charts of REE concentration in relation to their content in chondrite and in the upper part of the continental crust. Characteristic is the lack of negative Eu anomaly on both charts. In the microprobe study, calcioancylite-(Ce), synchysite-(Ce) as well as bastnasite and zircon were also detected in addition to the unidentified minerals from the anhydrous phosphate group enriched with REE (mainly Ce, La, and Nd) and monazite. The form and composition of the REE mineralization indicate clearly that it is of hydrothermal nature. During hydrothermal processes, REE underwent redeposition and concentrated within breccia and tectonic zones in the metasomatic changed rocks. The data on REE concentrations, presented in this paper, are only of indicative significance. The REE contents are much lower than the most interesting results obtained within the framework of research projects carried out in other geological units in Poland and published in separate papers.

Late Jurassic facies architecture of the Złoczew Graben: implications for evolution of the tectonic-controlled northern peri-Tethyan shelf (Upper Oxfordian–Lower Kimmeridgian, Poland)

In recent years, numerous wells have been completed in the area of the Zloczew Graben. Drill cores and data collected from wells have led to the recognition of an Upper Oxfordian–Lowermost Kimmeridgian sequence and to the construction of a 3D model of the graben with distribution of facies. Six facies types were distinguished, composed of numerous microfacies representing outer-, middle-, and inner-ramp depositional systems. The boundary of the Planula/Platynota zones is indicated by the transition from mid-inner carbonate ramp facies to mixed, carbonate–siliciclastic outer-ramp facies, as well as by appearance of debrites and calciturbidites. The distribution of gravity-flow deposits reflects the pattern of fault zones of the Zloczew Graben and their Late Jurassic activity. Comparison of Oxfordian–Lowermost Kimmeridgian facies types from central and southern Poland enabled the reconstruction of the general facies architecture in the Polish part of the northern peri-Tethyan shelf belonging to the Malopolska Block. The distribution of Upper Oxfordian–Lowermost Kimmeridgian facies follows the block structure of the basement and was controlled by reactivation of Paleozoic tectonic blocks in the Late Jurassic. The results of studies in the Polish basin correspond well to Upper Oxfordian–Lower Kimmeridgian sequences known from the ramp systems of western Europe where the basic change in deposition, from a carbonate ramp towards mixed, carbonate–siliciclastic sedimentation, was related to both North Atlantic and western European tectonics.

STREFA TEKTONICZNA KRAKÓW–LUBLINIEC NA ODCINKU KRAKOWSKIM W ŚWIETLE DANYCH UZYSKANYCH Z NOWYCH OTWORÓW BADAWCZYCH TROJANOWICE 2 I CIANOWICE 2

THE KRAKOW SECTOR OF THE KRAKOW LUBLINIEC TECTONIC ZONE IN THE LIGHT OF DATA OBTAINED FROM NEW BOREHOLES OF TROJANOWICE 2 AND CIANOWICE 2 Abstract. The paper presents the results of two fully cored exploratory boreholes of Trojanowice 2 and Cianowice 2 that targeted a depth of 600 m. They were drilled north of Krakow in 2007, in the villages of Grebynice and Zielonki. The main objective of the boreholes was to test the concepts on the nature of the contact zone between the Upper Silesian Block and the Malopolska Block in the northern outskirts of Krakow, and to map the trend of the Krakow–Lubliniec fault zone in this area. The zone is a boundary between the above-mentioned regional tectonic units. The Trojanowice 2 borehole reached the Lower Devonian deposits and the underlying Lower Cambrian rocks (Borzeta Formation (Fm.)) whose range is limited to the south-eastern part of the Upper Silesian Block. The Cianowice 2 borehole drilled (under the Jurassic) Ediacaran flysch-like siliciclastics, lithologically and tectonically similar to the coeval rocks identified in the western and southern part of the Malopolska Block. Therefore, it has been assumed that the Krakow–Lubliniec fault zone, separating the Upper Silesian Block from the Malopolska Block, is located between these boreholes. Based on data from the Trojanowice 2 borehole and other wells drilled in this area, it has been proved that the Krzeszowice Graben, accentuated in the structure of the Cenozoic (Miocene) and Mesozoic succession in the Krakow region, is of Variscan age and the bounding faults were reactivated during the Alpine movements. The Cianowice 2 borehole has enabled the examination and stratigraphic documentation of the Ediacaran rocks and allowed assigning the same age to the lithologically similar deposits in the adjacent Jerzmanowice, Beb³o and DB-4 boreholes. Previously, these deposits were included in the Silurian Mrzyglod Formation (Fm.). The paper also discusses the results of other studies that have been carried out during documenting of the boreholes.

MIKROSKAMIENIAŁOŚCI ORGANICZNE TERENEWU (KAMBR DOLNY) I PÓŹNEGO EDIAKARU (NEOPROTEROZOIK) OKOLIC KRAKOWA

THE TERRENEUVIAN AND LATE EDIACARAN ORGANIC MICROFOSSILS FROM KRAKOW AREA Abstract. This paper presents the characteristics of the oldest groups of organic microfossils that are documented in two new wells (Trojanowice 2 and Cianowice 2) located on the opposite sides of the fault zone Krakow–Lubliniec separating Upper Silesian and Malopolska blocks). The detail palynological research allowed to determine the age of clastic sediments drilled under Jurassic and Devonian. Two characteristic microfossils assemblages are documented: Late Ediacaran dating the age of the Malopolska Block basement and Terreneuvian known from the oldest Cambrian sediments of the Upper Silesian Block. The documented associations of organic microfossils include the oldest representatives of the bacteria, algae, fungi and animals.

The Precambrian and lower Paleozoic of the Brunovistulicum (eastern part of the Upper Silesian Block, southern Poland) – the state of the art

The Precambrian basement and Lower Paleozoic (Cambrian–Ordovician) sedimentary cover in the eastern part of the Upper Silesian Block (Brunovistulicum), known only in boreholes, is presented, and their palaeogeographic, facies and palaeotectonic development is discussed. The former is characterized by a heterogeneous structure that consists of Archean-Lower Proterozoic and Neoproterozoic rocks of different lithologies and origins, and the latter is almost exclusively represented by marine, transitional and terrestrial siliciclastic rocks. In contrast to the neighbouring region of the western part of the Malopolska Block, the siliciclastic sedimentation took place during the Early and Middle Cambrian in this area, however, the Ordovician deposits were encountered in several boreholes and no Silurian rocks have been reported in the northern part of this region. The authors present the most probable model of sedimentation, tectonics and origin of the geological structure of the Lower Paleozoic sedimentary cover in the Upper Silesian Block, define research problems, and justify the need for new drillings. Based on the geological and structural analysis of the depth to the top surface of the Lower Paleozoic, they define the optimal location for three 1500 m deep boreholes to solve the basic research problems.

New finds of Rusophycus from the lower Cambrian Ociesęki Sandstone Formation (Holy Cross Mountains, Poland)

The Ocieseki Sandstone Formation represents the Holmia-Schmidtiellus and the Protolenus-Issafeniella zones. Seven ichnospecies of Rusophycus , including Rusophycus exsilius isp. nov, are recognized in this formation. Moreover, Rusophycus ispp. A, B, C are recognized. The diagnoses for R. dispar , R. crebrus and R. magnus have been emended and the stratigraphic range of R. versans has been extended. The presence of Rusophycus dispar may suggest a palaeozoogeographical connection between the Malopolska Block, the Baltica palaeocontinent and the Laurentia palaeocontinent.

Condensation and phosphatization of the Middle and Upper Ordovician limestones on the Malopolska Block (Poland): Response to paleoceanographic conditions

The growth fault activity in the late Middle Ordovician resulted in the establishment of a horst-like submarine paleohigh in the northern Malopolska Block. This topographic submarine swell was the site of carbonate deposition characterized by a low overall net sediment accumulation rate. The sedimentary and ecological conditions on this paleohigh were controlled by a paleocurrent that flowed along the northern margin of the Malopolska Block, however seasonal intense storms associated with the mid-latitude location of this “terrane” cannot be excluded. The paleocurrent induced (seasonal?) upwelling of nutrient-rich waters from deeper parts of the current system that shifted onto the paleohigh and caused phosphatization of the sediment. The winnowing and reworking of sediment, together with slow carbonate production by a temperate-water biota and relatively long periods of omission, resulted in low accumulation rates and sediment condensation. The cessation of the paleocurrent and associated phosphatization coincides with changes in the oceanic circulation system due to the Late Ordovician collision of Avalonia with Baltica and gradual closure of the Tornquist Sea.

The Baltica-Gondwana suture in central Europe: evidence from K-Ar ages of detrital muscovites and biogeographical data

Abstract The Lysogory Unit, the Malopolska Massif and the Upper Silesian Massif in southern Poland are parts of a mosaic of contrasting crustal fragments separating the old Precambrian crust of the East European Platform (EEP) from the Phanerozoic mobile belts of western Europe. The geological histories of these blocks are markedly different. They have been regarded as integral parts of the palaeocontinent of Baltica (that is, the EEP), mostly because of presence of fossils typical for the Baltic realm, although geophysical and geological data and some faunal elements rather suggest linkages to the Peri-Gondwana plates. To provide additional constraints for the plate tectonic affinity of these blocks detrital muscovite grains extracted from Cambrian and Devonian clastic rocks were dated by the K-Ar method. The K-Ar cooling ages show a very complex provenance pattern for clastic material in Cambrian time. Combined with the biogeographical constraints, the new provenance data apparently show that the blocks of Lysogory, Malopolska, and Upper Silesia are in fact crustal fragments derived from the Gondwana margin, not displaced parts of the East European Craton. Thus, the Teisseyre-Tornquist Line (that is, the edge of the EEP) is the Baltica-Gondwana suture in central Europe. The combined data reveal an accretionary scenario in which the Malopolska Block was the first Gondwana-derived microplate that accreted to the margin of Baltica.

Debates about the pre-Variscan tectonics of Poland

The tectonic nature of the deformed Early Palaeozoic belt along the southwestern border of the East European Craton (EEC) has long been debated. The essence of these debates is reviewed and the recently published map of the Variscan tectonics in Poland is discussed from methodological and regional points of view. The terrane origin of the Pomeranian and Łysogory regions is questioned; they are inferred to be parts of the passive margin of the EEC (miogeocline), deformed into a marginal fold-and-thrust belt. The Malopolska Block and especially the Upper Silesian Block could be Caledonian (proximal?) terranes.