Constraining long-term denudation and faulting history in intraplate regions by multisystem thermochronology: An example of the Sudetic Marginal Fault (Bohemian Massif, central Europe)

The Rychlebské hory Mountain region in the Sudetes (NE Bohemian Massif) provides a natural laboratory for studies of postorogenic landscape evolution. This work reveals both the exhumation history of the region and the paleoactivity along the Sudetic Marginal Fault (SMF) using zircon (U-Th)/He (ZHe), apatite fission track (AFT), and apatite (U-Th)/He (AHe) dating of crystalline basement and postorogenic sedimentary samples. Most significantly, and in direct contradiction of traditional paleogeographic reconstructions, this work has found evidence of a large Cretaceous sea and regional burial (to >6.5 km) of the Carboniferous-Permian basement in the Late Cretaceous (~95–80 Ma). During the burial by sediments of the Bohemian Cretaceous Basin System, the SMF acted as a normal fault as documented by offset ZHe ages across the fault. At 85–70 Ma, the basin was inverted, Cretaceous strata eroded, and basement blocks were exhumed to the near surface at a rate of ~300 m/Ma as evidenced by Late Cretaceous–Paleocene AFT ages and thermal modeling results. There is no appreciable difference in AFT and AHe ages across the fault, suggesting that the SMF acted as a reverse fault during exhumation. In the late Eocene–Oligocene, the basement was locally heated to <70°C by magmatic activity related to opening of the Eger rift system. Neogene or younger thermal activity was not recorded in the thermochronological data, confirming that late Cenozoic uplift and erosion of the basement blocks was limited to less than ∼1.5 km in the study area

Hydrocarbon and aqueous inclusions in minerals: a review of analyses and interpretations for Paleozoic rocks in Poland

Two decades of microthermometric studies of fluid inclusions within cements of Paleozoic sedimentary rocks in Poland are reviewed. The inclusions contain palaeofluids of variable composition: aqueous, brine, and hydrocarbon. They may be primary and/or secondary in origin and have one, two or more phases. They display visual fluorescence in blue, sometimes yellow to red (oil) or dull blue (one phase, methane) colours, or do not fluoresce at all. Based on the fluorescence characteristics in ultraviolet light, the inclusions' hydrocarbons infill character may be estimated. The homogenization temperatures, which correspond to the minimum estimate of the trapping temperatures in the minerals, show variability in respect to the geological history of the area studied. They point to different geological stages in relation to the basin's burial evolution. Microthermometric analyses enable wider interpretation due to the combination of studies of both hydrocarbon and aqueous inclusions. The presence of oil and/or gas in inclusions is proof of the occurrence and/or migration of oil and gas in the rocks of a region

Fluid inclusion analysis of minerals in sedimentary rocks in Poland – an overview and remarks

Przedstawiono charakterystykę i wyniki mikrotermometrycznych badań inkluzji fluidalnych występujących w spoiwie skał osadowych wieku od kambru po perm oraz od jury po paleogen i miocen. Inkluzje mają charakter pierwotny i wtórny; na ogół są jedno- lub dwu-, rzadziej trójfazowe. Wypełniają je paleofluidy o zróżnicowanym składzie i różnej gęstości. Temperatura homogenizacji, która stanowi przybliżenie temperatury zamknięcia fluidu w minerale, wykazuje zmienność związaną z rodzajem spoiwa i z historią geologiczną badanego obszaru. Zasolenie fluidów również jest zmienne i zależy od rodzaju spoiwa i od lokalizacji. Połączenie analiz inkluzji np. z badaniami izotopowymi pozwala na szerszą interpretację wyników oznaczeń mikrotermometrycznych.Characteristics and results of microthermometric studies of fluid inclusions which occur in the cements of sedimentary rocks of the age oscillating form Cambrian to Permian and from Jurassic to Paleogene and Miocene are presented. The inclusions studied are primary and secondary in origin. They display one, two or, less frequently, three phases. The inclusions are filled by the paleofluids of variable compositions and densities. The homogenization temperature, which corresponds to the minimum estimation of the trapping temperature, shows variability in respect to the cement type and geological history of the study area. Salinities of fluids are also variable in respect to the cement type and locality. Wider interpretation of the microthermometric analyses is enabled when they are combined, e.g., with the isotopic studies

Geochronological studies on the crystalline bedrock from NE Poland : an overview and summary

Since the mid-1950s, when Jerzy Znosko started his huge contribution to the recognition of the crystalline basement of NE Poland, many different studies have followed the planned and implemented drilling projects. The drillings, conducted in the first decade under the leadership of Professor Znosko and under his description of the results, were further worked out by other researchers. Studies concerned petrological, geochemical and miner- alogical aspects. In that fan of methods applied, geochronological data started to be introduced to the bibliography of the area in the early 1960s. Geochronological methods that time mean mostly K-Ar and some Rb-Sr values. These materials are gathered in the paper aiming at its presentation, re-valuation and interpretation in terms of the significance of such data for further development of knowledge

Hydrocarbon inclusions in cements of sedimentary rocks and in vein minerals – characteristics and significance

Na podstawie badań przeprowadzonych w obrębie trzech obszarów w Polsce przedstawiono charakterystykę i efekty analiz mikrotermometrycznych inkluzji, występujących w spoiwach i minerałach skał osadowych różnego wieku (od kambru przez perm po paleogen) oraz wypełnionych węglowodorami (HCFI). Inkluzje mają charakter pierwotny i wtórny. Są na ogół jedno- lub dwufazowe. Charakteryzuje je fluorescencja w barwach biało-niebieskich (ropa naftowa) lub niebieskawej (metan), niekiedy żółtej lub czerwonej. Na podstawie barwy świecenia wstępnie oszacowano charakter węglowodorów, które wypełniają te inkluzje i krążą w skałach z tego regionu. Temperatura homogenizacji, która stanowi przybliżenie temperatury zamknięcia fluidu w minerale, wykazuje zmienność związaną z historią geologiczną badanych obszarów. Inkluzje węglowodorów współwystępują w badanych rejonach z inkluzjami solankowymi. Połączenie wyników analiz mikrotermometrycznych inkluzji węglowodorowych z rezultatami badań inkluzji wodnych pozwoliło na szerszą interpretację wyników wszystkich oznaczeń w poszczególnych rejonach. Obecność węglowodorów w inkluzjach świadczy o ich występowaniu i/lub migracji w skałach badanych regionów.Characteristics and results of microthermometric studies of fluid inclusions which occur in the cements of sedimentary rocks of various ages (from Cambrian through Permian to Paleogene) and filled with hydrocarbons (HCFI) are presented. The inclusions are primary and secondary in origin. They display one or two phases and fluorescence in white-blue (oil) or dull blue (methane) colours, sometimes yellow or red. Based on the fluorescence colour in the ultraviolet light a character of hydrocarbons that fill these inclusions and migrate in the rocks of the region can be estimated. The inclusions are filled with palaeofluids of different compositions. The homogenization temperatures, which correspond to the minimum estimation of the trapping temperatures in minerals, show variability with respect to the geological history of the study area. The hydrocarbon inclusions are often accompanied by brine inclusions. Wider interpretation of all microthermometric analyses was enabled due to the combination of studies on hydrocarbon and aqueous inclusions. The presence of hydrocarbons in inclusions is a proof of their occurrence and/or migration in the rocks of the regions studied

A reappraisal of K-Ar and new U-Pb age data for felsic rocks in the vicinity of the Kraków-Lubliniec Fault Zone (southern Poland)

New U-Pb zircon SHRIMP determinations from magmatic silicic rocks adjacent to the NE part of the Upper Silesia Coal Basin (USB) are provided and compared with earlier data obtained by K-Ar dating. The zircon samples studied came from the same boreholes and depth intervals previously sampled for K-Ar datings. Recalculations of the earlier K-Ar values for biotites yielded isochron ages in the range of 297-309 Ma. The zircon U-Pb SHRIMP values gave more precise ages between 300.1 ±1.2 Ma and 292.6 ±1.3 Ma (1б) consistent with U-Pb and Re-Os determinations. In two cases, the recalculated results of K-Ar dates were nearly identical with those obtained from the SHRIMP isotopic analyses. In this context, the granitoids and porphyries of the USB area, once assigned to the Carboniferous-Permian based on the older K-Ar studies, actually are of the same age as other felsic igneous rocks from the vicinity of the Kraków-Lubliniec Fault Zone, with a higher dating precision, however. The new data underline the importance of Late Carboniferous-Early Permian felsic magmatism at the SW margin of the Trans-European Suture Zone in southern Poland. In the zircon populations dated, besides the dominant Late Paleozoic ages, there are some inherited zircon cores, likely remnant detrital grains from a sediment component in the source rocks, that reveal much older ages which range from ~2051 to 569 Ma

Application of Fluid Inclusions to Petroleum Basin Recognition—A Case Study from Poland

Fluid inclusions were studied in rocks from different wells from the Barnówko–Mostno–Buszewo (BMB), the largest oil field in Poland and from the Lubiatów field. Sampling was performed at depths between about 3120–3220 m and 3221–3256 m, respectively. Different minerals (dolomite, calcite, anhydrite, quartz) reveal the presence of aqueous (AQFI) and hydrocarbon (HCFI) inclusions, the differentiation of which was checked by UV fluorescence and microthermometry. Inclusions occur in different abundances and are of variable character. The microthermometric studies of fluid inclusions resulted in the determination of temperatures of eutectic melting, ice melting, and homogenization. Based on the results obtained, three types of inclusions have been found. Two-phase non-fluorescent inclusions (AQFI) contain brines of differentiated salinity (from about 6 to 10 and from about 17 to 22 wt% NaCl equivalent). Two-phase fluorescent inclusions (HCFI 1) contain light mature oil of paraffin character. The oil is characterized by API gravity of about 41–42 degrees. Small one-phase non-fluorescent inclusions (HCFI 2) that homogenize in deep freezing contain methane with admixtures. The abundance of inclusions varies, depending on the mineral or well. They have been discussed in the context of hydrocarbon migration and accumulation