Origin and timing of spilitic alterations in volcanic rocks from Głuszyca Górna in the Intra-Sudetic Basin, Poland (original) (raw)
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Neues Jahrbuch für Mineralogie - Abhandlungen, 2006
Six samples from the Góry Sowie Massif gneisses in the West Sudetes, analyzed for the purpose of apatite fissiontrack dating (AFT) yielded ages ranging from 43 to 57 Ma. No regional variation in the results was observed and the samples form a rather uniform population. From confined-track length measurements, short values between 8.8 and 9.6 µm were obtained. Track length distribution in four of the six samples is bimodal. This suggests residence in temperatures corresponding to the partial annealing zone until relatively recent times and subsequent rapid cooling to ambient conditions. We propose a mid-Tertiary rise in the geothermal gradient as a possible factor responsible for reheating the Góry Sowie Massif after it had cooled to temperatures around 60-40˚C in the Oligocene. According to reverse-modelling results, the cooling began in the Cretaceous and therefore correlates with the event reported from elsewhere in the northern part of the Bohemian Massif. As Lower Carboniferous sedimentary rocks overlie the gneisses, the overburden which was responsible for keeping temperatures above 100˚C until early Tertiary was probably the Carboniferous-Permian Variscan molasse. The amount of the Cretaceous/early Tertiary denudation can be estimated to be 4-8 km. The recent, rapid cooling phase began 7-5 Ma ago and is interpreted as the combined result of decrease of geothermal gradient and/or increased tectonic activity in the Sudetes as evidenced by the presence of the Pliocene, coarse-clastic Gozdnica formation.
The main products of volcanic activity in the teschenite-picrite association (TPA) are shallow, sub-volcanic intrusions, which predominate over extrusive volcanic rocks. They comprise a wide range of intrusive rocks which fall into two main groups: alkaline (teschenite, picrite, syenite, lamprophyre) and subalkaline (dolerite). Previous 40 Ar/ 39 Ar and 40 K/ 40 Ar dating of these rocks in the Polish Outer Western Carpathians, performed on kaersutite, sub-silicic dio-pside, phlogopite/biotite as well as on whole rock samples has yielded Early Cretaceous ages. Fluorapatite crystals were dated by the U-Pb LA-ICP-MS method to obtain the age of selected magmatic rocks (teschenite, lamprophyre) from the Cieszyn igneous province. Apatite-bearing samples from Boguszowice, Puńców and Lipowa yield U-Pb ages of 103± 20 Ma, 119.6 ± 3.2 Ma and 126.5 ± 8.8 Ma, respectively. The weighted average age for all three samples is 117.8 ± 7.3 Ma (MSWD =2.7). The considerably smaller dispersion in the apatite ages compared to the published amphibole and biotite ages is probably caused by the U-Pb system in apatite being less susceptible to the effects of hydrothermal alternation than the 40 Ar/ 39 Ar or 40 K/ 40 Ar system in amphibole and/or biotite. Available data suggest that volcanic activity in the Silesian Basin took place from 128 to 103 Ma with the the main magmatic phase constrained to 128—120 Ma.
The Journal of Geology, 2013
Extensive geophysical investigations in NE Poland in the 1950s and 1960s led to the discovery of an alkaline and carbonatite magmatic province buried under thick (600-800 m) Meso-Cenozoic cover north of the Trans-European Suture Zone, or Tornquist Line. Drilling focused on geophysical anomalies identified three intrusions in the Paleoproterozoic metasedimentary and metavolcanic rocks of the Mazowsze Domain: the Pisz gabbro-syenite massif, the Ełk syenite massif, and the small, differentiated Tajno body consisting of clinopyroxenite cumulates and syenites crosscut by carbonatite veins. Emplacement ages for these intrusions have been obtained by (1) zircon U-Pb geochronology on a gabbro from Pisz, a syenite from Ełk, and an albitite from Tajno and (2) a Re-Os model age for pyrrhotite from a Tajno carbonatite. The ages measured by both methods fall in the narrow range 354-345 Ma (Early Carboniferous: Tournaisian). This is slightly younger than the Late Devonian (380-360 Ma) Kola Peninsula alkaline and carbonatite province (20 intrusions) of NW Russia and Karelia but is of comparable age to the first manifestations of the long-lasting (∼100 m.yr.) Carboniferous to Permian magmatic event (360-250 Ma) manifest in northern Europe (from the British Isles to southern Scandinavia, the North Sea, and northern Germany) in the foreland of the Variscan orogeny (in the so-called West European Carboniferous Basin) and the East European Craton.
Geochron, 2014
This study presents apatite LA-ICP-MS U-Pb age and trace elements concentrations data from different granite types from the Tatra Mountains, Poland. Apatite from monazite and xenotimebearing High Tatra granite was dated at 339 ± 5 Ma. The apatite LREE patterns reflect two types of magmas that contributed to this layered magma series. Apatite from a hybrid allanite-bearing diorite from the Goryczkowa Unit was dated at 340 ± 4 Ma with apatite LREE depletion reflecting the role of allanite and titanite during apatite crystallization. Apatite crystals from a hybrid cumulative rock from the Western Tatra Mountains were dated at 344 ± 3 Ma. Apatite is one of the main REE carriers in this sample and exhibit flat REE patterns. Taking into account the relatively low closure temperature of the U-Pb system in apatite (350-550°C), the c. 340 Ma apatite ages mark the end of high temperature tectonometamorphic activity in the Tatra Mountains.
Annales Societatis Geologorum Poloniae
Ab stract: In the Kraków-Lubliniec sec tion of the ma jor Ham burg-Kraków-Dobro gea Fault Zone (HKDFZ), the Stepha nian-Early Per mian mag matic ac tiv ity was si mul ta ne ous with sub si dence/up lift of formed blocks. In the prox im ity of the up lifted ar eas the sedi men ta tion started with fan glom er ates, dis tally pass ing into playa silt stone and was ac com pa nied by vol can ism. In the Nie po raz-Brod³a gra ben, ba sal tic trachy an des ite a-a lava flows with auto clas tic brec cias reach ca. 150 m in thick ness. The weath er ing re corded as ad he sive rims around brec cia clasts re flects pa laeo soil for ma tion dur ing qui es cence pe ri ods be tween the erup tions. The erup tions were ef fu sive al though sco ria ceous lava in di cates high vola tile con tent of the magma. The wa ter con tent be fore erup tion had to be over 2 wt. per cent. Only then the crys tal li sa tion model pre dicts ac cu rately the type, com po si tion and or der of the crys tal lis ing phases. Thus, the ba sal tic trachy an des ite magma origi nated from a source con tain ing hy drous phase (i.e., am phi bole or phlo go pite). All the stud ied ba sal tic trachy an des ites had faya litic oli vine on their liq ui dus re flect ing the crys tal li sa tion stage in a magma cham ber at crus tal depths. Dur ing fi nal de com pres sion on the magma as cent due to wa ter ex so lu tion, the oli vine was fol lowed by pla gio clase, spi nel, augite, il men ite, apa tite, K-feldspar and re sid ual high-K rhyo litic glass. The high po tas sium con tent of these vol can ics was thus a pri mary fea ture re flect ing the source geo chem is try and dif fer en tia tion trend, and its con se quence was po tas sium meta soma tism. Due to wa ter ex so lu tion the glass was al tered, how ever, ho moge nous in ter sti tial glass sur vived in some rocks. The glass is strongly en riched in in com pati ble trace ele ments, show ing that it is a highly frac tion ated re sid ual melt frac tion of the ba sal tic trachy an des ite magma. Thus, the glass geo chem is try re flects the trend of frac tional crys tal li sa tion in di cat ing that co-occurring K-rich fel sic rocks were not de rived from the same magma. All the ba sal tic trachy an des ites stud ied have calc-alkaline to al ka line af fin ity. They con tain faya litic oli vine and are low in MgO <5 wt. %, Cr and Ni, the fea tures char ac ter is tic for evolved mag mas. They show sig nifi cant nega tive Sr/Sr*» 0.5-0.80 and small Eu/Eu* » 0.9-1.0 anoma lies sug gest ing frac tiona tion of pla gio clase. The Eu/Eu* anom aly is proba bly com pen sated by am phi bole re tain ing in the source. Nega tive Nb, Ti anoma lies sug gest Fe-Ti ox ide frac tiona tion char ac ter is tic for calc-alkaline evo lu tion trend. A sig nifi cant en rich ment in LREE rela tively to HREE (La/Yb » 10) in di cates subduction-related meta so ma tism. How ever, the de scribed tec tonic con text is in con sis tent with sub duc tion re lated char ac ter is tics. Con clud ing, the ob served geo chemi cal char ac ter is tics in di cate re mark able role of wa ter in magma evo lu tion. The vol can ism was re lated to strike-slip dex tral move ment along the Kraków-Lubliniec sec tion of HKDFZ, trans formed into crus tal ex ten sion and sub si dence, the fea tures typi cal for the for ma tion of pull-apart ba sins, in the late stages of the Varis can oro gen evo lu tion.
Precambrian Research, 2021
The Mesoproterozoic Suwałki anorthosite massif (SAM) in NE Poland, intruded into a late Palaeoproterozoic domain in southeastern Fennoscandia, comprises anorthosite, Fe-Ti-V oxide ore deposits, gabbroic rocks and rapakivi-like granitoids. In the present study, a new set of age determinations on zircon grains from AMCG components (anorthosites and rapakivi granites) from different parts of the SAM massif, from granite veins cutting the AMCG rock suite, and from micro-coronas formed on Fe-Ti oxides, is presented. The new age results obtained using a SHRIMPIIe/MC change the previous interpretation (Re-Os NTIMS method on sulfides) that the SAM anorthosites were emplaced at ca 1.55 Ga. The new zircon SHRIMP ages indicate that anorthosites were intruded in several magmatic pulses culminating at ca. 1515 Ma and 1507 Ma. This is confirmed by single spot data and concordia ages of 1513 ± 6 Ma, 1509 ± 3 Ma and 1507 ± 3 Ma obtained for anorthosites. Similar singlespot peaks at 1515 Ma, 1509 Ma and 1496 Ma characterize rapakivi-type granites which also yielded concordia ages of 1513 ± 6 Ma, 1507 ± 6 Ma and 1499 ± 8 Ma. The SHRIMP data from the SAM anorthosites indicate an age of emplacement significantly younger than the ca 1.55 Ga age determined previously, and coeval to ages obtained for rapakivi granite. Both rock types contain entrained antecrysts, reflecting a two-step crystallization in a deep-seated magma chamber and continuous crystallization during the rising of the melt and incremental emplacement of the SAM. Abundant granitic aplites and pegmatites in sharp contact with the host AMCG rocks define a time frame for the entire SAM solidification. The crystallization ages of individual veins ranging between 1489 ± 6 Ma and 1475 ± 5 Ma are clearly older than cooling ages previously obtained by Ar-Ar and K-Ar methods. Microgranites with numerous inherited zircon cores were generated by re-melting of the local sources, including late Paleoproterozoic ca 1.83 Ga crust and SAM related rocks, within a shallow felsic magma chamber. Finally, zircon coronas on Fe-Ti oxides ilmenite grains record subsolidus ilmenite exsolution processes (from ilmenite) occurring simultaneously with the crystallization of the aplite and pegmatite veins.
The burial and thermal history of the Carboniferous gas source rocks in the Moravian-Silesian Unit (eastern part of the Fore-Sudetic Monocline, SW Poland) has been reconstructed by 1-D maturity modelling. It allowed to establish the timing of gas generation and expulsion in the Fore-Sudetic Monocline. In the Carboniferous sediments in the study area maturity of the III type kerogen increases toward the SE part of Fore-Sudetic Monocline. The vitrinite reflectance values are from 1.0 to 5.0%. The results of the 1-D maturity modelling indicates clearly, that Carboniferous sediments in the northern part of the Moravian-Silesian Unit attained their thermal maturity prior to the Late Permian. The burial of the source rocks in the Late Carboniferous was probably very high (2-4 km), and the heat flow in the Late Carboniferous was also high (~90-120 mW/m2). It might have been caused by the migration of hot fluids related to the volcanic activity. The thermogenic gas generation and expulsion ...
International Journal of Earth Sciences
The precise ages of Cenozoic basaltic rocks from 20 localities (24 samples) in south-western Poland were studied by means of the 40Ar/39Ar isotope method. Three phases of volcanic activity were identified in this area. The older, Ruphelian phase took place 31–29 Ma ago and the younger, Aquitanian phase occurred 22–21 Ma ago. Significantly younger ages (4.8–4.6 Ma: Zanclean phase) were obtained for the basalts cropping out in the vicinity of Lądek Zdrój only. Most of the analyzed basalts from the Ruphelian phase are classified as nephelinites. They occur in the area of Lausitz Masif, south of Sudetic Marginal Fault and in the Opole Depression. The volcanic rocks from the Aquitanian phase crop out in the wide area north of the Sudetic Marginal Fault. They are composed of alkali basalts. The youngest phase is represented by the basanites only. The deep discontinuous tectonic structures intersecting the areas of volcanic activity in SW Poland, parallel or oblique to the tectonic stress ...
Journal of Petrology, 2007
We report major and trace element abundances and Sr, Nd and Pb isotopic data for Miocene (16Á5^11 Ma) calc-alkaline volcanic rocks from the western segment of the Carpathian arc. This volcanic suite consists mostly of andesites and dacites; basalts and basaltic andesites as well as rhyolites are rare and occur only at a late stage. Amphibole fractionation both at high and low pressure played a significant role in magmatic differentiation, accompanied by highpressure garnet fractionation during the early stages. Sr^Nd^Pb isotopic data indicate a major role for crustal materials in the petrogenesis of the magmas.The parental mafic magmas could have been generated from an enriched mid-ocean ridge basalt (E-MORB)type mantle source, previously metasomatized by fluids derived from subducted sediment. Initially, the mafic magmas ponded beneath the thick continental crust and initiated melting in the lower crust. Mixing of mafic magmas with silicic melts from metasedimentary lower crust resulted in relatively Al-rich hybrid dacitic magmas, from which almandine could crystallize at high pressure. The amount of crustal involvement in the petrogenesis of the magmas decreased with time as the continental crust thinned. A striking change of mantle source occurred at about 13 Ma. The basaltic magmas generated during the later stages of the calc-alkaline magmatism were derived from a more enriched mantle source, akin to FOZO. An upwelling mantle plume is unlikely to be present in this area; therefore this mantle component probably resides in the heterogeneous upper mantle. Following the calc-alkaline magmatism, alkaline mafic magmas erupted that were also generated from an enriched asthenospheric source. We propose that both types of magmatism were related in some way to lithospheric extension of the Pannonian Basin and that subduction played only an indirect role in generation of the calc-alkaline magmatism.The calc-alkaline magmas were formed during the peak phase of extension by melting of metasomatized, enriched lithospheric mantle and were contaminated by various crustal materials, whereas the alkaline mafic magmas were generated during the post-extensional stage by low-degree melting of the shallow asthenosphere. The western Carpathian volcanic areas provide an example of long-lasting magmatism in which magma compositions changed continuously in response to changing geodynamic setting.