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Charakterystyka petrograficzno-mineralogiczna nowo rozpoznanych horyzontów tufowych z ogniwa Kłodnicy (turnej, wizen) w basenie lubelskim oraz towarzyszących im zlepieńców i piaskowców wulkanoklastycznych

Kozłowska Aleksandra, Waksmundzka Maria I.

Przegląd Geologiczny

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2023

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Vol. 71, nr 4

207--11

EN

The purpose of the study was petrographic-mineralogical analysis of volcaniclastic rocks occurring in the Lublin Basin, within the K³odnica Member (Tournaisian, Visean), in seven boreholes. Its results were linked with the results of sedimentological and sequence stratigraphy studies to reconstruct the genesis of the sediments, as well as spatial and age relationships. Fine and coarse ash tuffs were identified, whose composition indicates acidic and alkaline volcanism. Accompanying volcaniclastic conglomerates and sandstones were formed mainly in the Tournaisian, before volcanic activity began. These sediments fill incised valleys, and belong to the oldest Carboniferous sedimentary filling of the Lublin Basin.

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Gorceixite from the upper cambrian rocks of the Podwiśniówka Mine Pit, Holy Cross Mountains (South-Central Poland)

Migaszewski Zdzisław M., Starnawska Ewa, Gałuszka Agnieszka

Mineralogia

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2007

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Vol. 38, iss. 2

171--184

EN

This report presents the results of a petrographical, mineralogical (SEM/EDS, XRD) and geochemical (XRF, CV-AAS, ICP-MS) study of gorceixite (barium aluminophosphate) from the abandoned Podwiśniówka mine pit. This site is highlighted by the presence of highly acidic pit pond whose chemistry is strongly affected by the exposed pyrite-bearing zone. The gorceixite occurs in the Upper Cambrian carbonaceous clayey shales, quartzites and tuffs in form of minute accumulations varying from about 0.5 to 100 μm in diameter. These accumulations infill voids, cavities, cracks and partly fissures in the rocks examined. The other minerals of the crandallite series, i.e. florencite and goyazite, can be found only in trace amounts. The gorceixite-bearing rocks, especially carbonaceous clayey shales, are characterized by the highest concentrations of REE reaching 455.09 mg·kg-1. In addition, these rocks are distinctly enriched in light rare earth elements (LREE), with the La/Yb ratio ranging from 24.44 through 36.30. Some of the examined gorceixite accumulations are paragenetically linked to the veined pyrite and nacrite. The latter mineral is indicative of crystallization temperatures of about 200 to 300°C. The coexistence of gorceixite with the veined nacrite or pyrite mineralization and the volcaniclastic rocks, as well as the microtextural features and high concentrations of REE in the gorceixite-bearing parent rocks suggest that this mineral formed as a result of both hydrothermal and volcanic activity in a shallow-marine basin during the late Cambrian.

XX

Niniejszy artykuł przedstawia wyniki badań petrograficznych, mineralogicznych (SEM/EDS, XRD) i geochemicznych (XRF, AAS, ICP-MS) gorceixytu BaAl3H[(OH)6(PO4)2] z nieczynnego kamieniołomu Podwiśniówka. Wyrobisko to częściowo wypełnia zbiornik wodny o bardzo niskim pH, którego chemizm pozostaje pod silnym wpływem odsłoniętej strefy mineralizacji pirytowej. Gorceixyt występuje w górnokambryjskich łupkach ilastych, kwarcytach i tufach w postaci drobnych skupień o średnicy od około 0,5 do 100 m. Wypełniają one pory, próżnie, spękania i częściowo szczeliny w skałach. Pozostałe minerały z grupy crandallitu (florencyt i goyazyt) występują w ilościach śladowych. Skały wzbogacone w gorceixyt, a w szczególności węgliste łupki ilaste, wyróżniają się najwyższą zawartością pierwiastków ziem rzadkich, dochodzącą do 455,09 mgkg–1. W porównaniu z podobnymi stanowiskami na świecie, skały zawierające gorceixyt z kamieniołomu Podwiśniówka są wyraźnie bogatsze w lżejsze pierwiastki ziem rzadkich, wykazując stosunek La/Yb w zakresie od 24,44 do 36,30. Gorceixyt występuje miejscami w postaci paragenetycznych skupień z żyłowym pirytem i nakrytem. Ostatni z wymienionych minerałów jest wskaźnikiem średnich i wysokich temperatur krystalizacji. Współwystępowanie z nakrytem i pirytem, cechy mikroteksturalne oraz wysokie zawartości pierwiastków ziem rzadkich świadczą o genezie gorceixytu i pozostałych minerałów z grupy crandallitu z Podwiśniówki. Powstały one przypuszczalnie w wyniku działalności hydrotermalnej w płytkim basenie morskim w późnym kambrze. Należy jednak podkreślić, że działalność roztworów hydrotermalnych mogła zamaskować inne możliwości pochodzenia Al, Ba, P i pierwiastków ziem rzadkich. W szczególności pierwiastki te mogą być związane z działalnością wulkaniczną, której przejawy w postaci wkładek tufów i bentonitów występują w najstarszej serii skalnej odsłaniającej się w kamieniołomie.

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Litologia i geneza zmetamorfizowanych skał osadowych i wulkanicznych jednostki Chełmca (Góry Kaczawskie)

Baronowski Z., Haydukiewicz A., Kryza R., Lorens S., Muszyński A., Urbanek Z.

Geologia Sudetica

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1998

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Vol. 31, nr 1

33-59

EN

Based on detailed drill core studies from fourteen boreholes (up to 1500 m deep) and on field observations, the Chełmiec tectonic unit in the northern part of the Kaczawa Mts appears to contain two types of tectonostratigraphic elements. The first is fragments of a stratigraphic sequence, composed mainly of dark muddy slates (metamudstones) and variegated laminated silty-clayey slates (both considered as Ordovician), and of volcaniclastic rocks, greenstones and dia-bases. The second element is represented by mélange bodies which consist of dark muddy slates (matrix) enclosing fragments of various lithologies: dark siliceous and graphitic slates, light siliceous slates, quartzites, greywackes, variegated silty-clayey slates etc. (probably Upper Devonian or Lower Carboniferous). Due to the lack of biostratigraphic evidence, the stratigraphic subdivision is based on lithological criteria. Using e.g. the rule of superposition and analysis of lithological contacts and sedimentary and volcanogenic structures, the stratigraphic succession was defined, and three informal lithostratigraphic units were distinguished: (a) an association of metamudstones and diabases, (b) an association of metavolcaniclastic rocks (both within the stratigraphic sequence), and (c) a mélange association. The dark metamudstones and variegated silty-clayey slates of the association of metamudstones and diabases are interpreted as turbidites. The volcaniclastic rocks, of clearly epiclastic character, were delivered episodically from marginal parts of the basin or volcanic heights by denser turbiditic currents and other types of gravity flows. Simultaneously, volcanic activity occurred within the basin itself producing basaltic lavas (now observed as subvolcanic diabases and effusive greenstones), which geochemically correspond to recent mildly alkaline within-plate basalts. The geotectonic setting of the basin is difficult to define precisely but the sequence was probably emplaced in an outer fan or in a basin at a continental margin. The mélange represents a later stage of the evolution of the Kaczawa Complex. Most probably, it was deposited from gravity flows and slumps in a trench or on a trench slope. Its origin is thought to have been connected within the formation of a Variscian accretionary prism in Late Devonian and Early Carboniferous times. The rock complex of the Chełmiec Unit experienced several stages of deformation during the Variscian orogeny. The first event resulted in a system of thrusts (and associated folds?) and it was related to (or partly preceeded by) the formation of mélange. It is likely that deformation at this stage (and in particular in its later phase) took place under blueschist facies conditions. The second deformation event, probably under greenschist facies conditions, was associated with folding which steepened the earlier foliation and produced new asymmetric folds. The third deformation event, partly under semi-brittle/brittle conditions, is responsible for new thrusts cutting the earlier structures and the formation of large open folds, such as the Bolków-Wojcieszów antiform. The deformation of the rocks of the Chełmiec Unit was associated with greenschist facies metamorphism. In general, primary sedimentary and volcanic structures are well preserved in the rocks of this unit which often seem to have suffered weaker deformation and metamorphism than that observed in other units of the Kaczawa Mts. No clear evidence of the early high-pressure episode which is widespread in other tectonic units of the Kaczawa Complex has been found in the Chełmiec Unit so far.