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EN
Alkali feldspar crystals have been recognized in the troilite-graphite nodules of the Morasko IAB iron meteorite. Their chemical, microtextural and structural properties were studied using electron microprobe analysis (EMPA), laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), transmission electron microscopy (TEM) and Raman spectroscopy. The feldspars occur as perthitic or antiperthitic intergrowths, whereas the albite lamellae are perfectly twinned. The structural properties reveal intergrown phases with fairly disordered patterns. The electron microprobe analyses demonstrate that the intergrown phases are mainly rich in sodium or potassium, resulting in compositions that are close to those of albite or orthoclase. The compositions, calculated on the basis of a segmented perthite-antiperthite image, showed that the Or-to-Ab proportions in the homogenized crystals were almost 0.3:0.7, thus indicating that the anorthoclase crystallized under high-temperature conditions. Two hypotheses of crystal formation could account for these characteristics: crystallization from a melt or from a metasomatic solution. Relics with evidence of metasomatic replacement of former minerals were not found. Accordingly, this work focuses on arguments that support the other hypothesis. Large ion lithophile elements (LILEs, e.g., Ba, Sr, Rb, LREE, Pb, and Ga) were used to track the origin of the crystals. Their concentrations indicate crystallization from a parent melt strongly depleted in LILEs. Alkali feldspar is commonly a product of a highly differentiated melt. However, highly differentiated melts are typically enriched in LILEs, which here is not the case. The melt that crystallized the feldspar cannot be related to impact-induced partial melting of the chondritic material alone. The derived melt probably was contaminated by silica-rich target material during interaction between the IAB projectile and the target material and was accompanied by metal and sulphide melts that were both immiscible with a silicate melt.
EN
Monazite from the Stolpen monzogranite (SE Germany) was studied to constrain the Th-U-total Pb age of pluton formation. Monazite grains demonstrate subtle to distinct patchy zoning related to slight compositional variations. Textural and compositional characteristics indicate that the monazite formed in a single magmatic event in a slightly heterogeneous system, and was only weakly affected by secondary alteration, which did not disturb the Th-U-Pb system. Chemical dating of the monazite gave a consistent age of 299 ± 1.7 Ma. The current study presents the first geochronological data for the Stolpen granite. It provides evidence that Stolpen is the youngest Variscan granitic intrusion in the Lusatian Granodiorite Complex and indicates that magmatic activity related to post-collisional extension in this region lasted at least 5my longer than previously assumed.
EN
Raster digital models (digital concentration-distribution models - DC-DMs) as interpolations of geochemical data are proposed as a new tool to depict the crystal growth mechanism in a magmatic environment. The Natural Neighbour method is proposed for interpolation of Electron Microprobe Analysis (EMPA) data; the Natural Neighbour method and Kriging method are proposed for interpolating data collected by the LA-ICP-MS method. The crystal growth texture was analysed with the application of DC-DM derivatives: 3D surface models, shaded relief images, aspect and slope maps. The magmatic mass properties were depicted with the application of solid models. Correlation between the distributions of two elements on a single crystal transect was made by operations on the obtained raster DC-DMs. The methodology presented is a universal one but it seems to be significant for the depiction of magma mixing processes and the heterogeneity of the magmatic mass.
EN
Trace element behaviour during crystallization of three alkali feldspar crystals of mixed origin was investigated. The first crystal (gm1) was growing under an intensive magma mixing regime in an active region of an inhomogeneous magmatic field. The second crystal (ref) was growing in a coherent region of this field and the third one (gm2) was growing under moderate progress in magma mixing, with the process being close to completion. The Hurst exponent (H) was used as a tool for the description of the local heterogeneities of the magma field during the mixing process. Values of H were calculated for compatible trace element patterns along each traverse for each crystal. The gm1 crystal is strongly zoned. The value of the Hurst exponent (H) for zones reflecting intensive chemical mixing varies between 0.06 and 0.47. It emphasizes strong anti-persistent behaviour of elements during crystallization. The zones that grew in a slightly contaminated felsic magma exhibit H > 0.5. It means that the process goes over a longer path than a random walk and shows increasing persistence in element behaviour with decreasing hybridization. Similarly, zones crystallized in magma regions compositionally located close to coherent characteristic or in active domains featuring a high homogenization (crystals gm2, ref) show higher H values.
7
EN
Today the Ukrainian Mesozoic volcanic rocks are located in the relatively small area. They are concentrated near the Rachiv Massif and Chivchin Ridge, generally in the front of the Rahiv and Maramuresh (=Marmaros) nappes (Outer Flysch Carpathians) and in the Pieniny Klippen Belt. Several outcrops in these regions were studied in details by present authors. Rachiv nappe contains basaltic flows with numerous pillow lava horizons, ophicalcite(?) and with lava breccias on the top of volcanic sequence (Trostianets stream), as well as basaltic and tuffitic breccias (Lemskij stream). Maramuresh nappe contains andesites, basalts and tuffitic breccias often associated with light-grey micritic and coral limestones of Âtramberk-type facies (Kamennyj Potok stream). Most spectacular region of distribution of magmatic rocks belongs to Maramuresh unit and is located between Margetul, Radomir and Kwasnyj streams. These rocks are represented mainly by massive and pillow basalts, basaltic and tuffitic breccias and diabases as well as porphyritic conglomeratic/breccias. Usually they build huge klippes up to 50 meters and more. The contacts between huge pillow basaltic flows and surrounding deposits are usually covered by debris or vegetation but in Margetul stream the relationship between pillow lavas and pelagic, micritic limestones with cherts (Cieszyn Limestone Formation type) is very well visible. In the lower part of section small lenses of basaltic rocks occur within these limestones and basaltlimestone ratio increases upwards. Latest Jurassic - earliest Cretaceous age of these limestones was established helping to determine crucial age of a magmatic event to understand most important wide geodynamic processes. The basaltic rocks with pillow lavas are exposed in Veliky Kamenets quarry within Ukrainian part of the Pieniny Klippen Belt. These basalts cover the Middle Jurassic - lowermost Creataceous carbonate sequence, the contact is sharp and basaltic dykes also penetrate underlying Calpionella limestones. Above these basalts, there are younger limestones rich both in ammonites and benthic fauna (brachiopods, bivalves and crinoids) and they are overlain by 1 meters thick tuffites. The youngest deposits in the Veliky Kamenets section are yellowish limestone breccias showing presence of abundant Berriasian calpionellids. Sedimentological features of this breccia indicate submarine erosion connected with synsedimentary movements of the sea bottom causing redeposition of older rocks - in this case Calpionella limestones and basaltic fragments. These sediments correspond very well with Walentowa Breccia Member of the Dursztyn Limestone Formation which originated after strong Neo-Cimmerian uplift of the Czorsztyn Ridge. Additionally, in Vulhovchik stream, just below Veliky Kamenets hill, Jurassic/Cretaceous trachydolerites occur. These magmatic events correspond very well with major plate reorganization, which happened during the Tithonian time within western Tethyan Ocean. In the same time the Outer Carpathian rifts were developed with the extensional type of volcanism (teschenites) and the Silesian Basin originated as a result of such rifting process. The presumable triple-junction zone comprises the Rahiv-Sinaia zone (first arm), Silesian (second one) and its extension into the Pieniny Klippen Belt/Magura Basin (third arm). The origin of this triple junction is perhaps related to the opening of the Central Atlantic-Ligurian-Penninic oceanic system.
EN
This paper presents an insight into the geology of the area surrounding the ODDP proposed drilling site, and the structural development of the Carpathians in post-Palaeogene times. Since the deep drilling is proposed to be located in the Orava region of the Northern Carpathians, on the Polish-Slovak border, the structure and origin of the Neogene Orava Basin is also addressed in the paper. The outline of geology of the Carpathian Mountains in Slovakia and Poland is presented. This outline includes the Inner Carpathian Tatra Mountains, the Inner Carpathian Palaeogene Basin, the Pieniny Klippen Belt, the Outer Carpathians, the deep structure below the Carpathian overthrust, the Orava Basin Neogene cover, the Neogene magmatism, faults and block rotations within the Inner and Outer Carpathians, and the Carpathian contemporary stress field. The outline of geology is accompanied by the results of the most recent magnetotelluric survey and the detailed description of the post-Palaeogene plate tectonics of the circum-Carpathian region. The oblique collision of the Alcapa terrane with the North European plate led to the development of the accretionary wedge of the Outer Carpathians and foreland basin. The northward movement of the Alpine segment of the Carpathian-Alpine orogen had been stopped due to its collision with the Bohemian Massif. At the same time, the extruded Carpatho/ Pannonian units were pushed to the open space, towards a bay of weak crust filled up by the Outer Carpathian flysch sediments. The separation of the Carpatho/Pannonian segment from the Alpine one and its propagation to the north was related to the development of the N-S dextral strike-slip faults. The formation of the West Carpathian thrusts was completed by the Miocene time. The thrust front was still progressing eastwards in the Eastern Carpathians. The Carpathian loop including the Pieniny Klippen Belt structure was formed. The Neogene evolution of the Carpathians resulted also in the formation of genetically different sedimentary basins. These basins were opened due to lithospheric extension, flexure, and strike-slip related processes. A possible asteno- sphere upwelling may have contributed to the origin of the Orava Basin, which represents a kind of a rift modified by strike-slip/pull-apart processes. In this way, a local extensional regime must have operated on a local scale in the Orava region, within the frame of an overall compressional stress field affecting the entire West Carpathians. Nevertheless, many questions remain open. Without additional direct geological data, which can be achieved only by deep drilling under the Orava Deep Drilling Project, these questions cannot be fully and properly answered.
PL
W grudniu 1999 Polska dołączyła do programu wierceń kontynentalnych - International Continental Scientific Drilling Program (ICDP). W ramach tego programu jest przygotowywany projekt głębokiego wiercenia w strefie kontaktu teranu Karpat wewnętrznych i płyty północnoeuropejskiej. Praca przedstawia zarys geologii Karpat na terenie Polski i Słowacji, ze szczególnym uwzględnieniem Tatr, paleogenu wewnątrzkarpackiego, pienińskiego pasa skałkowego, zachodnich Karpat zewnętrznych, podłoża nasunięcia karpackiego na południe od Krakowa, neogeńskiego wulkanizmu i budowy geologicznej niecki orawskiej. Wiercenie "Orawa" byłoby usytuowane w rejonie Jabłonki-Chyżnego na linii przekroju sejsmicznego CELEBRATION CEL01, jak również w niedalekim sąsiedztwie głębokiego przekroju geologicznego Kraków-Zakopane i na linii przekroju Andrychów-Chyżne. Przekroje Kraków--Zakopane i Andrychów-Chyżne wykorzystują szereg wierceń Państwowego Instytutu Geologicznego i PGNiG, a także badania sejsmiczne i magnetote-luryczne. Usytuowanie wiercenia w rejonie przygranicznym pozwoli na międzynarodową współpracę z geologami i geofizykami słowackimi. Wiercenie to ma na celu wyjaśnienie szeregu problemów badawczych. Jednym z nich jest zagadnienie młodych i współczesnych ruchów tektonicznych w Karpatach. Przez obszar karpacki przebiega granica europejskiego pola plam gorąca, wyznaczona neogeńskim wulkanizmem oraz rozkładem strumienia cieplnego. Na obszarze pomiędzy Górną Orawą a Górnym Śląskiem, linia graniczna łącząca neogeńskie wulkanity Zakarpacia z andezytami rejonu przypienińskiego i bazaltami Dolnego Śląska przecina skośnie nasunięcia jednostek fliszowych Karpat Zewnętrznych. Równocześnie w rejonie Orawy do pienińskiego pasa skałkowego skośnie dochodzi oś karpackiej, ujemnej anomalii grawimetrycznej, a podłoże skonsolidowane występuje na głębokości nie większej niż 6-9 km, a więc w zasięgu głębokiego wiercenia, co sugerują wyniki badań megnetotellurycznych (Żytko, 1999) i magnetycznych. Podniesienie to, przy generalnym zapadaniu podłoża platformy europejskiej pod Karpaty ku południowi, może bya spowodowane warunkami geotermicznymi, na skutek podnoszenia się astenosfery i występowania pióropuszy płaszcza. Pióropusze te mogą bya niezależne od karpackiej kompresji i subdukcji. Z piórpuszami tymi łączy się lokalna i regionalna ekstensja w warunkach megaregionalnej kompresji. Zjawiska tego rodzaju nie są jeszcze dokładnie poznane, aczkolwiek występują w kilku miejscach na świecie (np. Panteleria na Morzu Śródziemnym). Opracowanie zagadnienia roli pióropuszy płaszcza i określenie ich relacji do kolizji i subdukcji mają zasięg globalny, a ich wyjaśnienie w rejonie karpackim pozwoli na stworzenie uniwersalnego modelu ewolucji orogenów. Nie jest wykluczone, że mamy do czynienia z orogenezą "modyfikowaną" przez pióropusz płaszcza. Powstanie niecki Orawy i Podhala mogłoby więc mieć związek z riftingiem spowodowanym wpływem pióropuszy płaszcza na pograniczu dwóch płyt. Ryft ten jest obrzeżony między innymi wyniesieniami Babiej Góry i Orawskiej Magury. Z ryftem może być związany wulkanizm ukryty pod neogeńskimi utworami niecki orawskiej, a widoczny jako wysokooporowe ciała na profilach megnetotellurycznych. Tektonikę tego obszaru komplikuje występowanie uskoków przesuwczych o różnym przebiegu i orientacji i związane z nimi tworzenie się basenów międzyprzesuwczych typu pull-apart. Proponowane wiercenie przyczyniłoby się do uzyskania odpowiedzi na postawione wyżej problemy. Dla określenia dokładnej lokalizacji wiercenia i jego właściwej interpretacji geologicznej konieczne będzie wykonanie dodatkowych prac geofizycznych. Płytka sejsmika wyjaśniłaby zasięg utworów neogeńskich i pozycję pienińskiego pasa skałkowego pod utworami neogenu, zaś głęboka sejsmika, a zwłaszcza zdjęcie 3-D, przyczyni łaby się do lepszego rozpoznania tektoniki wgłębnej.
EN
Sulphates belong to the most frequent compounds found in deteriorated stone monuments. The sources of sulphur within urban agglomeration area are diverse. Many of them are characterised by different sulphur speciation. The aim of this study was to determine the origin of the sulphur from sulphate minerals, formed due to deterioration of daubed resistive wall in the Wilanów Park, mainly gypsum. The mineral phase composition as well as their chemical composition has been determined. The chemical composition of the salts is highly correlated with that of rainfall, which in turn seemed to influence the sulphur isotopic fractionation. Rainfall seems also to be the main source of sulphur. 34S for nine samples has been estimated. The data obtained show narrow value range. The data alone do not allow precise identification of the main source of sulphur in the sulphate minerals.
EN
The Zadnie Kamienne shear zone is a high-angle Riedel type shear zone (R'), exhibiting an antithetic sense of displacement, which may have developed synchronously with the nappe-thrusting of the Giewont Unit (High-Tatric Nappe). The amount of displacement along this zone is very low and does not explain the very intense deformation, which is of the same character as that at the base of the Giewont Unit (mylonitization, stylolitization and vein forming). The explanation of this phenomenon lies in the multiple activity of this zone, the change of the direction of movement and the important role of pressure solution in hydrothermal conditions responsible for dissolution creep, mass loss and stress relaxation. This kind of shear can be referred to as a "ravenous" shear zone. Neo-forming minerals accompanying these processes were applied as a temperature gauge. Simultaneous growth of albite and adularia indicates a temperature of about 350 degrees C. Chlorites accompanying them occur in two thermal episodes, the first of which indicating a similar temperature (292-357 C).
EN
A method of reconstruction of the crystallisation temperature (Tc) of analcime has been proposed. The method is based on the compilation of two data sets: the IR absorption spectra and fluid inclusion study results. The water position in the analcime structure depends on the crystallisation temperature. Certain bands in the IR absorption spectrum are sensitive to the change in the temperature conditions of the analcime formation. Moreover, the IR absorption band positions are also influenced by the composition of the crystallisation system as well as by the crystallisation time. For more precise information about Tc, fluid inclusion studies were performed. They provide additional data about salt concentrations in the crystallisation system, water behaviour in the analcime structure and crystallisation temperature.
EN
Mantled alkali feldspar megacrysts from the porphyritic granite variety of the Karkonosze Variscan pluton (SW Poland) have been studied. The feldspars contain numerous inclusions of minerals (mainly plagioclases), which form inner rims, marking successive zones of megacryst growth, and they are surroundet by a plagioclase mantle (rapakivi texture). Although, due to maturation and coarsening, the feldspars display a heterogeneous exsolutions pattern, in the core part some homogeneous sectors (without visible decomposition) are also preserved. Chemical composition of alkali feldspar megacrysts (including barium concentration) and of plagioclases (inner inclusions and mantle) has been determined and used for evaluation of thermal conditions of melt crystallization. The highest calculated temperature for single equilibrium and close-to-equilibrium pairs of un-decomposed domains in alkali feldspar + plagioclase inclusion ranges 809-750 stopni C. The differences in crystallization temperature calculated for the pairs alkali feldspar domains (megacryst) and plagioclase inclusions from successive inner rims or for the pairs alkali feldspar domains (megacryst) - plagioclase mantle varied within 100 stopni C. Common lack of equilibrium for neighbouring pairs of plagioclase inclusion - alkali feldspar is noticeable. Growth morphologies of plagioclases (inclusions and mantle) and alkali feldspar have been proved by means of CL. Mostly the feldspars display sings of resorption and re-growth at many stages of their formation. The barium concentration in the feldspars also points to discontinuous growth. The crystallization path of the megacrysts and the formation of rapakivi texture were influenced by magma mixing, not by decompression processes.
13
Content available remote Mechanizm rozpadu piaskowców wywołany krystalizacją soli
PL
Geneza krzemieni i czertów należy do największych zagadek współczesnej geologii. Od 1999 r. zespół polsko-amerykański, reprezentowany przez autorów niniejszego artykułu, prowadzi badania nad wyjaśnieniem warunków tworzenia się krzemieni górnojurajskich w rejonie Ożarowa (NE obrzeżenie Gór Świętokrzyskich). Stwierdzono istnienie antykorelacji pomiędzy *D i *18O. Obecne badania koncentrują się nad dwoma najbardziej prawdopodobnymi modelami genetycznymi krzemieni: (1) zmian temperatur na skutek działalności podmorskich źródeł hydrotermalnych, (2) samoorganizującej się katalitycznej krystalizacji. Uzyskane wyniki będą stanowić istotny wkład do badań nad genezą krzemieni i czertów z różnowiekowych formacji skalnych.
EN
The reaction An-rich plagioclase + quartz + fluid = analcime (NaAlSi4O12 * 2H2O) - wairakite (CaAl2Si4O12 * 2H2O)[ss] (solid solution series) has been studied experimentally in the temperature range 350-200 stopni C. Distilled water or 0.1 M NaHCO3 solution was used as fluid. All experiments have been performed under low silica activity. Due to the short duration of the experiments the reaction had not approached equilibrium and partly metastable phases were formed. Wairakite nucleated in the laumontite stability field in the system plagioclase-quartz-H2O. Higher sodium activites led to the formation of mixed analcime-wairakite crystals or analcime crystals. The mechanisms of zeolite formation seems to comprise topotaxial growth on the plagioclase surface caused by a dissolution-precipitation process. Some variations in the nucleation and growth kinetics were noticed which appear to be due to different physico-chemical conditions of zeolite formation
EN
Cancrinite and analcime were synthesized in the two hydrothermal systems: acid plagioclase - Na2CO3 - H2O and basic plagioclase - Na2CO3 - H2O under widely varying temperatures and salt concentrations in the solution. The IR 1^H MAS NMR DTG/TG analyses were carried out to determine water position in the crystals. Additionally IR spectra were recorded during subsequent dehydration and rehydration processes. The results of the investigations indicate that the water environment in both minerals is sensitive to the conditions of crystal formation. Crystallization temperature is the most important factor influencing water position. The water sites in the analcime and cancrinite crystals depend on structure modifications. Variations of the structure result from different chemical composition of the source material, structure of the substrates and the salt concentration in the solution. The structures formed under lower temperatures incorporate more water than those formed at high temperatures. In the cancrinite and analcime two main types of water, H2O(I) and H2O(II) appear. Other OH[m] groups can also be recognized. The position of water H2O(II) is better defined than that of H2O(I). H2O(II)is the most sensitive indicator of thermal conditions of the formation of cancrinite as well analcime. The amount of H2O(II) equals thatof H2O(I) in the products of low temperature (300 stopni C) syntheses. In crystals synthesized at high temperature (550 stopni C) the presence of H2)(II) is very limited.
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