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Aluvijalno-jezersko-marinski kompleks na Medvednici: rano sin-riftno taloženje i paleogeografija (rani do srednji miocen, Sjevernohrvatski bazen)
No full textMt. Medvednica belongs to the western part of the Neogene rift-type North Croatian Basin that occupies the south-western Pannonian Basin System. The Lower to Middle Miocene continental to marine sedimentary complex was studied on Mt. Medvednica in order to interpret the early syn-rift depositional environment and reconstruct palaeogeography of the North Croatian Basin. Based on facies analysis, deposits are grouped into 16 facies based on their lithological characteristics. Six of the facies belong to the alluvial environment that is characterized by coarse-grained bedload siliciclastics. Nine facies are of lacustrine origin. They comprise: a) limestone of shallow lake carbonate bench with silty coal of vegetated marsh, b) deep lake and prodelta marl with sand and conglomerate intercalations deposited by gravity flows, and c) coarse-grained Gilbert-type delta conglomerate. The lacustrine deposits compose a transgressive-regressive sequence. The studied succession ends by facies of calcareous silt intercalated by conglomerates. These deposits belong to the marine offshore to prodelta as the consequence of establishment of the connection to the sea. The deposition was strongly controlled by allogenic factors, such as synsedimentary tectonics, climate, eustatic sea level changes and explosive volcanic activity. The alluvial deposits of Mt. Medvednica are the oldest syn-rift deposits and belong to the large alluvial plain that probably covered the entire North Croatian Basin in the Ottnangian and the Karpatian. These deposits are overlain by the lower Badenian lacustrine deposits, but the question of the existence of one large or several small lakes in the early Badenian North Croatian Basin remains open.Gora Medvednica pripada zapadnomu dijelu neogenskoga riftnog Sjevernohrvatskog bazena, koji zauzima jugozapadni dio Panonskoga bazenskog sustava. Donjomiocenski do srednjomiocenski kontinentalno-marinski taložni kompleks istražen je na području Medvednice, s ciljem interpretacije sin-riftnoga taložnog okoliša i paleogeografske rekonstrukcije ranoga Sjevernohrvatskoga bazena. Analizom facijesa, na temelju litoloških karakteristika sedimenti su svrstani u 16 facijesa. Aluvijalnome taložnom okolišu pripada šest facijesa, koji su krupnozrnasti i rezultat su odlaganja vučnim mehanizmima. Jezerskog je postanka devet facijesa. Uključuju vapnenac plitkoga jezera tipa “bench” sa siltnim ugljenom vegetirane močvare, lapor s proslojcima pijeska i konglomerata odlaganih gravitacijskim tokovima u dubokome jezeru I prodelti te konglomerat krupnozrnaste delte tipa Gilbert. Ovi jezerski talozi formiraju transgresivno-regresivnu sekvenciju. Cijeli slijed završava facijesom marinskoga vapnenačkog silta s proslojcima konglomerata, koji pripada pučinskome taložnom okolišu, odnosno prodelti, uslijed uspostave veze s morem. Taloženje je bilo pod snažnim utjecajem alogenih čimbenika, kao što su sinsedimentacijska tektonika, klima, eustatske promjene razine mora i eksplozivna vulkanska aktivnost. Taložni je kompleks rezultat procesa riftanja koji su formirali Sjevernohrvatski bazen i odražavaju njegovu ranu sin-riftnu fazu. Aluvijalne naslage Medvednice su najstariji sin-riftni talozi i pripadaju prostranoj aluvijalnoj ravnici koja je zauzimala vjerojatno cijeli Sjevernohrvatski bazen u otnangu i karpatu. Prekriveni su donjobadenskima jezerskim naslagama, no pitanje o razvoju jednoga velikog jezera ili više manjih ostaje otvoreno
Conceptual model based on groundwater dynamics in the Northern Croatian Dinaric Region at the transition from the deep karst and fluviokarst
No full textThe Dinaric karst in the north differs from the rest of the karst in Croatia in terms of karstifi- cation depth. The infiltrating precipitation drains in cascades from deeply karstified mountainous areas to the shallow or fluviokarst, forming the tributaries of the Kupa River. Time series analyses were conducted on a 5-year dataset to elucidate the hydrogeological conceptual model of the area and clarify disparate findings from tracer tests under varying hydrological conditions. The flow duration curve, autocorrelation functions, and recession curves were used to evaluate the spring discharge variability, the karstification degree, and the karst aquifer’s size. The crosscorrelation function and temperature dynamics were employed to assess the spring’s response to recharge and the hydrogeo- logical system behavior. Comparative analysis with previous studies was conducted to contextualize the obtained results. The research outcomes delineated several key findings: (i) the deep karst zone is less developed than the shallow karst zone; (ii) groundwater exchange is significantly faster in shallow karst; (iii) groundwater divides in the Kapela Mountain are zonal; (iv) the homogenization of groundwater occurs during periods of high water levels; (v) fast water exchange transpires without concurrent groundwater temperature homogenization; and (vi) a definition of the boundary between deep and fluviokarst in Croatia
Dinamična geometrija: vizualizirati, konstruirati, dokazati
No full textJedan od važnih zadataka nastave geometrije je pomagati u uređenju i tumačenju svijeta oko sebe pomoću matematičkih pojmova. Svjesnim opažanjem okoline i tumačenjem pojava saznajemo nešto (više) o svijetu oko sebe, učimo svoju okolinu vidjeti drugim očima. U radu će se riješiti dva zadatka modeliranja, s posebnim naglaskom na integriranje različitih geometrijskih aktivnosti poput vizualiziranja, analiziranja, konstruiranja i dokazivanja. Rad je motiviran drugim zadatkom čija se modifikacija može naći na poveznici (JMC, 2001.), a njegovo rješavanje u ovom je radu nadopunjeno konstrukcijskom i analitičkom obradom kroz prepoznavanje nepoznatih elemenata krivulja 2. stupnja (kružnice i elipse) iz grafičkog prikaza, te određivanja njihovih pripadnih jednadžbi. Budući da učenici često doživljavaju matematiku kroz razvoj izoliranih koncepata i vještina nužnih za rad u različitim matematičkim područjima (algebra, analiza, statistika, geometrija...), cilj je integracijom različitih aktivnosti pri rješavanju problema istaknuti temeljne značajke matematičke znanosti u različitim matematičkim domenama. Primjena konstrukcijske metode podržana je upotrebom programa dinamične geometrije i povezuje se s geometrijskim razumijevanjem jednostavnih gibanja (pravocrtnih i kružnih). Osim toga, odabrani problemi naglašavaju međusobnu povezanost prostora i ravnine koja uključuje aktivno i mentalno djelovanje učenika, s ciljem rješavanja problema iz svakodnevnog života. Iako se oba zadatka oslanjaju se na praktičnu primjenu jedne od niza konstrukcija elipse poznate i pod nazivom mehanička konstrukcija elipse, koja će biti opisana kasnije u radu, jednostavnija varijanta prvog zadatka iz ovog rada može se implementirati već u osnovnoškolsku matematiku jer zahtijeva primjenu Talesova poučka o obodnom kutu nad promjerom kružnice
Reclmation of abandoned surface mines : master's thesis
No full textU ovome radu dan je kratak pregled novih zakonskih regulativa koje donosi Zakon o rudarstvu (NN 56/13, 14/14, 52/18, 115/18, 98/19, 83/23) te što vjerniji prikaz neaktivnih i brisanih eksploatacijskih polja te lokacija ilegalne eksploatacije mineralnih sirovina po županijama na području Republike Hrvatske. Podaci su prikupljeni iz postojećih rudarsko-geoloških studija i Jedinstvenog informacijskog sustava mineralnih sirovina te su sistematizirani kroz 21 potpoglavlje ovog rada. Obrađeni podaci uključuju nazive eksploatacijskih polja i koordinate lokacija ilegalne eksploatacije te podatke o površinama, vrsti mineralne sirovine koja se eksploatirala. Na kraju su prikazani uspješni modeli prenamjene eksploatacijskih polja na području Republike Hrvatske i svijeta.This final thesis provides a overview of the new legal regulations enacted by the Law on Mining (Official Gazette 56/13, 14/14, 52/18, 115/18, 98/19, 83/23) and a overwiev of inactive, deleted and illegal locations where mining activity was recored by county in the territory of the Republic of Croatia. The data were obtained from mining-geological studies and the Unified Information System of Mineral Resources and were systematized through 21 subsections of this paper. The processed data includes the names of the exploitation fields and the coordinates of the locations of illegal exploitation, as well as data on the surfaces, the type of mineral raw material that was exploited.. At the end, successful models of reclmation of exploitation fields in the territory of the Republic of Croatia and the world are presented
First occurrence of dumortierite in Croatia: its chemical composition and appearance as an igneous mineral in leucogranite-hosted pegmatite
No full textIn this article, dumortierite from Croatia is described for the first time. Dumortierite formed in a pegmatite dyke cutting through Cretaceous two-mica leucogranite of the magmatic-metamorphic complex of Mt. Moslavačka Gora. The pegmatite dyke shows a magmatic mineral association of coarse-grained quartz, orthoclase, microcline and albite, less abundant muscovite, biotite, pinkish andalusite and blue-coloured prismatic dumortierite I crystals. Subsequent alteration by titanium-rich hydrothermal fluids led to partial replacement of dumortierite I and andalusite by secondary fibrous to acicular purple dumortierite II enriched in Mg and Ti. During temperature decrease perthite developed in feldspars and at a still later stage, sericite partially replaced not only feldspars but also andalusite and both types of dumortierite along grain boundaries and cracks. Final alteration at very low temperatures caused formation of clay minerals at the expense of feldspars. According to mineral chemical analyses, the feldspars are represented by albite and K-feldspar with a low albite component. Biotite corresponds to annite and its subhedral shape and chemical composition point to magmatic crystallisation from a peraluminous melt derived from a crustal source. Coarse muscovite flakes contain 1.31-1.48 wt.% FeO and 0.56-0.70 wt.% TiO2. Their Na/(Na+K) ratios (0.08–0.09) prove a magmatic origin, whereas lower ratios in sericite (0.04–0.06) indicate formation during retrogression. Magmatic muscovite is in textural equilibrium with andalusite, also implying an igneous origin for the latter, which belongs to the S3 textural type of andalusite in felsic igneous rocks. Electron microprobe analyses clearly show a strong positive correlation between Si tetrahedral deficiency (3-Si) and the sum of Al+Ti, (R2= 0.85) in both types of dumortierite, implying Al replacement by Ti. However, Al replacement by Ti is not restricted to Al in the octahedral position, as generally accepted, but most probably also in the tetrahedral position. Distinct pleochroic colours in dumortierite are usually explained by the [Fe/(Fe+Ti)]x100 factor, but according to this study, elevated Mg contents stabilize red to violet coloured dumortierite at higher [Fe/(Fe+Ti)] x100 factors than those previously suggested.
Dumortierite-bearing pegmatite and host two-mica leucogranite show strong chemical similarities in their major, minor and trace element contents. Both rock types have a strong peraluminous character (ASI = 1.6 in pegmatite vs 1.8 in leucogranite), low CaO/Na2O ratios (0.11 vs 0.14), high Rb/Ba (74.5 vs 16.4) and Rb/Sr ratios (78.4 vs 43.3) as well as relatively high Al2O3/TiO2 ratios (261 vs 210). For the leucogranitic melt these characteristics indicate derivation from a pelitic source and low melting rates at relatively low temperatures. With respect to the field relationships and the chemical similarities, formation of the pegmatitic melt by fractional crystallisation during solidification of the two-mica leucogranite is inferred. Based on the mineralogical composition, the dumortierite-bearing pegmatite from Mt. Moslavačka Gora may be a member of the abyssal pegmatite class and the AB-BBe subclass. However, its formation by fractional crystallisation from a granitic melt argues against this interpretation, as all other dumortierite-bearing granitic pegmatites occur in high-grade metamorphic host rocks and are thought to be products of anatectic melting of country rocks. Therefore, the investigated pegmatite is quite unique and not fully comparable with any previously described dumortierite-bearing pegmatite worldwide
Specifics of designing and completion of geothermal wells : master's thesis
No full textGeotermalna energija uz energiju vjetra, solarnu energiju, hidroenergiju i biomasu pripada u skupinu obnovljivih izvora energije a predstavlja alternativu fosilnim gorivima. Izrada geotermalne bušotine je skup složenih operacija i procesa koje zahtijevaju detaljno planiranje. Plan izrade bušotine određen je projektom istražne geotermalne bušotine bez kojeg se ne može započeti bušenje, a isti mora biti odobren od nadležnih institucija. Sami projekt bušotine mora sadržavati geološki i geofizički pregled područja zahvata, tehničko-tehnološki projekt bušotine, plan sanacije ukoliko se istražna bušotina proglasi negativnom i mjere sigurnosti i zaštite okoliša uz pomoć kojih se operacije izvode na siguran i ekološki prihvatljiv način. U radu je prikazan ogledni primjer tehničko-tehnološkog projekta istražne geotermalne bušotine X na istražnom području Z koji detaljno opisuje operacije koje se izvode prilikom izrade kanala bušotine, način na koji se iste provode te su navedeni materijali koji se planiraju koristiti.Geothermal energy, along with wind energy, solar energy, hydro energy and biomass, belongs to the group of renewable energy sources and represents an alternative to fossil fuels. The construction of a geothermal well involves a complex set of operations and processes that require detailed planning. A good construction plan is determined by the design of the exploratory geothermal well, and without it drilling cannot begin. It must also be approved by the competent authorities. The well project itself must include geological and geophysical surveys of the area, the technical and technological design of the well, a remediation plan if the exploratory well is deemed unsuccessful and measures for environmental safety and protection to ensure that operations are conducted in a safe and environmentally friendly manner. This thesis presents an exemplary technical and technological project of the exploratory geothermal well X in the research area Z, which describes operations performed during the construction of the wellbore, how they are carried out, and the materials planned for its cunstruction
Odobalna postrojenja za proizvodnju, skladištenje i iskrcaj nafte : završni rad
No full textPorast potražnje za naftom i naftnim derivatima utjecao je na proširenje područja istraživanja s kopna na more. Istraživanje dubljih dijelova mora i oceana rezultiralo je otkrivanjem većeg broja manjih naftnih polja. Razvoj tehnologije za privođenje takvih naftnih polja eksploataciji rezultiralo je razvojem odobalnih postrojenja za proizvodnju, skladištenje i iskrcaj nafte. Korištenjem takvih postrojenja smanjeni su troškovi proizvodnje i obrade nafte, a mogućnost prekrcaja nafte na tankere utjecala je na povećanje broja naftnih tankera većih dimenzija i veće nosivosti
Prezentacija novog sveučilišnog diplomskog studijskog programa RGN fakulteta Primijenjena geologija i geološko inženjerstvo : modul Geologija mineralnih sirovina i okoliša
No full textEnhancing the understanding of subsurface relations: machine learning approaches for well data analysis in the Drava Basin, Pannonian Super Basin
No full textThe aim of this study was to confirm if predictive regression algorithms can provide reliable results in missing geophysical logging data in the western and eastern parts of the Drava Super Basin, especially Gola Field, and to apply unsupervised machine learning methods for a better understanding of lithological subsurface relations. Numerous regression models have been used for the estimation of prediction accuracy, along with some clustering algorithms to support the estimation of lithology distribution estimations in well log datasets, consisting of 20 wells in total. Tree-based algorithms and the boosting algorithm have been optimized and proven valuable in predicting well log data when they are not measured or are unavailable at all depth intervals. For blind datasets, predictions become much less reliable. For this purpose, neural networks with at least one Long Short-Term Memory (LSTM) layer have significantly improved the accuracy and reliability of predictions, not in terms of absolute values but in the aspect of the trends in values that change with the depth and other well features, as well as in terms of the magnitudes. Trendlines can further be used for pattern recognition or as a newly engineered feature. Unsupervised learning has confirmed reliability in lithology recognition on validation sets and has proven to be a great asset in distinguishing variabilities in the petrophysical properties of sediments
Trend svjetline noćnog neba iznad Zagreba u razdoblju 2012.–2022.
No full textSvjetlosno onečišćenje iznad zgrade RGN fakulteta (u blizini središta Zagreba) mjereno je od siječnja 2012. do kolovoza 2022. Prvi dio podataka, od 2012. do 2017., je već bio obrađen i zaključci su objavljeni u Andreić (2018). Glavni zaključci te analize su ponovljeni ovdje radi usporedbe i kompletnosti. Rezultati analize preostalih podataka, od siječnja 2018. do srpnja 2022., su izneseni u ovom radu. Prva analiza je pokazala da se prosječna svjetlina noćnog neba nije znatno mijenjala u periodu od 2012. do 2017., osim razlika zbog godišnjih varijacija meteoroloških parametara. Drugi niz podataka (2018. do 2022.) pokazuje maleno smanjenje svjetline noćnog neba u usporedbi s prvim nizom. Smanjenje je malo, oko 0.2 mag/arcsec2 (srednje vrijednosti). Drugi set pokazuje lagani trend prema tamnijim noćima u kasnijim godinama koji je započeo prije tri ili četiri godine (oko 2019. ili 2020.). On je pripisan modernizaciji javne rasvjete, kod koje se zastarjele i loše svjetiljke pomalo zamjenjuju modernim LED svjetiljkama, i utjecaju klimatskih promjena koje donose toplije zime i vedrije noći.Svjetlosno onečišćenje iznad zgrade RGN fakulteta (u blizini središta Zagreba) mjere-no je od siječnja 2012. do kolovoza 2022. Prvi dio podataka, od 2012. do 2017., je već bio obrađen i zaključci su objavljeni u Andreić (2018). Glavni zaključci te analize su ponov-ljeni ovdje radi usporedbe i kompletnosti. Rezultati analize preostalih podataka, od siječnja 2018. do srpnja 2022., su izneseni u ovom radu.Prva analiza je pokazala da se prosječna svjetlina noćnog neba nije znatno mijenjala u periodu od 2012. do 2017., osim razlika zbog godišnjih varijacija meteoroloških para-metara. Drugi niz podataka (2018. do 2022.) pokazuje maleno smanjenje svjetline noćnog neba u usporedbi s prvim nizom. Smanjenje je malo, oko 0.2 mag/arcsec2 (srednje vrijed-nosti). Drugi set pokazuje lagani trend prema tamnijim noćima u kasnijim godinama koji je započeo prije tri ili četiri godine (oko 2019. ili 2020.). On je pripisan modernizaciji javne rasvjete, kod koje se zastarjele i loše svjetiljke pomalo zamjenjuju modernim LED svjetiljkama, i utjecaju klimatskih promjena koje donose toplije zime i vedrije noći