Provider: - Institution: - Data provided by Europeana Collections- Analiziran je prostor Bjelovarske subdepresije na lokalnoj (polje Šandrovac) i regionalnoj razini (cijela subdepresija). Ulazni ...podatci bile su dubine EK granice Pt/Tg i EK markera Rs7, Rs5, Z', Δ i D'. Statistički je analizirano više od sedamsto podataka očitanih s pravilne mreže kojom su prekrivene postojeće paleostrukturne karte, s ćelijama veličine 2x2 km. Kartirano je metodama Thiessenovih poligona (program SAGA GIS) i krigiranja (Surfer). Poligonalna, tj. zonalna procjena uporabljena je kao jednostavna i brza metoda prikaza dubina. Krigiranje je dalo znatno bolje regionalne karte. Obično krigiranje je dokazano u većini slučajeva kao najbolja moguća interpolacija podataka dubine (Pt/Tg, Rs7, Z' i D'), uz najmanje vrijednosti krosvalidacije. Njome su interpolirane karte debljina formacija iz kojih su reinterpretirani neogensko-kvartarni okoliši. Nadalje, unutar pojedinačnih struktura, tehnika univerzalnoga krigiranja određena je kao najprimjerenija interpolacijska metoda, jer je samo u takvim slučajevima bilo moguće izdvojiti jasan linearni trend u pružanju i dubinama promatrane strukture.- The area of Bjelovar subdepression was analyzed at the local (Šandrovac Field) and regional level (the entire subdepression). Input data were depths of Pt/Tg e-log border and Rs7, Rs5, Z’, Δ and D' e-log markers. More than seven hundred data were statistically analyzed. The data were collected in a regular grid that covers the existing paleostructural maps, with cells 2x2 km in size. Mapping was carried out using Thiessen polygon method (program SAGA GIS) and Kriging (Surfer). The polygonal, i.e. the zonal assessment was used as a simple and fast method for displaying depths. Kriging gave significantly better regional maps. Ordinary Kriging has been proved in most cases to be the best possible interpolation of depth data (Pt/Tg, Rs7, Z' and D'), with the lowest cross-validation values. It was used for interpolation of formation thickness maps from which Neogene-Quaternary environments were reinterpreted. Furthermore, within the individual structures, Universal Kriging technique is determined as the most appropriate interpolation method, because it was only possible in such cases to extract a clear linear trend in extent and depths of the observed structure.- All metadata published by Europeana are available free of restriction under the Creative Commons CC0 1.0 Universal Public Domain Dedication. However, Europeana requests that you actively acknowledge and give attribution to all metadata sources including Europeana
Provider: - Institution: - Data provided by Europeana Collections- Klastični sedimenti poznati kao Viviparus slojevi predstavljaju posljednju fazu jezerske sedimentacije u južnom dijelu PBS-a. ...Stratigrafski pripadaju pliocenu, a taloženi su unutar kata cernik u vremenskom rasponu od 4,5 – 2 milijuna godina. Na prostoru Vukomeričkih gorica, gdje su površinski najrasprostranjeniji, dokazano je taloženje donjih i gornjih Viviparus slojeva. Analizom facijesa i fosilnog sadržaja utvrđeno je da se njihovo taloženje odvijalo u plitkom slatkovodnom jezerskom i aluvijalnom okolišu. Donji Viviparus slojevi diskonformni su na miocensku podlogu, pripadaju zoni Viviparus kochanskyae i taloženi su u vrijeme umjereno tople i vlažne klime s izraženim sezonskim oscilacijama sezonalnošću. Gornji Viviparus slojevi taloženi su u uvjetima pliocenskog klimatskog optimuma, bez izražene sezonalnosti, a pripadaju zoni Viviparus hoernesi. Međusobno ispreplitanje jezerskih i aluvijalnih okoliša ukazuje na oscilacije razine vode uz zapadni rub tadašnjeg jezera Slavonija, a izostanak srednjih Viviparus slojeva pokazatelj je smanjenja površine jezera, odnosno jake regresije u srednjem cerniku. Modalni i kemijski sastav klastičnog detritusa ukazuje na njegovo dominantno podrijetlo iz starijih sedimentnih i kiselih magmatskih stijena čija su izvorišta bila lokalno izdignuta gorja i pretaloženi gornjomiocenski materijal alpske provenijencije.- Clastic sediments known as Viviparus beds represent the last phase of lacustrine sedimentation in the southern part of Pannonian Basin System. Based on stratigraphy they belong to the Pliocene epoch, within time period from 4.5 to 2 Ma as a part of the Cernikian stage. In the area of Vukomeričke gorice two stratigraphic horizons have been detected, Lower Viviparus beds and Upper Viviparus beds. Facies analysis and fossil content have shown that the deposition of these freshwater sediments occured in predominantly shallow lacustrine and alluvial environment. The Lower Viviparus beds lay disconformly on Miocene sediments, they belong to the Viviparus kochanskyae zone and they are deposited in the moderately warm and humid climate with strong seasonality. Upper Viviparus beds, belonging to Viviparus hoernesy zone, were deposited under conditions of the Pliocene climate optimum, without strong seasonality. Alternation of lacustrine and alluvial environment indicates the fluctuations of water level along the western edge of the former lake Slavonia while the absence of middle Viviparus beds suggests a decrease in the lake’s surface or its regression in the Middle Cernikian. Modal and chemical composition of clastic detritus indicates that it originates from the older sedimentary rocks as well as predominantley acidic igneous rocks whose source were locally raised mountains and resedimented material of Alpine provenance from Upper Miocene.- All metadata published by Europeana are available free of restriction under the Creative Commons CC0 1.0 Universal Public Domain Dedication. However, Europeana requests that you actively acknowledge and give attribution to all metadata sources including Europeana
Provider: - Institution: - Data provided by Europeana Collections- Nuotrauka- All metadata published by Europeana are available free of restriction under the Creative Commons CC0 1.0 Universal Public ...Domain Dedication. However, Europeana requests that you actively acknowledge and give attribution to all metadata sources including Europeana
Provider: - Institution: - Data provided by Europeana Collections- Fizikalno-kemijska svojstva nanočestica (NČ), prvenstveno visoka reaktivnost, utječe na biodostupnost i sudbinu NČ u vodenom ...okolišu. Ovaj rad opisuje primjenu elektroanalitičkih metoda u određivanju i karakterizaciji NČ. Kronoamperometrijskim (CA) i voltametrijskim mjerenjima su detektirane NČ metalnih sulfida (MeS) i elementarnog sumpora (So) u modelnim sustavima. Na osnovu primijenjenog potencijala živine elektrode (Hg) određena je vrsta NČ MeS. Naboj detektiranih šiljastih signala u CA ovisi o dijametru NČ, dok frekvencija udara ovisi o udjelu NČ s dijametrom manjim od 200 nm. S CA je praćen proces aglomeriranja u ovisnosti o primijenjenim eksperimentalnim uvjetima. Kako bi se potvrdila elektroanalitička mjerenja na Hg elektrodi, provedena su mjerenja pri istim eksperimentalnim uvjetima metodama koje se standardno koriste u karakterizaciji NČ (DLS, NTA, AFM i EC-STM). Razvijena CA metoda je primijenjena za detekciju NČ u prirodnim euksiničnim vodenim sustavima.- Physico-chemical properties of nanoparticles (NPs), mainly high reactivity, affect their bioavailability and fate in aquatic environment. This work shows development of electroanalytical methods in detection and characterization of NPs. Chronoamperometry (CA) and voltammetry were used for detection of the metal sulphide (MeS) and sulphur (So) NPs in modal solutions. Based on the applied potential of the working mercury electrode (Hg) it is possible to differentiate between MeS NPs. The charge of recorded spike like signals is related to NPs size, while signal frequency depends on the presence of the NPs smaller than 200 nm. With use of CA agglomeration processes under different experimental conditions were monitored. In order to confirm electrochemical measurements in parallel intercomparison measurements with methods used in the characterization of NPs (STM, AFM, DLS, NTA) were done under same experimental conditions. CA was applied in detection of the NPs in natural aquatic euxinic systems.- All metadata published by Europeana are available free of restriction under the Creative Commons CC0 1.0 Universal Public Domain Dedication. However, Europeana requests that you actively acknowledge and give attribution to all metadata sources including Europeana
U radu je opisana prva sveobuhvatna suvremena tipologija protočnih režima Hrvatske. U prvome dijelu daje se pregled dosadašnjih pristupa i metoda izdvajanja tekućica, odnosno protočnih režima u ...Hrvatskoj i svijetu. Nakon toga prikazani su rezultati klasifikacije 76 protočnih režima 51 tekućice u Hrvatskoj za razdoblje 1990. – 2009. Režimi su određeni upotrebom modulnih (Pardéovih) koeficijenata pa grupirani taksonomskom (klasterskom) metodom. Za grupiranje je upotrijebljena hijerarhijska Wardova metoda s primjenom Manhattan udaljenosti koja je provjerena nehijerarhijskom K-means metodom. Dobiveno je sedam tipova protočnih režima Hrvatske: 1) alpski snježno-kišni režim, 2) dinarski kišno-snježni režim, 3) peripanonski kišno-snježni režim, 4) panonski kišno-snježni režim, 5) panonski kišni režim, 6) sredozemni kišno-snježni režim, 7) sredozemni kišni režim. Svaki je tip opisan. Broj i prostorni raspored tipova upućuju na raznolikost protočnih režima rijeka u Hrvatskoj, koja je prije svega uvjetovana rasporedom i međuodnosom prirodnogeografskih elemenata te kod nekih rijeka i znatnijim ljudskim intervencijama. Rezultati trebaju biti polazište za kvalitetne prikaze, analize i održivo upravljanje tekućicama Hrvatske.
Provider: - Institution: University of Zagreb. Faculty of Science. Department of Geology. Division of Geology and Paleontology. - Data provided by Europeana Collections- Na prostoru sjeverne ...Dalmacije pet je geoloških stupova ranopaleogenskih karbonatnih naslaga (Čikola I i II, Novigrad, Ostrovica i Grabova Glava) bilo predmetom detaljnih sedimentoloških i mikropaleontoloških istraživanja, te su biostratigrafskim pristupom u kombinaciji s mikrofacijesnom analizom rekonstruirani karbonatni taložni okoliši tijekom taloženja. Taloženje se odvijalo u okolišima unutarnjih, srednjih i vanjskih dijelova rampi, a organizmi koji su obilježili te okoliše bile su velike bentičke foraminifere. Tijekom paleogena kolizijski procesi između Jadranske mikroploče i Euroazijske kontinentalne ploče uzrokovali su formiranje predgorskog bazena ispred uzdižućeg dinaridskog orogena, te je ranopaleogenska transgresija započela u različitim bazenima, odnosno u različitim dijelovima Vanjskih Dinarida, u različito vrijeme taloženjem naslaga bočatih laguna, koje su u literaturi poznate pod imenom Kozinske naslage. Istraživane naslage nalaze su u dijelu bazena poznatom kao sjevernodalmatinski bazen. Tijekom postojanja sjevernodalmatinskog dijela predgorskog bazena optimalni uvjeti za taloženje karbonatnih naslaga postignuti su u dva navrata, u ranom eocenu, kada su taloženi Foraminiferski vapnenci na širokom području forebulge sustava, te u srednjem eocenu kada su na padinama wedge-top bazena taloženi Gornji Numulitni vapnenci. Tijekom različitih vremenskih intervala, od ipra do bartona, na prostorima predgorskog bazena, pružanja SZ–JI, u okolišima nastalim na rampama, uz kontrolu sinsedimentacijske tektonike, taložen je nekoliko stotina metara debeo slijed naslaga u okolišima koje opisujemo kao Dinaridski sustav karbonatnih rampa.- In the Northern Dalmatia area five outcrops of the lower Palaeogene carbonate deposits (Čikola I i II, Novigrad, Ostrovica i Grabova Glava) have been the subject of detailed sedimentological, micropaleontological and microfacies research. Furthermore, the biostratigraphic approach in combination with conventional facies analysis was used to reconstruct a range of carbonate depositional systems. Carbonate sedimentation took place in the inner, middle to outer ramp environments, where the dominant organisms were Large Benthic Foraminifera. The collision processes between the Adriatic continental microplate and Euroasia continental plate caused the formation of the Dinaridic foreland basin, developed during the Palaeogene in front of the uplifting mountain belt. Early Palaeogene transgression occurred in different times in different basins, as parts of the Outer Dinarides, firstly by the brackish lagoonal deposits known in literature as Kozina beds. Studied deposits are part of the Northern Dalmatian foreland basin and during its existence the conditions for the carbonate sedimentation were attained on two occasions. During the Early Eocene Foraminifera limestones were deposited on the vast forebulge area, and in the Middle Eocene Upper Nummulitic limestones deposited on the limbs of the wedge-top basins. During the different time intervals, spanning from the Ypresian to the Bartonian, in the NW–SE oriented foreland basin, carbonate ramps developed, controlled by synsedimentary tectonics, creating a couple hundreds of meters of deposits within environments described as Dinaridic Carbonate Ramps System.- All metadata published by Europeana are available free of restriction under the Creative Commons CC0 1.0 Universal Public Domain Dedication. However, Europeana requests that you actively acknowledge and give attribution to all metadata sources including Europeana
Provider: - Institution: - Data provided by Europeana Collections- Nitrati predstavljaju jedno od glavnih onečišćivala podzemne vode u svijetu. U podzemnoj vodi zagrebačkoga vodonosnika ...okarakterizirani su kao jedna od pet glavnih grupa onečišćivala. Smanjenje koncentracije određenog onečišćivala najviše ovisi o definiranju njegovog podrijetla. Za potrebe određivanja podrijetla nitrata i povezanih geokemijskih procesa u podzemnoj vodi zagrebačkoga vodonosnika korištene su razne geokemijske i statističke metode. U okviru geokemijskih metoda određeni su stabilni izotopi kisika i vodika iz vode, te dušika i kisika iz nitrata. Također, napravljena je analiza molarnih omjera nitrata s kloridima, natrijem i kalijem. U okviru statističkih metoda korištene su korelacijske i multivarijatne statističke analize. Većina analiza napravljena je na dostupnim povijesnim kemijskim analizama podzemne vode, te na podacima izmjerenima u podzemnoj vodi i rijeci Savi uzorkovanoj za potrebe ovog rada. Stabilni izotopi vode pokazali su kako je podzemna voda izotopno najsličnija rijeci Savi i oborini iz Ljubljane. Interpretacijom rezultata stabilnih izotopa kisika i dušika iz nitrata utvrđeno je kako je podrijetlo nitrata za vrijeme uzorkovanja podzemne vode bilo organsko. Kao glavni izvori onečišćenja izdvojeni su otpadne vode i organsko gnojivo. Također, rezultati upućuju na to da denitrifikacija predstavlja zanemariv proces koji se odvijao u podzemnoj vodi zagrebačkoga aluvijalnog vodonosnika za vrijeme uzorkovanja. Korelacijske analize pokazale su kako kloridi i natrij predstavljaju vrlo bitne parametre u proučavanju podrijetla nitrata. Korištenje multivarijatnih statističkih analiza omogućilo je izdvajanje parametara koje su mogu koristiti kao pokazatelji antropogenog utjecaja. Također, korištenjem klaster analize određeni su piezometri na kojima glavni izvor onečišćenja predstavljaju otpadne vode, odnosno organsko gnojivo. Pritom se proučavanje molarnih omjera, prvenstveno nitrata i kalija, pokazalo kao ključno. Utvrđeno je kako se stabilni izotopi dušika i kisika iz nitrata, u kombinaciji s analizom molarnih omjera, mogu vrlo učinkovito koristiti u procjeni podrijetla nitrata na području zagrebačkoga vodonosnika. Osim toga, korelacijske i multivarijatne statističke analize pokazale su kako stabilnost i transformacija nitrata na promatranom području ovisi o koncentracijama otopljenoga kisika. Također, rezultati upućuju na to da se dušik u podzemnu vodu zagrebačkoga vodonosnika u velikim količinama unosi u obliku amonij iona nakon čega se nitrifikacijom pretvara u nitrate, što se slaže i sa izračunatim vrijednostima intervala karakterističnog za nitrifikaciju dušikovih spojeva. Trendovi su izračunati pomoću linearne regresije na četiri razine zajedno s njihovim intervalima pouzdanosti i predviđanja. Analiza
trendova nitrata utvrdila je postojanje statistički značajnih silaznih trendova koncentracija nitrata, osim u priljevnom području crpilišta Petruševec te Sašnjak i Žitnjak, na kojima su utvrđeni statistički značajni, uzlazni trendovi.- Nitrates present one of the major groundwater contaminants in the world. In the groundwater of Zagreb aquifer they are characterized as one of the five main groups of contaminants. The most important thing associated with decrease of contaminant concentration is the definition of its origin. Various geochemical and statistical methods have been used for the determination of nitrates origin and related geochemical processes in the Zagreb aquifer. Within geochemical methods, water stable isotopes and nitrate stable isotopes were calculated on sampled river and groundwater. Sava River and groundwater was sampled in the period from November 2015 to October 2016. Sampling was preliminarily performed on 56 observation wells, after which 30 observation wells were selected for monitoring of nitrate stable isotopes in time. Molar ratios of nitrate and chlorides, nitrate and sodium, and nitrate and potassium were calculated for both historical groundwater chemical analysis and for chemical analysis conducted on sampled river and groundwater. Correlation and multivariate statistical analysis have been used within statistical methods. All of the statistical analysis were done on historical groundwater quality data as well as on data measured on sampled river and groundwater. Historical data analysis of nitrate concentrations showed that there are two main areas of Zagreb aquifer where elevated nitrate concentrations have been identified. One area is located on the left bank of the Sava River, in the dominantly urban area, while other is located on the right bank, in the dominantly rural area, where agricultural activity is also present. Water stable isotopes showed that groundwater is isotopically most similar to Sava River and precipitation from Ljubljana, and least to the precipitation that falls in the area of Zagreb aquifer. Interpretation of nitrates stable isotopes showed that nitrate origin within the sampling period was organic. Wastewater and manure have been recognized as main sources of nitrate contamination. Comparison of δ15N-NO3- with nitrate concentrations, as well the values of calculated enrichment factors, suggest that denitrification is a negligible process that takes place in alluvial part of Zagreb aquifer. Results also suggest that nitrogen in Zagreb aquifer is in large extent introduced in the form of ammonium ions, after which is transformed to nitrates by nitrification. This assumption is supported by the calculated interval of δ18O-NO3- characteristic for nitrification of organic nitrogen compounds. Correlation analysis showed that chloride and sodium concentrations present very important parameters in study of nitrate origin. Factor and cluster analysis conducted on chemical analysis data showed that chlorides, sulphates, sodium and potassium present variables that can be used as main indicators of anthropogenic influence on groundwater
quality in the Zagreb aquifer. The use of cluster analysis allowed the definition of observation wells where nitrates concentrations were mostly related to wastewater or manure. Four clusters of observation wells were defined based on nitrate, chlorides, sulphates, sodium and potassium concentrations, values of stable nitrate isotopes and molar ratios of nitrates to all other used ions. For observation wells in three clusters wastewater was defined as main source of contamination. In that sense the study of the molar ratios, especially nitrate and potassium, was found to be crucial. Groundwater from observation wells were manure was identified as main source of contamination had the highest molar ratios and lowest δ15N-NO3- values. It has been concluded that investigation of molar ratios, in combination with nitrate stable isotopes, can be very effectively used in estimation of nitrate origin in groundwater of Zagreb aquifer. In addition, correlation and multivariate statistical analysis have shown that nitrates present parameter whose stability and transformation in the groundwater of Zagreb aquifer is basically dependent on the dissolved oxygen concentrations. The nitrate trend analysis established the existence of statistically significant decreasing trends of nitrate concentrations, except in Petruševec and Sašnjak and Žitnjak well field influence area. It has been shown that evaluation of nitrate trends in different levels, in combination with confidence and prediction intervals, can provide more realistic insight in areas where nitrates contamination occurs. Also, it has been concluded that linear regression presents appropriate method for estimation of nitrate trends.- All metadata published by Europeana are available free of restriction under the Creative Commons CC0 1.0 Universal Public Domain Dedication. However, Europeana requests that you actively acknowledge and give attribution to all metadata sources including Europeana
Razvoj znanstvenih disciplina koje se s raznih aspekata bave Zemljom, njenim postankom, njenom poviješću, sastavom i procesima kroz koje je prolazila ili upravo prolazi, izuzetno je napredovao ...posljednjih nekoliko desetljeća. Količina znanja se enormno povećala, a s njim i terminologija kojom se to znanje izražava. Točno poznavanje značaja nekog izraza posebno je važno za osobe koje se i same bave stručnim i znanstvenim radom, koji prate radove objavljene u stručnim časopisima i koje i same u njima objavljuju svoje radove.
Ovdje su prikazani prikupljeni pojmovi iz područja fenomena krša koji se odnose na njegove površinske i podzemne morfolološke oblike.
Provider: - Institution: University of Zagreb. Faculty of Science. Department of Geophysics. - Data provided by Europeana Collections- Intenzivne konvektivne oluje često predstavljaju potencijalnu ...opasnost za ljudski život i materijalna dobra, dok je vrijeme i mjesto nastanka te intenzitet istih još uvijek teško predvidiv i predstavlja jedan od najvećih izazova u prognozi vremena. Izuzetnu važnost u prognozi konvekcije imaju satelitski podaci i podaci o munjama, a njihovo karakteristično ponašanje prije i tijekom grmljavinskih oluja može uvelike poboljšati prognozu neposrednog razvoja vremena (eng. nowcasting). U ovom radu korišteni su podaci s geostacionarnih satelita druge generacije Meteosat-9 i Meteosat-10 te podaci o munjama iz međunarodnog LINET (od eng. LIghnting NETwork) sustava. Uspoređene su četiri objektivne satelitske metode koje se temelje na kombinaciji satelitskih kanala u infracrvenom dijelu spektra i služe za detekciju premašujućeg vrha (OT, od eng. Overshooting Top) iznad nakovnja kumulonimbusa (Cb), koji je posljedica jake uzlazne struje unutar konvektivne ćelije. Utvrđeno je da najmanji broj pogrešnih detekcija ima nova jednostavna objektivna satelitska metoda, nazvana COMB (od eng. COMBination). Većina pogrešno detektiranih OT-ova koristeći spomenutu metodu nalazila se u području specifičnih termičkih oblika na vrhovima konvektivnih oblaka (hladnog prstena ili hladnog U/V) koji su također karakteristični za intenzivnu konvektivnu aktivnost. U blizini detektiranih OT-ova najčešće dolazi do olujnih udara vjetra koji su često praćeni intenzivnim pljuskom, dok je u značajnom broju slučajeva zabilježen i izražen pad temperature. Analizom grmljavinske aktivnosti nad promatranim područjem utvrđeno je da su grmljavinski najaktivnija pred-alpska područja, a u Hrvatskoj Istra u ljeto i južni Jadran tijekom jesenskih mjeseci. Neposredno prije ili za vrijeme OT-a te prije pojave tuče pri tlu opažen je nagli porast broja ukupnih električnih izboja, izmjerene su najviše amplitude struje i opažen porast srednje visine munja između i unutar oblaka.- Extended abstract in the dissertation (pp. ii-x)- All metadata published by Europeana are available free of restriction under the Creative Commons CC0 1.0 Universal Public Domain Dedication. However, Europeana requests that you actively acknowledge and give attribution to all metadata sources including Europeana
Provider: - Institution: - Data provided by Europeana Collections- Tijekom srednjega trijasa na području Vanjskih Dinarida tektonika povezana s
otvaranjem Tetiskog oceana dovela je do značajne ...diferencijacije taložnih okoliša. Istovremeno
su egzistirala izdignuta područja sa značajkama subaerske vulkanske aktivnosti i trošenja
starijih stijena te njihova pretaloživanja, kao i plitkomorski prostori obilježeni karbonatnom
sedimentacijom te dublja, pelagička morska korita u kojima su taloženi različiti sedimenti
uključujući i vulkanoklastične i vulkanske stijene. Cilj provedenog istraživanja je bio definirati
i opisati srednjetrijaske vulkanoklastične naslage, odrediti njihov stratigrafski položaj u
Vanjskim Dinaridima, definirati taložne okoliše u kojima su nastale, geokemijskim podacima
povezati ih s geotektonskim okolišem u kojem je nastala magma koja je producirala
vulkanoklastične naslage te usporediti razvoj prostora Vanjskih Dinarida s okolnim prostorima
zapadnog Tetisa. Analizirane su petrološko-sedimentološke, mineraloške i geokemijske
karakteristike vulkanoklastičnih naslaga s pet lokaliteta u Vanjskim Dinaridima (Donje
Pazarište i Jovanović Draga u okolici Gospića, Bosansko Grahovo u Bosni i Hercegovini,
Zelovo u blizini Sinja, i Plavno u blizini Knina). Mikropetrografskim metodama određeni su
facijesi istraživanih stijena i mehanizmi njihova postanka čime je omogućena rekonstrukcija
taložnih okoliša. Analizama konodontnog materijala biostratigrafski je određena starost te je
postavljen vremenski okvir taloženja vulkanoklastita srednjega trijasa. Geokemijskim
analizama dobiveni su podaci koji su korišteni za klasifikaciju istraživanih stijena, odredbu
geotektonskog okvira i porijekla magme iz koje su nastale vulkanoklastične naslage, te je
omogućena rekonstrukcija petrogenetskog modela u srednjem trijasu Vanjskih Dinarida.
Vulkanoklastične naslage srednjega trijasa nastajale su u kopnenim i marinskim okolišima.
Većina istraživanih lokaliteta ima obilježja dubljevodne pelagičke sedimentacije. Taloženje
ovih naslaga u Vanjskim Dinaridima vezano je za prijelazni interval iz anizika u ladinik, kao i
u većini okolnih prostora zapadnog dijela nekadašnjeg Tetiskog oceana. Geokemijska obilježja
vulkanoklastičnih i vulkanskih stijena ukazuje na kalcijsko-alkalijsku magmu kontaminiranu
krustalnim materijalom nastalu u složenom geotektonskom sustavu. Sedimentološka obilježja
istraživanih vulkanoklastita i s njima udruženih sedimentnih stijena dokazuju postojanje
nepotpuno razvijenih malih riftnih sustava.- In the Middle Triassic times, the External Dinarides were a part of the Western Tethyan
domain (Haas et al., 1995; Stampfli & Borel, 2002; 2003; Scotese et al., 2004). A deposition of
the Early Triassic low energy carbonate-siliciclastic sediments of the epeiric ramp (Aljinović
et al., 2014) was interrupted in the Middle Triassic by vigorous and extensive tectonic activity
related to the opening of the Tethyan Ocean. Tectonic activity was accompanied by volcanism
and formation of volcanic and volcaniclastic rocks. These tectonic movements caused the
differentiation of the relief, thus forming different rift related tectonic structures. Some tectonic
blocks were uplifted and prone to subaerial erosion while others were subsided and developed
different deep marine, pelagic facies. All depositional environments were under the influence
of volcanic activity. However, some areas experienced long lasting shallow marine, mostly
carbonate sedimentation. The Middle Triassic volcanic and volcaniclastic rocks were
investigated by various authors (e.g. Poljak & Tajder, 1948; Lugović & Majer, 1983; Pamić,
1984; Marci et al., 1991; Trubelja et al., 2004; Garašić et al., 2006; Preglej, 2006; Hrvatović et
al., 2011; Aljinović et al., 2011). Some of them pronounced the controversial relation between
the geochemical data of volcanic rocks and geotectonic setting in the Middle Triassic (Lugović
& Majer, 1983; Pamić, 1984; Trubelja et al., 2004; Garašić et al., 2006). That resulted in the
unambiguous interpretation of the magma origin. Geochemical data all indicate calc-alkaline
magma composition, which is more common in the subduction areas than in rift zones. The
typical Middle Triassic rift related magmatic rocks (ophiolites) are still not found in the External
Dinarides.
The aim of this dissertation is to present the petrological, sedimentological,
stratigraphical and geochemical data of the investigated volcaniclastic rocks and to unravel its
genesis and origin. Therefore, volcaniclastic rocks at five localities in the External Dinarides
were investigated. The field methods included recording the sedimentary sections in which
different volcaniclastic rocks crop out. Petrographical methods were used to analyse
micropetrographic composition (in thinsections) and differentiate sedimentary facies based on
the lithology and depositional processes. The differentiation of the facies allowed
reconstruction of the depositional mechanisms and prediction of the sedimentary model for
each of the investigated localities. Carbonate sedimentary rocks associated with the
volcaniclastics served for conodont analysis that enabled the biostratigraphic constrains of the
volcanic activity. The high-resolution conodont biostratigraphy also enabled the correlation of
the investigated sequences. Geochemical analysis aimed to determine the magma composition
and according to that interpret geotectonic position of the investigated area.
In Lika, part of the Velebit Mts., the five small localities were investigated adjacent to
the village Donje Pazarište. In all five localities, the different volcaniclastic deposits were
recorded in different sedimentary sequences. The three sedimentary sequences, called Donje
Pazarište 1, Donje Pazarište 2 and Donje Pazarište 3 form almost continuous 97 m thick
succession with six different facies: Flysch facies (FF), Carbonate shale facies (KS),
Syneruptive resedimented pyroclastic facies (FSP), Platy limestone and pyroclastic facies
(FPV), Limestone breccia facies (VB) and Slumped limestone, chert and pyroclastic facies
(FSV). Near the investigated sections (Donje Pazarište 1, 2, 3) the Pyroclastic flow facies (FPT)
was determined (similarly as investigated by Preglej, 2006). The whole sequence has the
characteristics of deposition in the open marine, pelagic environment. The beginning of the
sequence was influenced by Flysch facies (FF) deposited by turbidity currents. Flysch facies
was conformably overlain by Carbonate shale facies (KS) slightly influenced by deposition of
pyroclastic material. Syneruptive resedimented pyroclastics (FSP) were redeposited from
relatively shallow parts of the depositional area to the deep pelagic areas via pyroclastic
turbidity currents. Deposition of the Platy limestone and pyroclastic facies (FPV), indicates
shallowing of the environment envisaged by prevalence of limestones. Limestone breccia facies
(VB) occassionaly occurres in the sequence and imply periods of intense tectonic activity.
Slumped limestone, chert and pyroclastic facies (FSV) was deposited in pelagic environment
influenced by the deposition of pyroclastic material primary sedimented through water settled
fall out on slopes. The sequence was strongly influenced by tectonic activity and tectonic block
movements. The Pyroclastic flow facies (FPT), located in vicinity of the youngest strata of the
Donje Pazarište section, has the characteristics of subaerial emplaced ignimbrite flow, as does
the same facies in the vicinity of the village Brušane, in the foothill of Vinac. Lithological
similarities of these rocks allow the interpretation that they possibly represent a unique
pyroclastic flow generated by pyroclastic column collapse and subaerial of shallow marine
emplacement. The time constraint of this facies is unfortunately missing due to lack of conodont
species in the associated shallow water limestones.
In the same area, the recorded profile Jovanović Draga consists completely of
volcaniclastic deposits (81 m thick) that are associated with the olivine basalt of Coherent facies
(KF). Among volcaniclastics, the Hyaloclastic facies (HF) was differentiated. It was formed by
autoclastic processes and limited pyroclastic activity. Fragments formed by autoclastic
processes were mixed with fragments of carbonate rocks probably formed by fragmentation of
the lithified carbonates during magma ascent. Explosive eruption was restricted due to water
depth that limited the spread of pyroclastic material (dominantly volcanic glass shards).
The recorded profile near the village Bosansko Grahovo (Bosnia and Herzegovina),
consists of 79 m thick dominantly autoclastic deposits. Four different volcaniclastic facies were
determined. The base of the profile is represented by the significant Limestone peperite facies
(FVP). It consists of bioclastic peckstones-weckstones with thin-shelled bivalves and
radiolarians indicating emplacement of hot lava in the pelagic environment. The Limestone
peperite facies is conformably overlain with the Pyroclastic flow facies (FPT), followed by a
Hyaloclastic facies (FH) divided into three lithotypes: resedimented basalt-andesite
hyaloclastite (Pba), in situ basalt hyaloclastite (ISb) and resedimented basalt hyaloclastite (Pb).
The top of the sequence is characterized by the occurrence of the Breccia-conglomerate peperite
(FBP). The facies distribution possibly represents both, the lateral and the vertical exchange of
recorded facies. According to the fossil content in the limestone parts of the peperite, the
sedimentary environment is determined as pelagic. Pyroclastic flow facies in this profile is
represented by a small volume ignimbrite formed in the low fountaining volcanic vent and was
constantly in contact with warm ascending magma throughout the emplacement time.
Hyaloclastic facies (FH) was formed by quenching fragmentation of the coherent facies. The
accurence of in situ basalt hyaloclasti
PDF
