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)
In this dissertation, the local similarity scaling approach was examined based on the multi-level measurements of atmospheric turbulence in the wintertime (December 2008 February 2009) stable ...atmospheric boundary layer (SBL) established over a heterogeneous surface influenced by mixed agricultural, industrial and forest surfaces. The 62 m tower (levels 20, 32, 40, 55 and 62 m above ground) was situated in the middle of some 120 m × 480 m area of hc = 18 m high walnut trees. The heterogeneity of the surface was characterized by spatial variability of both roughness and topography. In a first step local similarity theory in terms of flux-variance and flux-gradient relationships was investigated. Nieuwstadts local scaling approach was found to be suitable for the representation of all three wind velocity components. The roughness sublayer (RSL) influenced wind variances, and consequently the turbulent kinetic energy (TKE) and correlation coefficients at the lowest measurement level, but not the wind shear profile. After removing data points associated with the flux Richardson number (Rf) greater than 0.25, the observations support the classical linear expressions for the dimensionless wind shear (phim) even over inhomogeneous terrain. Leveling-off of phim at higher values of stability parameter was found to be a result of the large number of data characterized by small-scale turbulence (Rf > 0.25). Deviations from linear expressions were shown to be mainly due to small-scale turbulence rather than due to the surface heterogeneities, supporting the universality of the linear relationship. Additionally, the flux-gradient dependence on stability did not show different behavior for different wind regimes, indicating that the stability parameter is a sufficient predictor for flux-gradient relationships. Data followed the local z-less scaling for phim when the prerequisite Rfless than or equal to0.25 was imposed. Further investigations focused on the combined influence of the RSL found above tall vegetation and the internal boundary layer (IBL) on the turbulence spectral characteristics and TKE budget. The traditional surface layer scaling was tested against the canopy scaling, which is generally valid for the RSL. It was found that canopy scaling can be successfully applied even within the transition layer. For the present complex site local isotropy was not found. Vertical velocity spectra were smaller than horizontal spectra. Similarly, dissipation rates (epsilon) determined only from vertical spectra were smaller than epsilon estimates based on horizontal components. Therefore, it was necessary to normalize vertical wind speed spectra with phiepsilonw in order to get good correspondence with the Kansas spectral models. Extending the analysis to the Olesen approach, applied for the first time to the SBL over heterogeneous terrain, normalized spectra collapsed to one single curve. Finally, analyzing the budget terms of the TKE equation, non-equilibrium conditions were found. The non-local dynamics are considered to be the main reason for the observed imbalance of TKE in the transition layer as well as for the observed breakdown of z-less regime in the strongly stable conditions above heterogeneous surface. In the RSL, the turbulent transport of TKE above vegetated canopies is considered to be the main cause of the observed TKE imbalance in the neutral conditions. A less systematic behavior of the residual term was observed indicating that the advection term has more pronounced influence on the RSL than the upper levels.
In this dissertation, the local similarity scaling approach was examined based on the multi-level measurements of atmospheric turbulence in the wintertime (December 2008 February 2009) stable atmospheric boundary layer (SBL) established over a heterogeneous surface influenced by mixed agricultural, industrial and forest surfaces. The 62 m tower (levels 20, 32, 40, 55 and 62 m above ground) was situated in the middle of some 120 m × 480 m area of hc = 18 m high walnut trees. The heterogeneity of the surface was characterized by spatial variability of both roughness and topography. In a first step local similarity theory in terms of flux-variance and flux-gradient relationships was investigated. Nieuwstadts local scaling approach was found to be suitable for the representation of all three wind velocity components. The roughness sublayer (RSL) influenced wind variances, and consequently the turbulent kinetic energy (TKE) and correlation coefficients at the lowest measurement level, but not the wind shear profile. After removing data points associated with the flux Richardson number (Rf) greater than 0.25, the observations support the classical linear expressions for the dimensionless wind shear (phim) even over inhomogeneous terrain. Leveling-off of phim at higher values of stability parameter was found to be a result of the large number of data characterized by small-scale turbulence (Rf > 0.25). Deviations from linear expressions were shown to be mainly due to small-scale turbulence rather than due to the surface heterogeneities, supporting the universality of the linear relationship. Additionally, the flux-gradient dependence on stability did not show different behavior for different wind regimes, indicating that the stability parameter is a sufficient predictor for flux-gradient relationships. Data followed the local z-less scaling for phim when the prerequisite Rfless than or equal to0.25 was imposed. Further investigations focused on the combined influence of the RSL found above tall vegetation and the internal boundary layer (IBL) on the turbulence spectral characteristics and TKE budget. The traditional surface layer scaling was tested against the canopy scaling, which is generally valid for the RSL. It was found that canopy scaling can be successfully applied even within the transition layer. For the present complex site local isotropy was not found. Vertical velocity spectra were smaller than horizontal spectra. Similarly, dissipation rates (epsilon) determined only from vertical spectra were smaller than epsilon estimates based on horizontal components. Therefore, it was necessary to normalize vertical wind speed spectra with phiepsilonw in order to get good correspondence with the Kansas spectral models. Extending the analysis to the Olesen approach, applied for the first time to the SBL over heterogeneous terrain, normalized spectra collapsed to one single curve. Finally, analyzing the budget terms of the TKE equation, non-equilibrium conditions were found. The non-local dynamics are considered to be the main reason for the observed imbalance of TKE in the transition layer as well as for the observed breakdown of z-less regime in the strongly stable conditions above heterogeneous surface. In the RSL, the turbulent transport of TKE above vegetated canopies is considered to be the main cause of the observed TKE imbalance in the neutral conditions. A less systematic behavior of the residual term was observed indicating that the advection term has more pronounced influence on the RSL than the upper levels.
More je čovjeku uvijek bilo velika tajna. Nepredvidljivo je, puno iznenađenja, pa je ljudima koji žive uza nj i znaju sve njegove čudi, dobre i zle, pobuđivalo strah i osjećaj bespomoćnosti da se tim ...užasnim stihijama djelotvorno opru. Tajnovite morske dubine, pogibeljne nevere, orkanski vjetrovi, tihe bonace, hrabri pomorci i njihova daleka putovanja, vješti ribari i njihovi bogati ulovi, bili su inspiracija mnogim pučkim predajama, pričama, legendama o morskim zmijama, o čudovišnim hobotnicama, o morskom „čoviku i ženi“, o sirenama, o ukletim brodovima, o „barki karonte“ koja prevozi duše umrlih, o čudesnoj pomoći svetaca pomorcima, o jednookim ljudožderima, o brodolomcima koji zbog gladi odluče pojesti svoga druga, o vragu koji služi kao mornar na brodu, o golemoj ribi-otoku, pa o morskim vješticama, macićima, tintilinima, orku i dr. Naši su stari i mnoge prirodne pojave vezane uz more tumačili na svoj način i po njima predviđali kako će biti vrijeme, pa je i pučka meteorologija dio naša kulturne baštine kao i razne uzrečice, poslovice, kletve, molitvice, rugalice i slično.
Metasedimentne stijene Medvednice, koje se nalaze na prostoru Zagorje-Mid-Transdanubijske zone, zabilježile su nekoliko faza deformacija od kojih je najintenzivnija uzrokovala metamorfizam unutar ...facijesa zelenih škriljavaca. U radu su obrađene litostratigrafske jedinice Stari potok, Slani potok, Risnjak i Vila Rebar. Posebna pozornost je posvećena kloritoidnom škriljavcu iz jedinice Stari potok. Napravljene su petrografske i geokemijske analize (XRD, ICP-MS). Uvjeti metamorfizma određivani su pomoću geotermometara za klorit i parove klorit-kloritoid te geobarometara za muskovit (fengit). Konstruiran je dijagram pseudopresjeka za uzorak kloritoidnog škriljavca, izoplete udjela Mg u kloritu i kloritoidu te izoplete Si u muskovitu (fengit). Starost progradne faze metamorfizma izmjerena je na monacitima (EMP), pri čemu je dobivena starost srednje do gornje jure (153 ± 6,9 Ma). Mjerenje sadržaja izotopa U-Th-Pb napravljeno je na zajednici detritnih cirkona pomoću LA-ICP-MC-MS-a. Dobiveni starosni podaci cirkona dali su vrijednosti koje su grupirane u devet podgrupa, unutar šest starosnih grupa. Na temelju najmlađe starosne podgrupe cirkona procijenjena je maksimalna starost taloženja. Iz petrografskih analiza na uzorcima metasedimenata litostratigrafskih jedinica Stari potok, Risnjak, Vila Rebar i Slani potok, utvrđena je metamorfna mineralna asocijacija koju čine kvarc, bijeli tinjac, klorit, ± albit, ± biotit, ± kloritoid, ± turmalin, ± monacit, ± ksenotim, ± apatit. Sačuvani akcesorni detritarni minerali su cirkon i rutil. Mineralna asocijacija ukazuje na nizak stupanj metamorfizma unutar facijesa zelenih škriljavaca. Geokemijski podaci sugeriraju da su protoliti istraživanih metasedimentnih stijena uglavnom bili srednje do intenzivno trošeni zreli sedimenti, nastali taloženjem nakon trošenja stijena pretežito granitoidnog sastava, ugrađenih u vulkanski luk.
Metasedimentary rocks from Mt. Medvednica, located in Zagorje-Mid-Transdanubian zone, had undergone multiphase deformation history. The most intense deformation phase is manifested by the most intense metamorphic phase, which reached greenschist metamorphic facies. This thesis investigated Stari potok, Slani potok, Risnjak and Vila Rebar lithostratigraphic units, with special attention given to the occurrence of chloritoid schist in Stari potok unit. Petrographic and geochemical analysis were conducted (XRD, ICP-MS). Metamorphic conditions were investigated with geothermometers for chlorite and pairs of chlorite-chloritoid, while geobarometric conditions were calculated on muscovite (phengite). Pseudosection diagram, isopleths of XMg in chlorite and chloritoid, as well as XSi in muscovite (phengite) were modeled using software package PerpleX. Late Jurassic (153 ± 6.9 Ma) metamorphic age was determined based on sinmetamorphic monazite grains analysis. Ratios of U/Th/Pb from detrital zircon grains were measured on LA-ICP-MC-MS, resulting in recognition of nine subgroups within six detrital zircon age groups. Youngest subgroup of detrital zircons gave insight into deposition time of the protolith sediment. Petrographic analysis of metasediment samples of litostratigraphic units Stari potok, Slani potok, Risnjak and Vila Rebar indicated metamorphic mineral association of quartz, white micas, chlorite, ± albite, ± biotite, ± chloritoide, ± turmaline, ± monazite, ± xenotime, ± apatite. Accessory mineral phases are zircons and rutile. Mineral association is typical for low greenschist metamorphic facies. Geochemical data indicate that protolith sediments were mature, middle to intensively weathered sediments, produced by deposition after weathering of mainly volcanic arc granitoid rocks.
Sedimentological, macro- and micropaleontological analyses on sediment cores were carried out in the lower section of the Mirna and Neretva River valleys, in order to study depositional facies and ...environmental evolution during Late Pleistocene and Holocene. The Holocene marine transgression reached river valleys several kilometers upstream from the present-day coast, while in the last 7000 – 6000 years it was followed by progradation of the Mirna and Neretva intra-estuarine deltas. Sediment cores recorded these changes and each depositional environment contains distinctive sedimentary characteristics and fossil assemblages which reflect conditions in which sedimentation and life were occurring. This study highlights the potential role of hand augering in sampling and describing the subsoil for reconstruction of the geomorphological evolution of the area and supporting the study of past relative sea levels, climate changes, and impact of anthropogenic activities.
Sedimentological, macro- and micropaleontological analyses on sediment cores were carried out in the lower section of the Mirna and Neretva River valleys, in order to study depositional facies and environmental evolution during Late Pleistocene and Holocene. The Holocene marine transgression reached river valleys several kilometers upstream from the present-day coast, while in the last 7000 – 6000 years it was followed by progradation of the Mirna and Neretva intra-estuarine deltas. Sediment cores recorded these changes and each depositional environment contains distinctive sedimentary characteristics and fossil assemblages which reflect conditions in which sedimentation and life were occurring. This study highlights the potential role of hand augering in sampling and describing the subsoil for reconstruction of the geomorphological evolution of the area and supporting the study of past relative sea levels, climate changes, and impact of anthropogenic activities.
Sedimentološke, makro-paleontološke i mikro-paleontološke analize radile su se na sedimentnim jezgrama izvađenim iz deltnih ravnica rijeka Mirne i Neretve, s ciljem da se prouče i rekonstruiraju taložni facijesi i evolucija okoliša tijekom mlađeg pleistocena i holocena. Transgresija u holocenu dosegnula je uzvodno u riječne doline nekoliko kilometara od današnje obalne linije, a u posljednjih 7000-6000 godina uslijedila je progradacija delti u estuarijima rijeka Mirne i Neretve. Sedimentne jezgre sadrže zapis tih promjena, a svaki taložni okoliš sadrži karakteristične sedimentne značajke i fosilne zajednice koje odražavaju uvjete u kojima se odvijala sedimentacija i život. Ovo istraživanje naglašava potencijalnu ulogu ručnog uzorkovanja jezgri u opisivanju sedimenata, u svrhu rekonstrukcije geomorfološke evolucije područja i upotpunjava znanje o promjenama relativne razine mora, klime i utjecaja antropogenih aktivnosti.
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.
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.
U radu je opisan kemijski i mineralni sastav te je utvrđena starost i porijeklo tufova koji su tijekom
miocena taloženi na prostoru Sjevernohrvatskog bazena, smještenog u južnom dijelu Panonskog ...bazenskog
sustava. Osim toga, analiziran je fosilni sadržaj u naslagama iz neposredne podine i krovine tufa. Analizirani
tufovi s područja Banovine, Medvednice, Moslavine i Slavonije primarno su bili riolitnog do tefrifonolitnog
sastava, a naknadno su dijelom ili u potpunosti alterirani u smektite i heulandit. Vulkanska aktivnost najvećim
se dijelom odvijala tijekom sin-riftne faze razvoja bazena. Prema rezultatima datiranja 40Ar*/39Ar metodom
na sanidinima, najintenzivnija je bila u razdoblju od 17-14,4 Ma odnosno tijekom karpata, te donjeg i srednjeg
badena. Po prvi puta zabilježena je, znatno slabija, vulkanska aktivnost u postriftnoj fazi razvoja bazena,
krajem sarmata, prije oko 12 Ma. Prema klasifikacijskim dijagramima temeljenima na kemijskom sastavu
tufova, izvorište piroklastičnog materijala bio je aktivni kontinentalni rub koji je najvjerojatnije bio smješten
na prostoru Istočnih Karpata. Fosilna zajednica foraminifera, ostrakoda, nanoplanktona i palinomorfa
pokazala je da su tufovi stariji od 15,1 Ma taloženi u slatkovodnim ili bočatim jezerskim okolišima, a oni
datirani na 14,8 do 14,4 Ma u marinskim okolišima. Time je je marinska transgresija u Sjevernohrvatskom
bazenu, ranije uglavnom smještena na početak karpata, pomaknuta na približno 15 Ma, tj. na granicu donjeg
i srednjeg badena.
Tuffs have been deposited during the Miocene in the North Croatian Basin which is located in the
southern part of the Pannonian Basin System. In this thesis chemical and mineral composition of the tuffs as
well as their age and origin were determined. In addition, the fossil content was analyzed in the underlying
and overlying beds of the tuffs. Based on chemical composition tuffs have been classified as neutral
(tephriphonolite) to acid (riolite). In most tuffs volcanic glass was partially or completely altered to clay
minerals (smectite) or in some cases zeolites (heulandite). During the sin-rift phase of basin development
volcanic activity was at its peak. According to the results of the 40Ar*/39Ar dating on sanidine, the most
intensive period of volcanic activity was during the Karpatian and the Early and Middle Badenian (17 – 14.4
Ma). For the first time, the volcanic activity in the post-rift stage of the development of the basin has been
recorded at the end of Sarmatian ~ 12 Ma ago. Based on the content of immobile trace elements the source
of the pyroclastic material was placed on an active continental margin, most probably located in the Eastern
Carpathians area. The fossil assemblage of foraminifera, ostracods, nannoplankton and palinomorphs has
shown that the tuffs older than 15.1 Ma were deposited in freshwater or brackish lake environments, and
those dated from 14.8 to 14.4 Ma in marine environments. Older studies place the onset of the marine
sedimentation in Karpatian time, while this study suggests it should be moved to the Early/Middle Badenian
boundary.
U radu je opisan kemijski i mineralni sastav te je utvrđena starost i porijeklo tufova koji su tijekom
miocena taloženi na prostoru Sjevernohrvatskog bazena, smještenog u južnom dijelu Panonskog bazenskog
sustava. Osim toga, analiziran je fosilni sadržaj u naslagama iz neposredne podine i krovine tufa. Analizirani
tufovi s područja Banovine, Medvednice, Moslavine i Slavonije primarno su bili riolitnog do tefrifonolitnog
sastava, a naknadno su dijelom ili u potpunosti alterirani u smektite i heulandit. Vulkanska aktivnost najvećim
se dijelom odvijala tijekom sin-riftne faze razvoja bazena. Prema rezultatima datiranja 40Ar*/39Ar metodom
na sanidinima, najintenzivnija je bila u razdoblju od 17-14,4 Ma odnosno tijekom karpata, te donjeg i srednjeg
badena. Po prvi puta zabilježena je, znatno slabija, vulkanska aktivnost u postriftnoj fazi razvoja bazena,
krajem sarmata, prije oko 12 Ma. Prema klasifikacijskim dijagramima temeljenima na kemijskom sastavu
tufova, izvorište piroklastičnog materijala bio je aktivni kontinentalni rub koji je najvjerojatnije bio smješten
na prostoru Istočnih Karpata. Fosilna zajednica foraminifera, ostrakoda, nanoplanktona i palinomorfa
pokazala je da su tufovi stariji od 15,1 Ma taloženi u slatkovodnim ili bočatim jezerskim okolišima, a oni
datirani na 14,8 do 14,4 Ma u marinskim okolišima. Time je je marinska transgresija u Sjevernohrvatskom
bazenu, ranije uglavnom smještena na početak karpata, pomaknuta na približno 15 Ma, tj. na granicu donjeg
i srednjeg badena.
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 hyaloclastite is closely associated with the coherent facies of the
same compos
