Relative sea-level changes during the Late Cretaceous in the northwestern part of the Adriatic carbonate platform : doctoral thesis

Na području današnje Istre i kvarnerskih otoka kao sjeverozapadnog dijela nekadašnje Jadranske karbonatne platforme istraživane su relativne promjene morske razine zabilježene unutar gornjokrednih naslaga. Snimljeno je i uzorkovano ukupno petnaest geoloških stupova i profila (Dolina Mirne, Vodice–Jelovica, Vodice–Jelovica padina, Martinjak, Goli breg, Planik, Veprinac, Učka, Rabac, Barban, Medulin, Osor, Martinšćica A, Martinšćica B i Premuda). Pored mikrofacijesnih i biostratigrafskih analiza na pojedinim su uzorcima primijenjene i druge analitičke metode, poput rendgenske difrakcije, elektronske mikroskopije, analize stabilnih izotopa δ13C i δ18O i palinološke analize. Terenskim istraživanjem i analizama mikrofacijesa definirani su glavni litotipovi, značajke okoliša taloženja, te glavne dijagenetske promjene. Budući da su razmatrane i druge epizode potapanja SZ dijela Jadranske karbonatne platforme tijekom gornje krede pored najvažnijih neformalnih litostratigrafskih jedinica Milna (s članovima Rušnjak, Marušići, Vinkuran i Niska), Sv. Duh i Gornji Humac prikazane su i jedinice Crna, Sis, Belej (s članom Vrana), Veli Rat i Gornji Humac, a opisane su i pojave do sada neistraženih dubljemorskih naslaga stratigrafskog raspona konijak–santon na području vršnog dijela Učke i raspona turon–santon između Medulina i Marlere u južnoj Istri. Korelacijom izdvojenih litostratigrafskih jedinica i analizom drugih raspoloživih podataka izrađene su paleookolišne i paleogeografske rekonstrukcije istraživanog područja za razdoblja starijeg cenomana, srednjeg–mlađeg cenomana, cenomana–turona, turona–konijaka i starijeg santona. Na temelju rezultata istraživanja izdvojene su dvije stratigrafske razine s izrazitom facijesnom diferencijacijom i barem djelomičnim potapanjem platforme tijekom mlađe krede u istraživanom prostoru, međusobno odvojene kratkom epizodom isključivo plitkomorske sedimentacije tijekom mlađeg cenomana. Starija je epizoda uzrokovana sinsedimentacijskom tektonikom tijekom starijega cenomana, čime je u južnom dijelu Cresa i na Lošinju formirana karbonatna rampa s pučinskim utjecajem, a slabiji efekti sinsedimentacijske tektonike su zabilježeni i u područjima sjeverne i južne Istre – to je područje postupno zapunjavano tijekom starijeg, a mjestimice i srednjeg pa čak i starijeg dijela mlađeg cenomana. Mlađa je epizoda započela tijekom mlađeg cenomana potapanjem većeg dijela istraživanog područja zbog značajnog eustatskog porasta morske razine, pri čemu je u području današnje Ćićarije, istočne Istre i južnog Cresa plitkovodna sedimentacija ponovno uspostavljena tijekom turona. U isto su vrijeme pod djelovanjem sinsedimentacijske tektonike usprkos znatnom eustatskom porastu Sažetak IX morske razine područja Savudrijske antiklinale u sjevernoj Istri, sjevernog dijela Cresa i većine Krka okopnjela, dok je jugoistočni dio istraživanog područja produbljen, tako da je u južnoj Istri, na Lošinju i Premudi taloženje produženo do konijaka i santona.Relative sea-level changes have been studied in the area of Istria and Kvarner islands, the NW part of the Mesozoic Adriatic Carbonate Platform. A total of 15 geological columns and profiles was sampled (Mirna Valley, Vodice–Jelovica, Vodice–Jelovica Slope, Martinjak, Goli breg, Planik, Veprinac, Učka, Rabac, Barban, Medulin, Osor, Martinšćica A, Martinšćica B and Premuda). Besides standard microfacies and biostratigraphic analyses on some samples other analytical methods were performed, like X-Ray diffraction, electronic microscopy, δ13C and δ18O stable isotope analysis as well as palynological analyses. Based on the field data and microfacies analyses main lithotypes, environmental conditions and diagenetic changes have been defined. The study was focused on a very significant Cenomanian–Turonian eustatic sea-level rise, defined within deposits of the informal lithostratigraphic units Milna (including Rušnjak, Marušići, Vinkuran and Niska members), Sv. Duh and Gornji Humac. However, other drowning episodes and penecontemporaneous shallow-water successions have been studied too, so corresponding units Crna, Sis, Belej (with Vrana member), Veli Rat and Gornji Humac have also been described, as well as previously uninvestigated deeper-marine Coniacian–Santonian deposits in the apical part of the Učka Mt. and Turonian–Santonian deposits between Medulin and Marlera in southern Istria. Correlation of lithostratigraphic units and analysis of all available data enabled construction of palaeoenvironmental and palaeogeographic reconstructions of the study area during the Early Cenomanian, Middle–Late Cenomanian, Cenomanian–Turonian, Turonian–Coniacian and Early Santonian. Two episodes of significant facies differentiation and at least partial platform drowning have been delineated, separated by a short-lived epsiode of completely shallow-water deposition during Late Cenomanian. The first episode was caused by synsedimentary tectonics during the Early Cenomanian, resulting in formation of a carbonate ramp with pelagic influence in the present-day southern Cres and Lošinj.areas, as well as weaker deformation in northern and southern Istria areas – those deeper areas were gradually infilled during Early, Middle or even Late Cenomanian. The second, younger episode commenced in the Late Cenomanian by drowning of the major part of the study area due to the significant eustatic sea-level rise, followed by gradual recovery of shallow-marine deposition during the Turonian in the present-day Ćićarija, eastern Istria and southern Cres areas. Penecontemporaneously under the influence of the significant synsedimentary tectonics in spite of the eustatic sea-level rise Savudrija Anticline area in northern Istria, northern part of the island of Cres and most of the Krk island Abstract XI were uplifted and emerged, while SE part of the study area was drowned, resulting in prolonged deposition of deeper-marine deposits until Coniacian and Santonian

Relative sea-level changes during the Late Cretaceous in the northwestern part of the Adriatic carbonate platform : doctoral thesis

Na području današnje Istre i kvarnerskih otoka kao sjeverozapadnog dijela nekadašnje Jadranske karbonatne platforme istraživane su relativne promjene morske razine zabilježene unutar gornjokrednih naslaga. Snimljeno je i uzorkovano ukupno petnaest geoloških stupova i profila (Dolina Mirne, Vodice–Jelovica, Vodice–Jelovica padina, Martinjak, Goli breg, Planik, Veprinac, Učka, Rabac, Barban, Medulin, Osor, Martinšćica A, Martinšćica B i Premuda). Pored mikrofacijesnih i biostratigrafskih analiza na pojedinim su uzorcima primijenjene i druge analitičke metode, poput rendgenske difrakcije, elektronske mikroskopije, analize stabilnih izotopa δ13C i δ18O i palinološke analize. Terenskim istraživanjem i analizama mikrofacijesa definirani su glavni litotipovi, značajke okoliša taloženja, te glavne dijagenetske promjene. Budući da su razmatrane i druge epizode potapanja SZ dijela Jadranske karbonatne platforme tijekom gornje krede pored najvažnijih neformalnih litostratigrafskih jedinica Milna (s članovima Rušnjak, Marušići, Vinkuran i Niska), Sv. Duh i Gornji Humac prikazane su i jedinice Crna, Sis, Belej (s članom Vrana), Veli Rat i Gornji Humac, a opisane su i pojave do sada neistraženih dubljemorskih naslaga stratigrafskog raspona konijak–santon na području vršnog dijela Učke i raspona turon–santon između Medulina i Marlere u južnoj Istri. Korelacijom izdvojenih litostratigrafskih jedinica i analizom drugih raspoloživih podataka izrađene su paleookolišne i paleogeografske rekonstrukcije istraživanog područja za razdoblja starijeg cenomana, srednjeg–mlađeg cenomana, cenomana–turona, turona–konijaka i starijeg santona. Na temelju rezultata istraživanja izdvojene su dvije stratigrafske razine s izrazitom facijesnom diferencijacijom i barem djelomičnim potapanjem platforme tijekom mlađe krede u istraživanom prostoru, međusobno odvojene kratkom epizodom isključivo plitkomorske sedimentacije tijekom mlađeg cenomana. Starija je epizoda uzrokovana sinsedimentacijskom tektonikom tijekom starijega cenomana, čime je u južnom dijelu Cresa i na Lošinju formirana karbonatna rampa s pučinskim utjecajem, a slabiji efekti sinsedimentacijske tektonike su zabilježeni i u područjima sjeverne i južne Istre – to je područje postupno zapunjavano tijekom starijeg, a mjestimice i srednjeg pa čak i starijeg dijela mlađeg cenomana. Mlađa je epizoda započela tijekom mlađeg cenomana potapanjem većeg dijela istraživanog područja zbog značajnog eustatskog porasta morske razine, pri čemu je u području današnje Ćićarije, istočne Istre i južnog Cresa plitkovodna sedimentacija ponovno uspostavljena tijekom turona. U isto su vrijeme pod djelovanjem sinsedimentacijske tektonike usprkos znatnom eustatskom porastu Sažetak IX morske razine područja Savudrijske antiklinale u sjevernoj Istri, sjevernog dijela Cresa i većine Krka okopnjela, dok je jugoistočni dio istraživanog područja produbljen, tako da je u južnoj Istri, na Lošinju i Premudi taloženje produženo do konijaka i santona.Relative sea-level changes have been studied in the area of Istria and Kvarner islands, the NW part of the Mesozoic Adriatic Carbonate Platform. A total of 15 geological columns and profiles was sampled (Mirna Valley, Vodice–Jelovica, Vodice–Jelovica Slope, Martinjak, Goli breg, Planik, Veprinac, Učka, Rabac, Barban, Medulin, Osor, Martinšćica A, Martinšćica B and Premuda). Besides standard microfacies and biostratigraphic analyses on some samples other analytical methods were performed, like X-Ray diffraction, electronic microscopy, δ13C and δ18O stable isotope analysis as well as palynological analyses. Based on the field data and microfacies analyses main lithotypes, environmental conditions and diagenetic changes have been defined. The study was focused on a very significant Cenomanian–Turonian eustatic sea-level rise, defined within deposits of the informal lithostratigraphic units Milna (including Rušnjak, Marušići, Vinkuran and Niska members), Sv. Duh and Gornji Humac. However, other drowning episodes and penecontemporaneous shallow-water successions have been studied too, so corresponding units Crna, Sis, Belej (with Vrana member), Veli Rat and Gornji Humac have also been described, as well as previously uninvestigated deeper-marine Coniacian–Santonian deposits in the apical part of the Učka Mt. and Turonian–Santonian deposits between Medulin and Marlera in southern Istria. Correlation of lithostratigraphic units and analysis of all available data enabled construction of palaeoenvironmental and palaeogeographic reconstructions of the study area during the Early Cenomanian, Middle–Late Cenomanian, Cenomanian–Turonian, Turonian–Coniacian and Early Santonian. Two episodes of significant facies differentiation and at least partial platform drowning have been delineated, separated by a short-lived epsiode of completely shallow-water deposition during Late Cenomanian. The first episode was caused by synsedimentary tectonics during the Early Cenomanian, resulting in formation of a carbonate ramp with pelagic influence in the present-day southern Cres and Lošinj.areas, as well as weaker deformation in northern and southern Istria areas – those deeper areas were gradually infilled during Early, Middle or even Late Cenomanian. The second, younger episode commenced in the Late Cenomanian by drowning of the major part of the study area due to the significant eustatic sea-level rise, followed by gradual recovery of shallow-marine deposition during the Turonian in the present-day Ćićarija, eastern Istria and southern Cres areas. Penecontemporaneously under the influence of the significant synsedimentary tectonics in spite of the eustatic sea-level rise Savudrija Anticline area in northern Istria, northern part of the island of Cres and most of the Krk island Abstract XI were uplifted and emerged, while SE part of the study area was drowned, resulting in prolonged deposition of deeper-marine deposits until Coniacian and Santonian

Relative sea-level changes during the Late Cretaceous in the northwestern part of the Adriatic carbonate platform : doctoral thesis

Na području današnje Istre i kvarnerskih otoka kao sjeverozapadnog dijela nekadašnje Jadranske karbonatne platforme istraživane su relativne promjene morske razine zabilježene unutar gornjokrednih naslaga. Snimljeno je i uzorkovano ukupno petnaest geoloških stupova i profila (Dolina Mirne, Vodice–Jelovica, Vodice–Jelovica padina, Martinjak, Goli breg, Planik, Veprinac, Učka, Rabac, Barban, Medulin, Osor, Martinšćica A, Martinšćica B i Premuda). Pored mikrofacijesnih i biostratigrafskih analiza na pojedinim su uzorcima primijenjene i druge analitičke metode, poput rendgenske difrakcije, elektronske mikroskopije, analize stabilnih izotopa δ13C i δ18O i palinološke analize. Terenskim istraživanjem i analizama mikrofacijesa definirani su glavni litotipovi, značajke okoliša taloženja, te glavne dijagenetske promjene. Budući da su razmatrane i druge epizode potapanja SZ dijela Jadranske karbonatne platforme tijekom gornje krede pored najvažnijih neformalnih litostratigrafskih jedinica Milna (s članovima Rušnjak, Marušići, Vinkuran i Niska), Sv. Duh i Gornji Humac prikazane su i jedinice Crna, Sis, Belej (s članom Vrana), Veli Rat i Gornji Humac, a opisane su i pojave do sada neistraženih dubljemorskih naslaga stratigrafskog raspona konijak–santon na području vršnog dijela Učke i raspona turon–santon između Medulina i Marlere u južnoj Istri. Korelacijom izdvojenih litostratigrafskih jedinica i analizom drugih raspoloživih podataka izrađene su paleookolišne i paleogeografske rekonstrukcije istraživanog područja za razdoblja starijeg cenomana, srednjeg–mlađeg cenomana, cenomana–turona, turona–konijaka i starijeg santona. Na temelju rezultata istraživanja izdvojene su dvije stratigrafske razine s izrazitom facijesnom diferencijacijom i barem djelomičnim potapanjem platforme tijekom mlađe krede u istraživanom prostoru, međusobno odvojene kratkom epizodom isključivo plitkomorske sedimentacije tijekom mlađeg cenomana. Starija je epizoda uzrokovana sinsedimentacijskom tektonikom tijekom starijega cenomana, čime je u južnom dijelu Cresa i na Lošinju formirana karbonatna rampa s pučinskim utjecajem, a slabiji efekti sinsedimentacijske tektonike su zabilježeni i u područjima sjeverne i južne Istre – to je područje postupno zapunjavano tijekom starijeg, a mjestimice i srednjeg pa čak i starijeg dijela mlađeg cenomana. Mlađa je epizoda započela tijekom mlađeg cenomana potapanjem većeg dijela istraživanog područja zbog značajnog eustatskog porasta morske razine, pri čemu je u području današnje Ćićarije, istočne Istre i južnog Cresa plitkovodna sedimentacija ponovno uspostavljena tijekom turona. U isto su vrijeme pod djelovanjem sinsedimentacijske tektonike usprkos znatnom eustatskom porastu Sažetak IX morske razine područja Savudrijske antiklinale u sjevernoj Istri, sjevernog dijela Cresa i većine Krka okopnjela, dok je jugoistočni dio istraživanog područja produbljen, tako da je u južnoj Istri, na Lošinju i Premudi taloženje produženo do konijaka i santona.Relative sea-level changes have been studied in the area of Istria and Kvarner islands, the NW part of the Mesozoic Adriatic Carbonate Platform. A total of 15 geological columns and profiles was sampled (Mirna Valley, Vodice–Jelovica, Vodice–Jelovica Slope, Martinjak, Goli breg, Planik, Veprinac, Učka, Rabac, Barban, Medulin, Osor, Martinšćica A, Martinšćica B and Premuda). Besides standard microfacies and biostratigraphic analyses on some samples other analytical methods were performed, like X-Ray diffraction, electronic microscopy, δ13C and δ18O stable isotope analysis as well as palynological analyses. Based on the field data and microfacies analyses main lithotypes, environmental conditions and diagenetic changes have been defined. The study was focused on a very significant Cenomanian–Turonian eustatic sea-level rise, defined within deposits of the informal lithostratigraphic units Milna (including Rušnjak, Marušići, Vinkuran and Niska members), Sv. Duh and Gornji Humac. However, other drowning episodes and penecontemporaneous shallow-water successions have been studied too, so corresponding units Crna, Sis, Belej (with Vrana member), Veli Rat and Gornji Humac have also been described, as well as previously uninvestigated deeper-marine Coniacian–Santonian deposits in the apical part of the Učka Mt. and Turonian–Santonian deposits between Medulin and Marlera in southern Istria. Correlation of lithostratigraphic units and analysis of all available data enabled construction of palaeoenvironmental and palaeogeographic reconstructions of the study area during the Early Cenomanian, Middle–Late Cenomanian, Cenomanian–Turonian, Turonian–Coniacian and Early Santonian. Two episodes of significant facies differentiation and at least partial platform drowning have been delineated, separated by a short-lived epsiode of completely shallow-water deposition during Late Cenomanian. The first episode was caused by synsedimentary tectonics during the Early Cenomanian, resulting in formation of a carbonate ramp with pelagic influence in the present-day southern Cres and Lošinj.areas, as well as weaker deformation in northern and southern Istria areas – those deeper areas were gradually infilled during Early, Middle or even Late Cenomanian. The second, younger episode commenced in the Late Cenomanian by drowning of the major part of the study area due to the significant eustatic sea-level rise, followed by gradual recovery of shallow-marine deposition during the Turonian in the present-day Ćićarija, eastern Istria and southern Cres areas. Penecontemporaneously under the influence of the significant synsedimentary tectonics in spite of the eustatic sea-level rise Savudrija Anticline area in northern Istria, northern part of the island of Cres and most of the Krk island Abstract XI were uplifted and emerged, while SE part of the study area was drowned, resulting in prolonged deposition of deeper-marine deposits until Coniacian and Santonian

Influence of Lithofacies and Diagenetic Processes on the Physical and Mechanical Properties of Carbonate Rocks - Case Study from Sinawin-Sha\u27wa Area, Libya

Geological investigations were carried out in the Sinawin-Sha\u27wa area, in northwestern Libya, in order to find suitable rocks for aggregate in asphalt mixtures for Nalut - Ghadamis Road reconstruction. By combined field work and micropetrographical analysis four different carbonate lithofacies were determined within Upper Cretaceous sedimentary sequence: lithofacies A - micritic limestones; lithofacies B - dolomitic marls; lithofacies C - dolobiomicrites; lithofacies D -biosparites and biosparudites. Diagenetic processes of cementation, recrystallization, dolomitization and silicification were identified within these lithofacies. Stone samples, taken from three lithofacies A, C, and D, were analyzed in order to determine its physical and mechanical properties (apparent density, open porosity, water absorption, uniaxial compressive strength). In addition, aggregate produced by crushing of the rock from lithofacies D is tested on resistance to crushing and abrasion (LA test). Samples from lithofacies B were not included in the testing of physical and mechanical properties since it is estimated as not suitable rock material for crushed aggregate. Samples from lithofacies A, C and D showed significant differences in the physical and mechanical properties. These differences stem from differences in mineralogical and petrographical composition as well as from diagenetic processes. Stone of lithofacies D were estimated as the most appropriate rocks available in the area, for aggregate in asphalt mixtures

Cenomanian–Turonian Oceanic Anoxic Event (OAE2) Imprint on the Northwestern part of the Adriatic Carbonate Platform and a Coeval Intra-Platform Basin (Istria and Premuda Island, Croatia)

The Cenomanian–Turonian boundary (CTB) on the intra-Tethyan Adriatic Carbonate Platform (AdCP) is generally characterised by a transition between microbially laminated and/or bioclastic limestones to calcisphere-rich massive limestone with bioturbated intervals, organic-rich interbeds, firmgrounds, as well as neptunian dikes, carbonate turbidites, tempestites and slumped structures. Compilation of the results from two study sites in the northwestern part of the AdCP and from previous research (on Istria Peninsula and islands in the Adriatic Sea in Croatia) provides a more complete overview of geological events and paleoenvironmental conditions that transformed the formerly contiguous shallow-marine environments during this time period. For the first time, a comparison between protected inner-platform area (Barban section) and a coeval intra-platform basin (Premuda Island section) during the CTB was made. This study utilized a combination of litho-, bio-, and microfacies studies with SEM, EDS, TOC, δ13C and δ18O stable isotope analyses. The stratigraphic successions start with shallow-marine carbonate deposits of the Milna Formation that is conformably overlain by the drowned-platform deposits of the Sveti Duh Formation on the platform and by the Veli Rat Formation in the contemporaneously developed intraplatform basin. These deposits are in turn overlain by the Gornji Humac Formation, which represents re-establishment of shallow-marine depositional systems on the AdCP, whereas the deeper water environment persisted in the intra-platform basin until the Santonian. Despite diagenetic modifications of shallow-marine carbonate deposits, the results of TOC and stable isotope analyses indicate the influence of global Oceanic Anoxic Event 2 (OAE2). Combination of local and regional synsedimentary tectonics and global Late Cretaceous sea-level changes accompanied by anoxic and hypoxic conditions, extinction of numerous benthic foraminifera, diversification and expansion of planktonic foraminifera and calcareous dinoflagellates, provide new insights into the character of the CTB interval in this part of the Tethyan realm

Petrochronological study of chloritoid schist from Medvednica Mountain (Zagorje Mid-Transdanubian zone, Croatia)

The metamorphic conditions and evolution of the Palaeozoic-Mesozoic metamorphic complex of Medvednica Mountain (Zagorje-Mid-Transdanubian zone, Croatia) are still a matter of debate. The results of the investigation of five samples of metapelitic schists with the mineral association of quartz, white mica and chlorite are presented. The studied schists are part of the continental margin of Adria and were metamorphosed under upper greenschist- to amphibolite-facies conditions. The focus of this study is a sample representing the highest metamorphic grade that additionally contains chloritoid blasts. Pressure-temperature pseudosection modelling together with classical geothermobarometric calculations yielded peak metamorphic conditions of 0.94 ± 0.05 GPa and 550 ± 20 °C for chloritoid schist. Monazite in-situ U-Th-total Pb electron microprobe dating indicates two metamorphic events at 167 ± 2 Ma and 143 ± 2 Ma, which are interpreted as the time of monazite growth during two distinct metamorphic phases. The formation of the chloritoid paragenesis is related to the older event (around 167 Ma) and linked with the Middle Jurassic subduction-accretion processes of Neotethys-derived ophiolitic lithologies. The younger metamorphic event (around 143 Ma) is related to the obduction of ophiolites onto the continental margin of Adria

The Cenomanian–Turonian Boundary in the Northwestern Part of the Adriatic Carbonate Platform (Ćićarija Mtn., Istria, Croatia): Characteristics and Implications

The Cenomanian–Turonian boundary (CTB) in the Ćićarija Mountain region (northern Istria, Croatia) is characterized by calcisphere limestone successions with a firmground and glauconite horizon, bioturbated intervals, tempestites, and slumped structures as well as microbially laminated and organic-rich interbeds deposited in the northwestern part of the intra-Tethyan Adriatic Carbonate Platform (AdCP). Compilation of the results from three studied sections (Vodice–Jelovica, Martinjak and Planik) of litho-, bio-, and microfacies analyses, X-ray diffraction, SEM, EDS, and stable isotope analyses allowed reconstruction of marine paleoenvironmental conditions during this time period. Shallow-marine carbonate deposits of the Milna Formation underlie a drowned-platform succession of the Sveti (Sv.) Duh Formation. The contact between these two formations is sharp and commonly marked by slumped deposits. The Sv. Duh Formation consists of about 100 m of calcisphere wackestone enriched in organic matter. The results of preliminary δ13C and δ18O stable isotope analyses indicate the influence of the global Oceanic Anoxic Event (OAE2) on the deposition of this carbonate succession. Anoxic and hypoxic conditions in the water column lead to major changes in the shallow-marine carbonate system of the AdCP. Numerous benthic foraminifera declined during that time, but planktonic foraminifera and calcareous dinoflagellates diversified and expanded greatly. The results of this research provide new insights into the character of the CTB interval in this part of the Tethyan realm. Local and regional synsedimentary tectonics combined with global upper Cretaceous sea-level dynamics allows the correlation of the investigated deeper-marine lithostratigraphic units with OAE2