18 research outputs found
Upper Jurassic Platform succession with characteristics of a deeper water intraplatform trough (Mt. Svilaja, Croatia)
Abstract
From the middle part of the Late Jurassic (Kimmeridgian), the hitherto uniform depositional environment of the Adriatic carbonate platform began to show differentiation. In the central part of the platform two intraplatform troughs were formed, one of which stretched from the Karlovac area southward and is known as the LemeÅ” Trough. The depositional processes that took place within this trough can be observed in the sedimentary succession of Mt. Svilaja. Based on investigated facies characteristics five lithofacies units were distinguished, representing three paleoenvironmental units: (1) shallow subtidal zone below the fair-weather wave-base; (2) intraplatform trough; (3) shallow subtidal zone above the fair-weather wave-base. The environmental changes are related to the tectonically-controlled retrogradation of the shallow subtidal platform, when the deeper-water intraplatform trough area, connected with the open Tethys realm, spread over the sunken part of the platform. Progressive infilling of the trough with bioclastic material led to the re-establishment of the shallow subtidal environment, and the area of the previously existing intraplatform trough was occupied by coral-hydrozoan reefal buildups
Characteristics of a Triassic regional unconformity between the second and third shallow-marine depositional megasequences of the Karst Dinarides (Croatia)
Abstract
Two depositional megasequences of the Karst Dinarides that record two different, emersion-separated, depositional periods are presented; the older lasted from the upper part of the Middle Permian to the Middle Triassic, and the younger one from the Late Triassic to the Late Cretaceous. Both megasequences are typified by shallow-water platform deposits; the earlier megasequence formed under epeiric carbonate/clastic platform conditions and the later one under isolated carbonate platform conditions. Significant geodynamic movements within the southern Tethys realm led to Middle Triassic tectonic uplift, i.e. to the emersion of the huge platform area where a regional unconformity between two platform megasequences was formed. Four types of terrestrial phase horizons are identified, each representing different subaerial conditions that existed during the long-lasting emersion. These are: a significant disconformity and related stratigraphic gap between the Upper Scythian and Lower Norian; a tuffaceous horizon between the Upper Anisian and Lower Norian; an Upper Ladinian-Upper Norian brecciated horizon; and an Upper Ladinian-Lower Norian claystone/bauxitic horizon. Due to the widespread diachronous transgression during the Norian, shallow-water platform sedimentation was restored over the entire emergent area, initiating a long-lasting isolated carbonate platform regime
Trijaska kopnena faza zabilježena na slijedu karbonatne platforme krŔkih Dinarida (Hrvatska)
The Triassic carbonate platform succession of the Karst Dinarides was deposited at the southern Tethyan realm. The facies analysis and distant correlation suggests that a regional terrestrial phase occurred in that area during the Triassic. Due to its regional extent, this terrestrial phase has been viewed as a product of tectonically induced uplift of the huge platform area, causing an extensive emersion and distinct disruption in depositional regime when disconformity and/or various types of terrestrial depositional intervals were formed. Two geodynamic scenarios are presented; a) regional, contemporaneous tectonic uplift scenario; and b) diachronous and differential tectonic uplift scenario. During Norian, the uplifted, exposed platform area was flooded and covered by tidal flat-dominated shallow-water carbonates, marking the beginning of wide and long-lasting isolated platform regime.Trijaski karbonatni slijed KrÅ”kih Dinarida istaložen je na prostranstvu južnog Tetisa. Facijesna analiza i prostorna korelacija tog slijeda naslaga upuÄuje na regionalnu kopnenu fazu koja je tijekom Trijasa zahvatila ovaj prostor. Svojim regionalnim pružanjem, ova kopnena faza se sagledava kao posljedica tektonski izazvanog izdizanja prostranog platformnog podruÄja, a Å”to je uzrokovalo izrazito okopnjavanje i izrazit prekid dotadaÅ”njeg taložnog režima, Äime su nastali taložni diskonformiteti i/ili razliÄiti tipovi kopnenih taložnih slijedova. Predstavljena su dva geodinamska scenarija; a) scenarij regionalnog, istovremenog izdizanja prostranog platformnog podruÄja; i b) scenarij vremenom i intenzitetom razliÄitog izdizanja prostranog platformnog podruÄja. Tijekom Norika, to dotad izdignuto i izloženo platformno podruÄje bilo je preplavljeno i prekriveno plitkovodnim karbonatima plimne zone, oznaÄavajuÄi poÄetak prostranog i dugotrajnog taložnog režima izolirane karbonatne platforme
NEW DINOSAUR TRACKSITE IN THE LATE JURASSIC OF KIRMENJAK QUARRY (ISTRIA)
A new dinosaur tracksite was found in the Kirmenjak quarry in Istria. It is located about one kilometre from an already existing tracksite. The footprints are placed on a slightly inclined bedding plane at the base of the succession represented by heavily stylolitised limestones of the Kirmenjak informal lithostratigraphic unit. The age of the limestones is late Tithonian. Fifteen footprints of circular shape with no clear digit or claw impressions were found at the site and are interpreted to have been formed on a tidal flat during a sea-level fall. All of the footprints belong to sauropod dinosaurs. Pes prints are circular to elliptical in shape, whereas manus prints are more elliptical and of smaller size. The average length of the pes prints is 55 cm, which would correspond to a sauropod of approximately 16 meters in length. The trackway is of narrow-gauge type, where the internal trackway width often has a negative value. The length of the strides indicates slow movement of the individual with a speed of less than 2 km/h. Based on stratigraphic position and footprint morphology, the new and the pre-existing tracksites represent the same trackbearing layer
Upper Jurassic Carbonate Facies Succession at Breze (Velika Kapela, Croatia)
Environmental differentiation at the end of the Lower Malm, as observed at Breze, was caused by gradual synsedimentary tectonics when the hitherto uniform Adriatic carbonate platform was partly differentiated into two different sedimentary environments. Thus the sunken intraplatform trough of unknown dimensions, which was possibly connected with the open basin (similar to the modern āTongue of the oceanā?), formed the depositional site of deeper-water pelagic influenced platform carbonates. This gradual change in sedimentary environment can be defined as shallow-water platform facies retrogradation.
Periodic shedding of carbonate material, during the Upper Malm, from the perireefal/reefal margin of the intraplatform trough by mechanisms of gravity flows, caused the deeper-water inclined marginal part of the trough to be filled up resulting in the re-establishment of shallow-water sedimentary conditions. This process can be defined as shallow-water platform facies progradation whereby shallowing-upward sequence is formed
Distribution of sulphur, phosphorous, iron, and trace elements in bottom sediment cores, mussels and fish from the Punat Bay (Island of Krk, Croatia)
Ships and associated anthropogenic activities release a number of contaminant elements into the marine environment which can be particularly concentrated in restricted circulatory environments including Bays and marinas. One such locality is a Punat Bay, situated at the southern coastline of the island of Krk (west Croatia), which is the largest Croatian marina. The aim of this study was to examine depth profiles of sulfur (S), phosporous (P), iron (Fe), and trace elements (As, Ba, Be, Cd, Co, Cr, Cu, Hg, Mn, Mo, Ni, Pb, Sn, Sr, Ti, U, V, Y, and Zn) in six sediment cores (down to 20-30 cm), and from mussels and fish from Punat Bay, by determining their levels with ICP-OES. Data analysis showed that the majority of variables were elevated in a sediment core located closest a port of the marina. Minimum to maximum S, P, and Fe levels in sediments were as follows: 0.4-2.4%, 0.04-320 mg/kg, and 0.2-2.3%, respectively. Correlations among S, P, Fe, and various trace elements were mostly positive (p<0.05). Trace elements were not increased in mussels and fish. This paper shows that the Punat marina has only a limited impact on the environmental status. Several potentially toxic trace elemens (Pb, Cu, etc.) were found to be elevated in a sediment core located closest to the marina
Razvoj povjerenja u dijete i njegove moguÄnosti
U Nacionalnom kurikulumu za rani i predÅ”kolski odgoj i obrazovanje dijete se smatra cjelovitim, kreativnim i socijalnim biÄem koje odreÄuje svoj vlastiti život i razvoj. Razina povjerenja u dijete ovisi o naÅ”oj implicitnoj pedagogiji, o onoj nevidljivoj realnosti vrtiÄa koju saÄinjavaju vrijednosti i uvjerenja odgajatelja
RAZINE SUMPORA, METALA, POLUMETALA, RADIOAKTIVNOSTI I CITOTOKSIÄNOSTI U KRÅ KIM ISPUSTIMA VODE IZ NAPUÅ TENIH RAÅ KIH UGLJENOKOPA (SJEVERNI DIO JADRANSKOGA MORA)
RaÅ”a coal, mined on the Istrian Peninsula (NW Croatia) for nearly 400 years up to 1999, is notable for having superhigh organic sulfur, and high levels of selenium, uranium, vanadium, and molybdenum. Selenium is the poison responsible for the widespread loss of cattle and sheep. It is essential to human health in trace amounts, but higher concentrations can be harmful. An estimated 4.4Mt. of coal remains underground within marine carbonate rocks. The study area belongs to the coastal karst of the Adriatic Sea. Several abandoned coal-mine discharges (CMDs) were released into local streams and the RaÅ”a Bay for decades. Therefore, the water quality of a natural karst spring (Fonte Gaja), the RaÅ”a Bay seawater, municipal wastewater, and the RaÅ”a CMDs were investigated, focusing on sulfur, selected metal(loid)s (major, minor, and trace), radioactivity, and cytotoxicity. The Fonte Gaja spring water, unrelated to the RaÅ”a CMD, served as a reference. Its values of Se, U, V, and Mo (Āµg/L) were as follows: 1.09, 0.75, 1.37, and 2.04, respectively. However, the respective levels (Āµg/L) were increased in the rest of the water samples as follows: 10.9, 10.8, 4.60, and 33.1. Water sulfate levels were low though. Total beta activities of the CMDs and RaÅ”a Bay water were 235 and 1320 Bq/m3, respectively, below the guideline level of 2000 Bq/m3. The cytotoxicity of water samples on the RTG-2 fish cells was not statistically significant. The large volumes of water involved mean the transport of rather large amounts of Se and U, and their deposition in the Adriatic Sea. Due to the complexity of the karst hydrogeology, knowledge of Se and U circulation patterns is highly needed.Pridobivanje raÅ”koga ugljena u Istri (SZ Hrvatska) trajalo je gotovo 400 godina, sve do 1999. godine. RaÅ”ki ugljen poznat je po iznimno visokim koncentracijama organskoga sumpora te visokim razinama selena, urana, vanadija i molibdena. Otprije je poznata toksiÄnost selena na primjerima goveda i ovaca. Za ljudsko zdravlje selen je od presudne važnosti, ali u poviÅ”enim je koliÄinama Å”tetan. Procjenjuje se da je joÅ” 4,4 milijuna tona raÅ”koga ugljena ostalo pod povrÅ”inom, unutar marinskih karbonatnih stijena. PodruÄje istraživanja pripada obalnome krÅ”kom pojasu Jadranskoga mora. Na nekoliko mjesta nalaze se ispusti podzemne vode iz napuÅ”tenih rudnika ugljena (engl. CMD), gdje ta voda desetljeÄima izbija van na povrÅ”inu te se izravno ulijeva u lokalne vodotoke i na kraju u RaÅ”ki zaljev. Stoga su uzeti uzorci vode prirodnoga krÅ”kog izvora, morske vode RaÅ”koga zaljeva, komunalne otpadne vode te CMD. U uzorcima su izmjerene koncentracije sumpora, odabranih metala i polumetala (glavnih, sporednih i u tragovima), radioaktivnost te citotoksiÄnost. Izvorska voda, koja nije u dodiru s CMD-om, poslužila je u referentne svrhe. Njezine odgovarajuÄe vrijednosti Se, U, V i Mo (Ī¼g/L) bile su sljedeÄe: 1,09, 0,75, 1,37 i 2,04. MeÄutim, odgovarajuÄe razine tih Äetiriju elemenata (Ī¼g/L) bile su poviÅ”ene u ostatku uzoraka vode: 10,9, 10,8, 4,60 i 33,1. Razina sumpora u vodi bila je niska. Ukupne beta aktivnosti CMD-a i vode RaÅ”koga zaljeva iznosile su 235 i 1320 Bq/m3, Äime nije bila premaÅ”ena dopuÅ”tena vrijednost od 2000 Bq/m3. CitotoksiÄnost nekoliko odabranih uzoraka vode nije se pokazala statistiÄki znaÄajnom. Velike koliÄine vode podrazumijevaju transport priliÄno velikih koliÄina Se i U te njihovo taloženje u Jadranskome podmorju. Zbog složenosti krÅ”ke hidrogeologije nužno je istražiti obrasce cirkuliranja selena i urana na spomenutome podruÄju
Kiparske tehnike
Kiparstvo je umjetnost oblikovanja volumena u prostoru. Kiparska,
odnosno, skulptorska djela dijele se na samostojeÄu skulpturu i reljef.
SamostojeÄe skulpture su u svojoj biti trodimenzionalne forme u prostoru, koje su s tim prostorom u interaktivnom odnosu ā one ga zauzimaju, prožimaju ga, prostor prolazi kroz njih, ostaje zarobljen u njima ili se, pak, na neki drugi naÄin dopunjuju. Reljef je skulptura u kojoj je ploha nositelj prikaza. Jednako kao Å”to reljef u geografi ji oznaÄava sve ravnine i neravnine na zemljinoj povrÅ”ini, tako i u kiparstvu pojam reljefa oznaÄava masu oblikovanu na plohi koja stvara privid prostora i volumena. Za djecu je kiparstvo, odnosno oblikovanje u prostoru, sasvim prirodan i spontan naÄin izražavanja, Å”toviÅ”e, u predÅ”kolskoj dobi ona prstiÄima lakÅ”e oblikuju ono Å”to vide ili žele predoÄiti nekom drugom. Taktilnost kiparskog oblikovanja odliÄan je primjer osjetilnog istraživanja