26 research outputs found

    Biostratigraphy of Turonian to (?)Coniacian Platform Carbonates: A Case Study from the Island of Cres (Northern Adriatic, Croatia)

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    The shallow marine carbonate deposits on the island of Cres, overlying deeper-water Cenomanian–Turonian limestones, are characterized by an assemblage of rudists, benthic foraminifera, and associated microfossils. The paucispecific character of the fossil association suggests deposition in shallow areas of a carbonate platform, with low current-energies and restricted circulation. Similar assemblages indicating similar palaeoenvironments, are common in the Upper Cretaceous deposits of the Adriatic Carbonate Platform and adjacent areas. The assemblage of rudists (hippuritids) and microfossils indicate the Turonian to (?)Coniacian age of the investigated carbonate succession. The biostratigraphic importance of the so-called “primitive” hippuritids within the micropalaeontologically poorly defined biostratigraphy of deposits of this age, is accentuated

    Lower Aptian Rudist Faunas (Bivalvia, Hippuritoidea) from Croatia

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    Lower Aptian rudist faunas from Croatia consist of Requienia? zlatarskii PAQUIER, Toucasia sp., Agriopleura sp., Glossomyophorus costatus MASSE, SKELTON & SLISKOVIC, Himeraelites sp. and Offneria sp. This assemblage has a clear Southern Tethyan (Arabo–African) significance and typifies the Early Aptian. Faunas from the interior of the Adriatic Carbonate Platform in Istria are dominated by Requieniidae while those from the northeastern area in the vicinity of Tounj–Ogulin, close to the platform margin, exhibit a higher diversity and include, beside requieniids, Caprinidae, Caprotinidae and Monopleuridae, in conjunction with evidence of open marine conditions

    The application of UAV-derived SfM-MVS photogrammetry for the investigation of storm wave boulder deposits on a small rocky island in the semi-enclosed Northern Adriatic Sea

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    The inventory and categorization of an extensive coastal boulder assemblage originating from storm wave transport on the coastline of Fenoliga Island (Northern Adriatic Sea, southern Istria, Croatia) are presented and discussed herein. The study adopted the use of a commercial Uncrewed Aerial Vehicle (UAV) and Structure from Motion-MultiView Stereo (SfM-MVS) photogrammetry for the construction of a 3D model of the island. A Digital Elevation Model (DEM) and an orthomosaic were produced and employed for the mapping of the boulder assemblage in a GIS. In total, 592 boulders were identified and mapped. Using SfM-MVS-derived products allowed for the identified boulders to be categorized based on size classification. Amassed data relating to the boulder characteristics was inserted and stored in a GIS, including the results of a comparative assessment with historical Google Earth imagery which enabled the ‘quantification of boulder transport over a 9-year timeframe’. Field evidence indicates that boulders were created in-situ via the quarrying of bedrock strata by breaking waves causing increased water pressure within preexisting surfaces of weakness such as bedding planes and sub-vertical fractures. Once detached, the boulders were transported and deposited during storm wave events. Repeated storm events can further displace previously detached clasts

    Destructive M6.2 Petrinja Earthquake (Croatia) in 2020—Preliminary Multidisciplinary Research

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    On 28 December 2020, seismic activity in the wider Petrinja area strongly intensified after a period of relative seismological quiescence that had lasted more than 100 years (since the well-known M5.8 Kupa Valley earthquake of 1909, which is known based on the discovery of the Mohorovičić discontinuity). The day after the M5 foreshock, a destructive M6.2 mainshock occurred. Outcomes of preliminary seismological, geological and SAR image analyses indicate that the foreshocks, mainshock and aftershocks were generated due to the (re)activation of a complex fault system—the intersection of longitudinal NW–SE right-lateral and transverse NE–SW left-lateral faults along the transitional contact zone of the Dinarides and the Pannonian Basin. According to a survey of damage to buildings, approximately 15% of buildings were very heavily damaged or collapsed. Buildings of special or outstanding historical or cultural heritage significance mostly collapsed or became unserviceable. A preliminary analysis of the earthquake ground motion showed that in the epicentral area, the estimated peak ground acceleration PGA values for the bedrock ranged from 0.29 to 0.44 g. In the close Petrinja epicentral area that is characterized by the superficial deposits, significant ground failures were reported within local site effects. Based on that finding and building damage, we assume that the resulting peak ground acceleration (PGAsite) values were likely between 0.4 and 0.6 g depending on the local site characteristics and the distance from the epicentre

    A Deep Learning based Pipeline for Efficient Oral Cancer Screening on Whole Slide Images

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    Oral cancer incidence is rapidly increasing worldwide. The most important determinant factor in cancer survival is early diagnosis. To facilitate large scale screening, we propose a fully automated pipeline for oral cancer detection on whole slide cytology images. The pipeline consists of fully convolutional regression-based nucleus detection, followed by per-cell focus selection, and CNN based classification. Our novel focus selection step provides fast per-cell focus decisions at human-level accuracy. We demonstrate that the pipeline provides efficient cancer classification of whole slide cytology images, improving over previous results both in terms of accuracy and feasibility. The complete source code is available at https://github.com/MIDA-group/OralScreen.Comment: Accepted to ICIAR 202

    2022_Korbar-et-al_Mana

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    High-resolution geomorphological data from the island of Mana (Adriatic Sea, Croatia) used for analyses of the coarse-clast coastal strom deposit.THIS DATASET IS ARCHIVED AT DANS/EASY, BUT NOT ACCESSIBLE HERE. TO VIEW A LIST OF FILES AND ACCESS THE FILES IN THIS DATASET CLICK ON THE DOI-LINK ABOV

    Stratigraphic Framework, Discontinuity Surfaces, and Regional Significance of Campanian Slope to Ramp Carbonates from Central Dalmatia, Croatia

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    The sedimentology, microfacies, and stratigraphic age (from planktonic and benthic foraminifera and strontium-isotope stratigraphy) of a 300-m-thick Upper Cretaceous carbonate succession from the Island of Čiovo (central Dalmatia, Croatia) were analyzed in order to determine the lithostratigraphic, depositional, and chronostratigraphic framework. The Cretaceous strata were deposited in the southern part of the long-lasting (Late Triassic to Paleogene) Adriatic-Dinaridic Carbonate Platform (ADCP), one of a few late Mesozoic, intra-Tethyan, peri-Adriatic (sub)tropical archipelagos. The succession is separated by a firmground formational boundary into two lithostratigraphic units: the underlying Middle to Upper Campanian Dol Formation consisting of slope pelagic limestone with intercalated turbidites and debrites, and the overlying Upper Campanian Čiovo Formation composed of outer-ramp bioclastic-lithoclastic and echinoderm-dominated packstone. Age, lithology, and depositional settings of the Čiovo Formation are different from other penecontemporaneous, regionally important inner-platform carbonate successions within the ADCP domain. Therefore, the Čiovo Formation is proposed here as a new lithostratigraphic unit. Regionally important condensed intervals in the form of at least two firmground surfaces, characterized by Thalassinoides burrows (with phosphatic mineralization) that belong to the Glossifungites ichnofacies, occur in the lowermost part of the Čiovo Formation. Abrupt shallowing of depositional environments at the boundary between the Dol and the Čiovo Formation, and the generation of the formational boundary firmground, likely correlate with the regionally recorded Upper Campanian Event that represents a global eustatic sea-level fall. A regionally important subaerial exposure surface with nodular calcrete, rhizoliths, and Microcodium aggregates in the upper part of the Čiovo Formation represents a regional subaerial unconformity that was recorded across the ADCP domain and was interpreted as a consequence of diachronous and differential uplift of various parts of the platform in response to the formation of a forebulge in front of the approaching Dinaridic orogen

    The origin and dynamics of coastal boulders in a semi-enclosed shallow basin: A northern Adriatic case study

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    This paper documents the analysis of a coastal boulder deposit that was recently identified along the northern Adriatic coast (Premantura Promontory, Istria, Croatia). Accumulations of large boulders have not previously been reported in the northern Adriatic, which can be viewed as a semi-enclosed basin. A multidisciplinary approach was used to investigate the site including geological and geomorphological surveys, together with the use of an Unmanned Aerial Vehicle (UAV), digital photogrammetric analysis, hydrodynamic modelling and 14C AMS datings. Measurements of boulder position, elevation, size, shape and density were fed into hydrodynamic equations that are used to estimate the minimum storm and tsunami wave height required to enable the accumulation of boulders. Biogenic marine carbonate encrustations observed on 14 boulders suggest the infra- and sublittoral zones as source areas, while for most of the boulders a subaerial origin is hypothesised. The boulder deposit occurs on a flat promontory where the topography, together with the stratified limestone bedding planes and dense joint pattern constitute the predisposing factors for boulder size and detachment. Comparisons between satellite images taken between 2008 and 2017, pictures collected from Internet and a 2012 snorkel survey of the Istrian coast made it possible to highlight the emplacement of a boulder with an estimated weight of 7.65 t during late 2013 or early 2014. The study examines the mechanisms that may be responsible for the detachment and transport of these large limestone rock fragments from the emergent part of the coast and from the sea bed towards inland areas. The results suggest the occurrence of very recent extreme weather conditions as well as multiple historical storm events and exclude a tsunami origin of the boulders

    The origin and dynamics of coastal boulders in a semi-enclosed shallow basin: A northern Adriatic case study

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    This paper documents the analysis of a coastal boulder deposit that was recently identified along the northern Adriatic coast (Premantura Promontory, Istria, Croatia). Accumulations of large boulders have not previously been reported in the northern Adriatic, which can be viewed as a semi-enclosed basin. A multidisciplinary approach was used to investigate the site including geological and geomorphological surveys, together with the use of an Unmanned Aerial Vehicle (UAV), digital photogrammetric analysis, hydrodynamic modelling and 14 C AMS datings. Measurements of boulder position, elevation, size, shape and density were fed into hydrodynamic equations that are used to estimate the minimum storm and tsunami wave height required to enable the accumulation of boulders. Biogenic marine carbonate encrustations observed on 14 boulders suggest the infra- and sublittoral zones as source areas, while for most of the boulders a subaerial origin is hypothesised. The boulder deposit occurs on a flat promontory where the topography, together with the stratified limestone bedding planes and dense joint pattern constitute the predisposing factors for boulder size and detachment. Comparisons between satellite images taken between 2008 and 2017, pictures collected from Internet and a 2012 snorkel survey of the Istrian coast made it possible to highlight the emplacement of a boulder with an estimated weight of 7.65 t during late 2013 or early 2014. The study examines the mechanisms that may be responsible for the detachment and transport of these large limestone rock fragments from the emergent part of the coast and from the sea bed towards inland areas. The results suggest the occurrence of very recent extreme weather conditions as well as multiple historical storm events and exclude a tsunami origin of the boulders

    Impact of the October 2018 storm Vaia on coastal boulders in the northern Adriatic Sea

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    Boulder detachment from the seafloor and subsequent transport and accumulation along rocky coasts is a complex geomorphological process that requires a deep understanding of submarine and onshore environments. This process is especially interesting in semi-enclosed shallow basins characterized by extreme storms, but without a significant tsunami record. Moreover, the response of boulder deposits located close to the coast to severe storms remains, in terms of accurate displacement measurement, limited due to the need to acquire long-term data such as ongoing monitoring datasets and repeated field surveys. We present a multidisciplinary study that includes inland and submarine surveys carried out to monitor and accurately quantify the recent displacement of coastal boulders accumulated on the southernmost coast of the Premantura (Kamenjak) Promontory (Croatia, northern Adriatic Sea). We identified recent boulder movements using unmanned aerial vehicle digital photogrammetry (UAV-DP). Fourteen boulders were moved by the waves generated by a severe storm, named Vaia, which occurred on 29 October 2018. This storm struck Northeast Italy and the Istrian coasts with its full force. We have reproduced the storm-generated waves using unstructured wave model SimulatingWAves Nearshore (SWAN), with a significant wave height of 6.2 m in front of the boulder deposit area. These simulated waves are considered to have a return period of 20 to 30 years. In addition to the aerial survey, an underwater photogrammetric survey was carried out in order to create a three-dimensional (3D) model of the seabed and identify the submarine landforms associated with boulder detachment. The survey highlighted that most of the holes can be considered potholes, while only one detachment shape was identified. The latter is not related to storm Vaia, but to a previous storm. Two boulders are lying on the seabed and the underwater surveys highlighted that these boulders may be beached during future storms. Thus, this is an interesting example of active erosion of the rocky coast in a geologically, geomorphologically, and oceanologically predisposed locality
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