THE RUDISTS OF SOUTHERN ISTRIA - AN EXAMPLE OF ENVIRONMENTALLY INDUCED SUCCESSION WITHIN SANTONIAN LIMESTONES

Rudist bivalves thrived commonly in the shallow carbonate platforms of the Cretaceous Tethyan realm. The presence of two vertically separated Rudist assemblages along two well preserved Upper Cretaceous sections of cape Mrlera (southern part of the Istrian peninsula) is interpreted as environmentally induced faunal replacement. The first succession begins with pelagic limestones, followed by a mixed radiolitid-hippuritid assemblage, and by monogeneric floatstones-biostromes of radioliotids. The lower pelagic unit represents relatively open marine conditions while the uppermost radiolitid unit originated under more restricted marine conditions.Radiolitid floatstones with rare Gorjanovicia bouquets represent the beginning of the second succession. A mixed radiolitid-hippuritid assemblage, characterised by radiolitid floatstones where rare large Vaccinites individuals occur, replaces the radiolitid assemblages in vertical succession. In both sections, sea level changes were the most important factor causing the replacement of rudist assemblages. Slight differences between the two successions could be attributed to differences in submarine topography. Radiolitids and hippuritids might have occupied different biotopes within subtidal environments of the Adriatic carbonate platform. Hippuritids preferred more stable and deeper subtidal environments. By contrast, radiolitids preferred the shallowest parts of subtidal areas. Therefore, these two major rudist groups may be used for determination of different paleoecological conditions.&nbsp

FACIJESNE KARAKTERISTIKE I PALEOOKOLIŠ RADIOLITIDA GORNJOCENOMANSKIH PLITKOMORSKIH NASLAGA JUŽNOGA DIJELA JADRANSKE KARBONATNE PLATFORME, SJEVEROZAPADNI DIO OTOKA KORČULE, HRVATSKA

Upper Cenomanian limestones from the northwestern part of the island of Korčula in Croatia are shallow-water Chondrodonta-level deposits that represent a lateral equivalent of a foundered platform paleoenvironment. The succession consists of peritidal limestones organised in irregular shallowing-upward cycles, indicating the influence of sinsedimentary tectonics in the background of their formation. The peak of the transgression is marked by bioclastic rudstones, which represent the most open paleoenvironmental conditions. Radiolitids are present through biostromal floatstones-rudstones where individuals thrive as elevator or clinger palaeoecological morphotypes, indicating that the rate of carbonate sedimentation is a key palaeoecological factor in their presence/absence within a subtidal paleoenvironment.Gornjocenomanski vapnenci sjeverozapadnoga dijela otoka Korčule plitkovodne su naslage nivoa Chondrodonta, koje predstavljaju lateralni ekvivalent paleookoliša potopljene platforme. Sukcesija se sastoji od peritidalnih vapnenaca organiziranih u nepravilne cikluse oplićavanja koji upućuju na utjecaj sinsedimentacijske tektonike na njihovo formiranje. Vrhunac transgresije obilježen je bioklastičnim radstonom koji u istraživanome slijedu predstavlja paleoekološke uvjete najotvorenijega dijela potplimnoga okoliša. Radiolitidi su prisutni kao biostrome karakteristika floutston-radston s jedinkama paleoekološkoga morfotipa elevatora ili klingera, što upućuje na to da je brzina karbonatne sedimentacije jedanod glavnih paleoekoloških čimbenika za njihovu prisutnost ili odsutnost unutar potplimnoga paleookoliša

New paleomagnetic results from imbricated Adria: Ist Island and related areas

For the purpose of this work samples for palaeomagnetic analysis were taken from Upper Cenomanian and Lower Senonian shallow water limestones, as well as from Senonian pelagic limestones from both Ist and the surrounding islands. This area belongs to Imbricated Adria, which is characterized by gently folded and faulted strata with a Dinaridic (NW–SE) trend. An exception is Premuda island where the beds are strongly folded and are subvertical. A total of 96 samples were drilled from 10 localities distributed between eight islands. The samples were then subjected to standard palaeomagnetic laboratory analysis and statistical evaluation. Eventually, six localities yielded statistically well-defined palaeomagnetic directions, which were shown pre date the folding in age.The overall mean palaeomagnetic direction obtained for the study area, characterizing the Cenomanian–Early Senonian time period had a Declination of 334°, Inclination=+46°, with statistical parameters k=188, a95=4.9°, defining a palaeomagnetic pole at l(N)=63°, f(E)=254°, dp=4.0°, dm=6.2°. This was compared with palaeomagnetic directions obtained for rocks of similar ages from stable Istria and the Kvarner islands. As the three palaeomagnetic directions are statistically identical, we conclude that there was no significant relative movement between the three areas after the Early Senonian. The palaeomagnetic declination for the study area, which characterizes the post-Early Senonian rotation of the Adriatic microplate, is the same as the declination for the Pannonian–Pontian age group from the South Pannonian basin. As the palaeomagnetic signals in both cases are primary, the results of the present paper not only support the conclusion that the rotating Adriatic microplate triggered rotations in the South Pannonian basin, but also suggest that the Adriatic platform did not change its orientation between the late Cretaceous and the Early Pontian.</p

Upper Turonian–Santonian slope limestones of the Islands of Premuda, Ist and Silba (Adriatic Coast, Croatia)

Upper Turonian-Santonian limestones at three island locations (Ist, Silba and Premuda) in the southwestern part of the Adriatic carbonate platform, record slope deposition based on their sedimentological and palaeontological characteristics.These Upper Cretaceous successions consist of three vertically superimposed lithotypes: (1) pelagic mudstonespackstones, (2) laminated pelagic wackestones-packstones, and (3) bioclastic floatstones-rudstones to packstonesgrainstones with fossils of shallow marine organisms.According to the proximity of the shallow water carbonate platform interior the depositional setting of the slope deposits could be identified as relatively more proximal or distal. The proximal part is characterized by non laminated pelagic limestones with resedimented bioclastic limestones, while the more distal parts have both laminated and nonlaminated pelagic limestones with rare resedimented bioclastic limestones. The resedimented bioclastic limestones represent slope apron deposits. Locally, at Premuda Island, the slope apron includes blocks of laminated pelagic limestones. The depositional environments of the Ist and Premuda profiles could be interpreted as of more distal origin, while those of the Silba profile represents a more proximal part of the slope.</p

Face-Sensitive Processes One Hundred Milliseconds after Picture Onset

The human face is the most studied object category in visual neuroscience. In a quest for markers of face processing, event-related potential (ERP) studies have debated whether two peaks of activity – P1 and N170 – are category-selective. Whilst most studies have used photographs of unaltered images of faces, others have used cropped faces in an attempt to reduce the influence of features surrounding the “face–object” sensu stricto. However, results from studies comparing cropped faces with unaltered objects from other categories are inconsistent with results from studies comparing whole faces and objects. Here, we recorded ERPs elicited by full front views of faces and cars, either unaltered or cropped. We found that cropping artificially enhanced the N170 whereas it did not significantly modulate P1. In a second experiment, we compared faces and butterflies, either unaltered or cropped, matched for size and luminance across conditions, and within a narrow contrast bracket. Results of Experiment 2 replicated the main findings of Experiment 1. We then used face–car morphs in a third experiment to manipulate the perceived face-likeness of stimuli (100% face, 70% face and 30% car, 30% face and 70% car, or 100% car) and the N170 failed to differentiate between faces and cars. Critically, in all three experiments, P1 amplitude was modulated in a face-sensitive fashion independent of cropping or morphing. Therefore, P1 is a reliable event sensitive to face processing as early as 100 ms after picture onset

Paleoecology and proliferation of the bivalve Chondrodonta joannae (Choffat) in the upper Cenomanian (Upper Cretaceous) Adriatic Carbonate Platform of Istria (Croatia)

Chondrodonta joannae (Choffat) is a morphologically variable oyster-like bivalve with a predominately calcitic shell. An exceptional exposure of C. joannae-bearing strata of late Cenomanian age crops out along the seaside in northern Istria (Croatia) and permits a taphonomical and functional analysis in order to define the life habit and growth strategies of this bivalve. The C. joannae population from the studied succession is characterized by highly-elongated, large and curved shells, reaching about 50 cm in height and 5 cm in length. This shell shape is typical of the club-like bivalve morphotype, which was adapted to soft-bottom substrates with high sediment accumulation. The shell is slightly inequivalve and characterized by a reduced body cavity, a few centimetres high, and a dorsal region up to 10 times longer. The shell opening mechanism was mostly based on the resilium located between the chondrophores which protrude in the body cavity. The abandoned dorsal cavity is filled by a calcite hinge plate, the ventral edge of which acted as fulcrum for the valve flexibility. In the hinge plate, the function of chondrophores changed. They acted as a hinge to keep tightly interlocked the valves, which considerably emerged above the sediment-water interface. The individuals were arranged in low shrub-type congregations, which produced low-relief mounds. The functional morphology and taphonomic signature suggest that C. joannae individuals collected food at a greater distance from the bottom with respect to the co-occurring rudists. We speculate that the C. joannae proliferation could be related to a late Cenomanian phase of environmental instability predating the OAE2 with fluctuating climatic conditions and ocean fertility

MICROFACIES CHARACTERISTICS OF CARBONATE COBBLE FROM CAMPANIAN OF SLOVENJ GRADEC (SLOVENIA): IMPLICATIONS FOR DETERMINING THE FLEURYANA ADRIATICA DE CASTRO, DROBNE AND GUŠIĆ PALEONICHE AND EXTENDING THE BIOSTRATIGRAPHIC RANGE IN THE TETHYAN REALM

U potoku blizu izdanka s kampanskim naslagama u području Slovenj Gradeca uzet je uzorak dimenzija krupnoga šljunka s fosilnim ostatcima puževa roda Trochachtaeon. Zajedno s njima određene su bentičke foraminifere Fleuryana adriatica i Cuneolina ketini unutar potplimskoga okoliša s aglutiniranim i porculanskim foraminiferama koje dosada nisu nađene u ovome dijelu gornjokrednoga oceana Tetis. Stratigrafski podatci iz okolnih gornjokrednih naslaga, zajedno s određenom mikrofosilnom zajednicom iz spomenutoga uzorka krupnoga šljunka, upućuju na kronostratigrafsku starost koja odgovara gornjemu dijelu donjega kampana, što podrazumijeva širi stratigrafski raspon vrsta F. adriatica i C. ketini. Paleoniša, u kojoj je F. adriatica obitavala najplići je dio potplimskoga okoliša. Obitavala je na relativno tvrđem substratu koji je rezultat lateralno strmijega paleoreljefa. Izostanak vrste F. adriatica unutar muljnih karbonatnih naslaga potplimskoga okoliša može biti zbog relativno veće brzine sedimentacije, te u paleookolišima relativno povišene energije koje karakteriziraju grejnston-pekston varijeteti podloge.A carbonate cobble was collected in a creek near Slovenj Gradec (Slovenia). It comprises Trochactaeon gastropods as well as foraminifera Fleuryana adriatica and Cuneolina ketini from a subtidal environment with agglutinated and porcelaneous benthic foraminifera. Packstone-grainstone of the structural type contains the abovementioned foraminiferal taxa, which are previously undetermined in this part of the Upper Cretaceous Tethyan realm. Stratigraphic data from this area, together with the determined microfossil assemblage of the carbonate cobble, indicate the upper part of Lower Campanian age, implying an extension of the F. adriatica and C. ketini stratigraphic range. The paleoniche within the Tethyan realm in which F. adriatica thrive is the shallowest part of the subtidal, close to peritidal conditions. It was developed on a relatively harder substrate that resulted from a laterally more pronounced paleorelief which enabled the shifting of hyaline benthic foraminifers towards the shallowest part of the subtidal. Their paleoniche is laterally absent from protected paleoenvironments with soft muddy substrate and a relatively high carbonate sedimentation rate, colonized with elevator rudists, as well as from relatively higher water energy paleoenvironments with completely hard grainstone-rudstone substrate

Recent foraminifera from the Croatian Adriatic seacoast

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Backscattering measurement of 6He on 209Bi: Critical interaction distance

An elastic backscattering experiment has been performed at energies below the Coulomb barrier to investigate static and dynamic effects in the interaction of 6He with 209Bi. The measured cross sections are presented in terms of the dσ/dσRuth ratio, as a function of the distance of closest approach on a Rutherford trajectory. The data are compared with a three-body CDCC calculation and good agreement is observed. In addition, the critical distance of interaction was extracted. A larger value was obtained for the exotic 6He nucleus as compared with the weakly bound 6Li and 9Be nuclei and the tightly bound 4He, 12C, and 16O nuclei.Ministerio de Economía y Competitividad FIS2013-41994-P FIS2014-53448-C2-1-