Abstract Carbon isotope composition of dissolved inorganic carbon (DIC) was studied at springs, lakes and tributaries of the Plitvice Lakes. The Plitvice Lakes are a unique and complex karst lakes system consisting of 16 flow-through lakes connected by waterfalls and streams and characterized by intense calcium carbonate precipitation in the form of tufa and lake sediments. Two main springs have different 14 C concentrations due to different geology and their variations were controlled by flow rates. Further downstream, at lakes to the Korana River that outflows from the lakes, the 14 C activity and δ 13 C consistently increased down the flow. Carbon isotope composition from 2010 to 2015 was compared with the values measured 30 years earlier. The variation in δ 13 C DIC was accounted for seasonal change, while 14 C activity of surface water DIC decreased 7–12% during the 30 years. Using a semi-empiric model, it is calculated that the downstream increase is controlled by the exchange of DIC and atmospheric CO 2 carbon and by introduction of decomposed biogenic carbon from the top soil organic matter of the lakes surrounding area in almost equal proportions.

ABSTRACT An unusual deposit at the Cretaceous-Paleogene (K-Pg) boundary within the Adriatic carbonate platform shallow-water succession is interpreted as a major tsunamite, and a possible mechanism that links it to the Chicxulub asteroid impact on Yucatan (Mexico) is speculated. Although the K-Pg boundary hiatus is a common feature within the shallow-marine successions of the Adriatic carbonate platform, three exceptional sections were discovered that are characterized by continuous sedimentation and the event beds at the K-Pg boundary. Two sections include ~5-m-thick coarse-grained complex event beds intercalated within more than 100-m-thick successions of predominantly micritic carbonates deposited in the protected low-energy inner-platform setting, relatively proximal to the platform-margin embayments. The third section is characterized by an ~10-cm-thick event bed showing distinct soft-sediment bioturbation, and it is interpreted as a more distal section. It has been reported previously that the Chicxulub impact cratering generated an almost global tsunami, while the seismic waves caused collapses of the North American southeastern margins. It is hypothesized that the collapses could have generated a megatsunami in the Atlantic Ocean that could pass through a deep seaway between the Atlantic and western Tethys Oceans and finally terminate on the Adriatic carbonate platform, located ~10,000 km from the impact site. Considering the fact that there are potential sedimentological indications for such a huge sedimentary event in NW Africa (Morocco), focused research is needed in the region, along with landslide tsunami modeling, for a relevant evaluation of the hypothesis.

ABSTRACT An ~10-m-thick sequence of Quaternary eolian sands from the island of Vis (Croatia) was investigated with the aim to unravel and understand their origin, characteristics, and age. The sand deposit is situated in a karstic depression in the eastern part of the island at an altitude of ~100 m above sea level (a.s.l.), and it is composed of a subhorizontally laminated unit at the bottom underlying a cross-bedded unit. The sand is very well sorted and fine grained and composed predominantly of carbonate lithic fragments, which most likely originated from the Dinaric karst region. The siliciclastic component of these sands reflects a more complex lithological source, including older sedimentary (e.g., flysch successions in the area, as well as older Quaternary deposits), magmatic, and metamorphic rocks probably originating from the Inner Dinarides, which were eroded and comminuted by glacial and periglacial activity during the last glacial period, and transported toward the Adriatic foreland by major rivers such as the Cetina and Neretva. Grain size and shape characteristics of the sands as well as their sedimentary structure indicate their eolian origin. Optically stimulated luminescence (OSL) dating was applied to determine the depositional age of the sediment. The obtained ages can be correlated to the Last Glacial Maximum (oxygen isotope stage [OIS] 2), implying that during the peak of that glaciation, the central Adriatic basin was dry land, a vast plain exposed to eolian deflation.

ABSTRACT We present the results of a compositional characterization study of amphorae from the ancient Greek town of Pharos, today Stari Grad, on the island of Hvar, in central Dalmatia, Croatia. The aim of the study was to identify the provenance of amphorae unearthed in Pharos, to determine the locally produced amphorae, and to identify the provenance of imported amphorae with a scientific-based approach, using optical thin-section petrography and bulk geochemical analysis by wavelength-dispersive X-ray fluorescence on 19 samples of different types of amphorae and reference materials. The results of the analyses allowed us to identify a group of imported amphorae from Corinth or Corfu and a group of imported amphorae from southern Italy, probably from Calabria. We were also able to identify a third group of imported amphorae from an as-yet-unknown provenance/workshop. Finally, according to the geochemical composition and close match with the reference material, namely, kitchenware, only two amphorae from the examined collection could be identified as local products. The results of the compositional characterization of amphorae from Pharos show us that an ancient Greek town had trade contacts beyond the Adriatic-Ionian region, and they provide opportunities for further studies of ancient amphorae production and circulation in this part of the Mediterranean.

ABSTRACT In this paper, we review ~140 yr of investigations about pelagosite, a usually black aragonitic encrustation with a vitreous luster that forms in the splash zone of Mediterranean rocky coasts. Prior to the mid-1920s, the geologic community considered pelagosite to be a separate mineral of uncertain composition, but then in 1926, Italian mineralogist Ettore Onorato determined that pelagosite has the same structure as aragonite (orthorhombic CaCO 3 ), and also that it contained cells of blue-green algae (i.e., cyanobacteria). Once pelagosite was declassed from the status of a mineral, and its name was eliminated from catalogues and textbooks, Onorato’s documentation of the cyanobacterial cells contained in this encrustation seems to have fallen into almost total oblivion during the rest of the twentieth century. We revisited pelagosite in its original type locality, the remote southern Adriatic island of Pelagosa (today’s Croatian island of Palagruža), as well as in the Dalmatian island of Hvar. Using modern analytical methods and techniques, we redefined the mineralogical and geochemical composition of pelagosite, the nature and significance of its microbial content, and the origin of its pisolitic “tree-ring” internal structure, which probably reflects cyclic climate changes.

ABSTRACT Final closure of the Neotethys Ocean basin along the Eurasian margin in southeastern Europe during Eocene–Oligocene time was accompanied by upper-crustal extension expressed as a series of low-angle detachments, basins bounded by normal faults, and volcanism. This extensional belt spanned the southern Balkan Peninsula from the Albanides along the southern Adriatic coast in the west to western Anatolia in the east. Despite the widespread occurrence of this phenomenon within the southern Balkan region, similar extension has not previously been observed in association with the Neotethys closure in the Dinarides, which form the western geographic continuation of this orogenic belt, ending in the Austrian Alps in the northwest. The Mid- Bosnian Schist Mountains are a fault-bounded body of greenschist-facies metamorphic rocks located along the paleogeographic margin of the present-day Adria continental block in the Internal Dinarides. We combine low-temperature thermochronometric ages with field observations of kinematic shear sense indicators and demonstrate that the Mid- Bosnian Schist Mountains were exhumed along a normal fault between 43 and 27.5 Ma. The most rapid cooling occurred between ca. 35 and 27 Ma, coincident with a regional-scale magmatic event. These data constitute the first evidence for major extension in the Dinarides contemporaneous with collision between Adria and the Eurasian margin, and they are consistent with removal of a subducting slab during the transition between oceanic subduction and continental collision.