Jabuka Shoal, a New Location with Igneous Rocks in the Adriatic Sea

Petrographic and XRF analyses of the magmatic rock from Jabuka Shoal, 2300 m west of Jabuka Islet (central Adriatic Sea) revealed that the rock is gabbro. This new location of magmatic rocks in the Adriatic confirms their linear arrangement, and indicates the presence of an important fault line which predisposed the occurrences of magmatic rocks

Benthic Foraminiferal Assemblages in a Restricted Environment - An Example from the Mljet Lakes (Adriatic Sea, Croatia)

Benthic foraminiferal assemblages from a peculiar restricted marine environment, the Mljet Lakes (Mljet Island, Adriatic Sea, Croatia) have been studied. These lakes are drowned karst dolines, which are connected with the Adriatic Sea through a narrow, shallow channel. Occasional stagnant conditions in the marine lakes cause hypoxic and anoxic conditions in the bottom waters. Such stressed conditions are reflected in oligospecific benthic foraminiferal assemblages with a Shannon-Wiener species diversity index (H) ranging from 0.8 to 1.0 and equitability index (E) ranging from 0.18 to 0.26, identified in samples from each marine lake. In the more dysoxic Malo Jezero, Haynesina depressula dominates an assemblage of 12 benthic foraminiferal species. In the less (and less frequently) hypoxic Veliko Jezero, we found an Asterigerinata mamilla assemblage with 18 foraminiferal species. A more diverse assemblage containing 55 different benthic foraminiferal species occupies an adjacent open-sea station. Long-term salinity measurements indicate that H. depressula tolerates higher salinity than formerly presumed (up to 38‰), and is well adapted to stressed hypoxic conditions

Holocenska sedimentacija u solinskom kanalu (Mljetska jezera, Jadransko more)

A 103 cm long core from the Soline Channel (Mljet Island, Adriatic Sea), which is at present a surface connection between the peculiar marine Mljet Lakes and the open sea, indicates substantial changes of the sedimentary environment in the Holocene. In the layer dated to 4,600 B.P., 25–30 cm below the bottom (which is at 2.8 m depth), freshwater algae represented by species of Chara/Nitella were found along with the gastropod Limnea stagnalis. This dominantly brackish sediment extends from 10 to 60 cm below the bottom. Above that interval marine sediment was found and below it quartz dominated the subareal or freshwater sediment. This indicates that the surface marine connection between Mljet Lakes and the sea was established after deposition of freshwater/brackish sediments i.e. not earlier than ca. 4 kyr B.P.Jezgra dugačka 103 cm izvađena iz kanala Soline (otok Mljet, Jadransko more), koji je danas površinska veza između jedinstvenih morskih Mljetskih jezera i otvorenog mora, ukazuje na bitne promijene taložnog okoliša u holocenu. U sloju čija je starost procijenjena na 4,600 godina, 25–30 cm ispod dna (koje se nalazi na dubini od 2.8 m), nađene su slatkovodne alge iz roda Chara/Nitella zajedno s puževima Limmnea stagnalis. Ti pretežno bočati sedimenti protežu se od 10 do 60 cm ispod dna. Iznad njih nalaze se marinski sedimenti a ispod kopneni ili slatkovodni sedimenti. To ukazuje da je površinska veza morem između Mljetskih jezera i otvorenog mora uspostavljena nakon taloženja slatkovodnih/bočatih sedimenata tj. ne prije oko 4 tisuće godina

Sedimentological and Surface Characteristics of the Northern and Central Adriatic Sediments

The results of this investigation reveal mutual relationship between some sedimentological and surface chemical characteristics, such as granulometric and mineral composition, specific surface area (SSA) and organic matter content, of northern and central Adriatic surface sediments. Grain size distribution and mineral composition enabled the reconstruction of the sedimentation pattern in the northern and central Adriatic Sea. It was shown that sands are spread in the east, along the Croatian coast. Toward the west, the share of finer sediments increases, so that the western region (parallel to the Italian coast) is covered with pelites. Such a pattern is typical for the northern Adriatic and the 401-407 profile of the central Adriatic. Most of the central region is covered with pelites. Granulometric and mineral composition are interrelated, indicating that sediments having more clay minerals (aluminosilicates) are always fine-grained, while coarser sediments contain more quartz and carbonates. The SSA and organic matter content are dependent on the grain size and mineral composition - fine-grained clay minerals have larger SSA’s and contain more organic matter attached to their surface. These organic substances influence considerably the SSA of sediments. It was noted that, after removing the organics, the SSA of sediments changed. This indicates that, effecting the SSA of sediments, organic matter effects their adsorptive ability

Seabed and Surface Sediment Map of the Kvarner Region, Adriatic Sea, Croatia (Lithological Map, 1:500,000)

A lithological map of recent marine sediments and the seabed of the Kvarner region (Adriatic Sea, Croatia) is presented on a scale of 1:500,000. The map was compiled from existing published and unpublished data. This is an area characterised by a number of islands located between the Istrian Peninsula and the Vinodol-Velebit coast. Water depths in channels between the islands reach up to 125 m, compared to depths of 40-50 m in the open waters of the adjacent northern Adriatic. Over most of the Kvarner area, muddy and sandy sediments cover the seafloor. Mud (M) is found on the bottom in Rijeka Bay, the northern part of the Kvarner, in Kvarneric, and in the Vinodol and Velebit channels, whereas over the rest of the Kvarner region seafloor sandy mud (sM) prevails, with subordinate occurence of gravelly mud (gM). Sandy sediments, i.e. muddy sands (mS) dominate in the SW part to the open Adriatic, and west of Rab Island, in the Pag and Velebit Channels. Previous investigations indicate that the fine grained particles that are found in deeper parts of Rijeka Bay, Kvarneric, and Vinodol Channel are of recent origin, and are deposited at water depths below the wave base. Sources of these particles are local permanent and temporary streams and the direct input from weathering processes, along with input by submarine springs (vrulje) near the coast. The large areas of the bottom not covered with sediments, or covered with gravelly and sandy sediments are found above the wave base, i.e. in the erosional wave zone. Coarse-grained material is lithic and/or biogenic. However, due to the very rapid Late glacial-Holocene transgression, when sea-level rose more than a hundred metres, coarse sandy sediments are found below the recent wave base in the SW part towards the open Adriatic, and west of Rab Island, in the Pag and Velebit Channels. Therefore the sediment distribution in the Kvarner region is only partly in dynamic equilibrium with modern hydrodynamic conditions

Some Anthropometric Characteristics, Reactions on Physical Stress, and Blood Pressure in Males Aged 18 in »Primorsko- Goranska« County, Croatia

The paper presents the distribution and average values of some anthropometric characteristics in 1,210 males aged 18 in »Primorsko-Goranska« County, as well as some manifestations of physical fitness parameters and some correlations between these two groups of characteristics. The prevalence of hypertensive and limit values for systolic blood pressure (SBP) was 8.6% and for diastolic blood pressure (DBP) 2.1%. Body weight and body mass index were in a significantly positive correlation with SBP and DBP. Body mass index showed a significantly positive correlation with heart rate after step test. Therefore, it can be concluded that overweight reduces tolerance on workload

Karst landforms and prehistoric settlement patterns: a case study from Korčula Island (Croatia)

This study is aimed at testing if and how a detailed assessment of geomorphological features in the territory nearby can complement palaeoenvironmental evidence revealed by the archaeological stratigraphy from a cave site. In the test site, located in the western part of the Adriatic island of Korčula (central Dalmatian coast, Croatia), the stratigraphy of the prehistoric cave settlement of Vela Spila reveals a tight relationship between postglacial environmental changes and human settlement patterns. In this work the territory outside the cave was investigated from a geomorphological point of view. A 1:25000 scale geomorphological map of the western part of the island was created through remote sensing and field survey. Two cores were drilled in Blatsko Polje, a large karst depression shaping the western part of the island to verify if the sediment record trapped in the depression was a suitable candidate for future palaeoenvironmental studies. The geomorphological context was also related to archaeological evidence from surface archaeological surveys in Western Korčula. The result of these combined methods shows a karst landscape typical of the Dalmatian coast and highly influenced by the island’s underlying structural and tectonic characteristics, with several landforms such as debris flows and pocket valleys indicating possible episodes of wetter, more erosive conditions both before and after the last ice age. The sediment cores from the Blatsko Polje, which is now artificially drained, show previous phases of intermittent flooding and a drier episode that led to the area being exploited more by humans in the Neolithic (8-4 ka BP). This is indicated both by the placement of archaeological sites of different phases around the Polje, and by finds of lithics, pottery, and microfauna in the cores themselves. Geomorphological analysis supports evidence of a tight relationship between environmental changes and human settlement patterns inferred from the cave stratigraphy and provides some information on the features of the landscape exploited by the cave dwellers. Finally, the polje infill proved to be a potential palaeoenvironmental archive (albeit an unusual one), that would warrant future investigation with higher resolution core samplin