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High lead concentrations in soils of Croatian karst occur on the sharp geomorphological boundary where the Mediterranean climate abruptly changes into a cold continental climate. These were determined by geochemical baseline mapping of the topsoil cover in the Croatian karst regions of Istria, Gorski kotar, Kvarner and Lika which was performed through the analysis of over 800 sampling sites. A total of 25 major and trace elements including (Mo, Cd, Pb, Zn, As, Ni, Cu, Co) was analyzed by ICP-AES and Hg by FAAS. Lead isotope ratios were determined on selected soil and sediment profiles by ICP-MS. The patterns of geochemical distributions of Pb, Hg, Cd, and total S in topsoil indicate anomalous concentrations in the Gorski kotar and Velebit Mountain regions. The anomalies (especially Pb) overlap with the contours of mean annual precipitation of more than 2500 mm, indicating an association of these elements with airborne contamination. The Gorski kotar region of the Dinaric Alps is one of the most anomalous wet zones, which exhibits the highest mean precipitation values in the mesoscale climatology of the Alpine region. The detected high Pb contents and their spatial distribution in topsoil obtained during the geochemical baseline survey of topsoil in Croatia are in correspondence with precipitation anomalies (Fig. 1). The most striking difference is expressed by Pb in samples taken at altitudes higher than 1000 m above sea level, where most samples have concentrations above 80 mg/kg, which is almost twice the median content of lead (38 mg/kg) in the whole region. Detailed studies of the Pb distribution in the soil profiles showed concentrations of lead in remote regions up to 200 mgkg-1 in the upper 4 cm of the soil profiles.The isotopic ratio 206Pb/207Pb in all topsoil samples (0-10 cm depth), from both remote sites and those close to major roads, has a narrow range from 1.18 to 1.185 despite that samples taken at depths of >25 cm show a much wider range (from 1.21 to 1.32).

The Tithonian carbonates of the southern part of the Adriatic Platform are more than 700 meters thick, and have an accumulation rate of up to 15 cm/k.y. during a time of relatively uniform subsidence. The platform interior consists of numerous shallowing upward parasequences 1 to 3 meters thick. Facies include dasyclad and oncoid wackestone, skeletal packstone-grainstone, lime mudstone, and microbial and fenestral laminites. Late Tithonian parasequences commonly contain radial-ooid grainstone that occurs at transgressive bases of parasequences, or less commonly, in upper regressive parts of parasequences. Fischer plots are a simple graphical method to define relative sea level changes on "cyclic" carbonate platforms, by graphing cumulative departure from mean cycle thickness (corrected for subsidence) as a function of time. The preliminary plots of the Late Jurassic data suggest that the Fischer plots are effective in extracting 3rd order accommodation cycles from the data, but there is only a weak 4th order (100 and 400 k.y. signal) evident. The accommodation plots measure the combined effects of sea-level plus subsidence. Accommodation (Fischer) plots of the Late Jurassic cyclic succession show four 3rd order accommodation events (0.5 to 5 m.y. long). Differences between the plots for the Adriatic Platform, the Arabian Platform and the Haq and Al-Qahtani (2005) curve may in part be due to the effects of local tectonics. A combination of spectral analysis of time series constructed using some measure of relative water depth plotted against stratigraphic thickness, plot of cycle thickness vs. cycle number, and Fischer plots are being used to examine the possible influence of Milankovitch forcing on the formation of the platform interior cycles.

Na stijenama u zoni prskanja valova javlja se crna ili sivkasta prevlaka, koja izgleda poput stakla. STOSSICH (1878) je prema otoku Palagruži (Pelagosa) pojavu nazvao pelagozit. Priroda pelagozita zbunjivala je prve istraživače. VÉLAIN (1874) je mislio da se radi o silikatnoj tvari, MARCHESETTI (1876) piše o crnom opsidijanu, BIANCONI (1877/78), (prema BARIĆ 1974) ga smatra fulguritom, a CAPELLINI (1878) produktom izgaranja nekog plina (prema BARIĆ 1974). TSCHERMAK (1878) je pojavu pokušao objasniti utjecajem morske vode na vapnence i dolomite u podlozi, no već ga DES CLOIZEAUX (1874) i VÉLAIN (1878) nalaze i na feldspatskim stijenama Korzike i obalama Orana, te na bazaltima Réuniona. Na jadranskim otocima pelagozit se osim na vapnencima i dolomitima, također javlja i na eruptivima, pa ga tako GÖNNER (1916) spominje na Brusniku. Već prve kemijske analize pelagozita pokazale su da se radi o karbonatnom mineralu CLOËZ (1877), VIERTHALER (1878), STOSSICH (1878), SQUINABOL & ONGARO (1901), te ONORATO (1926). GÖNNER (1916) opisuje i gotovo bijele prevlake na Biševu za koje je bojenjem utvrdio da se sastoje od kalcita, a bijeli pelagozit našao je i na otoku Sv. Andrija (Svetac). Slijedi niz radova kojima se nastojalo saznati radi li se o kalcitu ili aragonitu, da bi konačno CLERICI (1921) i ONORATO (1926) utvrdili aragonit. Rendgenske analize pelagozita s otočića Kamik kod Visa (inv. br. 6699:MP1), te školja kod otoka Svetac pokazale su nedvosmisleno da se u tim primjerima radi o aragonitu BARIĆ (1972/1973 ; 1974). U sklopu projekta "Hrvatski otoci Jadrana" prikupljeni su uzorci pelagozita na otocima Velika i Mala Palagruža, Svetac, Kamik kod Sveca, Brusnik, te na našem najudaljenijem otočiću Galijulu. Izdvojeno je više morfoloških tipova koji su istraženi optički, a vrsta karbonata određena je bojenjem. Detaljna istraživanja provedena su skenirajućom elektronskom mikroskopijom, a kemizam glavnih komponenti energetsko disperzivnom spektroskopijom. Dobiveni podaci daju uvid u primarnu i dijagenezom izmijenjenu strukturu pelagozita. Pelagozit se na prikupljenim uzorcima javlja u raznolikim oblicima, a boja mu varira od gotovo crne do svjetlo sive. Izuzetno, mogu se naći i bijeli poput neglaziranog porculana. Na mnogim tamnim varijetetima vidljivi su sićušni kristalići gipsa, često u obliku sraslaca. Analiziran je gotovo crni pelagozit, s otočića Brusnika i bijeli iz uvale Maldefust na otoku Velika Palagruža. Brusnički pelagozit istražen je optički, a oba su testirana na aragonit Feigl-ovom otopinom. Na uzorku s Palagruže analizirana je dolomitna podloga (sl.1 ; tab. 1), te krupnozrnasta i sitnozrnasta lamina pelagozita. Dobiveni energetsko disperzivni spektri (EDS) obuhvaćaju K, L i M tranzicije unutar 10 KeV s mogućnošću identifikacije lakih elemenata kao što su kisik i ugljik. Elementarni sastav izračunat je pomoću programa INCA 200. Iz sadržaja Ca i Mg izračunat je udio karbonatnih minerala i njihov kemizam, a ugljik (C), predstavlja "suvišak", koji ne ulazi u sastav dobivenih faza, tj. organski ugljik. Brusnički pelagozit je aragonitni, svjetlosmeđ, s laminama debljine oko 3&micro ; ; m.Vlakanca aragonita su okomita na laminu, a setovi lamina izmjenjuju se s pojedinačnim tamnim i gotovo neprozirnim "slojićima". Bijeli, kalcitni pelagozit s V. Palagruže građen je od lamina s "krupnijim" ekvidimenzionalnim kristalićima i paketa vrlo fine vlaknaste građe (sl. 2). Preračun EDS spektra pokazuje da vlaknasta lamina sadrži kalcit s nešto malo magnezija (Ca0, 934Mg0, 073CO3) i organski ugljik (tab.1, spektar 1 ; sl.2. spektar 1).Lamina s većim kristalima kalcita sadrži nešto više magnezijske komponente (Ca0, 921Mg0, 079CO3), više slobodnog (organskog) ugljika i neznatnu količinu kalija i silicija (tab.1, spektar 2 ; sl.2., spektar 2). Različita boja lamina aragonitnog pelagozita vjerojatno odražava različiti udio organske tvari. Sitnozrnasta lamina kalcitnog pelagozita s manje magnezija i manje organskog ugljika, usporedljiva je s paketom svjetlije obojenih lamina aragonitnog pelagozita, dok je krupnozrnasta lamina kalcitnog pelagozita s većim "suviškom" ugljika usporedljiva s tamnom, organskom tvari bogatijom laminom u brusničkom aragonitnom pelagozitu. Stoga se može pretpostaviti da je bijeli oblik, u vadoznim uvjetima izmijenjeni i kalcitizirani primarno aragonitni pelagozit.

UVOD:O porijeklu i genezi pjeskovito-lesnih sedimenata otoka Suska mnogi su istraživači iznosili različita mišljenja (citirani u BOGNAR, 1983 ; 2003). Većina ih smatra eolskim, fluvio-eolskim ili fluvio-marinskim naslagama. Za razliku od njih, KIŠPATIĆ (1910) je smatrao da predstavljaju netopivi ostatak vapnenaca, koji je podzemnim vodenim tokovima transportiran i taložen na morskom dnu, te kasnije izdignut iz mora. Na njegovom originalnom materijalu koji se već gotovo stotinu godina čuva u Mineraloško-petrografskom odjelu Hrvatskog prirodoslovnog muzeja, načinjene su nove analize. ANALITIČKI MATERIJAL I METODE ISTRAŽIVANJA: Redeterminacija 8 sačuvanih uzoraka pijeska s otoka Suska, koje je Kišpatić početkom 1910. prikupio na raznim mjestima i na različitim dubinama, obuhvatila je određivanje udjela netopivog ostatka, separaciju teške i lake mineralne frakcije pomoću bromoforma, te njihovu analizu polarizacijskim mikroskopom. Za separaciju teških minerala korištena je frakcija 0, 05-0, 125 mm netopivog ostatka. Udio pojedinih minerala izražen u postocima dobiven je brojanjem oko 400 zrna u svakom preparatu. REZULTATI i ZAKLJUČAK:Udio karbonata u redeterminiranim uzorcima varira od 6, 6 do 33, 7%. Netopivi ostatak sadrži 3, 51-7, 12 % teške frakcije. U lakoj frakciji prevladava kvarc (do 60, 5%), zatim čestice stijena (do 30%) i feldspati (do 13%). Većina čestica stijena je rožnjačkog tipa, manje je čestica sericitskih škriljavaca i metamorfita s listićastim mineralima, te epidotom i coisitom. U nekim preparatima nalazimo još i grudice limonita i smeđe poluprozirne čestice, vjerojatno piroklastičnog podrijetla. U teškoj frakciji čestice stijena su znatno manje zastupljene (1, 5 - 8, 1%), zatim slijede opaka zrna (3, 4-13, 6%), a najčešći su listićasti minerali - muskovit i flogopit, klorit, te biotit (17, 5 -61, 9%) (Tablica). Ostali prozirni teški minerali čine 30, 1-68, 1% sastava (Sl. 1). Među teškim mineralima najzastupljenija je skupina amfibola (aktinolit, hornblenda, glaukofan), epidot-coisita, te granati. Rjeđe nalazimo piroksene i disten. Ultrastabilni minerali cirkon, turmalin i rutil čine najviše do 5% prozirnih teških minerala (Sl. 2). Zrna su većinom slabo zaobljena, naročito u sitnijoj frakciji. Poneka zrna piroksena pokazuju nazubljene krajeve, kao posljedicu dijagenetskih procesa. KIŠPATIĆ (1910) je u pijescima otoka Suska mikroskopski determinirao 22 minerala, uključujući 19 koje danas ubrajamo u tešku frakciju. Vrlo je detaljno opisao njihove mikrofiziografske osobine, no stupanj abrazije, odnosno zaobljenosti, koji su bitni za utvrđivanje podrijetla materijala ne navodi (kao uostalom niti većina drugih istraživača toga vremena). Prve vrlo detaljne opise morfoloških osobina zrna i sastava nalazimo tek u radovima MAMUŽIĆ & MUTIĆ (1965), MUTIĆ (1967). Osim minerala koje je našao Kišpatić, tijekom ovih istraživanja zapaženi su još silimanit, andaluzit, kloritoid, spinel i serpentin. Značajna je i prisutnost piroksena, za koje Kišpatić navodi da nisu utvrđeni sa sigurnošću. Ono po čemu se bitno razlikuju Kišpatićeve analize od analiza novijih istraživača je nedostatak podataka o međusobnom količinskom udjelu pojedinih minerala. Naime, on je određivanja provodio na preparatima koji su sadržavali samo minerale slične gustoće, a ne ukupnu asocijaciju teških minerala. Otuda vjerojatno i konstatacija o obilnoj zastupljenosti cirkona. Vjerujemo da nedostatak piroksena u njegovim analizama znači da je preparat (od njih stotinjak) u kojemu su oni bili koncentrirani vjerojatno bio zagubljen ili ga je previdio. Kišpatićevo uvjerenje da pijesak otoka Suska predstavlja netopivi ostatak vapnenaca i dolomita, zasniva se dijelom na TUĆANOVIM (1911) podacima o netopivim ostacima karbonata, s kojima je Kišpatić bio upoznat još prije objavljivanja. Prema njima, piroksen je vrlo rijedak, pa Kišpatić time objašnjava i "nedostatak" piroksena u susačkom pijesku. No, kako niti TUĆAN (1911) ne navodi međusobni udio pojedinih minerala, CRNJAKOVIĆ (1994) je na temelju analize sačuvanog dijela Tućanovih preparata pretpostavila da se njihov udio može procijeniti na temelju broja uzoraka u kojima se oni javljaju. Također je utvrdila da većina detritičnih minerala (Tućan je smatrao da su svi autigeni) potječe iz sedimentnih stijena, s obzirom na stupanj zaobljenosti, te razmjerno visok udio ultrastabilnih cirkona, turmalina i rutila. Stoga bi i u pijescima otoka Suska očekivali visok indeks CTR, što međutim nije slučaj (slika 2). Dakle, vrlo nizak stupanj zrelosti sedimenta (izuzetno nizak CTR), sačuvani nestabilni minerali kao što su pirokseni, te razmjerno nizak stupanj abrazije, ukazuju na materijal prvog ciklusa sedimentacije, a mineralna asocijacija na metamorfite alpskog područja kao izvorišne stijene što je u skladu s rezultatima drugih istraživača (BOGNAR et al., 1983 ; BOGNAR et al. 2003 ; MUTIĆ, 1967).

U radu je prikazan originalan postupak procjene dinamike rasta sedrenih barijera koristeći hidrološke nizove podataka o vodostajima, protokama, kao i podatke o konsumpcijskim značajkama. Utvrđeno je da prosječan rast sedrenih barijera na jezeru Kozjak iznosi 0, 56 cm/god, a kod Prošćanskog oko trostruko veći.

Izdvojeni elementi geološke baštine mogu se čuvati u muzejima i zbirkama, no cjelovito jedino u prirodi, na primjer u nacionalnim parkovima ili drugim zaštićenim lokalitetima.

Srednjoeocenski fliš značajno je zastupljen u geološkoj građi primorskog dijela Hrvatske. U svim područjima taj je litološki kompleks više ili manje izložen eroziji. Međutim, u slivu Slanog potoka u području Vinodola erozija fliša je prekomjerna. Zajedno s pratećim klizištima, razmatrana površina iznosi oko 3 km2 (sl. 1). Na njoj dolazi do potpune degradacije okoliša pri čemu nastaju tereni tipa &laquo ; badlands&raquo ; . Fliš na toj lokaciji, kao i na okolnom području koje nije izloženo pretjeranoj eroziji, zastupljen je uglavnom kalcitičnim glinovitim prahovnjakom i kalcitičnom prašastom glinom, manjim dijelom laporima i prašastim pješčenjacima (sl. 2). Mineralni i granulometrijski sastav glinovitih prahovnjaka i prašastih glina također je u cijelom području Vinodola sličan. Ove stijene sadrže muskovit i ilitični materijal (do 30 mas. %), kvarc (do 25 mas. %), kalcit (do 15 mas.%), feldspate (do 10 mas. %), klorit, kaolinit i smektit, a u nekoliko uzoraka određene su i male količine pirita (sl. 3). Udio sitnih čestica je velik ; frakcija čestica < od 2 mm iznosi do 45 mas. %, a onih promjera 2-4 mm do 15 mas. % (sl. 4). U inženjerskom smislu, litološke komponente fliša većim dijelom predstavljaju prijelazno područje: čvrsto tlo – mekana stijena (HS – SR) (sl. 5). Trošenjem toga kompleksa nastaje tlo izrazito sklono klizanju i plastičnom tečenju. Pojava eflorescencije u obliku bijeloga praha za vrijeme sušnog ljetnog perioda na nekim litološkim članovima je jedinstvena. Primjenom XRD određeno je da se bijeli prah sastoji od tenardita (natrijevog sulfata) i neznatnih količina gipsa (sl. 6). Najveći kristaliti tenardita opaženi pomoću SEM promjera su do 2 mm (sl.7). Pojave toga, u vodi topivog minerala, upućivale su da neke komponente fliša Slanog potoka sadrže u vodi topivi natrij, koji u kišnom periodu pospješuje dezagregaciju za kojom slijedi intenzivna erozija. Ove pretpostavke potvrđene su eksperimentalno nizom fizičkih i kemijskih testova. Uzorci fliša podvrgnuti su pokusima stabilnosti (pinhole test i postupak opetovanog vlaženja i sušenja ; IGH, Zagreb) koji su ukazali na visoku erodibilnost tla. Stupanj ekspanzivnosti inženjerskih tala procijenjen je na slici 8. Topive soli u pornoj vodi fliša određene su prema modificiranoj proceduri opisanoj u VAN REEUWIJK (2002). Na temelju kriterija određenih u SHERARD et al. (1976) analizirani fliš spada u grupu disperznih, a time i erodibilnih tala (sl. 9). Određene su i koncentracije iona u potočnoj vodi. Dobivene vrijednosti za Na+ i SO42- višestruko su veće od prosječnih vrijednosti za ove ione u slatkoj vodi. Opisana pojava tenardita prvi je nalaz toga minerala u Hrvatskoj. Pretjerana erozija flišnih naslaga Slanog potoka događa se zbog: litološkog sastava s pretežito sitnozrnatim članovima, pa čak i česticama nanometarskih dimenzija ; skupine materijala poznate kao tvrdo tlo – mekana stijena ; minerala sklonih bubrenju ; kemizma porne vode koja je obogaćena natrijevim ionom ; prisutnosti natrijeva minerala – tenardita, kao indikatora uzroka pretjerane erozije. Significant amount of Mid-Eocene flysch is present in the costal parts of Croatia. In the whole region flysch is subjected to the erosion to lesser or greater extent. However, there is an excessive flysch erosion in Slani potok (&laquo ; Salt creek&raquo ; ) catchment (in the area of Vinodol) which, together with accompanying landslides, covers the area of approx. 3 km2 (Fig. 1). At this location, the total site degradation takes place forming terrains of &laquo ; badlands&raquo ; type. Slani potok flysch, as also the one from surrounded area without excessive erosion, is represented mainly with calcareous clayey siltstone and calcareous silty claystone and to lesser extent with marls and silty sandstones (Fig. 2). There are no significant differences in the mineral content and grain size distribution of clayey siltstone and silty claystone in the whole area of Vinodol. These rocks contain muscovite and illitic material (up to 30 wt. %), quartz (up to 25 wt. %), calcite (up to 15 wt.%), feldspars (up to 10 wt. %), chlorite, kaolinite and smectite, and in some samples small quantity of pyrite (Fig. 3). There is a great amount of small particles. The particle size fraction smaller than 2 mm and fraction 2-4 mm sum up to 45 wt. % and up to 15 wt. %, respectively (Fig. 4). In terms of ingeneering geology, lithological components of flysch are in transition between hard soil – soft rock (HS – SR) (Fig. 5). Soil produced by weathering of this complex tends to slide and flow. Phenomenon of efflorescent salt crust on flysch in Slani potok during dry period of the year is unique in the area. The mineral content of white salt crust determined by XRD is represented by thenardite (sodium sulphate) and negligible amount of gypsum (Fig. 6). The largest thenardite crystallites observed by means of a scanning electron microscope (SEM) have a diameter of 2 mm (Fig. 7). Occurrence of this water soluble mineral, indicates that some components of flysch encompass sodium, which accelerates disintegration followed by intensive erosion. A series of physical and chemical tests are carried out in an attempt to verify mentioned assumption. Flysch samples are submited to physical tests of stability (pinhole test and cyclic dry-wet repeat treatment ; Civil Engineering Institute of Croatia, Zagreb) indicating high soil erodibility. Degree of expansiveness of engineering soils are described by Fig. 8. Determination of soluble salts in flysch pore water was carried out following modified procedure used by the International Soil Reference and Information Centre (VAN REEUWIJK, 2002). Based on criteria established by SHERARD et al. (1976), analysed flysch fall in the group of dispersive, i.e. erodible soils (Fig. 9). The analysis of stream water for soluble salts was carried out as well. Obtained concentrations of Na+ and SO42-are manyfold than average in fresh water. Illustrated appearance of thenardite is the first finding of this mineral in Croatia. Excessive erosion of Slani potok flysch complex occurs due to: lithological composition dominantly presented with fines including nanometer particles ; group of materials known as HS – SR ; presence of swelling minerals ; pore water rich in sodium ; presence of sodium mineral – thenardite, indicating cause of the excessive flysch erosion. Literatura References SHERARD, J.L., DUNNINGAN, L.P. & DECKER, R.S. (1976): Identification and Nature of Dispersive Soils.- Journal of the Geotechnical Engineering Division. ASCE, 102, GT 4, 287-301. VAN REEUWIJK, L.P. (ed.) (2002): Procedures for soil analysis.- International Soil Reference and Information Centre, technical paper, sixth edition, Wageningen. WILLIAMS, A.A.B. & DONALDSON, G. (1980): Building on expansive soils in South Africa.- Proc. 4th Int. Conf. on Expansive Soils, Denver, 2, 834-838.

Although the Mesozoic has long been considered greenhouse, the stacking patterns on Jurassic-Cretaceous platforms suggest that some intervals have formed under sea level changes that are too large for an ice free world. This is manifested in juxtaposition of facies or biotas in parasequences that represent 10 to 30 m shifts in water depths in excess of that expected from simple shallowing of several meters (the parasequence thickness). The presence of obliquity and short and long term eccentricity cycles also is suggestive of ice rather than the abundant precessional cycles that typify greenhouse platforms. We present data showing that the Late Tithonian of the Adriatic Platform represents a greenhouse phase. Well exposed Mesozoic sections along the southern Dalmatian islands (southern Croatia) can be used to evaluate the Jurassic-Cretaceous paleoclimate. The detailed stacking patterns of facies within the Late Jurassic (Tithonian) shallow platform interior (over 700 m thick) were examined. Facies include deeper lagoon dasyclad wackestone, oncoid wackestone, shoal-water skeletal and radial ooid packstone-grainstone, restricted lagoon lime mudstone, tidal flat microbial and fenestral laminites. They are arranged in 1 to 3 m thick parasequences. Parasequences likely are precessional (roughly 20 k.y. given the accumulation rates). They are arranged in sets 8 to 15 m thick composed of 3 to 6 parasequences, and possibly 100 k.y. duration. Lower Tithonian sets are dominated by subtidal parasequences passing up into thin, more shallow water parasequences. Upper Tithonian parsequences commonly have radial ooid grainstones at the base, and less commonly in upper regressive parts. Upper Tithonian parasequence sets have well developed tidal flat facies in upper parts. Estimation of water depths using the fenestral/microbial carbonate as a sea-level datum, shows that the subtidal facies formed in water depths of less than 5 m, and had overlapping depth ranges, implying mosaic-like facies patterns. These shallow water depths support very small precessional sea level changes forming the parasequences, compatible with very warm greenhouse climate. The high Tithonian subsidence rates favored relatively complete preservation of precessional cycles with few missing beats ; this also required that any eccentricity signal was very small, otherwise many precessional beats would not have been deposited on the platform top. Emergence near the Jurassic/Cretaceous boundary formed extensive sequence-bounding subaerial clayey and limestone breccia horizons interstratified with lowermost Cretaceous (Berriasian) cyclic carbonates. These Early Cretaceous emergence events were due to long term relative sea level fall, coupled with decreased subsidence rates. Thus the Late Tithonian appears to be a very warm greenhouse phase in the mid-Jurassic-Early Cretaceous cool mode. The Jurassic-Cretaceous sections of the Adriatic platform in Croatia may provide important paleoclimatic data for this time interval during which some of the world's major petroleum reservoirs were generated.

1. Introduction Barite mineralization in Lokve is a stratabound ore deposit conformably situated at the Permian-Triassic boundary. It is composed exclusively of pyrite and barite, separated into two distinct, juxtaposed horizons, stretching for tens of kilometers (PALINKAŠ et al., 1993). Stable isotopic composition of organic matter and carbonates are widely used as an indicator of depositional environment, and for the assessment of paleoclimates and paleoceanography of ancient marine environments. The distributions of hydrocarbons (HC) from ancient sediments have been used to infer biological origin, maturity, and proportions of marine and terrestrial organic matter, as well as sedimentary facies and paleosalinity. The isotopic compositions of the individual HC serve to identify the biological precursors of HC in ancient sediments (SCHWAB & SPANGENBERG, 2004). The aim of this study is to estimate the type of organic matter associated with barite-pyrite mineralization. 2. Geological setting Middle and Upper Permian sediments siliciclasitc sediments occurring near Lokve village originated from newly exposed dry land areas, uplifted during an early continental rifting phase in the Dinarides. The final members of the Upper Permian clastic rocks are green-grey and grey-violet fine-grained siltstones and pelites. Extensive low-lying coastal areas in the Dinarides became sites of evaporate deposition in lagoons and coastal sabhkas. Smoothing of the relief halted clastic deposition, which together with a concurrent change in climate from humid-arid to moderate-warm, triggered carbonate deposition and formation of the basal dolomite. All the Lower Triassic carbonate lithotypes with stratabound mineralization in the Gorski Kotar area, adjacent to the conformable contact with the Permian clastics, originated in a sedimentary environment near mean sea level (BABIĆ, 1968 ; ŠĆAVNIČAR, 1973). The Lokve barite deposits are situated along the edges of the Upper Permian terrain, adjacent to the contact with the Lower Triassic dolomites. The largest deposits occur in the vicinity of the villages of Homer and Mrzle vodice (PALINKAŠ et al., 1993). 3. Samples and methods Four samples collected from Lokve deposit were selected for organic geochemical analyses. Two samples from Homer locality are sandstones with pyrite. Two samples of barite-pyrite ore are collected at Školski brijeg locality. To remove any superficial contamination from handling and weathered material, the rock samples were cut in slabs with a water cooled saw, washed with analytical grade and glass distilled acetone, ethanol, and water, and dried at 50°C for 48 h. The cleaned samples were powdered in an agate ball-mill, and analyzed for distribution and isotopic composition of HC according to the procedure described by SPANGENBERG & MACKO, 1998. The extracts were fractionated by silica-alumina liquid chromatography into aliphatic, aromatic and NSO compounds. Chemical characterization of the aliphatic and aromatic HC were performed with an Agilent Technologies 6890 GC coupled to an Agilent Technologies 5973 quadrupole mass selective detector (GC/MSD). The compound specific C isotope analyses of the aliphatic HC were obtained by the use of an Agilent Technologies 6890 GC coupled to a Finnigan MAT Delta S IRMS by a combustion (C) interface III (GC/C/IRMS) under a continuous He flow. 4. Results The n-alkanes in the C11-C28 range and the acyclic isoprenoids pristane (Pr) and phytane (Ph) are the dominant resolvable compounds in the m/z 71 ion chromatograms of all samples. The low unresolved complex mixture (UCM) eluting between n-C11 and n-C30 is presented in sandstone samples. The n-alkanes have distribution with no odd-even predominance. Isoprenoids in the range C15 (farnesane) to C20 (phytane) are generally present in all samples. Non-aromatic cyclic HC, such as terpanes and steranes, are present in the saturated HC fraction extracted from the sandstones samples. Terpanes are found in one sample of barite-pyrite ore. Terpanes in the range from C23 to C32 were detected in the m/z 191 ion chromatograms. A series of low molecular-weight steranes were detected in the m/z 217 ion chromatograms. The gas chromatograms traces of the aromatics extracted from all samples from the Lokve deposit are dominated by methylated-naphthalenes, methylated-fluorenes and methylated-phenanthrenes. The  13C values of the measured alkanes range from -24.2 to -35.4 ‰ V-PDB. The low molecular weight n-alkanes (C

Introduction: Studying heavy mineral assemblages of beach sands and possible source rocks can often gain useful insight concerning supply patterns by which beaches are nourished with detritus. Beaches represent a delicate environment, one that is easily subject to destructive processes if imbalance is created between the supply of detritus and erosion. Such insights are thus of particular importance considering the rising pressure the Adriatic natural coast is experiencing with increased development of tourism and industry in recent years. Previous research on beach sands from the Island of Rab (CRNJAKOVIĆ et al., 1998) has shown that considerable variability exists in their heavy mineral compositions. The proposed sources of detritus were Eocene and Pleistocene siliciclastic rocks, which are present over a considerable area of the Island. In the current study new data is being obtained from both ancient rocks and recent beach sands with the intent of more precisely defining the source-beach relationship. Materials and Methods: Beach sands have been sampled at 8 beach locations (Figure 1). Several additional samples have been taken from Eocene and Pleistocene arenites to test similarities in heavy mineral associations. Obtaining heavy mineral concentrates was performed by commonly used procedures (MANGE & MAURER, 1992). Additionally, particle composition of arenites has been studied using thin sections made from artificially cemented sands. Results: Transparent heavy mineral associations from beach sands show specific differences. Most conspicious are the differences in the proportion of garnet and the ultrastable minerals zirkon, tourmaline and rutile. Garnet proportion varies between 12% and 72%, while ultrastable minerals vary from 11% to 67%. A higher proportion of garnet relates to a lower proportion of ultrastable minerals, and vice versa. Among the other most common heavy minerals are epidote/zoisite, Cr-spinel, staurolite and kyanite. Discussion and conclusion: The consistent variability in the garnet versus ultrastable mineral proportions in heavy mineral associations of the studied beach sands seems to be a consequence of the derivation of these sands. A comparison of Eocene and Pleistocene arenites shows similar difference. While the Eocene heavy mineral associations resemble that of the garnet-rich and ultrastable mineral-poor beach sands, the Pleistocene heavy mineral associations are similar to those beach sands rich in ultrastable minerals and poor in garnet. These relationships suggest that some beaches are dominantly supplied from source areas consisting of Eocene sandstones, some dominantly from source areas consisting of Pleistocene sands, while several beaches show HM associations suggesting a mixed source. Such relationships between beach sands and Eocene/Pleistocene arenites have previously been suggested based on the study of three beaches of the Island of Rab (CRNJAKOVIĆ et al., 1998), and the beaches in northern Dalmatia (PAVIČIĆ et. al., 2000). This study confirms previously proposed interpretations and shows that the relevant consistencies in heavy mineral variability in beach sands represent a rule for the northern half of the Croatian Adriatic coast. As the spatial relationship of beaches and their interpreted type of source areas show close vicinity, it follows that the supply of detritus to the beaches is greatly controlled by immediate hinterland erosion. Other possible supply paths such as longshore drift or a derivation from a distant source are much less significant. In conclusion, the source areas and the natural nourishment pathways of beach sands for the studied coasts can be successfully identified using a heavy mineral approach. The result of this is useful knowledge gained pertaining to the problem of sustaining Croatian beaches (PAVIČIĆ et. al., 2000). The need for evaluating how relevant natural processes will change with accelerated development of the coastal zone is growing. Otherwise, ignorance will inevitably bring damage to this natural and economic resource of the country.

Petrography, mineralogy and geochemistry are usful tools in provenance and technology studies of ancient pottery and their comparison. This approach was used to characterize potsherds from colluvial and alluvial fan deposits in the southern part of Vrana lake catchment. The potsherds were further used to explain slope processes during late Holocene. Most of the soil cover in the southern part of the Vrana lake catshment was washed out during the Bronze Age. Erosion of dolomite bedrock has been active throughout most of the late Holocene to the present day.

1. Introduction The Allchar polymetallic ore field is located at the southern margin of the Vardar zone, 110 km SE from Skopje, FYR Macedonia. Mineralization of Allchar is subdivided into three zones: (1) High temperature sulfide mineral paragenesis represented mainly by Sb and As mineralization ; (2) Sulfide mineralization barren of Sb and enriched in As and Tl and (3) Low temperature mineral paragenesis represented by barite, native sulfur, calcite, chalcedony and opal (IVANOV, 1986). The Allchar deposit is related to a Pliocene volcano-intrusive complex which occurs along a major regional fault zone between the rigid Pellagonian block on the west and the labile Vardar zone on the east. The basement is composed of Triassic sediments, the Jurassic ophiolites and the Cretaceous sediments (JANKOVIĆ & JELENOVIĆ, 1994). The rocks of volcano-intrusive complex range from andesite-quartz latite to rhyolite and trachyte (BOEV, 1993). Mineralization is spatially related to zonal hydrothermal alterations. The main types of alterations are silicification and argilization. The silification in the southern part of the ore field (zone I) represented by small quartz grains is related to antimony and gold mineralization. Argillitization is mainly developed in the volcanic rocks. In the northern part of the ore field (zone III) silification is represented by occurrence of chalcedony and opal (BOEV, 1993). 2. Samples and methods A fluid inclusion (FI) study was carried out to estimate the P-T conditions during mineralization and to characterize the mineralizing fluid. Microthermometric measurements were performed on primary FIs within doubly polished, ~0.5 mm thick, wafers of: (1) Quartz associated with high temperature sulfide mineralization (zone I) ; (2) Realgar and orpiment associated with sulfide mineralization barren of Sb and enriched in As and Tl (zone II) and (3) Opal associated with low temperature mineralization (zone III). Ultraviolet (UV) fluorescence microscopy was used to estimate the presence of hydrocarbons bearing inclusions. Analyses of evaporate mounds by scanning electron microscope equipped with EDX (SEM/EDX) were performed in order to constrain the chemical composition of mineralizing fluid. Analyses were focused on realgar and orpiment used for microthermometry. Evaporate mounds were prepared according to the procedure described by KONTAK (2004). 3. Results Microscopic examination of quartz, realgar and orpiment revealed the following types of FIs: Type I. Two phases (L+V) aqueous FIs frequently show progressive formation of negative crystal forms. Degree of fill (F) is between 0.85 to 0.95 ; Type II. Monophase, secondary, liquid FIs show mostly irregular forms. In quartz samples the FIs of Type III. are also present (monophase, anisotropic solid inclusions, with prismatic habitus and of primary origin). The following types of inclusion within opal were distinguish: Type I. Three phases (L1+L2+V) inclusions with irregular shapes and uniform degree of fill (0.95) ; Type II. Multiphase hydrocarbons inclusions usually occur as large, randomly distributed groups, restricted to healed fractures and sharp trails ; Type III. Monophase organic solid inclusions coexist with Type II inclusions. Microthermometric measurements were performed on FIs of Type 1 within quartz samples. Eutectic temperature (Te) between -44.0 and -58.0°C indicates presence of bivalent cations. Melting temperature of hydrate (Tmhyd1) varies between -42.0 and -24.2°C. Ice melting temperatures (Tmice) in the range from -2.4 to -18.1°C points to salinity between 4.0 to 21.3 wt.% NaCl equ. Homogenization into liquid phase is recorded in interval between 131.0 to 201.0°C. Microthermometry measurements within realgar confirmed presence of two different fluid inclusion types. Phase transitions were observed only within inclusions of Type I. Te is recorded in interval between – 50.3 and – 54.2°C. Melting runs in the temperature range between -35 and 0°C determined existence of two hydrates. Melting of the first hydrate (Tmhyd1) was recorded in temperature interval between -22.0 and -24.5°C. Temperature interval of the final melting of the second hydrate (Tmhyd2) is observed between -11.0 and -15.4°C. Tmice between -1.5 and -4.1°C corresponds to salinity of 2.56 to 6.85 wt.% NaCl equ. Homogenization (Th) follows disappearance of vapor at 120-141.1°C. Microthermometry measurements performed on FIs within orpiment samples gave data in the same range as those within realgar. Th was not recorded due to massive decrepitation of FIs at lower temperatures. Heating/freezing runs were performed on FIs of Type I and Type 3 within opal. Type I: Freezing was observed by the collapse of vapor bubble. During melting runs first phase change within FIs occur in temperature range from 2.4 to 7.0°C, by the abrupt appearance of vapor bubble. Total homogenization to liquid state was recorded at temperature range from 102.0 to 125.0°C. Complex hydrocarbons bearing inclusions of Type 2 did not freeze even at minimum stage temperature of -180°C. Th was not recorded due to massive decrepitation of FIs in the interval between 170 to 180°C. Analyses of realgar samples indicate Na and K chlorides composition of evaporate mounds. The presence of Al is also observed. A comparison of composition of evaporates mounds and microthermometric measurements points to composition of hydrates present within frozen inclusions. Hydrate with final melting temperature between -22.0 and -24.5°C (Tmhyd1) is hydrohalite (NaCl×2H2O). Hydrate with temperature between -11.0 and -15.4°C (Tmhyd2) is KCl×nH2O. Analyses of orpiment samples point that evaporate mounds consist only of Na and K chlorides. 4. Discussion and conclusion The Allchar deposit shows characteristics of Carlin-type mineralization: (1) strong structural control of mineralization by faults and folds ; (2) calcareous sedimentary host rocks of diverse facies, + igneous rocks ; (3) decarbonation, argillization, silification and sulfidation alterations ; (4) submicron gold in assocciation with pyrite, arsenian pyrite and arsenopyrite and (5) geochemical signature of Au, As, Hg, Sb and Tl. Gold was probably carried by bisulfide complexes and deposited in both intensely silicified parts and marginal argillic alteration zone, due to a combination of decreasing pressure and temperature, culminating in boiling and increasing pH. Thallium minerals (sulfides and oxides) can not be formed in neutral and acid conditions (Naumov, 2000). The hydrothermal fluids become alkaline as a result of degassing and removing CO2 in epithermal conditions. In such conditions the alkaline hydrotherms can deposit the thallium minerals in association with adular, zeolite, illite and other minerals - indicators of the high pH values. The role of organic matter in Carlin-type of mineralization is still unknown. BOEV, B (1993): Geology of Allshar polymetallic deposit, Macedonia. – Geologica Mecedonica, 7, 35-39. IVANOV, T. (1986): Allshar the richest ore deposit of Tl in the world. – In: NOLTE, E. (ed.): Proceedings of the Workshop on the feasibility of the Solar Neutrino Detection with 205Pb by geochemical and mass spectroscopical measurements. – Report GSI-86-9: Technische Universität München, pp. 1-6. JANKOVIĆ, S. & JELENOVIĆ, R. (1994): Thallium mineralization in the Allchar Sb-As-Tl-Au deposit. -N. Jb. Miner. Abh. 167: 283-297. KONTAK, D.J. (2004): Analysis of evaporate mounds as a complement to fluid-inclusion thermometric data: case studies from granitic environments in Nova Scotia and Peru. – Can.Mineral., 42, 1315-1329. NAUMOV, E. (2000): Behaviour of Thallium in Ore-Forming Processes on Gold-Mercury and Antimony-Mercury Deposits. -In: EMPG VIII Journal of Conference Abstracts, vol. 5, no. 1, Bergamo, Italy

Republika Hrvatska na svom, površinom malom teritoriju ima niz bioloških i geoloških različitosti. Danas je u Republici Hrvatskoj zaštićeno 449 područja i objekata. Odlukom Zemaljskog zavoda za zaštitu prirodnih rijetkosti arboretum Opeka proglašen je 1947. godine prvim zaštićenim spomenikom prirode. Isti je zavod 1948.g. proglasio lokalitet Rupnica prvim geološkim spomenikom prirode, a nalazište Hušnjakovo prvim paleontološkim spomenikom prirode.

Prema modernim geokemijskim shvaćanjima, Periadriatsko-savsko-vardarska zona, koja se po pružanju može pratiti oko 1700 km, predstavlja suturnu zonu, odnosno konvergencijsko područje između euroazijske i afričke ploče. Ona je presječena Prelaznom Alpsko-dinaridskom zonom koja je prostorno definirana Periadrijatskom i Zagreb-Zemplen rasjednom zonom. Kredno-tercijarne magmatske, sedimentne i metamorfne formacije Periadriatsko-savsko-vardarske zone paleogeografski su vezane za zalučni bazen koji je nastao nakon prve gornjojurske intraoceanske obdukcije ofiolita.

U radu su prikazani rezultati istraživanja prve i druge faze složenog klizišta na sjeveroistočnoj padini doline Rječine između brane Valići i naselja Pašac. Bokovi doline oblikovani su u paleogenskom flišu i kvartarnim padinskim tvorevinama. Na vrhovima su zastupljene vapnenačke stijene tvoreći litice. Nastanak istražene kompleksne pojave klizišta predodređen je geološkom građom i morfogenezom doline Rječine. To je složeno retrogresivno klizište, koje se počelo razvijati od stope prema vrhu padine. Na padini je otkriveno 13 pojedinačnih kliznih tijela. Klizanjem je zahvaćen materijal padinskih tvorevina. Klizna ploha uglavnom je predisponirana morfologijom flišne podloge. Veći dio kliznog tijela saturiran je podzemnom vodom koja se procjeđuje kroz pokrivač po kontaktu s nepropusnom flišnom podlogom. Pokrenuti su i megablokovi vapnenačke stijene na vrhu padine, koji klize po flišnoj podlozi. To je posebna pojava, netipična za klizišta na flišnim padinama u široj okolici Rijeke. Vapnenci na litici jako su oštećeni i u njima su vidljive svježe pukotine.

Iz uzoraka stijena iz sedam bušotina u hrvatskom dijelu Panonskog bazena paleontološkim analizama utvrđeni mikrofosili i makrofosili sarmatske su starosti. Nalaz rijetke vrste Semseya lamellata značajan je biostratigrafski podatak, budući da je ona isključivo vezana za niže slojeve donjeg sarmata. Kako su u njemu česti ostaci badenske mikrofaune, ona kao provodni mikrofosil ukazuje na kontinuiranu sedimentaciju badena u sarmat kao u bušotinama Sveta jana-1, Velika Barna-1 i Bujavica-12. Naslage iz kojih su izdvojeni uzorci izgrađene su iz sitnozrnatih pješčenjaka, konglomeratičnih pješčenjaka, konglomerata, pjeskovitih i listićavih lapora i biokalkarenita. U njima dobro očuvane mikrofosilne zajednice bentičkih foraminifera, od kojih su dominantni elfidiji s provodnim vrstama Elphidium hauerinum, E. josephinum i E. reginum, upućuju da se taloženje sedimenata odvijalo u prijelaznom marinsko-brakičnom okolišu s promjenjivom energijom vode te progresijom oslađivanja.

The fluids in vein-quartz from the Midd-Bosnian Schist Mts. were investigated by cryometric and thermometric measurement. There are two groups of fluid inclusions (FIs): aqueous and aqueous-carbonic FIs. Aqueous FIs were determined in all observed samples, and aqueous-carbonic FIs were observed only in the samples from Čemernica and Međuvršje. Aqueous FIs from Čemernica are KCl-NaCl-H2O FIs. Aqueous-carbonic FIs from Čemernica contain, except CO2, other volatiles (CH4, N2). In the FIs from the area of Međuvršje and Raštelica could be developed 4 or 5 types of hydrates. This type of FIs was determined as CaCl2 FIs with presence of other cations. Aqueous-carbonic FIs from Čemernica contain high concentration of other volatiles. Salinity of aqueous FIs is higher then salinity of aqueous-carbonic FIs. Salinity in the both types of FIs is higher in fluids from Međuvršje and Raštelica then into FIs from Čemernica. Temperatures of homogenization of all types of FIs are similar and were around 300°C.

Kasnodijagenetska dolomitizacija može biti odgovorna za "brisanje" prvotnih strukturnih i teksturnih zapisa, što rezultira poteškoćama pri razumijevanju okoliša taloženja prvotnih vapnenačkih taloga. U nedostatku pokazatelja važnih za interpretaciju okoliša taloženja karbonata, neke geokemijske karakteristike, kao test na sadržaj mangana, mogu poslužiti kao njihova nadopuna ili nadomjestak. Ispitan je sadržaj mangana gornjojurskih dolomita, vapnenaca i kerogeno-bituminoznih naslaga te donjokrednih vapnenaca područja Koreničko Vrelo, s ciljem dobivanja dodatnih informacija o dubini taloženja prvotnih vapnenačkih taložina. Zamisao je temeljena na pozitivnim predhodnim iskustvima razlikovanja plitkomorskih i dubokomorskih vapnenaca pomoću mangana i provjerenoj činjenici da dolomitizacija bitno ne utječe na njegov sadržaj (FLUGEL, 1982). Plitkovodni vapnenci, utvrđeni i temeljem mikrofacijesa, imaju niske vrijednosti sadržaja Mn. Rezultati istraženih dolomita ne odudaraju znatno od istraženih plitkomorskih vapnenaca, što znači da su prvotni vapnenački talozi bili plitkomorski. Vapnenac, biomikrit sa pelagičkom biokomponentom sadrži najviše Mn i ukazuje na dublji okoliš taloženja.

Razmatra se erozija prouzročena kišom u mediteranskom podneblju i njezine posljedice iskazane produkcijom nanosa. Za primjer je odabran sliv bujičnog vodotoka Posert u središnjoj Istri, koji je cijelim obuhvatom u području izgrađenom od eocenskog fliša. Fenomen produkcije nanosa ovdje se nameće kao inženjerski problem zbog skraćivanja vijeka trajanja planirane akumulacije "Grobnik". Za razliku od parametarske metode, koja je još standardno u uporabi, u radu su iskorišteni rezultati mjerenja na licu mjesta na pokusnoj plohi Abrami kod Buzeta. S tim se kvantitativnim pokazateljima pokušalo napraviti kartu erozije inženjerskogeološkim kartiranjem. Ona je kartografski prikaz razvijenosti erozijskih procesa u odnosnom slivu. Godišnju produkciju nanosa od 10.000 m3 i specifičnu od 450 m3/km2/god s 90% površine sliva uspoređuje se s vrijednostima koje su dobivene raznim metodama u istovjetnim terenima neposrednog okruženja.