Holocene palaeo-environmental reconstruction of the Karin sea, Novigrad sea and Velebit channel catchments : doctoral thesis

Istraživano područje obuhvaća četiri sliva na području Ravnih kotara i Bukovice, a vodotoci utječu u Karinsko more, Novigradsko more ili Velebitski kanal. Na četiri lokacije prikupljene su neporemećene jezgre nekonsolidiranih morskih sedimenata pomoću plutajuće platforme s tornjem, vitlima i klipnim korerom, a u pripadajućim slivovima petnaest kopnenih jezgara ili profila. Navedeno područje istraženo je podmorskim geofizičkim metodama. Uzorci su analizirani geokemijskim, mineraloškim, magnetometrijskim, spektrofotometrijskim, granulometrijskim i paleontološkim metodama. Starost sedimenata je utvrđena radiometrijskim metodama pomoću izotopa 14C i 137Cs. Istraživanje je omogućilo rekonstrukciju paleookolišnih uvjeta, određivanje izdizanja morske razine i utvrđivanje potencijalnih izvorišnih materijala iz sliva tijekom holocena. Početkom holocena na području današnjeg Novigradskog i Karinskog mora egzistirao je niz riječnih kanala koji su tekli po pleistocenskim klastitima. Terigeni brakični sedimenti zapunjavali su veće depresije i nepravilne erozijske forme klastita. U tri morske jezgre (KAR-A, NOV-3 i MOD-A) nabušeni su obalni ili kopneni sedimenti, prema kojima je moguće utvrditi relativno izdizanje morske razine tijekom ranog holocena. Marinski okoliš utvrđen je u Novigradskom moru od 10.750 BP, na području uvale Modrič od 10.210 BP, a najkasnije u Karinskom moru od 9.870 godina. Nakon prodora mora u današnje područje Novigradskoga i Karinskoga mora započinje faza brakičnih uvjeta sličnih onima u današnjim krškim jezerima. Daljim izdizanjem relativne razine mora započinje taloženje morskog sedimenta koji se taloži do danas. Povećani donos materijala u posljednjih 1.900 g. uzrokovan deforestacijom koja omogućuje eroziju tla i njegovo odnošenje u taložni bazen. Maksimumi erozije u slivovima su bili u razdoblju malog ledenog doba (od 160 do 265 BP), u vrijeme vladavine Mlečana i Turaka.Four long marine sediment cores (3,5-to 6,5 m) were sampled in the semi-enclosed bays of Novigrad and Karin Sea and Velebit channel, in locations at Zrmanja river mouth (named ZRM-A), Novigrad Sea (NOV-3), Karin Sea (KAR-A) and Modrič bay (MOD-A). Fifteen soil sediment cores or profiles were sampled in their respective catchments. Marine sediments span over the last 11.500 yr. Three marine sediment cores penetrated the marine sediment sequences and terminated in terrestrial sediments predating the Holocene flooding by the Adriatic Sea. The core at the mouth of Zrmanja river estuary covered a 4.500 yr. sequence of marine sediments. The main objective of this study is to outline the Holocene palaeo-environmental evolution (last 11.500 years) in catchments. Environmental changes in the catchments were determined by high resolution analysis using multi-proxy approach comprising chemical analysis (including C/N), particle size analysis, bulk and clay mineralogical XRD analysis, magnetic susceptibility (MS) and remanent magnetism analysis, and L*a*b* spectrum. To determine the age of the sediments, Carbon–14 (14C AMS) and Cesium-137 (137Cs) isotopes were used. Results were analysed using multivariate statistical methods and GIS modelling of catchment evolution. Spatial distribution of determined sequences was determined in geoacoustic underwater survey using side scan sonar, echosounder and subbottom profiler. Seismic data shows river channels incised in Pleistocene clastic rocks that existed during early Holocene. Larger channel, flowing from Karin Sea into Novigrad Sea was connected to river Zrmanja flow, and flew further through Novsko ždrilo into Velebit channel. Seismic data points to existence of braided river system. Larger depressions and irregular erosional forms were filled with freshwater or later brackish sediments. Marine cores NOV-3 and MOD-A terminated in terrestrial sediments predating the Holocene flooding by the Adriatic Sea. In the NOV-3 core terrestrial sediments occur after 10.750 cal. yr. BP, in MOD-A after 10.210 cal. yr. BP, and in KAR-A at 9.870 cal. yr. BP. Determined dates of marine transgression into semi-closed bays fit well with current relative sea-level curves for Adriatic. The shallow and isolated Karin Sea bay (15 m deep) shows evidence of a brackish lake/marsh system in the period from 7.480 to 8.500 cal. yr. BP. It is recognized by high Ca concentration, low Sr/Ca ratio, elevated Sr/Ba, Pb/Al, Mg/Al ratios, elevated C/N, pollen and foraminiferal assemblages. High Ca concentrations and low siliciclastic input typical for karstic lake sedimentation is also visible in core NOV-3 until 10.140 cal BP. This period is followed by sedimentation of fine grained dominantly silty sediments with dominance of calcite and quartz. Dark, low MS sediment with low TOC, C/N, Sr/Ca, Mg/Al and Mn/Fe ratios is typical for marine sedimentation, which lasts until today. Thickness of Holocene marine sediments according to subbottom profiler data is up to 16,5 m in Novigrad Sea and up to 9 m in Karin Sea. River Zrmanja delta has up to 27 m of deposits down to klastic base. Younger parts of the sediment cores recovered from the enclosed bays show marine sediment influenced by the terrestrial supply in the last 1.900 years. Evidence of anthropogenic changes with pronounced erosion due to deforestation in the subcatchments is evident in all marine cores as elevated χlf, χfd(%), changes in color (influx of red terra rossas visible as high a* and b*), elevated Pb, lithogenic elements, TOC, C/N and decreased carbonates. Indicators of anthropogenic influence occur at different periods in the subcatchments due to different periods of settlement. The earliest anthropogenic impact (deforestation and erosion) is visible in river Zrmanja mouth at 1.880 cal BP followed by Modrič bay at 1.715 cal BP, and 715 cal BP in Karin sea. Significant influx of terrigenous material is visible from 720 cal BP at ZRM-A, 515 cal BP in KAR-A and 240 cal BP in MOD-A. Highest erosion period in all three locations is similar, and lasts from 160 to 265 cal BP. Similar event is evident in Krupa river floodplain (Zrmanja catchment), where high organic peat-like sedimentation is sharply replaced by high terrigenous input due to deforestation in the surrounding slopes at 1.875 cal BP. Heavy metal concentrations increase at the same time as the increase in terrigenous input. Normalizing heavy metal concentrations with Al concentration showed anthropogenic influence is evident only for Pb and Cu, and it lasts from 1.400 cal BP, while increased pollution is visible in last 150 years. Concentrations of Ni, Zn and Mn show natural variations in concentrations with no visible human influence. Analysis of clay content and ratios Cr/Al vs Ni/Al and V/Al vs Ni/Al in soil sediments from adjacent catchments was used to determine possible sources of marine sediments. Clay minerals in core KAR-A are similar to cores 508/T and 508/F. Core ZRM-A in river Zrmanja mouth has two different sources of sediment. Sediment in the upper 160 cm has clay composition similar to Krupa catchment sediments, while sediment in the lower part of the core is similar to Žegarsko polje and upper Zrmanja catchment sediments. Sediments in NOV-3 located in the deep part of Novigrad Sea are similar to lower parts of KAR-A marine sediment core and soils from Karin Sea catchment

Holocene palaeo-environmental reconstruction of the Karin sea, Novigrad sea and Velebit channel catchments : doctoral thesis

Istraživano područje obuhvaća četiri sliva na području Ravnih kotara i Bukovice, a vodotoci utječu u Karinsko more, Novigradsko more ili Velebitski kanal. Na četiri lokacije prikupljene su neporemećene jezgre nekonsolidiranih morskih sedimenata pomoću plutajuće platforme s tornjem, vitlima i klipnim korerom, a u pripadajućim slivovima petnaest kopnenih jezgara ili profila. Navedeno područje istraženo je podmorskim geofizičkim metodama. Uzorci su analizirani geokemijskim, mineraloškim, magnetometrijskim, spektrofotometrijskim, granulometrijskim i paleontološkim metodama. Starost sedimenata je utvrđena radiometrijskim metodama pomoću izotopa 14C i 137Cs. Istraživanje je omogućilo rekonstrukciju paleookolišnih uvjeta, određivanje izdizanja morske razine i utvrđivanje potencijalnih izvorišnih materijala iz sliva tijekom holocena. Početkom holocena na području današnjeg Novigradskog i Karinskog mora egzistirao je niz riječnih kanala koji su tekli po pleistocenskim klastitima. Terigeni brakični sedimenti zapunjavali su veće depresije i nepravilne erozijske forme klastita. U tri morske jezgre (KAR-A, NOV-3 i MOD-A) nabušeni su obalni ili kopneni sedimenti, prema kojima je moguće utvrditi relativno izdizanje morske razine tijekom ranog holocena. Marinski okoliš utvrđen je u Novigradskom moru od 10.750 BP, na području uvale Modrič od 10.210 BP, a najkasnije u Karinskom moru od 9.870 godina. Nakon prodora mora u današnje područje Novigradskoga i Karinskoga mora započinje faza brakičnih uvjeta sličnih onima u današnjim krškim jezerima. Daljim izdizanjem relativne razine mora započinje taloženje morskog sedimenta koji se taloži do danas. Povećani donos materijala u posljednjih 1.900 g. uzrokovan deforestacijom koja omogućuje eroziju tla i njegovo odnošenje u taložni bazen. Maksimumi erozije u slivovima su bili u razdoblju malog ledenog doba (od 160 do 265 BP), u vrijeme vladavine Mlečana i Turaka.Four long marine sediment cores (3,5-to 6,5 m) were sampled in the semi-enclosed bays of Novigrad and Karin Sea and Velebit channel, in locations at Zrmanja river mouth (named ZRM-A), Novigrad Sea (NOV-3), Karin Sea (KAR-A) and Modrič bay (MOD-A). Fifteen soil sediment cores or profiles were sampled in their respective catchments. Marine sediments span over the last 11.500 yr. Three marine sediment cores penetrated the marine sediment sequences and terminated in terrestrial sediments predating the Holocene flooding by the Adriatic Sea. The core at the mouth of Zrmanja river estuary covered a 4.500 yr. sequence of marine sediments. The main objective of this study is to outline the Holocene palaeo-environmental evolution (last 11.500 years) in catchments. Environmental changes in the catchments were determined by high resolution analysis using multi-proxy approach comprising chemical analysis (including C/N), particle size analysis, bulk and clay mineralogical XRD analysis, magnetic susceptibility (MS) and remanent magnetism analysis, and L*a*b* spectrum. To determine the age of the sediments, Carbon–14 (14C AMS) and Cesium-137 (137Cs) isotopes were used. Results were analysed using multivariate statistical methods and GIS modelling of catchment evolution. Spatial distribution of determined sequences was determined in geoacoustic underwater survey using side scan sonar, echosounder and subbottom profiler. Seismic data shows river channels incised in Pleistocene clastic rocks that existed during early Holocene. Larger channel, flowing from Karin Sea into Novigrad Sea was connected to river Zrmanja flow, and flew further through Novsko ždrilo into Velebit channel. Seismic data points to existence of braided river system. Larger depressions and irregular erosional forms were filled with freshwater or later brackish sediments. Marine cores NOV-3 and MOD-A terminated in terrestrial sediments predating the Holocene flooding by the Adriatic Sea. In the NOV-3 core terrestrial sediments occur after 10.750 cal. yr. BP, in MOD-A after 10.210 cal. yr. BP, and in KAR-A at 9.870 cal. yr. BP. Determined dates of marine transgression into semi-closed bays fit well with current relative sea-level curves for Adriatic. The shallow and isolated Karin Sea bay (15 m deep) shows evidence of a brackish lake/marsh system in the period from 7.480 to 8.500 cal. yr. BP. It is recognized by high Ca concentration, low Sr/Ca ratio, elevated Sr/Ba, Pb/Al, Mg/Al ratios, elevated C/N, pollen and foraminiferal assemblages. High Ca concentrations and low siliciclastic input typical for karstic lake sedimentation is also visible in core NOV-3 until 10.140 cal BP. This period is followed by sedimentation of fine grained dominantly silty sediments with dominance of calcite and quartz. Dark, low MS sediment with low TOC, C/N, Sr/Ca, Mg/Al and Mn/Fe ratios is typical for marine sedimentation, which lasts until today. Thickness of Holocene marine sediments according to subbottom profiler data is up to 16,5 m in Novigrad Sea and up to 9 m in Karin Sea. River Zrmanja delta has up to 27 m of deposits down to klastic base. Younger parts of the sediment cores recovered from the enclosed bays show marine sediment influenced by the terrestrial supply in the last 1.900 years. Evidence of anthropogenic changes with pronounced erosion due to deforestation in the subcatchments is evident in all marine cores as elevated χlf, χfd(%), changes in color (influx of red terra rossas visible as high a* and b*), elevated Pb, lithogenic elements, TOC, C/N and decreased carbonates. Indicators of anthropogenic influence occur at different periods in the subcatchments due to different periods of settlement. The earliest anthropogenic impact (deforestation and erosion) is visible in river Zrmanja mouth at 1.880 cal BP followed by Modrič bay at 1.715 cal BP, and 715 cal BP in Karin sea. Significant influx of terrigenous material is visible from 720 cal BP at ZRM-A, 515 cal BP in KAR-A and 240 cal BP in MOD-A. Highest erosion period in all three locations is similar, and lasts from 160 to 265 cal BP. Similar event is evident in Krupa river floodplain (Zrmanja catchment), where high organic peat-like sedimentation is sharply replaced by high terrigenous input due to deforestation in the surrounding slopes at 1.875 cal BP. Heavy metal concentrations increase at the same time as the increase in terrigenous input. Normalizing heavy metal concentrations with Al concentration showed anthropogenic influence is evident only for Pb and Cu, and it lasts from 1.400 cal BP, while increased pollution is visible in last 150 years. Concentrations of Ni, Zn and Mn show natural variations in concentrations with no visible human influence. Analysis of clay content and ratios Cr/Al vs Ni/Al and V/Al vs Ni/Al in soil sediments from adjacent catchments was used to determine possible sources of marine sediments. Clay minerals in core KAR-A are similar to cores 508/T and 508/F. Core ZRM-A in river Zrmanja mouth has two different sources of sediment. Sediment in the upper 160 cm has clay composition similar to Krupa catchment sediments, while sediment in the lower part of the core is similar to Žegarsko polje and upper Zrmanja catchment sediments. Sediments in NOV-3 located in the deep part of Novigrad Sea are similar to lower parts of KAR-A marine sediment core and soils from Karin Sea catchment

Holocene palaeo-environmental reconstruction of the Karin sea, Novigrad sea and Velebit channel catchments : doctoral thesis

Istraživano područje obuhvaća četiri sliva na području Ravnih kotara i Bukovice, a vodotoci utječu u Karinsko more, Novigradsko more ili Velebitski kanal. Na četiri lokacije prikupljene su neporemećene jezgre nekonsolidiranih morskih sedimenata pomoću plutajuće platforme s tornjem, vitlima i klipnim korerom, a u pripadajućim slivovima petnaest kopnenih jezgara ili profila. Navedeno područje istraženo je podmorskim geofizičkim metodama. Uzorci su analizirani geokemijskim, mineraloškim, magnetometrijskim, spektrofotometrijskim, granulometrijskim i paleontološkim metodama. Starost sedimenata je utvrđena radiometrijskim metodama pomoću izotopa 14C i 137Cs. Istraživanje je omogućilo rekonstrukciju paleookolišnih uvjeta, određivanje izdizanja morske razine i utvrđivanje potencijalnih izvorišnih materijala iz sliva tijekom holocena. Početkom holocena na području današnjeg Novigradskog i Karinskog mora egzistirao je niz riječnih kanala koji su tekli po pleistocenskim klastitima. Terigeni brakični sedimenti zapunjavali su veće depresije i nepravilne erozijske forme klastita. U tri morske jezgre (KAR-A, NOV-3 i MOD-A) nabušeni su obalni ili kopneni sedimenti, prema kojima je moguće utvrditi relativno izdizanje morske razine tijekom ranog holocena. Marinski okoliš utvrđen je u Novigradskom moru od 10.750 BP, na području uvale Modrič od 10.210 BP, a najkasnije u Karinskom moru od 9.870 godina. Nakon prodora mora u današnje područje Novigradskoga i Karinskoga mora započinje faza brakičnih uvjeta sličnih onima u današnjim krškim jezerima. Daljim izdizanjem relativne razine mora započinje taloženje morskog sedimenta koji se taloži do danas. Povećani donos materijala u posljednjih 1.900 g. uzrokovan deforestacijom koja omogućuje eroziju tla i njegovo odnošenje u taložni bazen. Maksimumi erozije u slivovima su bili u razdoblju malog ledenog doba (od 160 do 265 BP), u vrijeme vladavine Mlečana i Turaka.Four long marine sediment cores (3,5-to 6,5 m) were sampled in the semi-enclosed bays of Novigrad and Karin Sea and Velebit channel, in locations at Zrmanja river mouth (named ZRM-A), Novigrad Sea (NOV-3), Karin Sea (KAR-A) and Modrič bay (MOD-A). Fifteen soil sediment cores or profiles were sampled in their respective catchments. Marine sediments span over the last 11.500 yr. Three marine sediment cores penetrated the marine sediment sequences and terminated in terrestrial sediments predating the Holocene flooding by the Adriatic Sea. The core at the mouth of Zrmanja river estuary covered a 4.500 yr. sequence of marine sediments. The main objective of this study is to outline the Holocene palaeo-environmental evolution (last 11.500 years) in catchments. Environmental changes in the catchments were determined by high resolution analysis using multi-proxy approach comprising chemical analysis (including C/N), particle size analysis, bulk and clay mineralogical XRD analysis, magnetic susceptibility (MS) and remanent magnetism analysis, and L*a*b* spectrum. To determine the age of the sediments, Carbon–14 (14C AMS) and Cesium-137 (137Cs) isotopes were used. Results were analysed using multivariate statistical methods and GIS modelling of catchment evolution. Spatial distribution of determined sequences was determined in geoacoustic underwater survey using side scan sonar, echosounder and subbottom profiler. Seismic data shows river channels incised in Pleistocene clastic rocks that existed during early Holocene. Larger channel, flowing from Karin Sea into Novigrad Sea was connected to river Zrmanja flow, and flew further through Novsko ždrilo into Velebit channel. Seismic data points to existence of braided river system. Larger depressions and irregular erosional forms were filled with freshwater or later brackish sediments. Marine cores NOV-3 and MOD-A terminated in terrestrial sediments predating the Holocene flooding by the Adriatic Sea. In the NOV-3 core terrestrial sediments occur after 10.750 cal. yr. BP, in MOD-A after 10.210 cal. yr. BP, and in KAR-A at 9.870 cal. yr. BP. Determined dates of marine transgression into semi-closed bays fit well with current relative sea-level curves for Adriatic. The shallow and isolated Karin Sea bay (15 m deep) shows evidence of a brackish lake/marsh system in the period from 7.480 to 8.500 cal. yr. BP. It is recognized by high Ca concentration, low Sr/Ca ratio, elevated Sr/Ba, Pb/Al, Mg/Al ratios, elevated C/N, pollen and foraminiferal assemblages. High Ca concentrations and low siliciclastic input typical for karstic lake sedimentation is also visible in core NOV-3 until 10.140 cal BP. This period is followed by sedimentation of fine grained dominantly silty sediments with dominance of calcite and quartz. Dark, low MS sediment with low TOC, C/N, Sr/Ca, Mg/Al and Mn/Fe ratios is typical for marine sedimentation, which lasts until today. Thickness of Holocene marine sediments according to subbottom profiler data is up to 16,5 m in Novigrad Sea and up to 9 m in Karin Sea. River Zrmanja delta has up to 27 m of deposits down to klastic base. Younger parts of the sediment cores recovered from the enclosed bays show marine sediment influenced by the terrestrial supply in the last 1.900 years. Evidence of anthropogenic changes with pronounced erosion due to deforestation in the subcatchments is evident in all marine cores as elevated χlf, χfd(%), changes in color (influx of red terra rossas visible as high a* and b*), elevated Pb, lithogenic elements, TOC, C/N and decreased carbonates. Indicators of anthropogenic influence occur at different periods in the subcatchments due to different periods of settlement. The earliest anthropogenic impact (deforestation and erosion) is visible in river Zrmanja mouth at 1.880 cal BP followed by Modrič bay at 1.715 cal BP, and 715 cal BP in Karin sea. Significant influx of terrigenous material is visible from 720 cal BP at ZRM-A, 515 cal BP in KAR-A and 240 cal BP in MOD-A. Highest erosion period in all three locations is similar, and lasts from 160 to 265 cal BP. Similar event is evident in Krupa river floodplain (Zrmanja catchment), where high organic peat-like sedimentation is sharply replaced by high terrigenous input due to deforestation in the surrounding slopes at 1.875 cal BP. Heavy metal concentrations increase at the same time as the increase in terrigenous input. Normalizing heavy metal concentrations with Al concentration showed anthropogenic influence is evident only for Pb and Cu, and it lasts from 1.400 cal BP, while increased pollution is visible in last 150 years. Concentrations of Ni, Zn and Mn show natural variations in concentrations with no visible human influence. Analysis of clay content and ratios Cr/Al vs Ni/Al and V/Al vs Ni/Al in soil sediments from adjacent catchments was used to determine possible sources of marine sediments. Clay minerals in core KAR-A are similar to cores 508/T and 508/F. Core ZRM-A in river Zrmanja mouth has two different sources of sediment. Sediment in the upper 160 cm has clay composition similar to Krupa catchment sediments, while sediment in the lower part of the core is similar to Žegarsko polje and upper Zrmanja catchment sediments. Sediments in NOV-3 located in the deep part of Novigrad Sea are similar to lower parts of KAR-A marine sediment core and soils from Karin Sea catchment

First palynological results from the archaeological site Sopot, Croatia

This paper presents first results of research drilling and pollen analysis at the eponymous site of Sopot. Drilling was conducted in 2010 to give an overview of the spatial relationship of the “tell” with the immediate surroundings and preliminary data on geological and cultural layering of Sopot. Among other things, the goal of the research was finding suitable organic sediments, in order to take test for palynological analysis, to try to reconstruct the vegetation cover, agricultural development and land use

Vulnerability of the karst area related to potentially toxic elements

Soil samples from 31 locations in the Una river spring catchment were subject to chemical extraction analyses. The data were presented as distribution maps of potentially toxic elements (Al, Cu, Mn, Pb and Zn) in the surface soil of the area. To evaluate the vulnerability of the immediate spring zone of the karst catchment, the vulnerability map was derived from the application of the PI methodology proposed by the European COST Action 620. The PI method used to produce the vulnerability map takes into account the protective cover (P) and the infiltration conditions (I). It is based on the origin-pathway-target model. The π-factor (π = P ´ I) describes the vulnerability in the area, subdivided into 5 classes: π-factor in the range 0-1 implies an area of extreme vulnerability, while π-factor in the range 4-5 implies an area of very low vulnerability. The extraction procedure for the elements Al, Cu, Mn, Pb and Zn, has been applied in order to determine the potential mobility and redistribution of elements that could influence the groundwater and affect its quality. The applied extraction was the second step of the sequential procedure proposed by TESSIER et al. (1979), i.e. extraction with 1 mol dm-3 CH3COONa/CH3COOH buffer (pH 5). The results provide information on the potential mobility of the studied elements, indicating the possibility of their mobilization through changes in pH. Lead shows the greatest amount of mobility, with a mean of 9% (max. 16%) extracted under an acidic condition. Manganese follows with a mean of 5% (max. 11%) and zinc, copper and aluminium show less than 1% (mean) mobility. The vulnerability map of the karst area was produced in order to predict potential problem areas of karst aquifers. The Una spring catchment area presents generally low to moderate vulnerability; 8% of the studied area can be considered as extremely vulnerable according to the PI-methodology. Based on these data it was possible to delineate areas with a low protection cover i.e. combining the vulnerability map of the karst area with the distribution maps of potentially toxic elements, areas considered extremely vulnerable could be identified.</p

Environmental history in Central Croatia for the last two millennia – vegetation, fire and hydrological changes under climate and human impact

U ovome radu predstavljena je paleookolišna rekonstrukcija creta u blizini sela Blatuše, s naglaskom na promjene u strukturi i sastavu vegetacije, hidrološkoga režima i povijesti požara na području Banovine/Korduna tijekom posljednja dva tsućljeća. U svrhu paleookolišne interpretacije, napravljena je analiza akumuliranoga peluda, nepeludnih palinomorfa i pougljenjenih čestica. Upotrebom CONISS statističkoga modela mogu se razlučiti tri različite (pod)zone akumulacije: vegetacija „joha-bukva/hrastovi“ dominanira razdobljem od 2. stoljeća do sredine 7. stoljeća, nakon čega slijedi dominacija vegetacije „trave-bukva/hrastovi“ do kraja 13. stoljeća, te naposlijetku vegetacije „trave-grab/hrastovi“ u razdoblju od 14. do početka 20. stoljeća. Obilje spora maha tresetara (Sphagnum) u razdoblju od 11. do kraja 14. stoljeća vjerojatno je utjecano povećanom količinom oborina i učestalijim padalinama tijekom srednjovjekovne klimatske anomalije. Prijelaz iz ombrotrofije u minerotrofiju same cretne površine, tijekom maloga ledenog doba, uzrokovan je promjenom zasićenosti supstrata vodom, s nešto vlažnijim razdobljem do sredine 17. stoljeća i djelomično sušnijim do početka 20. stoljeća. Iako se pelud žitarica ne pojavljuje do kraja 14. stoljeća i udjeli sekundarnih antropogenih indikatora su niski tijekom cijeloga razdoblja srednjeg vijeka, veliki broj pougljenjenih čestica ukazuje na jaču antropogenu aktivnost no što se to može iščitati iz promjenama u biljnome pokrovu. Ipak, snažan porast udjela peluda nedrvenastih vrsta tijekom Seobe naroda više je rezultat procesa sukcesije na površini samoga creta nego nepobitan dokaz avarsko-slavenskoga utjecaja na sastav i strukturu vegetacije. Izravni antropogeni pritisak, koji se očituje učestalom pojavom peluda korovnih vrsta i žitarica, može se pratiti tek od razdoblja kasnoga srednjeg vijeka nadalje.This paper presents the paleoenvironmental reconstruction of a mire sequence near the village Blatuša, with a focus on changes in vegetation composition, hydrological regime and fire history of the Banovina/Kordun area during the last two millennia. For this purpose, pollen, non-pollen and charcoal analysis were done. By the application of CONISS statistical analysis three different pollen assemblage (sub)zones could have been distinguished: a dominance of alder-beech/oaks from the 2nd to the middle of the 7th century, followed by a prevalence of grasses-beech/oaks till the end of the 13th century. Finally, an assemblage of grasses-hornbeam/oaks populated the area from the 14th to the beginning of the 20th century. The high abundance of peat mosses (Sphagnum) from the 11th to the end of the 14th century must indicate increased precipitation and higher frequencies of rainfall during the Medieval Climate Anomaly. Transition from an ombrotrophic to minerotrophic phase of mire evolution during the Little Ice Age is caused by changing in moisture level, with somewhat wetter period prevailing till the middle of the 17th century followed by drier conditions till the beginning of the 20th century. Although cereal pollen grains first appear from the layers dated to the late 14th century and the proportion of secondary anthropogenic indicators were low during the entire Middle Ages, a large number of charcoal particles suggests stronger anthropogenic activity than indicated by observed changes in vegetation composition. Still, a sharp rise of non-arboreal pollen during the Migration period most likely reflect a general natural succession process on mire surface than persuable proof of Avaric-Slavic impact on vegetation. Direct anthropogenic pressure indicated by weeds and cereal pollen can be tracked from the Late Middle Ages onwards

Geomorphology of Canyon Outlets in Zrmanja River Estuary and Its Effect on the Holocene Flooding of Semi-enclosed Basins (the Novigrad and Karin Seas, Eastern Adriatic)

Detailed multi-beam bathymetry, sub-bottom acoustic, and side-scan sonar observations of submerged canyons with tufa barriers were used to characterize the Zrmanja River karst estuary on the eastern Adriatic coast, Croatia. This unique karst environment consists of two submerged karst basins (Novigrad Sea and Karin Sea) that are connected with river canyons named Novsko Ždrilo and Karinsko Ždrilo. The combined use of high-resolution geophysical data with legacy topography and bathymetry data in a GIS environment allowed for the description and interpretation of this geomorphological setting in relation to the Holocene sea-level rise. The tufa barriers had a predominant influence on the Holocene flooding dynamics of the canyons and karst basins. Here, we describe the possible river pathways from the basins during the lowstand and the formation of a lengthening estuary during the Holocene sea-level rise. Based on the analyzed morphologies and the relative sea-level curve for the Adriatic Sea, the flooding of the Novsko Ždrilo occurred 9200 years before present (BP) and Karinsko Ždrilo was flooded after 8400 years BP. The combination of high-resolution geophysical methods gave an accurate representation of the karst estuarine seafloor and the flooding of semi-isolated basins due to sea-level rise

Chemical Weathering Rates of Soils Developed on Eocene Marls and Sandstones in a Mediterranean Catchment (Istria, Croatia)

Physical and chemical weathering, together with biological and biochemical processes, form soil from bedrock and strongly influence the chemical composition of natural waters. Erosive processes, primarily through the agents of running water and wind, remove the products of weathering from catchments. The aim was to determine the chemical weathering of minerals because of changes in land-use and natural forestation in two small neighboring catchments of the rivers Argilla and Bazuja. Agricultural land-use practice is very intense in the Argilla catchment, while the Bazuja catchment’s arable land is mostly abandoned, with progressive forestation. Chemical weathering in soils and sediments was evaluated with the aid of bulk chemistry analysis focused on major elements, trace elements, and zirconium. Weathering indices, mass balance, and strain were calculated. The abandonment of arable land and intense forestation in the Bazuja catchment caused increased chemical weathering with the loss of base cations (Ca and Mg) and enrichment of conservative elements (Zr and Ti) in surface horizons. EIC and MTF values are positive (enrichment) in areas with agricultural activities, while forested areas show negative values (loss). A comparison of the oldest and youngest parts of the overbank sediment profiles in the swallow hole zone and stream sediments shows that chemical and mechanical weathering in the Bazuja catchment was similar to present weathering in the Argilla catchment, while agriculture was active in the Bazuja catchment. The integrated knowledge gained in small catchment studies can be broadly applicable to larger systems