remnants of the hercynian orogen along the calabrian peloritan arc southern italy a review remnants of the hercynian orogen disturbed by alpine tectonics occur widely along the calabrian peloritan arc indications of former oceanic conditions for example palaeozoic ophiolites and original deep water sediments are lacking metamorphism developed under intermediate to low pressure conditions the post metamorphic plutonism appears to be more compatible with intracontinental orogenic processes than with an active continental margin the possible evolution of this segment of the hercynian orogen is discussed

synchronous uplift of the lower crust of the ivrea zone and of southern calabria and its possible consequences for the hercynian orogeny in southern europe abstract along the border of the adriatic microplate pre alpine granulite facies rocks from the deepest crust are outcropping at only two places in the ivrea zone of the southern alps and in southern calabria in these two areas the main features of the present crustal structures i e overlapping of large continental crustal and upper mantle segments are interpreted as resulting from their hercynian geodynamic evolutions the tilted nearly complete crustal sections in both areas display very similar lithological sequences and experienced a common geological evolution as deduced from petrological and radiometric dates at the end of hercynian time 295 m y the ivrea body and the lower crustal rocks of southern calabria were contemporaneously sheared off from the upper mantle and uplifted into intermediate crustal levels where they slowly cooled during mesozoic time the tectonic uplift was accompanied by granitoid plutonism and andesitic to rhyolitic volcanism which continued after the hercynian uplift considering the presently similar crustal structures and the upper carboniferous and permian geological evolutions along the whole adriatic plate boundary the ivrea zone and southern calabria are used to resolve the pre alpine history of the boundary zone between the adriatic and the central european block the uplift of the lower crustal upper mantle flakes of the adriatic block was due to flat overthrusting of these flakes on the continental crust of central europe the material of the central european crust underthrust subducted thereby melted during the re equilibration of the geotherms which had been disturbed by the subduction process this led to an extensive calc alkaline plutonism and volcanism of crustal origin along the adria boundary in this boundary region the overlying uppermost crustal levels schiefergebirgsstockwerk were synchronously folded asturian phase in response to the overlapping of the deeper crustal levels subsequently to the orogeny the mountain chain was eroded and molasse basins developed on the overthrust adriatic crustal segment during the lower permian in this model the granulite facies flakes of the ivrea zone and of southern calabria are interpreted as pre hercynian lower crustal segments which were thrust into the middle crust during the hercynian orogeny thus giving rise to wave velocity inversions in the crust further it is proposed that similar geodynamic processes have played a role in the genesis of the conrad discontinuity which is present in many parts of the hercynian fold belt but only in the ivrea zone and in southern calabria the crustal discontinuities formed in hercynian time were uplifted to the surface as a result of alpine reactivation of the adriatic boundary zone and due to their special positions in the bends of the alpine apennine maghrebide mountain system according to the present knowledge of the carboniferous paleogeography and of the orogenic evolution on both sides of the adria sufure zone this fault zone was located within the european continent its role during the hercynian orogeny is discussed envisaging two possibilities an a subduction zone or a subfluence zone in the sense of behr and weber

granulite amphibolite facies metasediments from the serre calabria southern italy their protoliths and the processes controlling their chemistry abstract in the northwestern serre a near continuous section through the palaeozoic lower continental crust crops out this paper deals with granulite facies metasedimentary rocks of this section fifty five chemical analyses major elements sc v cr co ni rb sr y nb and ba are given chemical data indicate that the original sedimentary sequence was made up of arenites in the lower part and mainly fe and mg rich pelites in the upper part the metapelites experienced anatexis and removal of some melt whereas the meta arenites suffered only incipient anatexis and became dehydration granulites the various rock types display an overall relatively low k rb ratio due mainly to the stability of k and rb retaining phases a weighted mean composition of the fragment of the lower continental crust outcropping in the serre has been established by integrating the chemical data for metasediments 55 analyses metabasites 92 analyses and dioritic and tonalitic gneisses 10 analyses with the field data this composition compared to the compositions of the bulk continental crust and of other sections considered as belonging to the lower crust confirms the hypothesis that 1 the lower crust is heterogeneous and 2 it is more basic than the continental crust

middle oligocene extension in the mediterranean calabro peloritan belt southern italy insights from the aspromonte nappes pile the calabro peloritan belt constitutes the eastward termination of the southern segment of the alpine mediterranean belt this orogenic system was built up during the convergence between the eurasian and the african plates roughly directed north south since the upper cretaceous it was subsequently fragmented during the opening of the western mediterranean basins since oligocene times the curved shape of the calabro peloritan belt was acquired during the opening of the tyrrhenian basin since tortonian the origin kinematics and significance of the calabro peloritan tectonic pile are still debated our data in the aspromonte massif of southern calabria reveal an alpine history marked by two main superimposed kinematic regimes i a first phase corresponds to the piling up of basement nappes with a top to the se vergence i e in a direction orthogonal to the belt trend and towards the adriatic foreland this external vergence is similar to what is observed in both northeastern sicily and northern calabria in sicily the age of nappe piling is alpine as evidenced by pinched slices of mesozoic sediments in the aspromonte massif thrusting age is less constrained our data suggest remnants of late hercynian structuration before the alpine stacking ii a second phase corresponds to the thinning of the continental crust dated at around 30 ma by both geochronological and stratigraphical data this extension is mainly localized on two low angle detachment contacts with top to the ne displacement the lower one corresponds to the reworking of the former main nappe contact the upper one is a large detachment fault cutting across the pile from upper sedimentary levels down to metamorphic basement extension of similar alpine age and similar internal vergence has been already recognized in other parts of the calabro peloritan arc in the basement nappes of northeastern sicily and in the ophiolitic units of northern calabria coming back to the original geometry and position of the calabro peloritan belt before its bending and the opening of the liguro provencal and tyrrhenian basins we evidence a homogeneous oligocene ne sw extension all along the calabro peloritan segment of the alpine mediterranean belt this tectonometamorphic history is best explained within the framework of the continuous tertiary westward dipping subduction of the tethyan oceanic domain below the european active margin and the progressive eastward retreat of the apennine trench since oligocene times

an investigation about natural radioactivity hydrochemistry and metal pollution in groundwater from calabrian selected areas southern italy the increasing interest in radioactivity has brought about the need for an assessment of human exposure to radiation it is therefore necessary to examine naturally occurring radioactivity in the environment especially its occurrence in groundwater the aim of this work was then to study the levels and behavior of the most significant natural radionuclides also in order to improve the knowledge of the hydrochemical processes involved in the selected groundwater systems natural radioactivity in fifteen calabrian groundwaters for human use was investigated through high resolution gamma spectrometry with a negative biased ortec hpge detector and liquid scintillation measurements particular attention was given on those radionuclides 3h 238u 226ra and 228ra which contribute in a significant way to the overall effective dose received by members of the public due to the intake of drinking water originating from groundwater systems the activity concentration of 238u varied from 1 to 51 mbq l as a result of the geology of the investigated area and of the oxidizing conditions that favored u dissolution 226ra presented a broad range of activity concentrations 0 011 0 14 mbq l lower than uranium ones because radium occurs in groundwater under reducing conditions some heavy metals cd pb be hg ag as tl sb se and ni were also investigated through icp ms measurements and compared with the limits set by the italian legislation metals are released into the environment by both natural and anthropogenic sources they leach into underground waters moving along water pathways and eventually depositing in the aquifer

magmatic muscovite in felsitic parts of rhyolites from southwest germany in felsitic parts of rhyolites from the permian volcanism in southwest germany muscovite phenocrysts of magmatic origin were observed they occur besides two other light mica components of secondary formation a permian tuff from the saarnahe area also contains this primary muscovite type

multiple injections of magmas along a hercynian mid crustal shear zone sila massif calabria italy abstract syn tectonic late hercynian granitoids emplaced at mid crustal level through multiple dyke injections are well exposed in a 1 km long section in the southern sila massif calabria italy the fieldwork study permitted us to reconstruct the following order of emplacement i granodiorites with euhedral kfs megacrystals grd1 in the main text and heterogranular granodiorites with coarse rounded pl and kfs in a fine grained biotite rich matrix grd2 ii granodiorites with a nearly homogeneous grain size grd3 iii tonalite and iv granite both in the wall rock represented by migmatitic paragneisses and in the deformed granitoids the foliation attitude is substantially homogeneous striking about n140 with a dip of 50 60 to the ne the magmatic lineation is defined by the preferred alignment of euhedral feldspars parallel to the mineral lineation observed in the host rocks micro and meso structural analyses indicate that foliation evolved from melt present to solid state conditions feldspar tiling s c structures type structures c axis quartz orientations commonly suggest a top to the west sense of shear during magma injection and deformation under decreasing temperatures age of magma emplacement is constrained by u pb datings at 304 300 ma coeval with the regional metamorphic peak foliated granitoids and wall rock are intruded by poorly foliated hbl gabbro and finally by undeformed leucogranite pegmatite and felsic porphyritic dykes new u pb datings of the last intrusion event indicate an age of emplacement of 281 8 ma providing a minimum estimate for the end of the shear strain at mid crustal level

degradation and maturity controls on oil field petroleum column heterogeneity in the gullfaks field norwegian north sea abstract a geochemical mapping of the gullfaks reservoir petroleum column based on 226 reservoir core extracts and 23 drill stem test dst and repeat formation test rft oil samples indicates the presence of statistically testable lateral compositional heterogeneities in the petroleum column these different petroleum populations can be related to lateral filling of the field from two source basins and a more pervasive subsequent episode in reservoir biodegradation petroleum maturity gradients within the field were detected using conventional biomarker gc ms methods on saturated hydrocarbon fractions the degree of biodegradation was monitored by quantitative gc of n alkanes in whole oil samples using a squalane internal standard the observed compositional differences in the gullfaks petroleum column are consistent with diffusion being the primary mixing process thermal convection being eliminated on both compositional and modeling grounds compositional differences between core extracts and dst samples from the same intervals suggest that fractionation of petroleum might occur during testing and that interpretation of reservoir petroleum columns from mixed sample sets should be treated cautiously

petrostratigraphic analysis of a late miocene mixed siliciclastic carbonate depositional system calabria southern italy implications for mediterranean paleogeography abstract mixed siliciclastic carbonate sediments are common in shallow water environments in which clastic deposition and carbonate production coexist in the mediterranean basin the tortonian messinian sedimentary successions are commonly comprised of marls alternations of marls with diatomites sands and sandstones limestones especially algal and coral reefs and evaporites most of the studies in the mediterranean basin have been focused on carbonate facies analysis whereas the siliciclastic portions are poorly described similarly to the other marginal settings of the mediterranean basin the capo vaticano area southern calabria southern italy experienced mixed sedimentation at that time petrological analysis was performed on 56 weakly cemented sandstones linking compositional signatures to stratigraphic data with the aim of investigating sedimentary response to the tortonian messinian transgression and its influence on the carbonate production the information obtained is used to refine the regional sediment dispersal pathways and paleogeography by means of bio stratigraphic evidence the studied succession to coeval mixed deposits dislocated in the mediterranean basin is correlated

organic geochemistry and depositional environment of the aptian bituminous limestone in the kale gumushane area ne turkey an example of lacustrine deposits on the platform carbonate sequence the jurassic lower cretaceous aged carbonate sequence is widely exposed in the southern zone of eastern pontides aptian black bituminous limestone is found in the upper part of this sequence in the kale area gumushane this limestone contains faunal remains e g gastropod ostracod characean stems and miliolid type benthic foraminifera that indicate a freshwater lacustrine depositional environment the total organic carbon toc values of the bituminous limestone samples range from 0 11 1 30 with an average toc value of 0 54 the hydrogen index hi varies from 119 448 mg hc g toc average hi 298 mg hc g toc indicating that the limestone contains gas prone as well as oil prone organic matter pyrolysis data prove that the organic matter content in the bituminous limestone consists of type ii kerogen the average tmax value for bituminous limestone samples is 438 c 434 448 c bitumen toc ratios for bituminous limestone are 0 05 and 0 04 the tmax values and the ratios indicate that the bituminous limestone samples contain early mature to mature organic matter analysis of solvent extracts from the two richest bituminous limestones show a predominance of high carbon number c26 c30 n alkanes the pr ph ratio and cpi value are 1 34 and 0 96 respectively c29 is the dominant sterane with c29 c27 c28 the bituminous limestone samples have low c22 c21 ratios high c24 c23 tricyclic terpane ratios and very low c31r c30 hopane ratios 0 25 these data are consistent with the bituminous limestones being deposited in a lacustrine environment

petrogenesis of contrasting hercynian granitoids from the calabrian arc southern italy abstract the granitoids of the southern calabrian arc have been investigated for whole rock and phase chemistry zircon typology ree sr and nd isotopes two distinct granitoid associations which are related in time and partly in space are present a calc alkaline one and a peraluminous one the prevailing calc alkaline association is compositionally expanded sio2 48 70 and biotite dominated with tonalites and granodiorites as predominant rock types the peraluminous association is compositionally restricted sio2 67 76 and contains two mica al silicates distinct peraluminous typologies occur also as core facies within the calc alkaline types all granitoids are ilmenite bearing the cittanova cn villa s giovanni vsg and capo rasocolmo cr peraluminous granites display zircon typology ree patterns srt 51 to 113 and ndt values 8 5 to 4 6 at 290 ma suggesting a dominantly quartzofeldspathic metasedimentary source in more detail the cn types and the cr vsg types require heterogeneous and different sources the calc alkaline granitoids display very variable ree patterns cen 25 227 and ybn 3 5 18 5 in the tonalites granodiorites and variable age corrected ndt values 8 5 to 0 25 whereas sr values vary little 82 to 93 thus in terms of ndt srt covariation the data points define a vertical array which is inconsistent with a model involving crustal contamination by mantle derivatives a more viable mechanism seems to be the melting of hydrous and heterogeneous mafic lower crust and or basic underplate producing distinct magma batches evolving independently crustal contamination mingling and fractionation processes may all have contributed to the observed geochemical variations within the granitoids the peraluminous granodiorites occurring within the serre and capo vaticano multipulse calc alkaline plutons exhibit isotopic ratios ndt 6 11 to 0 33 and srt 93 to 97 which are similar to those of the calc alkaline host rocks suggesting a possible genetic link geologic and geochemical data indicate a continental collision setting for this plutonic activity the magmas were produced during late thickening to exhumation phases following collision and moderate crustal overthickening and were emplaced subsequently during a short time span a mantle contribution should have favoured melting which affected various sectors of the continental crust

fission track analysis and provenance studies in calabrian are sedimentary rocks southern italy fission track analysis has been applied to the stilo capo d9orlando formation of southern italy this is a terrigenous syn orogenic sedimentary deposit of oligo miocene age that accumulated during a phase of accelerated denudation that affected the nearby crystalline basement rocks of the calabrian arc between c 30 and 15 ma seven conglomerate clasts and two sandstone samples from the base of the formation have produced eight apatite fission track ages nine zircon fission track ages and six apatite confined track length analyses the zircon fission track data confirm that detritus was derived from local hercynian igneous and metamorphic rocks in addition apatite fission track results from the two sandstone samples reveal that the basal part of the stilo capo d9orlando formation was exposed to maximum palaeotemperatures in excess of 70 c after deposition despite this apatite fission track ages much older than those obtained from the in situ crystalline basement source rocks of the calabrian are have been acquired these ages are interpreted as being derived from lost cover that is rocks originating from the structurally highest levels of the basement complex that have now been completely removed by erosion fission track analysis demonstrates that erosion in addition to previously identified extensional tectonism was a major factor during accelerated denudation of the calabrian are basement rocks during the late oligocene and early miocene

mid crustal shear zone evolution in a syn tectonic late hercynian granitoid sila massif calabria southern italy by means of petrogrological meso and microstructural analyses the fabric of a syn tectonic late hercynian k feldspar megacryst bearing granodiorite is described in this paper the granodiorite was emplaced at 293 ma within migmatitic paragneisses which had reached the regional peak metamorphic conditions at 304 300 ma the granodiorite and the migmatitic paragneisses are both affected by the same ductile shear zone in the core of the shear zone mylonites show a clear grain size reduction and microstructures related to deformation at high to medium temperature conditions migmatitic paragneisses foliated granodiorites and mylonites mostly show concordant lineation and foliation orientations in addition the preferred orientation of euhedral feldspars in granodiorites indicates that the fabric anisotropy started to develop in the magmatic state these features strongly suggest that shear deformation was active during crystallisation of granitoids and continued under subsolidus conditions in wall rocks and mylonites kinematic indicators such as and type porphyroclasts s c fabrics shear bands and quartz c axis orientations suggest a top to the w sense of shear this is similar to the magma flow direction indicated by the tiling of euhedral feldspar megacrysts in granodiorites shear deformation developed preferentially by partitioning of strain in the granodioritic crystal mush geobarometry indicates that deformation took place at middle crustal levels p 400 500 mpa whole rock white mica rb sr geochronological analysis of an undeformed pegmatite crosscutting the mylonitic foliation provided an age of 265 ma timing of deformation is therefore bracketed between 293 ma and 265 ma

biological marker characteristics of oils and asphalts from carbonate source rocks in a rapidly subsiding graben dead sea israel abstract a detailed gc ms study of biological marker compounds in the saturated and aromatic hydrocarbon fractions of oils and asphalts from the dead sea area israel provided decisive information to the solution of a long lasting controversy by showing that the asphalts are products of early generation in an immature stage from the same type of carbonate source rock which generated more mature oils the asphalts are not biodegraded residues of the oils oils from six different wells and asphalts from wells outcrops and a floating block from the dead sea all have very similar sterane and triterpane patterns they all lack rearranged steranes diasteranes indicating a carbonate source matrix and compare reasonably well with a sample of upper cretaceous bituminous chalk from nebi musa the main difference between the oils and the asphalts is a significantly higher triaromatic to mono plus triaromatic steroid hydrocarbon ratio in the former this is explained as a result of rapid subsidence and heating of their source rock close to the deep parts of the dead sea graben the oils thus were generated in the more deeply buried source rock blocks under the graben fill whereas the asphalts either originate from an immature source rock section closer to the graben rims or represent an earlier phase of generation and expulsion this study also provides general information on the evolution of biological markers in carbonate source rocks low activation energy processes like isomerisation of steranes appear to occur much faster at low temperatures than in shales the high sulfur content and less cross linking of the biogenic organic matter into a complex kerogen structure are suggested to be responsible for this care should be taken when using only sterane isomerisation to assess the maturity of hydrocarbons from carbonate rocks and of carbonate derived oils

fission track analysis of the crystalline basement rocks of the calabrian arc southern italy evidence of oligo miocene late orogenic extension and erosion abstract fission track analysis is used to provide low temperature and time constraints on the late orogenic cooling and exhumational history of the crystalline basement rocks of the calabrian arc southern italy 65 samples yielded 57 apatite fission track ages 54 zircon fission track ages and 25 apatite confined fission track length distributions interpretation of this data reveals a phase of increased cooling rates related to exhumation between approximately 35 ma mid oligocene and 15 ma middle miocene evidence from the sedimentary record indicates significant oligo miocene erosion related to this period of exhumation new chronological constraints are also applied to localised late orogenic extensional tectonism that has recently been identified within the basement rocks of the calabrian arc this information is used to produce a new model of the oligo miocene tectonic evolution of the calabrian arc it proposes that the crystalline basement rocks were part of a critical orogenic wedge between the mid oligocene and the middle miocene

pressure temperature evolution of the late hercynian calabria continental crust compatibility with post collisional extensional tectonics the late hercynian tectonic evolution of the calabria crust is characterized by peak metamorphic conditions up to 800 c and 1000 mpa and coeval mid crustal granitoid emplacement at 304 300 ma to check if a post collisional extensional framework similar to that of other hercynian massifs can explain petrologic data we model the pressure temperature evolution of the crust during extension following granitoid emplacement model parameters are constrained by petrologic geochemical and structural data computed p t paths are characterized by nearly isothermal decompression followed by isobaric cooling which show a good fit to petrologic p t paths for duration of extension between 5 and 10 ma the model results therefore support an interpretation of the magmatic and metamorphic evolution of the calabria crust in terms of the late hercynian extension in this framework slab break off is a reasonable explanation for the common evolution of the southern european hercynian massifs

effects of the mineral matrix on the distribution of geochemical markers in thermally affected sedimentary sequences the distribution of geochemical markers in bitumen fractions both free and associated with minerals was studied in bituminous chalk and black shale samples upper cretaceous israel upper cretaceous west greenland affected by combustion metamorphism and the latter also by dyke intrusion the bitumen fractions were obtained by stepwise extraction in conjunction with stepwise dissolution of the carbonate and subsequently silicate minerals they show differences in their bulk composition and in the distribution of n alkanes alkylcyclohexanes isoalkanes isoprenoids steranes and triterpanes at low maturity in the country rocks the distribution of the biomarkers in the various bitumen fractions reflects mainly the source or organic matter and minerals detrival vs autochthonous associated during transport and sedimentation with increasing maturation processes take place like i the formation of hydrogen bonded associations of clay minerals with organic matter ii the isomerisation of steranes which reaches different degrees free bitumen carbonate associated silicate associated in the bituminous chalk while bound free in the black shales iii the formation of isoalkanes and alkylcyclohexanes which occur only in the mineral associated fractions the particular effects of mineral groups on the geochemical markers during sedimentation generation and primary migration necessitates the consideration of the composition of the mineral matrix for the interpretation of the geochemical markers the generation of hydrocarbons during maturation probably involves the mobilization of bitumen from minerals and kerogen

crystalline and sedimentary rocks from the scarps of the sicily sardinia trough and cornaglia terrace southwestern tyrrhenian sea italy paleogeographic and geodynamic implications abstract the petrographic and stratigraphic analysis of crystalline and sedimentary rocks dredged in the west sardinia channel southwestern tyrrhenian sea led to the careful stratigraphic and structural reconstruction of a lower miocene submerged orogenic belt previously analysed only on seismic sections the deformed units which include some flakes of the sardinia margin have a hercynian type crystalline basement of amphibolite facies sillimanite bearing metamorphic rocks intruded by granitoids ranging in composition from granite to tonalite this is quite different from the sardinia basement because of the peraluminous character of the plutonic rocks it can therefore be attributed to the generic kabylo calabrian domain which may extend far beyond the investigated area the crystalline basement is directly overlain by a thick lower miocene synorogenic sequence consisting of deep sea arkosic turbidites which probably accumulated in a foreland basin or in minor basins migrating on a shortening continental margin most of the rocks of the kabylo calabrian domain exhibit a common post hercynian structural and metamorphic evolution which can be attributed to a low grade tectono metamorphic event corresponding to low greenschist facies conditions this possibly took place during the early miocene as regards the geodynamic setting it should be pointed out that the penetrative structures and metamorphic reequilibration of the kabylo calabrian units seem to result from an intracontinental collision which contemporaneously affected the sardinia block leading to the formation of a crustal shear zone the early miocene age of the metamorphism and turbiditic sedimentation suggests that crustal shortening was probably connected with the drifting and rotational phases of the corsica sardinia microplate

the ghomarides nappes rif coastal range morocco a variscan chip in the alpine belt the ghomarides nappes are the uppermost basement nappes in the rifan alpine belt paleozoic rocks constitute the prominent part of these nappes together with triassic and younger cover sediments four nappes are distinguished each one with a distinct stratigraphical sequence especially for the devonian and carboniferous periods sedimentological and structural arguments plead for an initial location on the northern margin of the african continent the main folding and metamorphic events are shown to be eo variscan late acadian tectonic vergence was to the north present coordinates late variscan hercynian shortening gave upright nw se trending folds alpine ductile overprints are scarce except at the base of the lowest nappe where k ar phengite ages are about 25 ma the ghomarides nappes correlate with the malaguides nappes betic cordilleras southern spain the kabylian northern algeria and calabrian southern italy paleozoic nappes the tuscan south alpine basement and the upper austro alpine nappes the proposed correlations allow us to restaure the southern margin of the hercynian belt along northwestern africa

reconstruction of a destructive debris flow event via numerical modeling the role of valley geometry on flow dynamics debris flows are widespread natural phenomena characterized by high mobility high velocity and long runout distance and impact forces which frequently cause human casualties and significant damage to infrastructure to better understand the dynamics of such events analyzing in particular the effect induced by the valley geometry on flow velocity runout and mobilized volumes in this work we reconstruct a real debris flow event through numerical modeling specifically we used a modified version of the bing model a fluid dynamic depth integrated numerical model for debris flows which has been properly modified to account for width changes along the valley the studied event which occurred in scaletta zanclea messina north eastern sicily italy on october 1 2009 is exceptionally well constrained by field and topographic information in this respect the flow velocity estimated from two specific locations on the basis of field evidence the distribution of erosional and depositional areas along the racinazzo valley based on the comparison of pre and post event digital elevation models dems and the runout distance were used as constraints to calibrate the model furthermore we report a detailed description of the main event characteristics based on hydrological records and witness reports the numerical modeling results are consistent with witness reports and the severe damage recorded in the scaletta marina village and highlight the effect of the valley geometry on both the debris flow velocity and the erosion deposition processes the effect of changing valley width has been also quantified resulting in accelerations of the debris in correspondence of the valley narrowing and stagnations at the plateaus copyright 2015 john wiley sons ltd

some problems regarding the paleozoic paleogeography in mediterranean western europe the present paper suggests that if the paleomagnetically derived maps of scotese et al 1979 are right the implication is that in the mediterranean region hercynian folded chains may be the result of a continental collision between africa and north europe south europe is considered as a part of the gondwanaland nevertheless the affinities of the devonian faunas suggest that the carnian block must be considered a fragment of the northern continents laurussia consequently in the devonian paleogeographic picture the italian peninsula should have been separated from the iberian provence region and placed eastwards along the northern margin of gondwana so as to join the carnian block during the hercynian orogeny and thus form the apulian microplate the collision model adopted excludes an early devonian carboniferous opening of the tethys between southern europe and gondwana that being in conflict with the evidence for large scale hercynian deformations in mediterranean western europe as regard

organic geochemistry of the lower cretaceous black shales and oil seep in the sinop basin northern turkey an oil source rock correlation study abstract in the sinop basin a thick liassic to quaternary sedimentary section is exposed a lower cretaceous aged caglayan formation crops out in the basin and consists of claystone siltstone sandstone marl and black coloured shale that exhibits a fair to good source rock potential an oil seep from the caglayan formation is located in the ekinveren region of the sinop basin the average total organic carbon toc values of two shale samples from the caglayan formation in the ekinveren and the burnuk sections ekin 8 bur 7 are 1 48 and 1 26 wt respectively and the hydrogen index hi values are 190 and 244 mghc g toc respectively the potential yield py value of the samples is 2 0 mghc g rock which indicates fair good hydrocarbon potential for the caglayan formation a unimodal n alkane distribution with dominant light end components is observed on the gas chromatograms of the shale samples from the caglayan formation low tar terrigenous aquatic organic matter ratios low c 19 c 20 c 23 tricyclic terpane ratios and a higher type ii kerogen content indicate that the shale samples predominantly contain marine organic matter the pr ph ratios of the shale samples are 1 39 and 0 89 respectively the pr ph values in combination with a high c 30 diahopane c 29 ts ratio imply a suboxic anoxic depositional environment for the caglayan formation the t max values of the ekinveren and burnuk shale samples are in the range of 425 432 c and 431 434 c respectively and the average t max values are 429 c and 433 c respectively based on the t max data the caglayan formation shales are immature early mature in the ekinveren location and early mature mature in the burnuk location the cpi values isoprenoid n alkane ratio 20s 20s 20r c 29 sterane and 22s 22s 22r c 32 homohopane ratios indicate that the shales from the burnuk location are more mature than those of the ekinveren location the large ucm unresolved complex mixture and low amounts of n alkanes and isoprenoid alkanes observed in the gas chromatogram of the oil seep indicate that the oil has been heavily biodegraded the m z 191 and m z 127 mass chromatograms of the samples from the caglayan formation and the ekinveren oil seep were similar in their distributions of tricyclic terpane c 23 dominant c 24 tetracyclic terpane norhopane hopane homohopane with dominant c 31 and a decreasing amount of the higher number homologues diasterane and pregnane the c 27 c 28 and c 29 sterane distributions for the oil and the shale samples were also similar demonstrating a c 27 c 29 c 28 relationship thus the biomarker data strongly indicate that the black shales and the ekinveren oil seep are related to each other in other words the oil has been derived from the caglayan formation

hydrogeochemical processes in clastic sedimentary rocks south korea a natural analogue study of the role of dedolomitization in geologic carbon storage abstract for long term mineral trapping of sequestered co 2 in deep saline aquifers base cations such as ca 2 and mg 2 are essential as a natural analogue study of geologic carbon storage in deep aquifers hosted in sedimentary formations we examined the hydrochemistry of sulfate rich up to 1140 mg l so 4 2 and moderately high p co 2 10 1 1 to 10 2 4 atm groundwater in a cretaceous non marine sedimentary basin in south korea with the objective to elucidate water rock interactions controlling the concentrations and behavior of base cations principal component analysis of the acquired hydrochemical data indicated that dissolution of carbonates calcite and dolomite and evaporite minerals halite and gypsum controls the chemical composition of groundwater resulting in substantial increases of the concentration s of ca 2 mg 2 na cl so 4 2 and total dissolved solids tds in deep groundwater na versus cl and ca 2 mg 2 versus hco 3 so 4 2 plots provided evidence for dissolution of halite and gypsum progressively increasing 34 s values of dissolved so 4 2 from 15 1 to 19 2 with increasing sulfate concentrations indicated gypsum dissolution ion ion plots esp mg 2 ca 2 ca 2 so 4 2 and mg 2 so 4 2 and saturation indices of calcite dolomite and gypsum suggest that the groundwater chemistry esp the concentrations of ca 2 and mg 2 is controlled by dedolomitization driven by gypsum dissolution groundwater in the study area does not reach complete equilibrium with respect to calcite and dolomite because of gypsum dissolution which controls the mg 2 ca 2 ratios of groundwater continued calcite precipitation triggered by an excess ca supply from gypsum dissolution reduces the concentrations of dissolved inorganic carbon dic in groundwater the increase of 13 c dic values from 11 1 to 6 5 concomitantly with increasing sulfate concentration was explained via geochemical modeling by dedolomitization under the rate constant ratio of about 0 038 between dolomite and calcite the model results agree well with the observed mg 2 ca 2 ratios and further suggest a potential increase of the void volume in the aquifer through dedolomitization by about 0 72 cm 3 l based on this analogue we suggest that dedolomitization in concert with dissolution of gypsum may constitute an important process releasing base cations for mineral trapping of injected co 2 in non marine clastic sedimentary strata containing carbonates and gypsum in south korea and elsewhere