the geology of the yellow trachytic tuff roccamonfina volcano italy abstract the 227 ka yellow trachytic tuff ytt of the roccamonfina volcano is a multiunit ash pumice scoria and lithic ignimbrite with a proximal sandwave surge deposit the ytt has an estimated volume of 0 42 km3 it erupted in the northern subsided sector of the volcano from gli stagli caldera and was channelled down ravines northward between the limestone range of m cesima and m camino that bounds the depression up to 5 ytt units occur close to the outer part of the northern rim of gli stagli the basal four units are separated by lithic rich marker layers which are inferred to result from gravity segregation followed by shearing the first three units are consolidated by chabazite cementation the fourth one is not consolidated the uppermost unit is altered one or two units characterize the ytt deposits in medial to distal zones here the unconsolidated unit underlies the consolidated one absence of markers precludes correlation with proximal stratigraphy the ytt is poorly sorted and except the surge deposit and the altered facies which are very fine grained has moderate median diameter typical of pyroclastic flows matrix pumice and scoria clasts are poorly vesicular matrix shards are equant blocky shaped hydrated and range from non vesicular to vesicular these features suggest that magma water interaction played a role in the ytt eruption process with some magmatic fragmentation the complex near gli stagli rim ytt sequence could record the arrival of successive flows from the source vent or also form by interaction of one or two flows with the caldera rim in both cases the absence of basal plinian deposits in ytt units suggests that the eruptions were low pyroclastic fountains the ytt distribution was controlled by interaction with the northern rim of gli stagli caldera and with the limestone range that bounds the northern depression the near rim stratigraphy shows the complete record of the eruption whereas the medial to distal sequences provide only the initial pyroclastic flow possibly with the final flow spilling over the caldera rim the proximal surge episode probably resulted from higher velocity of a later pyroclastic flow due to steeper slope of the volcano in that locality

occurrence stratigraphy and geochemistry of late quaternary tephra layers in the aegean sea and the marmara sea abstract several discrete tephra layers occur in 2 5 10 3 m long cores from the aegean sea whereas a single tephra is identified in 3 5 9 7 m long cores from the marmara sea major and trace element data on these tephras delineate eight distinct groups the geochemical data and multivariate statistics allow the correlation of the tephra layers with six previously described marine tephras from the eastern mediterranean sea potential terrestrial sources are suggested for the others the chronostratigraphy of the tephra layers was established using several radiocarbon dates and the oxygen isotope stratigraphy from two long piston cores four widespread tephra layers occur within the upper quaternary sediments of the aegean sea the two youngest widespread tephra layers were derived from the santorini volcano of south central aegean sea z2 the minoan eruption ca 3 6 ka and y2 the cape riva eruption ca 21 7 ka the y2 tephra is also identified in three piston cores from the marmara sea the two older widespread tephra layers originated from the eruptions which emplaced the campanian ignimbrite of the italian volcanic provinces i e the y5 tephra ca 39 3 ka and from the nisyros volcano of the southeastern aegean sea the consistent occurrence of the nisyros tephra below the y5 tephra confirms similar findings in a lake core on the island of lesbos linear extrapolations using the oxygen isotope stratigraphy suggest an age of 42 44 ka for the nisyros eruption three additional tephra layers with a limited regional distribution are identified in the aegean sea cores two of these tephras originated from the yali volcano of the southeastern aegean sea and from the aeolian islands i e x1 tephra a series of six mugearite tephra beds in the south skiros basin is interpreted as a set of redeposited turbidites

distal tephra record for the last ca 105 000 years from core prad 1 2 in the central adriatic sea implications for marine tephrostratigraphy abstract core prad 1 2 located on the western flank of the mid adriatic deep contains a continuous sediment record extending back to upper mis 11 the upper part of the record which spans the mid holocene to mis 5 4 the last ca 105 000 years has been investigated for tephra content a total of 25 discrete tephra layers were discovered only one of which was visible in the core sequence the other 24 are not visible to the naked eye nor were the majority detected by routine down core scanning methods a total of 625 geochemical measurements obtained from individual glass shards using wds epma enabled 21 of the 25 tephras to be assigned to known volcanic events emanating from the campanian province campi flegrei somma vesuvius and ischia island the results provide an independent basis for establishing an age depth profile for the upper part of the prad 1 2 record this study demonstrates that the number of non visible tephra layers can significantly exceed the number of visible layers in some deep marine sequences routine testing for the presence of non visible tephra layers can therefore prove rewarding leading to the detection of additional isochrons for dating and correlating marine sequences and for their synchronisation with terrestrial records

a new contribution to the late quaternary tephrostratigraphy of the mediterranean aegean sea core lc21 tephra layers preserved in marine sediments can contribute to the reconstruction of volcanic histories and potentially act as stratigraphic isochrons to link together environmental records recent de velopments in the detection of volcanic ash tephra at levels where none is macroscopically visible so called crypto tephra have greatly enhanced the potential of tephrostratigraphy for synchronising environmental and archaeological records by expanding the areas over which tephras are found in this paper crypto tephra extraction techniques allow the recovery of 8 non visible tephra layers to add to the 9 visible layers in a marine sediment core lc21 from the se aegean sea to form the longest single core record of volcanic activity in the aegean sea using a novel shard specific methodology sources of the tephra shards are identified on the basis of their major and trace element single shard geochemistry by comparison with geochemical data from proximal mediterranean volcanic stratigraphies the results indicate that the tephra layers are derived from 14 or 15 separate eruptions in the last ca 161 ka bp 9 from santorini 2 or 3 from kos yali or nisyros 2 from the campanian province and one from pan telleria the attributions of these tephra layers indicate that 1 inter plinian eruptions from santorini may have produced regionally significant tephra deposits 2 marine tephrostratigraphies can provide unique and invaluable data to eruptive histories for island volcanoes and 3 tephra from both pantelleria and campania may be used to correlate marine records from the aegean sea to those from the tyrrhenian adriatic and ionian seas

pulsed uplift estimated from terrace elevations in the coast of rome evidence for a new phase of volcanic activity abstract the most recent phase of activity from the roman volcanoes since 45 ka has been interpreted to be the waning stage of the older explosive activity that peaked between 550 and 250 ka yet substantial regional uplift from approximately 250 ka suggests that magma chambers beneath the area are growing rather than shrinking we have estimated the uplift history of the region using radioisotopically and paleomagnetically constrained coastal terrace elevation data that allow us to correlate these terraces with marine oxygen isotopic stages 1 22 elevations have been corrected for glacio eustatic sea level change our study shows that over the last million years regional uplift of coastal terraces occurred in pulses that preceded volcanic activity at roughly 800 ka in the monti sabatini and 600 ka in the alban hills the recent pulse of uplift since 250 ka occurred primarily during a period of relative volcanic dormancy that lasted from 250 to 45 ka we hypothesize that the most recent volcanic activity since 45 ka may reflect the completion of magma chamber recharge suggesting the start of a new volcanic epoch it is also possible that the local tectonic stress field changed recently from one dominated by transpression to one dominated by extension allowing magma to more easily reach the surface via normal faults

major explosive activity in the monti sabatini volcanic district central italy over the 800 390 ka interval geochronological geochemical overview and tephrostratigraphic implications abstract a review of the existing chronological stratigraphic and chemo petrologic data of the major eruptive units from the early phase of activity 800 390 ka in the monti sabatini volcanic district msvd belonging to the ultra potassic magmatic region of central italy is presented along with new radioisotopic age determinations and geochemical analyses through the combined use of electron microprobe glass compositions selected trace element compositions and single crystal 40ar 39ar age determinations we provide a new chrono and chemo stratigraphic classification of the products emplaced in the 800 390 ka time interval besides giving insights on the petrologic evolution of the roman comagmatic region the large dataset provides fundamental information that is applicable to tephrostratigraphic studies in the wide region encompassing the tyrrhenian sea margin to the adriatic sea basin distal tephras from this volcanic activity also act as important geochronologic markers for the coastal sedimentary successions deposited in response to glacio eustatic fluctuations as well as for successions in the quaternary tectonic basins of the central and southern apennines an innovative approach based on the use of discrimination diagrams of zr y vs nb y ratios for fingerprinting altered volcanic rocks recently developed and successfully employed in archaeometric studies is here combined to the glass compositions for classifying the msvd deposits and tested on two distal tephra layers showing its potentiality for tephrostratigraphic correlation

paleoenvironmental changes at the lower pleistocene montalbano jonico section southern italy global versus regional signals abstract integrated high resolution data from calcareous plankton assemblages foraminifera and nannofossils together with geochemical and mineralogical investigations have been collected at the on land montalbano jonico section southern italy in order to reconstruct the paleoenvironmental changes through marine isotope stages mis 23 37 time series analysis on globigerina bulloides and cassidulina carinata 18o records and on selected calcareous plankton proxies mainly revealed the occurrence of precession and obliquity forcing the deposition of sapropel layers which are interbedded in the montalbano jonico section was driven by water column stratification insolation cycle i 104 and enhanced sea surface water productivity insolation cycle i 112 i 102 and i 86 different paleoenvironmental conditions mark the sedimentary evolution of the section from 1240 to 1082 ka mis 37 mis 32 high percentage abundances of warm and oligotrophic planktonic foraminifera and calcareous nannofossil taxa indicate the establishment of oligotrophic and stratified surface water conditions a key paleoenvironmental change occurred during mis 31 from about 1080 to 1065 ka which was a very warm interglacial characterized by an increase of tropical subtropical globigerinoides ruber group and globigerinoides trilobus and low salinity braarudosphaera bigelowii sea surface water taxa during this interval more humid climate conditions coupled with changes in local paleomorphology may have triggered a higher and unusual freshwater input and the creation of a new entry point for sediment supply into the basin from a different drainage area from about 1065 to 1010 ka mis 30 mis 29 a cool and dry climate prevailed in the circum mediterranean area during a time of precession maxima this favored lowered sea surface temperatures and an increase of polar water neogloboquadrina pachyderma left coiling there are also indications of a reduction of the terrigenous input from the new source area from 1010 ka upward mis 28 mis 23 the higher abundances of globigerina bulloides turborotalita quinqueloba and calciosolenia spp indicate enhanced productivity conditions probably related to high turbidity of sea surface waters triggered by a more conspicuous sediment input from land analysis of the long term trends in the multiproxy patterns suggests that the major paleoenvironmental changes occurred as a consequence of the combined effect of orbitally controlled global climate and regional processes

revised chronology of the sulmona lacustrine succession central italy we present new stratigraphic palaeomagnetic 87sr 86sr and 40ar 39ar data from a lacustrine succession of the sulmona basin central italy which according to an early study included six unconformity bounded lacustrine units from sul6 oldest to sul1 youngest spanning the interval 600 to 2 ka the results of the present study on the one hand confirm some of the previous conclusions but by contrast reveal that units sul2 and sul1 previously attributed to the holocene are actually equivalent to the older sul6 and sul5 units here dated to 814 530 ka and 530 457 ka respectively and that the u series dates previously published for both former sul2 and sul1 units yielded abnormally young ages in light of the present results a reassessment of the chronology of the sulmona basin succession and a revision of the tephrostratigraphy of the sul2 sul6 and sul1 sul5 units is in order copyright 2013 john wiley sons ltd

the montalbano jonico marine succession an archive for distal tephra layers at the early middle pleistocene boundary in southern italy abstract the lithological content and mineralogical assemblage of main tephra layers v1 v2 v3 v4 v5 v7 embedded in the montalbano jonico succession have been fully characterized major element analyses were carried out on the juvenile glass fractions and main crystal phases and trace element contents were determined on glasses extracted from the thickest layer of the sequence v5 single crystal 40 ar 39 ar laser fusions were performed on sanidine from the v4 layer yielding a weighted mean age of 773 9 1 3 ka the vulture volcano is likely the source of two tephra layers v3 and v4 embedded to the middle part of the interval b of the sequence which represent the oldest products of this center ever found moreover the v4 layer was emplaced near the matuyama bruhnes chron boundary and thus serves as an important chronostratigraphic marker complete chemical characterization of v5 allows us to suggest the campanian volcanic zone as its eruptive source corroborating the idea that activity there began at 720 ka and spanned most of the middle pleistocene finally we insert our new framework from the montalbano jonico sequence into a reappraised tephra sequence from the middle pleistocene to present in southern italy which results in a more robust series of tephrostratotypes and improves the reliability of inter archive correlations

tephrochronological dating of varved interglacial lake deposits from pianico sellere southern alps italy to around 400 ka the sediment record from the pianico palaeolake in the southern alps is continuously varved spans more than 15 500 years and represents a key archive for interglacial climate variability at seasonal resolution the stratigraphic position of the pianico interglacial has been controversial in the past the identification of two volcanic ash layers and their microscopic analysis provides distinct marker layers for tephrochronological dating of these interglacial deposits in addition to micro facies analyses reconstructing depositional processes of both tephra layers within the lake environment their mineralogical and geochemical composition has been determined through major element electron probe micro analysis on glass shards comparison with published tephra data traced the volcanic source regions of the pianico tephras to the campanian volcanic complex of roccamonfina italy and probably the puy de sancy volcano in the french massif central available dating of near vent deposits from the roccamonfina volcano provides a robust tephrochronological anchor point at around 400 ka for the pianico interglacial these deposits correlate with marine oxygen isotope stage mis 11 and thus are younger than early to middle pleistocene previously suggested by k ar dating and older than the last interglacial as inferred from macrofloral remains and the geo logical setting copyright 2006 john wiley sons ltd

pumice deposits of the santorini lower pumice 2 eruption on anafi island greece indications for a plinian event of exceptional magnitude abstract isolated patches of santorini pumice deposits are analysed from the non volcanic island of anafi at a distance of 31 38 km east from the centre of the santorini caldera the deposits are plinian fall profiles with a primary thickness at this distance of 1 2 1 5 m and mp maximum pumice and ml maximum lithic diameters of 5 and 4 cm respectively the characteristic profile sequence of the analysed anafi deposits corresponds perfectly with the plinian sequence of the lower pumice 2 lp2 profiles on thera the main island of the santorini group with the sub divisions into lp2 a2 1 lp2 a2 2 and lp2 a3 pumice glass chemistry phenocryst assemblage and the significant content of grey cauliform scoriae make the compositional correlation with the plinian lp2 eruption of santorini unambiguous with the new identification of lp2 deposits on anafi together with an 4 5 times greater thickness in the main axis of dispersal of the proximal plinian lp2 deposits compared to the minoan fallout on thera the plinian opening phase of the 172 ka lp2 eruption lp2 a is regarded by far as the most voluminous of all plinian eruptive phases on santorini

first evidence of a distal early holocene ash layer in eastern mediterranean deep sea sediments derived from the anatolian volcanic province article i nfo a hitherto unknown distal volcanic ash layer has been detected in a sediment core recovered from the southeastern levantine sea eastern mediterranean sea radiometric stratigraphic and sedimentological data show that the tephra here termed as s1 tephra was deposited between 8970 and 8690 cal yr bp the high silica rhyolitic composition excludes an origin from any known eruptions of the italian aegean or arabian volcanic provinces but suggests a prevailing central anatolian provenance we compare the s1 tephra with proximal to medial distal tephra deposits from well known mediterranean ash layers and ash fall deposits from the central anatolian volcanic field using electron probe microanalyses on volcanic glass shards and morphological analyses on ash particles we postulate a correlation with the early holocene dikkartin dome eruption of erciyes dag volcano cappadocia turkey so far no tephra of the central anatolian volcanic province has been detected in marine sediment archives in the eastern mediterranean region the occurrence of the s1 tephra in the south eastern part of the levantine sea indicates a wide dispersal of pyroclastic material from erciyes dag more than 600 km to the south and is therefore an important tephrostratigraphical marker in sediments of the easternmost mediterranean sea and the adjacent hinterland

the last 40 ka tephrostratigraphic record of lake ohrid albania and macedonia a very distal archive for ash dispersal from italian volcanoes abstract a 1075 cm long core lz1120 was recovered in the south eastern part of the lake ohrid republics of macedonia and albania and sampled for identification of tephra layers magnetic susceptibility investigations show rather high magnetic values throughout the core with peaks unrelated to the occurrence of tephra layers but instead to the relative abundance of detrital magnetic minerals in the sediment naked eye inspection of the core allowed us to identify of two tephra layers at 896 897 cm and 1070 1075 cm laboratory inspection of the grain size fraction 125 m allowed for the identification of a third cryptotephra at 310 315 cm major element analyses on glass shards of the tephra layers at 896 897 cm and 1070 1075 cm show a trachytic composition and indicate a correlation with the regionally dispersed y 3 and y 5 tephra layers dated at ca 30 and 39 cal ka bp the cryptotephra at 310 315 cm has a mugearitic benmoreitic composition and was correlated with the fl eruption of mt etna dated at 3370 70 cal yr bp these ages are in agreement with five 14 c ams measurements carried out on plant remains and macrofossils from the lake sediments at different depths along the core the recognition of distal tephra from italian volcanoes allows us to link the lake ohrid succession to other archives located in the mediterranean area and in eastern europe the benmoreitic mugearitic tephra layer at 310 315 cm is the first recognition in the balkan area of a distal ash deposit from a mid intensity explosive eruption of mt etna as far as 600 km from the source

transition from calc alkaline to potassium rich magmatism in subduction environments geochemical and sr nd pb isotopic constraints from the island of vulcano aeolian arc the problem of mantle metasomatism vs crustal contamination in the genesis of arc magmas with different potassium contents has been investigated using new trace element and sr nd pb isotopic data on the island of vulcano aeolian arc the analysed rocks range in age from 120 ka to the present day and cover a compositional range from basalt to rhyolite of the high k calc alkaline hkca to shoshonitic sho and potassic ks series older vulcano products 30 ka consist of hkca sho rocks with sio2 48 56 they show lower contents of k2o rb and of several other incompatible trace element abundances and ratios than younger rocks with comparable degree of evolution 87sr 86sr ranges from 0 70417 to 0 70504 and increases with decreasing mgo and compatible element contents 206pb 204pb ratios display significant variations 19 31 to 19 76 and are positively correlated with mgo 143nd 144nd 0 512532 0 512768 207pb 204pb 15 66 15 71 and 208pb 204pb 39 21 39 49 overall geochemical and isotopic data suggest that the evolution of the older series was dominated by assimilation fractional crystallisation afc with an important role for continuous mixing with mafic liquids magmas erupted within the last 30 ka consist mostly of sho and ks intermediate and acid rocks with minor mafic products except for a few acid rocks they display moderate isotopic variations e g 87sr 86sr 0 70457 0 70484 206pb 204pb 19 28 19 55 but 207pb 204pb 15 66 15 82 which suggest an evolution by fractional crystallisation or in some cases by mixing with little interaction with crustal material the higher sr isotopic ratios 87sr 86sr 0 70494 0 70587 of a few low volume intermediate to acid rocks support differentiation by afc at shallow depths for some magma batches new radiogenic isotope data on the aeolian islands of alicudi and stromboli as well as new data for lamproites from central italy are also reported in order to discuss along arc compositional variations and to evaluate the role of mantle metasomatism geochemical and petrological data demonstrate that the younger k rich mafic magmas from vulcano cannot be related to the older hkca and sho ones by intra crustal evolutionary processes and point to a derivation from different mantle sources the data from alicudi and stromboli suggest that even though interaction between magma and wall rocks of the calabrian basement during shallow level magma evolution was an important process locally a similar interpretation can be extended to the entire aeolian arc

millennial scale phase relationships between ice core and mediterranean marine records insights from high precision 40ar 39ar dating of the green tuff of pantelleria sicily strait abstract with the advent of annually resolved polar ice records extending back to 70 ka marine and continental paleoclimate studies have now matured into a discipline where high quality age control is essential for putting on an equal pace layer counted timescale models and late quaternary sedimentary records high resolution u th dating of speleothem records and 40ar 39ar dating of globally recorded geomagnetic excursions have recently improved the time calibration of quaternary archives reflecting the cross disciplinary effort made to synchronize the geologic record at the millennial scale yet tie points with such an absolute age control remain scarce for paleoclimatic time series extending beyond the radiocarbon timescale most notably in the marine record far travelled tephra layers recorded both onland and offshore provide an alternative in such instance to synchronize continental and marine archives via high resolution 40ar 39ar dating of the parent volcanic eruption high resolution 40ar 39ar data are reported herein for one such volcanic marker the green tuff of pantelleria and its y 6 tephra equivalent recorded throughout the central and eastern mediterranean published radiochronometric and 18o orbitally tied ages for this marker horizon scatter widely from about 41 ka up to 56 ka our new 40ar 39ar age at 45 7 1 0 ka 2 reveals that previous estimates are biased by more than their reported errors would suggest including recent orbital tuning of marine records hosting the tephra bed that are reevaluated in the context of this study this improved estimate enables potential phase lags and leads to be studied between deep sea and terrestrial archives with unrivaled near millennial 40ar 39ar precision in the marine record

the alban hills and monti sabatini volcanic products used in ancient roman masonry italy an integrated stratigraphic archaeological environmental and geochemical approach abstract the rocks of alban hills and monti sabatini volcanoes central italy and their associated epiclastic deposits have been extensively used as building material in ancient rome from about viiith century bce to ivth century ce however the identification of the source areas of these rocks is difficult due to the lack of an integrated stratigraphic and geochemical analysis of the relationships between the two volcanic districts and to the alteration affecting the primary products as consequence of weathering and pedogenetic processes here a comprehensive upgraded stratigraphic and geochronological review of the two volcanic districts corroborated by new geochronological data for several eruptive units and altered deposits is presented coupled to a complete geochemical background achieved by means of newly determined major and trace element analyses for all the main eruptive units a study of the alteration processes of the primary products is also presented and the age of the main weathering and pedogenetic phases associated to quaternary climatic changes are also investigated the results are integrated with those from literature in order to construct discriminant diagrams based on selected trace elements and allow us to characterize the primary and altered volcanic deposits in the rome area distinguish products of different volcanic districts discuss the effects of different weathering processes on the mobility of some elements and provide a reference frame for the provenance of the volcanic materials employed in ancient roman masonry the interdisciplinary data set and results presented here provide groundwork for volcanological climate pedological and archaeological provenance studies

impact of volcanism on the evolution of lake van ii temporal evolution of explosive volcanism of nemrut volcano eastern anatolia during the past ca 0 4ma thirty two new single crystal ages document 400 000 years of widespread explosive volcanism of historically active nemrut volcano towering over huge alkaline lake van eastern anatolia the dated deposits were selected to monitor the volcanic and compositional evolution of nemrut volcano through time and thus to provide a rigorous temporal framework for the tephra record of the paleovan drilling project tephra samples were taken from large volume deposits or those that occur in medial to distal localities well exposed stratigraphic sections or from the initial phase of an eruptive sequence mainly fallout deposits were chosen because most ignimbrites show more complex and corroded feldspar populations owing to compositional zoning and magma mixing moreover fallout deposits held the promise to be more clearly identifiable with and correlatable to 300 tephra layers in the paleovan drill cores even though commonly in amounts marginal or insufficient in thickness to allow well supported single crystal dating the crystals dated are dominantly anorthoclase the main phenoctyst phase in the trachytic to rhyolitic slightly to strongly peralkaline nemrut magmas ages obtained so far range from ca 400 ka to ca 30 ka for nemrut volcano the causes of significant changes in the frequency volume and composition of tephra layers per unit time are discussed in terms of external erosion climate changes geodynamic factors and internal forcing changes in magma supply and composition and incubation periods preceding large volume rhyolitic eruptions for example the low frequency of tephra layers deposited prior to ca 200 ka may be due to low explosive activity severe erosion between mis 9 and mis 11 or both nevertheless the overall frequency of explosive eruptions appears to have increased during the past ca 200 ka we also recognize a slight peak in explosive eruptions during warm periods e g mis 5 and mis 7 and speculate on lithospheric unloading triggering increased partial melting or magma reservoir unloading following massive glacier melting the ages of 5 dated ignimbrites span ca 250 000 years suggesting that nemrut volcano went through a polycyclic evolution with multiple caldera collapses and major pyroclastic flow eruptions the oldest dated so far as 265 ka the widely held view of the impressive nemrut caldera now dated to have formed at ca 30 ka as the main paroxysmal event during the evolution of the volcano is no longer tenable distinct and coherent compositional characteristics especially in trace element concentrations characterize several groups of trachytic tephras we speculate that the growth of nemrut volcano caused the isolation of the lake van basin on account of their mineralogical anorthoclase hedenbergite fayalite aenigmatite and alkalic chemical compositions and large volume dated nemrut fallout tephras are likely to represent excellent markers in lakes and other sites of paleoclimatological or archeological interest in neighboring countries to the northeast of lake van as far as the caspian sea in what may be called the east anatolian tephra province

mesozoic tertiary tectonic evolution of albania in its regional eastern mediterranean context abstract research carried out since the opening of albania to the western geological community in the 1990s allows the geology and tectonics of this small balkan country to be integrated into an overall interpretation of neotethys in the eastern mediterranean region specifically greece and the former yugoslavia region albanian geology is most famous for the occurrence of contrasting ophiolites of jurassic age the country is sub divided into three main geotectonic units those in the west i e sazani ionian kruja krasta cukali and the albanian alps relate to the western margin of apulia effectively part of north africa from early mesozoic time onwards in the east is the korabi zone interpreted as a microcontinent located further northeast within neotethys between the two is the mirdita zone dominated by two contrasting jurassic ophiolites the western type ophiolite and the eastern type ophiolite taking account of evidence from greece and former yugoslavia the following tectonic evolution is proposed from early mesozoic time onwards neotethys in albania existed as a northward continuation of the pindos oceanic basin in greece pindos mirdita ocean a korabi microcontinent was rifted off apulia in the early mid triassic followed by passive margin subsidence until late middle jurassic time a rifted slow spreading mor type ophiolite formed within the western pindos mirdita oceanic basin in late triassic early late jurassic time using present co ordinates the shkoder peje scutari pec lineament in the north of albania is interpreted as an important transform fault zone that influenced the regional tectonic evolution during the entire mesozoic early tertiary rift drift emplacement history of the pindos mirdita ocean taking account of evidence from the greek and former yugoslavia ophiolites the easterly albanian ophiolites formed within the pindos mirdita ocean above a westward dipping intra oceanic subduction zone in the early late jurassic metamorphic soles were formed during initial intra oceanic displacement ca 162 174 m y and underlying melanges originated as subduction accretion complexes the mor western type ophiolite evolved into the iat boninitic eastern type ophiolite after subduction began during tithonian berriasian time trench margin collision emplaced the ophiolites eastwards over the korabi margin coupled with redeposition of ophiolitic and continental margin material as exotic blocks debris flow deposits and turbidites these were emplaced onto the upper surface of the ophiolitic thrust sheet during the latest stages of emplacement onto the korabi microcontinent following collision in the east oceanic crust remained within a small remnant pindos mirdita oceanic basin passive conditions were restored in the mid late cretaceous with shallow water carbonate deposition on microcontinental units and both pelagic and redeposited carbonates in basinal settings from the maastrichtian onwards africa eurasia convergence resulted in large scale westward thrusting deforming the apulian foreland in oligo miocene time the suture zone was re activated in oligo miocene time as the albanie thassalie piggy back type basin in central and southern albania albania as a whole was rotated 45 clockwise as part of the western aegean arc in post eocene time coastal and offshore albania experienced strong subsidence after early miocene time forming the periadriatic basin including the tirana depression interpreted as a foredeep related to continuing regional convergence southern albania experienced extensional tectonics in plio quaternary time related to southward roll back of the aegean active margin

the role of the crust in the magmatic evolution of the island of lipari aeolian islands italy volcanic rocks on the island of lipari show the entire range of sr nd pb isotopic compositions displayed by other islands in the aeolian archipelago the rapid isotopic evolution of subaerial volcanic rocks on lipari towards crustal values together with the appropriate isotopic composition of the neighbouring calabrian crust serre indicate that many geochemical characteristics observed in the lavas can be attributed to contamination and mixing with crustal materials and melts interpretation of the data is complicated by the fact that underplating onto the crust mantle boundary and the specific lithologies present in the crustal section differ underneath each individual sector of the island in the central and northern parts of the island metapelitic rocks were incorporated to provide the more radiogenic sr isotopic compositions of some lavas the products from m guardia in the southern part of lipari where activity is restricted to the last 30 40 ka bear geochemical similarities to the island of vulcano where it is proposed that considerable remobilization of the crust took place in the presence of mafic mantle derived melts on lipari the petrogenetic processes of magma mixing and assimilation dominate over fractional crystallization and the observed increase of k2o over na2o can be correlated with contributions from metapelitic crustal lithologies it is suggested that the variability in isotopic composition and the budget of alkalis na2o versus k2o in the lavas can be explained by invoking a heat source from an intruding asthenospheric morb type mantle into a cooler lithospheric crust mantle during the opening of the tyrrhenian basin

marine tephra from the cape riva eruption 22 ka of santorini in the sea of marmara abstract a discrete tephra layer has been discovered in three marine sediment cores from the sea of marmara eastern mediterranean the rhyodacitic glass chemistry and the stratigraphical position suggest a santorini provenance and in particular a correlation with the marine y 2 tephra that is known from the southern aegean sea and eastern levantine basin this tephra represents the distal facies of the cape riva eruption of santorini which has been dated by 14c on land at 21 950 cal yr bp hitherto the y 2 tephra has been detected only in marine sediment cores recovered south to southeast of its volcanic source the new occurrence in the sea of marmara approximately 530 km nne of the santorini eruptive centre suggests a more north easterly dispersal of fallout products of the cape riva eruption than previously supposed

petrology and geochemistry of volcanic rocks from the island of panarea implications for mantle evolution beneath the aeolian island arc southern tyrrhenian sea abstract major trace element and radiogenic isotope sr nd pb data are reported for a suite of rocks from the panarea volcano a large structure that is largely hidden below sea level and outcrops only as a group of small islands between lipari vulcano and stromboli in the eastern aeolian arc the exposed rocks mostly consist of high potassium calc alkaline hkca andesites dacites and some rhyolites shoshonitic basalts have been collected from submarine centres mafic calc alkaline ca rocks occur as thin layers of late erupted strombolian scoriae major and trace element data are scattered but define generally linear trends on inter element diagrams sr isotope ratios do not display significant increase with evolution although rough positive trends of 87sr 86sr versus sio2 and rb sr can be recognised within some units the mafic rocks display varying enrichment in potassium from ca to shoshonitic compositions and are characterised by variable abundances of incompatible trace elements which increase with potassium there is an increase of 87sr 86sr ratios and a decrease of 143nd 144nd and 206pb 204pb ratios from ca to hkca and shoshonitic mafic rocks the scattered and incomplete nature of the outcrops make it difficult to constrain magmatic evolution at panarea geochemical and isotopic data suggest that afc and mixing were important evolutionary processes however geochemical modelling does not support the possibility that the first order compositional variations observed in the mafic rocks are the result of these processes and suggests a genesis in a heterogeneous mantle source recent studies have highlighted strong differences in terms of incompatible trace element ratios and isotopic signatures between the western central and the eastern aeolian arc rocks from the western islands alicudi filicudi salina vulcano have typical magmatic arc geochemical signatures and relatively unradiogenic sr isotope compositions by contrast the eastern island of stromboli has a more radiogenic sr isotope signature and shows trace element abundances and ratios that are intermediate between arc and intraplate compositions panarea mafic rocks have geochemical and isotopic signatures that are intermediate between those observed in the two sectors of the arc the late erupted ca scoriae of panarea have trace element and isotopic compositions similar to those of the mafic rocks from the western islands of filicudi and alicudi whereas the hkca and shoshonitic mafic rocks have isotopic and trace element signatures that are closer to those of stromboli this reflects the particular position of panarea which is sited midway between the western central arc and stromboli according to some recent views subduction of the ionian sea plate is actively occurring beneath the eastern aeolian arc with rollback of the subduction zone toward the southeast the tindari letoianni malta escarpment fault zone is considered to be the boundary between the active subducting plate in the east and the african plate and western aeolian arc in the west it is suggested that the rollback of the ionian plate generated inflow of mantle material from below the western arc into the mantle wedge above the subducting ionian slab this situation generated a hybrid mantle beneath panarea which resulted in a mixture of western type and resident eastern arc mantle materials the latter had a composition akin to the source of stromboli magmas early hkca and shoshonitic magmatism tapped such a hybrid source whereas the younger ca activity has been derived from melting of unmodified western type mantle material the late eruption of ca rocks with a composition similar to western arc can be explained by assuming that a continuing inflow process had increased the amount of western type mantle with time thus favouring the late appearance of ca magmas this hypothesis accounts for the overall decrease of potassium with time which is the opposite of the trend observed in other aeolian islands

on the anatomy of magma chamber and caldera collapse the example of trachy phonolitic explosive eruptions of the roman province central italy abstract textural and compositional features of pyroclastic products erupted during caldera forming events often reveal the tapping of different portions of variably zoned magma chambers due to changing geometries of the conduit vent systems here we report on ultrapotassic trachytic phonolitic explosive eruptions of the roman province central italy which show remarkable changes of textural features and glass compositions in the juvenile material even if the bulk chemical composition is essentially constant in each example the lower eruption sequence contains whitish crystal poor leucite free highly vesicular pumice emplaced by early plinian fallout and or pyroclastic currents upsection the eruption sequence contains black low porphyritic sanidine leucite bearing moderately vesicular scoria or spatter emplaced by major pyroclastic flows red tuff with black scoria and associated co ignimbrite coarse lithic rich breccias this suggests a shift from a central feeder conduit tapping the central part of the magma chamber to a ring fracture vent system tapping the peripheral portions of the magma chamber during caldera collapse key features of these evacuating magma chambers are the thermal and volatile concentration xvol gradients that produce the observed textural and compositional spectrum of trachy phonolitic rock types in particular the degrees of freedom during the crystallization of these ultrapotassic magmas are increased by the variation of the leucite stability field at different ph2o conditions both leucite free and leucite bearing differentiated ultrapotassic rock types can be produced in the course of individual eruptions as a result of pre eruptive conditions in the feeder magma with no need to invoke different differentiation suites related to mantle source heterogeneities of parental magmas

isotopic sr nd and major element fingerprinting of distal tephras an application to the middle late pleistocene markers from the colli albani volcano central italy abstract we describe the diagnostic lithological and chemical features of distal tephras from major middle late pleistocene 560 36 ka explosive eruptions of the colli albani volcanic district central italy in particular we explore the time dependent variability of the sr and nd isotope compositions as a tool for recognising and pinpointing individual colli albani tephra in distal settings the distal tephras investigated are in lacustrine and fluvial sediments of central apennine intermountain basins located 70 km 100 km east of colli albani the recognition of the colli albani tephras is essentially based on the k foiditic composition of their glass which within the italian volcanological framework is a distinctive character of the colli albani pyroclasts in detail these tephras are attributed to the following eruptive units tufo pisolitico di trigoria 561 2 ka tufo del palatino tufo di bagni albule 530 2 527 2 ka tufo di bagni albule pozzolane rosse air fall sequence 517 1 to 500 3 ka pozzolane rosse 457 4 ka villa senni 365 4 ka and albano 5 7 41 7 to 36 1 ka these correlations are supported by 40 ar 39 ar dating of the distal tephras correlated to the pozzolane rosse 457 4 1 7 ka villa senni 365 2 ka and albano 5 7 41 9 ka and by 87 sr 86 sr measured on clinopyroxene crystals and fresh glassy scoria from distal colli albani tephras that range from 0 711 to 0 709 these ratios are similar to those that characterise the individual proximal correlative units and show the same decreasing trend over time in contrast the 143 nd 144 nd ratios for proximal and distal bulk samples and clinopyroxene increase from 0 51212 to 0 51215 from the oldest to the youngest tephra deposit in summary the study of sr and nd isotope compositions that is here applied on products from the colli albani volcanic district is a powerful complementary tool to the more traditional tephrostratigraphic methods e g componentry and electron microprobe analysis for fingerprinting of distal tephras over a large region of the central mediterranean and over a large time interval such as from 560 ka to 36 ka

plinian activity during the early eruptive history of the sabatini volcanic district central italy abstract the early activity of the sabatini volcanic district svd central italy was characterised by highly explosive eruptions that produced widespread subplinian and plinian fall deposits in this study four major eruptive units informally named as units a b c and d were recognised in the 514 449 ka age interval in particular unit d was emplaced during the early phase of the 449 ka tufo rosso a scorie nere pyroclastic flow forming eruption the most important event in the whole svd activity history estimates of relevant eruptive parameters indicate tephra fall volumes up to 4 km3 for individual units peak eruption column heights in the range of 14 29 km and corresponding mass eruption rates of 7 8 106 1 3 108 kg s isopach and isopleth maps of fallout deposits as well as the distribution of the proximal lag breccia of the tufo rosso a scorie nere consistently indicate a common vent area which does not correspond to any volcanic centre identified up to now in the svd this was located along ne sw trending tectonic lineaments that also controlled the location of the other major volcanic centres of the svd the characterisation by means of field aspects grain size componentry and density and chemical composition of juvenile clasts renders the studied fall deposits as valuable stratigraphic markers for the svd and well beyond it in fact their wide areal dispersals toward the e and se may allow correlations on a regional scale for the quaternary successions of intermountain basins of the central apennine and the adriatic sea basin successions finally the correct identification of distal tephra from plinian and co ignimbrite plumes and their attribution to specific explosive eruptions of the svd and the other volcanic districts of the roman province rather than to local intra apennine centres provides crucial implications for geodynamic reconstructions

new insights into the magmatism in the northern margin of the south china sea spatial features and volume of intraplate seamounts the extensive intraplate seamounts are obvious features in the northern south china sea scs however the distribution volume and origin of these seamounts are not well understood which greatly hinders our understanding of magmatism in the scs based on high resolution bathymetric data and 147 seismic profiles and combining gravity and magnetic data we first identify 45 seamounts in the northern margin of the scs and simulate their shape with elliptical cones results show that the total volume of these 45 seamounts above seafloor is estimated at about 1885 3078 km3 and the total volume of intrusive magma above moho is about 0 15 mkm3 which is close to the estimates for classic large igneous provinces across the world these seamounts are mostly located on the continental slope with thin crust approximately 12 18 km which reduces the overlying pressure and shortens the magmatic conduits the dominant azimuth of elliptical major axis in seamounts is consistent with the synrift and synspreading fault strikes ne nee indicating that these pre existing faults provide magmatic conduits for the subsequent postrift intraplate seamounts based on three existing clues i e 1 the intraplate seamounts high velocity layer and hainan mantle plume are contiguous in 3 d space 2 the high velocity layer is thicker beneath the continental shelf but thinner beneath the slope and 3 the basalts dredged from certain seamounts show oib type geochemical features we propose a magmatic upwelling pattern which contains hainan mantle plume to explain the spatial and morphological characteristics of these intraplate seamounts

tephra layers in late quaternary sediments of the central adriatic sea abstract magnetic susceptibility curves of ten cores collected in the western adriatic shelf and in the mid adriatic deep allowed us to recognize thirty tephra layers whose age based on physical and biostratigraphic data encompass a time interval ranging from less than 70 ka to the present chemical features of the tephra defined by sem eds analyses performed on glass shards indicate alkaline affinity mainly with k na 1 and trachytic compositions with two minor benmoreitic and phonolitic groups these characteristics are consistent with campanian and subordinate etnean provenances because of chemical and age constraints the glass shards can be referred to six tephra layers already described in the literature such as c20 c14 citara ischia c10 campanian ignimbrite c2 nyt neapolitan yellow tuff ams pf agnano monte spina phlegrean fields from campanian area and y1 from etna volcano indicating an age ranging from about 70 to 4 ka ams pf and c2 nyt dated 4 4 and 12 3 ka respectively are the most widespread tephra beds in the study cores the occurrence of ams pf never recorded in marine sequences up to now represents a very good marker for holocene adriatic sediments c2 nyt already recorded in the central tyrrhenian sea in lacustrine sediments from southern italy and in the campanian area is a good stratigraphic marker for inter sea and sea land correlations y1 tephra dated 14 2 ka also occurs in on land sediments of central italy and in marine sediments from the tyrrhenian and ionian seas it now represents one of the most widespread stratigraphic markers in the central mediterranean region

oldest human footprints dated by ar ar fossilized human trackways are extremely rare in the geologic record these bear indirect but invaluable testimony of human hominid locomotion in open air settings and can provide critical information on biomechanical changes relating to bipedalism evolution throughout the primitive human lineage among these the devil s footsteps represent one of the best preserved human footprints suite recovered so far in a pleistocene volcanic ash of the roccamonfina volcano southern italy until recently the age of these footprints remained speculative and indirectly correlated with a loosely dated caldera forming eruption that produced the brown leucitic tuff despite extensive hydrothermal alteration of the pyroclastic deposit and variable contamination with excess 40ar detailed and selective 40ar 39ar laser probe analysis of single leucite crystals recovered from the ash deposit shows that the pyroclastic layer and the footprints are 345 6 kyr old 1 confirming for the first time that these are the oldest human trackways ever dated and that they were presumably left by the modern human predecessor homo heidelbergensis close to climatic termination iv

a high resolution tephrochronological record of mis 14 12 in the southern apennines acerno basin italy abstract lithological mineralogical and glass chemical analyses on juvenile fragments extracted from 20 tephra layers embedded within the lacustrine sediments of the acerno basin southern apennines italy were carried out together with four sanidine 40 ar 39 ar age determinations the measured ages span the interval between 561 and 493 ka middle pleistocene eruptive activity at roman province volcanoes was identified as the main possible source of the investigated tephra layers some of them were correlated with precise terrestrial counterparts corresponding to large explosive events of the sabatini e g tufo giallo della via tiberina and alban hills volcanic districts e g tufo pisolitico di trigoria the integration of tephrochronology and pollen analyses allowed the acerno lacustrine sedimentation to be constrained between mis 14 and 12 which overlaps with several well studied lacustrine successions of the southern apennines the correlation with other tephrostratigraphic records from intramontane basins in central southern apennines testifies to the wide dispersal of at least three tephra layers that serve as marker layers thus improving the resolution of the middle pleistocene italian tephrostratotype

recognition of the minoan tephra in the acigol basin western turkey implications for inter archive correlations and fine ash dispersal here we report the recognition of the minoan tephra layer in the acigol basin western turkey which represents the most eastward occurrence of this tephra on land and the first in continental deposits out of lacustrine sediments in mainland turkey the correlation is supported by glass and mineral geochemistry which includes solution and laser ablation icp ms data for trace and rare earth elements thickness and grain size data allow the extension of already described occurrences to an area of about 359 000 km 2 from the eastern mediterranean to black sea throughout central western turkey coupling dispersal area and grain size data suggests the joint influence of high and low atmosphere dynamics in dispersal of fine ash during volcanic eruptions the thickness and lateral continuity of the minoan tephra in the acigol basin testifies to the widespread impact on the late bronze age environment of mainland turkey of this important ash deposit copyright 2013 john wiley sons ltd

the role of cryptotephra in refining the chronology of late pleistocene human evolution and cultural change in north africa abstract sites in north africa hold key information for dating the presence of homo sapiens and the distribution of middle stone age msa middle palaeolithic mp and later stone age lsa cultural activity in the late pleistocene here we present new and review recently published tephrochronological evidence for five cave sites in north africa with long msa mp and lsa cultural sequences four tephra horizons have been identified at the haua fteah cyrenaica libya they include cryptotephra evidence for the campanian ignimbrite ci eruption dating to 39 ka that allows correlation with other palaeolithic sequences in the eastern mediterranean and as far north as russia cryptotephra have also been recorded from the moroccan sites of taforalt rhafas and dar es soltane 1 at taforalt the geochemical composition suggests a provenance in the azores while examples from sodmein egypt appear to derive from central anatolia and another unknown source in these latter examples chemical compositional data from relevant proximal volcanic centres is currently lacking so the identification of tephra in layers of known age and cultural association provides the first reliable age determinations for distal volcanic events and their geographical extent the future potential for tephrochronological research in north africa is also discussed

middle and late pleistocene glaciations in the campo felice basin central apennines italy the present paper refers to research conducted in the tectonic karst depression of campo felice in the central apennines italy in which glacial alluvial and lacustrine sediments have been preserved stratigraphic interpretations of sediments underlying the campo felice plain are based on evidence obtained from nine continuous core boreholes the boreholes reach a depth of 120 m and provide evidence of five sedimentation cycles separated by erosion surfaces each cycle is interpreted as an initial response to a mainly warm stage characterized by low energy alluvial and colluvial deposition pedogenesis and limited episodes of marsh formation in turn a mainly cold stage follows during which a lake formed and glaciers developed and expanded leading to deposition of glacial and fluvioglacial deposits the chronological framework is established by eleven accelerator mass spectrometer 14c ages and three 39ar 40ar ages on leucites from interbedded tephra layers these age determinations indicate five glacial advances that respectively occurred during marine oxygen isotope stages 2 3 4 6 10 and 14

age and geochemistry of tephra layers from ischia italy constraints from proximal distal correlations with lago grande di monticchio unraveling the eruptive history of the island of ischia southern italy is problematic due to its burial caldera collapse resurgent uplift and erosion here we present new major and trace element glass data for 39 75 ka proximal tephra deposits including those of the caldera forming monte epomeo green tuff megt eruption correlations with the distal tephra archive preserved at lago grande di monticchio lgdm are used to constrain the timing of as yet undated eruptive events out of 13 lgdm tephras analysed from the 39 104 ka time window glass geochemical data show that all are compositionally consistent with the explosive volcanic eruptions of ischia whilst 5 of them can be correlated with specific proximal deposits pre megt pyroclastic sequences comprise three compositional groups these groups occur repeatedly in sucessive eruptions proximal distal correlations indicate that the porticello eruption occurred at 59 2 ka and the tisichiello eruption probably occurred at 76 3 ka the megt eruption is correlated with lgdm tm 19 which has been directly dated at 55 2 ka post megt tephras form compositional groups that overlap with the pre megt but are displaced to lower feo and tio2 and lower incompatible element contents proximal distal correlations indicate that the schiappone and pietre rosse eruptions occurred at 50 6 2 0 ka and 45 6 ka respectively tephra from the megt eruption span a wide compositional range broadly overlapping the three pre megt compositional groups but are displaced to higher nd and y and contain an additional less evolved glass population glass geochemistry is used to recognise and confirm distal equivalents of the megt at lgdm tm 19 and in the ionian y 7 adriatic prad 1870 and tyrrhenian c 18 md 28 seas distal occurences of megt tephra define a dispersal axis to the south southeast and are found as far as 540 km from ischia making the megt one of the most widely dispersed late quaternary pyroclastic deposit erupted in the campanian region we estimate a volume of approximately 40 km3 for the fallout portion of the megt pyroclastic sequence on the basis of proximal and distal deposit thicknesses

from basalt to dacite origin and evolution of the calc alkaline series of salina aeolian arc italy the island of salina comprises one of the most distinct calc alkaline series of the aeolian arc italy in which calc alkaline high k calc alkaline shoshonitic and leucite shoshonitic magma series are developed detailed petrological geochemical and isotopic sr nd pb o data are reported for a stratigraphically well established sequence of lavas and pyroclastic rocks from the middle pleistocene volcanic cycle 430 127 ka of salina which is characterized by an early period of basaltic volcanism corvo capo rivi fossa delle felci group 1 and a sequence of basaltic andesites and andesites and dacites in the final stages of activity fossa delle felci groups 2 8 major and trace element compositional trends rare earth element ree abundances and mineralogy reveal the importance of crystal fractionation of plagioclase clinopyroxene olivine orthopyroxene titanomagnetite amphibole apatite in generating the more evolved magma types from parental basaltic magmas and plagioclase accumulation in producing the high al2o3 contents of some of the more evolved basalts sr isotope ratios range from 0 70410 to 0 70463 throughout the suite and show a well defined negative correlation with 143nd 144nd 0 51275 0 51279 pb isotope compositions are distinctly radiogenic with relatively large variations in 206pb 204pb 19 30 19 66 fairly constant 207pb 204pb 15 68 15 76 and minor variations in 208pb 204pb ratios 39 15 39 51 whole rock 18o values range from 6 4 to 8 5 and correlate positively with sr isotope ratios overall the isotopic variations are correlated with the degree of differentiation of the rocks indicating that only small degrees of crustal assimilation are overprinting the dominant evolution by crystal liquid fractionation afc type processes the radiogenic and oxygen isotope composition of the salina basalts suggests derivation from primary magmas from a depleted mantle source contaminated by slab derived fluids and subducted sediments with an isotopic signature of typical upper continental crust these magmas then evolved further to andesitic and dacitic compositions through the prevailing process of low pressure fractional crystallization in a shallow magma reservoir accompanied by minor assimilation of crustal lithologies similar to those of the calabrian lower crust

temporal evolution of the roccamonfina volcanic complex pleistocene central italy abstract the roccamonfina volcanic complex rvc in southern italy is an early to middle pleistocene stratovolcano sharing temporal and morphological characteristics with the somma vesuvius and the alban hills both being associated with high volcanic hazard for the cities of naples and rome respectively the rvc is important for the understanding of volcanic evolution in the roman and campanian volcanic provinces we report a comprehensive study of its evolution based on morphological geochemical and k ar geochronological data the rvc was active from c a 550 ka to 150 ka its evolution is divided into five stages defining a volcanic pulse recurrence time of c a 90 100 kyr the two initial stages consisted in the construction of two successive stratovolcanoes of the tephrite phonolite namely high k series the first stage was terminated by a major plinian eruption emplacing the trachytic rio rava pumices at 439 9 ka at the end of the second stage the last high k series stratovolcano was destroyed by a large sector collapse and the emplacement of the brown leucitic tuff blt at 353 5 ka the central caldera of the rvc is the result of the overlapping of the rio rava and of the blt explosions the plinian eruption of the blt is related to the emptying of a stratified deep seated hks magma chamber during the upwelling of k series ks magma marking a major geochemical transition and plumbing system re organization the following stage was responsible for the emplacement of the lower white trachytic tuff at 331 2 ka and of basaltic trachytic effusive products erupted through the main vent the subsequent activity was mainly restricted to the emplacement of basaltic shoshonitic parasitic cones and lava flows and of minor subplinian deposits of the upper white trachytic tuff between 275 and 230 ka the northern crater is most probably a maar that formed by the phreatomagmatic explosion of the yellow trachytic tuff at 230 ka the latest stage of activity featured the edification of the central shoshonitic domes at c a 150 ka

marine continental tephra correlations volcanic glass geochemistry from the marsili basin and the aeolian islands southern tyrrhenian sea italy abstract major minor and trace element analysis of volcanic glass in proximal and distal it is evident that correlation of proximal continental and distal marine tephras at a high level of confidence requires a full complement of major minor and trace element data in conjunction with considerations of the mineralogy and morphology of juvenile deposits these data help define petrological lineages such that precise provenance can be established whilst a precise proximal distal match must be based on identical major minor and trace element concentrations it is clear that resurgent activity from a single volcano can produce magmas with identical compositions in such cases stratigraphic relationships must complement any geochemical study occasionally proximal stratigraphies may be unrepresentative of the complete eruptive history because of a lack of exposure due to burial by more recent effusive and explosive activity or sector collapse which can remove vital stratigraphy particularly on volcanic islands

tephrostratigraphy of the last 170 ka in sedimentary successions from the adriatic sea abstract in this study are discussed new sem eds analyses performed on glass shards from five cores collected in the central adriatic sea and two cores recovered from the south adriatic sea a total of 26 tephra layers have been characterized and compared with the geochemical features of terrestrial deposits and other tephra archives in the area south adriatic sea and lago grande di monticchio vulture volcano the compositions are compatible with either a campanian or a roman provenance the cores located on the central adriatic inner and outer shelf recorded tephra referred to explosive events described in the literature ap3 sub plinian activity of the somma vesuvius 2710 60 14 c years bp avellino eruption somma vesuvius 3548 129 14 c years bp agnano monte spina phlegrean fields 4100 400 years bp mercato eruption somma vesuvius 8010 35 14 c years bp agnano pomici principali eruption phlegrean fields 10 320 50 14 c years bp neapolitan yellow tuff phlegrean fields 12 100 170 14 c years bp some of these layers were also observed in the south adriatic core in68 9 in addition to younger ap2 sub plinian eruption somma vesuvius 3225 140 14 c years bp and older layers pomici di base eruption somma vesuvius 18 300 150 14 c years bp significant is the tephra record of core rf95 7 that for the first time in the adriatic sea reports the occurrence of tephra layers older than 60 ka the well known mediterranean tephra layers x2 ca 70 ka w1 ca 140 ka and v2 roman origin ca 170 ka as well as other tephra layers attributed on the basis of geochemistry and biostratigraphy to explosive eruptions occurred at vico 138 2 and 151 3 ka bp and ischia 147 140 ka bp previous tephra correlations performed on other cores in the central adriatic sea were also critically revised according to new available data and integrated with the results of this study for a correlation at a regional scale the most important key beds for correlation are the agnano monte spina and neapolitan yellow tuff tephra layers which occur in both central and south adriatic sea other tephra layers younger than 15 ka are relatively less frequent the y1 etna 14 180 260 14 c years bp and agnano pomici principali in the more recent record in the shelf cores north of gargano promontory the ap3 tephra layer is also frequent

geochronology of the most recent activity in the sabatini volcanic district roman province central italy abstract the presence of young highly explosive volcanoes in the densely populated roman area central italy makes the evaluation of the long term volcanic hazard a crucial point the sabatini volcanic district svd part of the potassic quaternary roman province extends over an area of 1800 km2 including the city of rome here we report twenty six new 40ar 39ar age analyses of pyroclastic and lava units in order to put time constraints on the most recent svd eruptive activity i e post dating 400 ka as a groundwork for a detailed reconstruction of the whole volcano tectonic evolution integrated geochronological and field evidence shows that svd volcanism maintained a typical areal character through the whole history both effusive and explosive activity phases from different source areas and volcano tectonic settings overlapped in time and space while climactic phases migrated repeatedly through time in particular new geochronological data better constrain a climactic phase of activity at around 300 ka related to the bracciano volcano tectonic depression and the sacrofano caldera and point out that the most recent eruptive activity in the svd took place from time space clustered hydromagmatic centres at least up to 90 ka in addition we remark some parallelism among major activity phases in the svd and the nearby districts of the roman province with possible implications on quaternary regional tectonics finally new age data put constraints on tephrostratigraphic correlations through the apennine chain and the adriatic sea

petrogenesis of monte vulture volcano italy inferences from mineral chemistry major and trace element data the paper presents major and trace element data and mineral compositions for a series of foiditic tephritic to phonolitic rocks coming from monte vulture southern italy and investigates their origin evolution and relationship with the other centres of the roman province

stratigraphy chronology and sedimentology of ignimbrites from the white trachytic tuff roccamonfina volcano italy abstract we describe the stratigraphy chronology and grain size characteristics of the white trachytic tuff wtt of roccamonfina volcano italy the pyroclastic rock was emplaced between 317 and 230 ma bp during seven major eruptive events units a to g and three minor events units bc cd and de these units are separated by paleosol layers and compositionally well differentiated pyroclastic successions stratigraphic control is favored by the occurrence at the base of major units of marker layers four wtt units 1 to 4 occur within the central caldera these are not positively correlated with specific extracaldera units the source of most of the wtt units was the central caldera units b and c were controlled by the western wall of the caldera whereas units d and e were able to overcome this barrier spreading symmetrically along the flanks of mc the maximum pumice size mp of units increases with distance from the caldera whereas the maximum lithic size ml decreases mp and ml of the marker layer of unit d mkda mkdp do not show any systematic variations with respect to the central caldera in contrast the thickness of surge mkda decreases with distance from the source and mkdp accumulates to the north of mc probably controlled respectively by mobility transport power and by wind blowing northwards the grain size characteristics of the wtt deposits are used for classifying the units there is no systematic variation of the grain size as a function of stratigraphic height either among units or within single units large variation of components in subunit e1 with repetitive alternation of pyroclastic flow to surge through fallout vs surge deposits suggests that the process of eruption took place in a complex or piecemeal fashion pumice concentration zones pcz occur at all wtt levels on the volcano but they are much thicker and pumice clasts are much larger within the central caldera these were probably originated by the disruption of lava flow or dome to pumice fragments and fine ash due to sudden depressurization and interaction with lake waters of the molten lava local basal pcz are in some cases similar to the lapilli rich layer 1p that has been described elsewhere and may have been deposited from currents transitional between pyroclastic surge and flow other basal pcz formed in response to small undulations in the substrate or can be originated by fallout lenticular pcz within ignimbrite interiors and tops are interpreted to record marginal pumice levees and pumice rafts some of which were buried by subsequant pyroclastic flows lithic concentration zones lcz also occur at various stratigraphic height within the extracaldera ignimbrites whereas intracaldera lcz are absent probably due to the fact that ignimbrite currents are strongly energetic and erosive near vent lcz at the top of basal inversely graded layers are formed by mechanical sieving or dispersive pressure in response to variable velocity gradients and particle concentration gradients a segregation process coarse lcz and coarse lithic breccias lb that reside in the interior or tops of pyroclastic flows and that occur in medial to distal areas are interpreted to be the result of slugs of lithic rich debris introduced by vent collapse or rockslides into the moving pyroclastic flows along their flow paths these lcz become mixed to varying degrees due to differential densities and velocities relative to the pyroclastic flows desegregation processes

the eruptive history of pantelleria sicily channel in the last 50 ka six silicic eruptive cycles have been recognized in the last 50 ka at pantelleria the products of each cycle exhibit a compositional variation from pantellerite to less peralkaline rhyolite or to trachyte the relationships between the range of chemical variation the erupted volume and the time of eruptions allow us to estimate an average differentiation rate of 5 crystal fractionation per 1000 years and a constant long term rate of magma discharge of 0 1 km3 per 1000 years pressure increase in the magma chamber caused by the addition of new magma accumulation of highly differentiated volatile rich magma in the roof zone and a concomitant build up of a vapour phase is postulated as a possible triggering mechanism for eruptions

cooling and crystallization recorded in trachytic enclaves hosted in pantelleritic magmas pantelleria italy implications for pantellerite petrogenesis abstract this study focuses on the comenditic trachyte enclaves hosted in pantelleritic lava and pumices emplaced during one of the most recent eruptive events at pantelleria 6 ka enclaves range from mm sized fragments to dm sized blocks with spheroidal to amoeboid shapes and characteristic globular surfaces they are crystal rich with 30 vol large anorthoclase less abundant fe rich olivine clinopyroxene and fe ti oxides vesicles ranging from a few mm to 1 2 cm in size are distributed throughout the enclave and are commonly filled with microlite free vesicular glass the groundmass presents spectacular textures including fine to coarse spherulites and hopper and skeletal microlites mostly anorthoclase with 10 35 vol residual glass and 10 15 vol small vesicles 2 accordingly the microlite composition is close to that of the host pantellerite these textures were acquired during a magma mixing event prior to the eruption i a vapor saturated comenditic trachyte magma intruded the shallower cooler pantellerite magma body triggering a first degassing event first boiling and rapid crystallization with a high degree of undercooling t 100 150 c ii vapor exsolution induced by rapid crystallization second boiling produced the microvesicular groundmass and iii vapor pressure forced the residual pantelleritic liquid to migrate into the large vesicles and or outside the enclaves based on this interpretation these enclaves can be used as a natural laboratory for identifying the chemical and physical processes driving the evolution of silicic magmas at pantelleria in particular they can be used to assess whether pantellerite melts can be obtained from comenditic trachytes after extensive crystallization followed by gas driven filter pressing and consequent pantellerite melt segregation

an integrated stratigraphical approach to the middle pleistocene succession of the sessano basin molise italy abstract an integrated stratigraphical approach was applied to the sessano sedimentary succession molise investigated through an 80 m core and an 11 m trench section the lithostratigraphical study allowed reconstruction of the palaeoenvironmental conditions during the existence of a palaeo marsh based on tephrostratigraphical analysis the significant volcanoclastic inputs recorded along the sessano succession were correlated to the explosive activity of the nearby roccamonfina volcano and in particular to the high k series hks period of activity lasted from 546 to 364 ka the 40 ar 39 ar age of 437 9 1 9 ka obtained at the base of the trench section which stratigraphically overlaps the core succession confirms the tephrostratigraphical model and indicates that the marsh dried up during the glacial phase of marine isotope stage mis 12 on this basis the glacial interglacial cycle recognised in the core through pollen analysis was ascribed to mis 14 and 13 while the interglacial phase identified at the core base was tentatively ascribed to mis 15 the duration of the marshy phase was estimated between 130 and 150 ka the floral composition of the pollen spectra shows a more modern character with respect to coeval pollen records from campania confirming that the heterochronous disappearance of the last subtropical elements from italy had a latitudinal character

tephrostratigraphy chronology and climatic events of the mediterranean basin during the holocene an overview the identification and characterisation of high frequency climatic changes during the holocene requires natural archives with precise and accurate chronological control which is usually difficult to achieve using only 14c chronologies the presence of time spaced tephra beds in quaternary mediterranean successions represents an additional independent tool for dating and correlating different sedimentary archives these tephra layers are potentially useful for resolving long standing issues in paleoclimatology and can help towards correlating terrestrial and marine paleoclimate archives known major tephras of regional extent derive from central and southern italy the hellenic arc and from anatolia a striking feature of major holocene tephra deposition events in the mediterranean is that they are clustered rather than randomly distributed in time several tephra layers occurred at the time of the s1 sapropel formation between c 8 4 and 9 0 ka bp mercato gabellotto fiumebianco e1 cappadocia and ot

chronostratigraphy of monte vulture volcano southern italy secondary mineral microtextures and 39ar 40ar systematics the eruptive history of monte vulture has been the subject of several geochronological investigations during the past decades which reliably dated only a small number of eruptions understanding the causes of sub optimum data yield in the past requires an interdisciplinary approach we re analyzed samples from previous works and present new data on samples from the main volcano stratigraphic units of monte vulture so as to provide an improved consistent chronostratigraphic database imaging of minerals by cathodoluminescence and backscattered electrons reveals that heterochemical high temperature deuteric reaction textures are ubiquitous such observations are common in metamorphic rocks but had not frequently been reported from volcanic rocks in view of the mineralogical complexity we base our chronological interpretation on isochemical steps defined as steps for which the cl k and or the ca k ratios are constant isochemical steps carry the isotopic signature of chemically homogeneous mineral phases and therefore allow a well constrained age interpretation comparison of old and new 39ar 40ar data proves the reproducibility of age spectra and their shapes this quantifies the analytical reliability of the irradiation and mass spectrometric analyses anomalous age spectra are a reproducible property of some specific samples and correlate with mineralogical anomalies the present data allow us to fine tune the age of the volcanostratigraphic units of monte vulture during the known interval of main volcanic activity from ca 740 to 610 ka after a very long stasis the volcanic activity in the monte vulture area resumed with diatremic eruptions one of which lago piccolo di monticchio the site of a palynological paleoclimatological drilling was dated at ca 140 ka

volcanology of trachytic and associated basaltic pyroclastic deposits at roccamonfina volcano roman region italy abstract the 274 ka basalt trachytic tuff of tuoripunzoli tbtt from roccamonfina volcano roman region italy consists of a basaltic scoria lapilli fall unit a overlain by a trachytic sequence formed by a surge unit b repetitive pumice lapilli and ash rich layers both of fallout origin unit c and a pyroclastic flow deposit unit d the tbtt is widespread 40 km 2 in the northern sector of the volcano but limited to a small area on the southern slopes of the main cone interpolation between the northern deposits and the latter one yields a minimum depositional area of 123 km 2 and an approximate bulk volume of 0 2 0 3 km 3 isopach and isopleth maps are consistent with a source vent within the main caldera of roccamonfina unit a shows a fairly good sorting and a moderate grain size glass fragments are cuspate and vesicular unit b is fine grained and poorly sorted shards are blocky and nonvesicular pumice lapilli of unit c are moderately sorted and moderately coarse grained glass shards are equant and vesicular lithic clasts are strongly comminuted to submillimetric sizes by contrast the ash rich internal divisions are very fine grained and poorly sorted they consist of a mixture of equant shards which are prevailingly blocky and poorly vesicular unit d is a massive poorly sorted moderately coarse grained deposit glass fragments are nearly equant and slightly or nonvesicular the tbtt is interpreted as due to eruption of a basaltic magma followed in rapid succession by one trachyte magma unit a formed by subplinian fallout of a moderate purely magmatic column interaction between a trachyte magma and water resulted in eruption of surge unit b a high standing eruption column erupted alternating fallout pumice lapilli and fallout ashes pumice lapilli originated prevailingly from the inner part of the eruption column whereas magma water interaction on the external parts of the column resulted in ash fallout the uppermost pyroclastic flow unit d is interpreted as due to final collapse of the eruption column

recent volcanic history of pantelleria a new interpretation abstract the island of pantelleria is located in the pantelleria rift between sicily and africa this rift is floored by a 20 km thick continental type crust that is characterized by horsts and grabens formed by nw se tensional faults and ne sw shear faults several faults and fractures that intersect the island follow these regional trends prominent volcano tectonic features on the island include two calderas the younger being related to the eruption of the green ignimbrite and the uplifted montagna grande block pantelleria mostly consists of peralkaline silicic rocks with minor trachytes and basalts volcanism on the island is characterized by both explosive and effusive activity reconstruction of the volcanic history of the island since the eruption of the green ignimbrite is based on geological and geochronological data the eruption of the green ignimbrite 50 000 y b p was followed by collapse of the monastero caldera that has been the site of most of the subsequent acid volcanism the montagna grande volcanic complex 35 000 y b p fills the central part while the lower pantelleritic lava flows 16 000 y b p erupted along its rim very probably the young mt gelfiser and khaggiar domes are also located on the caldera rim the montagna grande block rose within the caldera at an estimated average rate between 1 0 and 1 5 cm y for about 20 000 y subsequent pumice cones 9 000 y b p endogenous domes and lava flows also erupted inside this caldera among the main acid volcanic units younger than the green ignimbrite only the mt gelkhamar endogenous dome is not linked to this caldera in the last 50 000 years basaltic activity only occurred in the northern part of the island the basaltic vents are aligned parallel with the main tensional trends of the rift at least two phases have been recognized the older is about 29 000 y b p and the younger is a few thousands of years old a change occurred in the eruptive style after the eruption of the green ignimbrite and collapse of the monastero caldera explosive activity diminished and extrusion of lava became dominant

temporal evolution of a three component system the island of lipari aeolian arc southern italy the volcanic products from lipari define an evolutionary trend with a high gradient of k enrichment similar to the calc alkaline to potassic volcanism of other islands in the aeolian arc stratigraphic reconstruction of the island based on field and geochronological data indicate that the volcanic activity can be subdivided in two stages the first stage from 223 to 42 ka consists of six eruptive cycles and is characterized by basalts and basalt andesites showing progressive increase in both sio2 and k2o contents with time the second stage consists of four cycles erupted since 42 ka and is marked by an apparent rejuvenation of the geochemical system with the appearance of the first rhyolitic products fractional crystallization assimilation and mixing models suggest that the geochemistry of lipari volcanism evolved with time by a complex interplay between two mantle derived components one sub alkaline and the other alkaline in addition to crustal melts and or crustally derived materials a petrogenetic model in which fractional crystallization was subordinate to mixing best fits the geochemical data and petrographic observations of macro and microscopic features melts from the crustal and mantle end members are almost always present in the system but the relative proportions appear to vary with time the sub alkaline mantle component source of tyrrhenian tholeiites is an important contributor to the early evolution of the volcanism in lipari input from the alkaline mantle component source of the roman comagmatic province increases with time and the crustal component becomes dominant in the later activity the preferred petrogenetic model for the temporal evolution of the volcanic system in lipari involves melting initially caused by an increase in the thermal input related to the opening of the tyrrhenian sea and or to subduction processes the quick rise of the isotherms and almost contemporaneous melting of source materials with different compositions favored complex mixing during ascent of the melts

magma evolution at mount vulture southern italy the vulture complex is made up of foiditic tephritic phonolitic trachytic and phonolitic products new rock analyses have been performed in order to ascertain whether the various rock types derive from a unique parental magma and if so to define its nature the data presented support that the vulture suite originated from a foiditic melt which had differentiated at low pressures the main process determining the foidite tephrite phonolitic trachyte evolution seems to be the crystal fractionation of mainly clinopyroxenes and opaques with the contribution of plagioclases and hauyne too in the tephrite trachyte evolution additionary role must have been played by a mixing of melts at different evolution stages occurred in a shallow seated magma chamber

the evolution of the monte vulture volcano southern italy inferences from volcanological geological and deep dipole electrical soundings data abstract the activity of monte vulture started in the middle pleistocene stratigraphic evidence suggests that the volcanic events may have occurred in the following succession 1 formation of widespread pyroclastic pumice deposits 2 sporadic and localized explosive and minor extrusive eruptions 3 highly explosive eruptions with the formation of some tuff cones and of the oldest part of the monte vulture central volcano and 4 activity at the central volcano initially mainly explosive and successively increasingly effusive the western part of the composite volcano and probably also its summit part were affected by caldera collapses the volcanic activity ended with hydromagmatic explosion which formed two explosion craters monte vulture was built up on the external units of the southern apennines at the western border of the foretrough the upper part of the sedimentary substratum consists mainly of clayey formations of the lagonegro and sannitic units beneath these terrains radiolarites and cherty limestones of the lagonegro units outcrop west of monte vulture rocks of the apulia carbonate platform were drilled east of the volcano deep dipole electrical soundings showed a resistant basement at a depth ranging from 0 2 km down to 4 3 km beneath monte vulture volcanological geological and geoelectrical data allow us to hypothesize that a the magma chamber could be located at the boundary between the rigid resistant basement and the overlying conductive plastic terrains b the apulia carbonate platform forms a structural high beneath the monte vulture and c the overthrusting of the lagonegro units on the apulia platform may be located beneath the floors of the calderas of monte vulture

volcanic ash hazard in the central mediterranean assessed from geological data volcanic ash produced during explosive eruptions can have very severe impacts on modern technological societies here we use reconstructed patterns of fine ash dispersal recorded in terrestrial and marine geological archives to assess volcanic ash hazards the ash dispersal maps from nine holocene explosive eruptions of italian volcanoes have been used to construct frequency maps of distal ash deposition over a wide area which encompasses central and southern italy the adriatic and tyrrhenian seas and the balkans the maps are presented as two cumulative thickness isopach maps one for nine eruptions from different volcanoes and one for six eruptions from somma vesuvius these maps represent the first use of distal ash layers to construct volcanic hazard maps and the proposed methodology is easily applicable to other volcanic areas worldwide

a revision of the structure and stratigraphy of pre green tuff ignimbrites at pantelleria strait of sicily abstract at pantelleria peralkaline silicic magmas were erupted across a range of eruptive typologies and magnitudes pyroclastic flows plinian to strombolian pumice fallout and lava flows in this paper we focus on the intermediate cycle of eruptive activity which is bracketed by ignimbrite units slightly older than the two caldera collapses which marked the volcanological activity of the island this age interval 180 85 ka was punctuated by six ignimbrite forming eruptions silicic and variably peralkaline for a cumulative erupted magma volume of approximately 6 km 3 dense rock equivalent based on new 40 ar 39 ar na k feldspar ages and petrographic data we propose an updated volcanostratigraphic scheme for these welded and rheomorphic ignimbrites that can be summarised as follows i the age of the old la vecchia caldera collapse is now tightly constrained between 140 and 146 ka and the caldera forming eruption can be traced to a lithic rich welded tuff breccia that outcrops in two opposite sectors of the island south west and north east ii four ignimbrite units previously considered unrelated are now merged in two distinct eruptive paroxysmal events at 107 and 85 ka in particular the 85 ka eruptive event is comparable in magnitude to the younger caldera forming green tuff plinian eruption iii the recurrence patterns of the 107 and 85 ka eruptions compared to the green tuff allow us to qualitatively assess that the climax in production of low temperature silicic and peralkaline melt was focused in the age interval 85 45 ka

the upper and lower nisyros pumices revisions to the mediterranean tephrostratigraphic record based on micron beam glass geochemistry abstract the greek island of nisyros is the source of tephra found in distal settings throughout the aegean in this contribution we define geochemical fingerprints for the lower and upper pumice eruptions of nisyros based on micron beam major empa and trace la icp ms element data these two eruptions are compositionally distinct from each other the high phenocryst content of proximal lower and upper pumice tephra means that the differences between the two magmas are masked in whole rock analyses we demonstrate that all previous reports of distal marine and continental tephras correspond to the younger upper pumice not the older lower pumice this has important implications for the marine tephrochronology of the mediterranean and for the age of the upper and lower pumice eruptions we suggest an age of at least 47 ka for the upper pumice and an older unconstrained age for the lower pumice

major and trace element characterization of tephra layers offshore pantelleria island insights into the last 200 ka of volcanic activity and contribution to the mediterranean tephrochronology a detailed tephrochronological study was carried out on the deep sea core collected from site 963a in the sicily channel during odp leg 160 the chronology of the succession is provided by an age depth model based on isotope stratigraphy and quantitative eco biostratigraphy major trace and rare earth element content was obtained on single glass grains through electron probe micro analysis and laser ablation inductively coupled plasma mass spectrometry techniques from six well preserved tephra layers characterized by a discrete thickness found along the succession these deposits were correlated with the volcanic activity of pantelleria and dated at 42 5 127 5 128 1 129 1 188 7 and 197 7 ka this detailed chemical characterization of the studied deposits aims to provide a valuable reference database for scientists working on both proximal and distal products erupted at pantelleria island during the late pleistocene this study moreover offers the opportunity to better identify pantelleria related marker tephras within the tephrochronological framework of the central and eastern mediterranean area copyright 2012 john wiley sons ltd

a 90 000 200 000 yrs marine tephra record of italian volcanic activity in the central mediterranean sea abstract a detailed tephrochronological study was undertaken in three deep sea cores collected in the tyrrhenian and ionian seas the age and the origin of the marine tephra were inferred from oxygen isotope records of foraminifera and from major element compositions of glass shards seventy one eruptions were detected in the time interval 90 000 200 000 yrs during which the volcanoes of the roman and campanian regions and of the southern italy were in activity this is attested by the consistency of the geochemical compositions of both marine and terrestrial deposits most of the marine tephra consisted in trachytes and phonolites characterizing a roman and campanian origin several tephra were proposed as key horizons for proximal and distal sediments among them one tephra originating from mount etna 149 300 yrs and five tephra from pantelleria island 130 000 yrs 163 600 yrs 192 500 yrs 197 400 yrs and 198 400 yrs were northerly dispersed several other key horizons originated from the campanian or roman provinces were detected as far as 1000 km from the vents

revised tuning of ocean drilling program site 964 and kc01b mediterranean and implications for the δ18o tephra calcareous nannofossil and geomagnetic reversal chronologies of the past 1 1 myr 1 high resolution color reflectance records of kc01 and kc01b calabrian ridge ionian sea are presented and compared with a modified spliced high resolution color reflectance record of ocean drilling program odp site 964 this comparison revealed that kc01b is characterized by intensive deformation between 27 and 28 5 m piston depth and that some sapropels are tectonically reduced in thickness moreover the piston coring has caused considerable stretching in the top of kc01 and kc01b using a new splice of odp site 964 as guide previous astronomical tuned timescales of kc01b and odp site 964 were evaluated this evaluation resulted in a new sapropel based astronomical timescale for the last 1 1 myr the new timescale implies a much more uniform change in sedimentation rate for the ionian sea cores two prominent excursions to lighter values in the 18o record of the planktonic foraminiferal species globigerinoides ruber occur during marine isotopic stages 12 and 16 applying the new timescale these shifts correspond with maxima in obliquity and are punctuated by minima in the precession cycle they are absent in global ice volume records and are interpreted as reflecting a summer low salinity surface water lens that floats on top of extremely saline intermediate and deep waters at times of the very low sea levels during these glacial periods all biostratigraphic and magnetostratigraphic events found in kc01b and odp site 964 were re dated according to the new timescale and the ages of 33 tephra layers were reviewed the new ages for the calabrian ridge 2 and 3 magnetic events in the brunhes are concordant with minima in the global sint800 composite record derived from worldwide deep sea records of relative paleointensity and have been attributed to the big lost and la palma excursions respectively

plinian fall deposits from vulsini volcanic district central italy stratigraphic investigations of the vulsini volcanic district indicate the existence of five prominent plinian fall deposits deposited over a period of about 0 34 ma the oldest deposit basal pumices crops out mainly in the peripheral areas and is one of the largest plinian events in the vulsini district with a volume of about 9 km3 and a calculated column height exceeding 30 km subcircular patterns of isopachs and isopleths around the bolsena lake indicate emplacement in wind free conditions and suggest a source vent location in the northernmost sector of the present bolsena lake where it is possible that an older central volcanic structure existed the four younger plinian fall deposits are related to bolsena activity the oldest of these named the ponticello and orvieto bagnoregio pumices are mainly distributed on the north eastern sector of the vulsini district their volumes are an order of magnitude lower than that of the basal unit and the estimated column heights do not exceed 20 km the younger ospedaletto pumice deposit has a ne sw dispersal axis whereas the youngest casetta pumice deposit is found only in the north eastern sector of the district their estimated volumes are respectively 1 2 and 0 1 km3 whereas the inferred vent areas appear to be located slightly to the east of the ponticello and orvieto bagnoregio pumice deposit source areas the chronology of the ospedaletto and casetta pumices indicates that the final plinian activity from the bolsena complex is contemporaneous with the latera activity the decreasing volumes from the oldest to the youngest units together with the progressive shifting northeastwards of the source vents may be related to the volcano tectonic subsidence of the bolsena area the source vents for the post basal pumices events are mainly clustered just north of bolsena village where the greatest displacement during subsidence occurred accordingly source vent shifting appears to be related to the progressive opening of normal faults from the inner to the outer margin of the bolsena depression

introduction to the special issue actualistic models of sediment generation conceptual models in sedimentary petrology that relate verticaland lateral compositional signatures during the lling of sedimentarybasins to their internal and external control factors have beendeveloped in the 80 ies and 90 ies of the last century althoughre ned petrographic and geochemical analyses have focussed ondeciphering complex events in time and space such as tectonic evo lution of source terranes changes in sediment dispersal patterns orpalaeoclimate uctuations quantitativemodelsarestillintheirinfancy despite a long history of research one reason for this state of affairs isthe strong interdisciplinary nature of the subject matter another isthe lack of appropriate modelling tools capable of dealing with thecomplex nature of sediment properties the recent proliferation ofquantitative data acquisition techniques coupled with progress indata processing and modelling approaches has led to the emergenceof a new eld of study aimed at solving the fundamental problem ofreconstructing mass transfer from source areas to sedimentary basins the term sediment generation acts as a convenient umbrella for thecomplex web of processes acting between source and sink quantitative models of sediment generation aim at providing anassessment of the type amount and rateof supplyof detritalmaterialfrom identi able parent rock assemblages to a basin ll in order toful l this objective two key questions must be addressed i how much sediment is being delivered ii what are the compositional and textural characteristics of thesediment the rst question is intimately connected to sediment budget as sessments and their derivative with respect to time i e erosion ordenudation and sedimentation rates the second one refers to the

geology of the peralkaline volcano at pantelleria strait of sicily situated in a submerged continental rift pantelleria is a volcanic island with a subaerial eruptive history longer than 300 ka its eruptive behavior edifice morphologies and complex multiunit geologic history are representative of strongly peralkaline centers it is dominated by the 6 km wide cinque denti caldera which formed ca 45 ka ago during eruption of the green tuff a strongly rheomorphic unit zoned from pantellerite to trachyte and consisting of falls surges and pyroclastic flows soon after collapse trachyte lava flows from an intracaldera central vent built a broad cone that compensated isostatically for the volume of the caldera and nearly filled it progressive chemical evolution of the chamber between 45 and 18 ka ago is recorded in the increasing peralkalinity of the youngest lava of the intracaldera trachyte cone and the few lavas erupted northwest of the caldera beginning about 18 ka ago inflation of the chamber opened old ring fractures and new radial fractures along which recently differentiated pantellerite constructed more than 25 pumice cones and shields continued uplift raised the northwest half of the intracaldera trachyte cone 275 m creating the island s present summit montagna grande by trapdoor uplift pantellerite erupted along the trapdoor faults and their hingeline forming numerous pumice cones and agglutinate sheets as well as five lava domes degassing and drawdown of the upper pantelleritic part of a compositionally and thermally stratified magma chamber during this 18 3 ka episode led to entrainment of subjacent crystal rich pantelleritic trachyte magma as crenulate inclusions progressive mixing between host and inclusions resulted in a secular decrease in the degree of evolution of the 0 82 km3 of magma erupted during the episode

central mediterranean explosive volcanism and tephrochronology during the last 630 ka based on the sediment record from lake ohrid abstract lake ohrid located in the central mediterranean region downwind of the italian volcanoes has great potential for developing a detailed record of the explosive activity of these volcanoes electron microprobe and laser ablation inductively coupled plasma mass spectrometry geochemical analyses of juvenile glass fragments of previously not analysed tephra layers of the deep site sediment record of lake ohrid expand the existing tephrostratigraphy for the interval marine isotope stages 1 16 the geochemical signatures of all tephra layers suggest an origin exclusively from the italian volcanism eight of these tephra layers have potential equivalents in marine and terrestrial archives of the central mediterranean region oh dp 1966 sc5 a7 oh dp 1955 ces1 a2 oh dp 1055 s1 oh dp 1006 s2 oh dp 0997 s3 oh dp 0710 s8 c 51 oh dp 0766 odp5 p 13 oh dp 0505 odp4 nine tephra layers which have not been described so far help to reconstruct the late volcanic activity of mount vulture oh dp 2439 and the paleovulsini oh dp 1998 the pre and post rio rava activity of the roccamonfina volcano oh dp 1911 1812 1733 1640 1527 the early activity of the aeolian arc oh dp 1513 1520 and the bracciano activity of the monti sabatini volcanic district oh dp 1175 the multi proxy dataset and chronology of the deep site sediments allowed definition of the climatostratigraphic position for all tephra layers and constrain the ages of so far unknown and or undated tephra layers the presented data provide a crucial increase of knowledge of the middle pleistocene tephrostratigraphy in the central mediterranean back to 630 ka and allows new insights of the volcanic activity of roccamonfina the roman province the campanian volcanic zone cvz the aeolian arc pantelleria and mount vulture

the detailed tephrostratigraphy of a core from the south east black sea spanning the last 60 ka one visible volcanic ash layer and 21 non visible cryptotephra horizons have been identified in the m72 5 25 gc1 core from the south east black sea that spans the last 60 ka glass chemistry suggests that the tephras derive from italian hellenic and turkish sources the visible tephra layer is trachytic in composition and has been correlated to the 39 ka campanian ignimbrite super eruption from campi flegrei caldera italy two cryptotephra layers are associated with eruptions from acigol volcano turkey around the last glacial maximum another is linked to activity at erciyes dagi in the early holocene perikartini or karagullu and a cryptotephra layer near the top of the core correlates to the 3 6k cal a bp minoan marine z2 tephra from santorini thera greece this extends the known dispersal area for all these volcanic ash units many other calc alkaline rhyolite layers preserved in the core are likely to be from central anatolian sources but the lack of detailed proximal data for many of the volcanoes in the region prohibits further correlations the tephrostratigraphy and glass compositional data presented here allow the tephra layers to be used to correlate sedimentary archives across the region and help to extend the mediterranean tephrochronology framework towards the east

correlation between rate of sea level change and frequency of explosive volcanism in the mediterranean volcanic activity has frequently been linked to quaternary environmental change either by driving climate modification1 2 or in response to environmental changes3 although a link has been established between large explosive eruptions and small 0 5 c brief 1 2 years falls in global temperatures4 both the evidence and mechanisms responsible for longer episodes of eruption induced planetary cooling remain questionable1 2 5 6 in contrast recent research based on ice core data suggests that rapid climate changes during the past 110 000 years increased explosive volcanic activity7 here we present a statistical analysis relating the frequency of explosive activity of mediterranean volcanoes based on dated8 9 10 11 tephra layers in deep sea sediment cores to the rate of late quaternary sea level change the nonlinear correlation between the two is tentatively explained in terms of dynamic responses of the volcanoes to stress related influences on various spatial scales the correlation supports a mechanism or mechanisms by which the climate driven growth and decay of large ice sheets can influence the eruptive chronologies of distant volcanic edifices via changes in global sea level