tectonic evolution of the qinling orogenic belt central china new evidence from geochemical zircon u pb geochronology and hf isotopes abstract the qinling orogenic belt qob located between the north china craton ncc and the yangtze craton yzc is composed of the northern qinling belt nqb and the southern qinling belt sqb this study presents new geochemical data zircon u pb ages and hf isotopes from a suite of metamorphic rocks from the kuanping qinling danfeng douling and wuguan groups in the nqb and the sqb our results suggest that the qinling group in the nqb formed in an active continental margin related to the subduction of the songshugou ocean under the southern ncc during grenvillian period the kuanping group in the northern nqb was deposited in the within plate extension basin during late neoproterozoic to early paleozoic the detritus of sedimentary rocks of the kuanping group were mainly sourced from the nqb and subordinately from the basement rocks of the ncc the danfeng group in the southern nqb formed later than 827 ma with the sediments derived mainly from the qinling terrane the nqb witnessed multiphase tectono thermal events from mesoproterozoic to early paleozoic including several magmatic events and the early paleozoic metamorphic event the original douling group in the sqb represents the basement complex of the sqb which is composed of rocks with different formation ages the oldest rock in the complex is represented by 3 0 ga granitic gneiss which underwent at least two periods of metamorphism at 2 5 ga and 0 97 0 91 ga in this study the douling group is redefined as a suite of neoproterozoic 860 750 ma rocks formed in an extensional setting after the subduction of the songshugou ocean the wuguan group in the sqb formed in the middle late neoproterozoic later than 740 ma and was subjected to early paleozoic metamorphism our data indicate that the sqb experienced early neoproterozoic 970 865 ma and early paleozoic 444 ma metamorphism and strong middle neoproterozoic 870 730 ma magmatism the age spectra of zircons from the nqb trace major tectono thermal events at 1462 ma 927 ma and 412 ma which are different from those recorded in the southern ncc and northern yzc suggesting that the nqb had a distinct evolution during mesoproterozoic to early neoproterozoic grenvillian the hf isotopic compositions of zircons from the various rocks suggest that the nqb probably developed on the basement of the southern ncc the rocks in the sqb show zircon age spectra and hf isotope compositions similar to those in the northern yzc suggesting a close affinity we therefore interpret the sqb to have developed on the basement of the northern yzc integrating the new data in this study with those from previous works we propose a new tectonic model for the formation and evolution of the qob during late mesoproterozoic to early paleozoic involving the following major events 1 late mesoproterozoic to early neoproterozoic grenvillian northward subduction of the songshugou ocean 2 early middle neoproterozoic 870 800 ma bidirectional subduction and collision 3 middle neoproterozoic 800 710 ma post collision extension 4 middle late neoproterozoic 710 600 ma within plate extension 5 late neoproterozoic early paleozoic 600 520 ma opening of the shangdan ocean and 6 early paleozoic 520 420 ma subduction collision we thus trace at least two distinct wilson cycles in the qob

exploring the explosive effusive transition using permanent ultra violet cameras understanding the mechanisms that cause effusive eruptions is the key to mitigating their associated hazard here we combine results from permanent ultra violet uv cameras and from other geophysical observations seismic very long period thermal and infrasonic activity to characterize volcanic so2 flux regime in the period prior during and after stromboli s august november 2014 effusive eruption we show that in the two months prior to effusion onset the so2 flux levels are two times average level we explain this anomalously high so2 regime as primarily determined by venting of rapidly rising pressurized so2 rich gas pockets produced by strombolian explosions being more frequent and intense than usual we develop a procedure to track and count in the uv camera record the so2 flux pulses produced by individual explosions and puffing activity active degassing we find that these so2 pulses are far more numerous 67 47 events hour before the effusion onset than during normal activity 20 15 events hour this observation combined with geophysical evidence demonstrates an elevated gas bubble supply to the shallow conduits causing elevated explosive and puffing activity this increase 0 1 m3s 1 in magma transport rate in the north east feeding conduits finally triggers effusion onset active degassing remains elevated also during the effusive phase supporting the persistence of explosive and puffing activity during the effusive eruption deep in the volcanic conduit our results demonstrate that permanent uv cameras can valuably contribute to monitoring at high sampling frequency gas dynamics and fluxes thus opening the way to direct comparison with more established geophysical observations

an automated so 2 camera system for continuous real time monitoring of gas emissions from kīlauea volcano s summit overlook crater abstract so 2 camera systems allow rapid two dimensional imaging of sulfur dioxide so 2 emitted from volcanic vents here we describe the development of an so 2 camera system specifically designed for semi permanent field installation and continuous use the integration of innovative but largely off the shelf components allowed us to assemble a robust and highly customizable instrument capable of continuous long term deployment at k lauea volcano s summit overlook crater recorded imagery is telemetered to the usgs hawaiian volcano observatory hvo where a novel automatic retrieval algorithm derives so 2 column densities and emission rates in real time imagery and corresponding emission rates displayed in the hvo operations center and on the internal observatory website provide hvo staff with useful information for assessing the volcano s current activity the ever growing archive of continuous imagery and high resolution emission rates in combination with continuous data from other monitoring techniques provides insight into shallow volcanic processes occurring at the overlook crater an exemplary dataset from september 2013 is discussed in which a variation in the efficiency of shallow circulation and convection the processes that transport volatile rich magma to the surface of the summit lava lake appears to have caused two distinctly different phases of lake activity and degassing this first successful deployment of an so 2 camera for continuous real time volcano monitoring shows how this versatile technique might soon be adapted and applied to monitor so 2 degassing at other volcanoes around the world

formation and evolution of the tancheng lujiang wrench fault system a major shear system to the northwest of the pacific ocean abstract in the northwestern peri pacific tectonic belt on the continental margin of east asia there is a series of major faults trending ne nne i e the tancheng lujiang wrench fault system this fault system extends more than 5000 km with a width of 800 1000 km in the continent and a general strike of n30 e on the basis of the results of special research on the major faults and a lot of new information about the fault system the authors discuss early mesozoic triassic jurassic period sinistral transcurrent faulting in the different regions it is suggested that in the eastern continent of east asia the e w trending tectonic pattern of the paleozoic and beginning of the mesozoic appear in the nuclei of the sino korean continent massif and the yangtze continent massif these ancient continent massifs accreted both southwards and northwards which finally led to their collision and suturing to the angura continent massif later this tectonic framework was changed greatly by the tancheng lujiang wrench fault system along which left lateral horizontal displacement of 1000 1500 km took place since the mesozoic the dislocation and deformation of horizontal displacement of the tancheng lujiang fault system produced a series of structures trending ne nne in the continental margin which have greatly transformed the ancient structures of the preceding mesozoic this is an important diktyogenese in the continent of east asia during the horizontal displacement motion of these faults the folds nappes and decollement structures pull apart basins and subductions within the continent occurred in the continent at the same time some large sinistral ductile shear zones of horizontal displacement appeared the depth of the deformed horizon of ductile shear which belongs to simple shear was controlled by the tectonic element and distance away from the continental margin whilst the ductile shear deformation occurred the fault dynamo thermal metamorphism and the fault remelting took place and magma activity appeared within the continent in the mesozoic the fault zones used to be high energy zones and recently became the seismic belts within the continent formation of the tan lu fault system was due to the collision between the southern and northern blocks its large sinistral horizontal displacement in the mesozoic was closely related to the kula plate moving northwards therefore the continent disintegrated by shearing which produced some new terranes the shear edge belt was formed between the continent and ocean the change of relative motion between the continent and pacific ocean plate transformed the tan lu fault system into first extension and then compression clarifying the characteristics of the tan lu fault system is an important key in understanding the evolution of the east asia continent since the mesozoic

changing stress field in the middle segment of the tan lu fault zone eastern china abstract the tan lu active fault zone is an important tectonic boundary in east china minor structures associated with the fault show that the nature of displacement on the middle segment of the fault zone has changed in consecutive episodes since the cretaceous normal faulting during the cretaceous sinistral strike slip and reverse faulting at the end of the cretaceous or in the early tertiary and dextral strike slip and reverse faulting from the late tertiary to the present the regional orientation of the maximum principal compressive stress based upon the statistical study of minor shear fracture orientation is 6 s52 w in the late tertiary to quaternary this stress field may be related to the collision between india and tibet and the microspreading of the japan sea

reducing disparity in radio isotopic and astrochronology based time scales of the late eocene and oligocene a significant discrepancy of up to 0 6 myr exists between radio isotopically calibrated and astronomically tuned time scales of the late eocene oligocene we explore the possible causes of this discrepancy through the acquisition of high precision 206pb 238u dating of zircons from 11 volcanic ash beds from the umbria marche sedimentary succession which hosts the global stratotype section and point for the base of the oligocene our results indicate that the four 40ar 39ar dates from the umbria marche succession which underpin the late eocene oligocene portion of the paleogene geomagnetic polarity time scale in the 2012 edition of the geological time scale are anomalously old by up to 0 5 myr conversely when integrated with the established magnetic polarity record of the umbria marche succession 206pb 238u zircon data from this study result in oligocene magnetic reversal ages that are generally equivalent to those obtained through the tuning of ocean drilling program odp site 1218 equatorial pacific furthermore our results indicate that the late eocene tuning of odp site 1218 and international ocean discovery program iodp sites u1333 1334 equatorial pacific to the 405 kyr eccentricity signal is accurate at least back to 36 ma propagating the full uncertainty of our radio isotopic data set and where appropriate taking into account locally derived astronomical time scales we arrive at an age of 34 09 0 08 ma for the eocene oligocene boundary and 28 11 0 17 ma for the base of the chattian

periodic volcanic degassing behavior the mount etna example 1 in contrast to the seismic and infrasonic energy released from quiescent and erupting volcanoes which have long been known to manifest episodes of highly periodic behavior the spectral properties of volcanic gas flux time series remain poorly constrained due to a previous lack of hightemporal resolution gas sensing techniques here we report on so2 flux measurements performed on mount etna with a novel uv imaging technique of unprecedented sampling frequency 0 5hz which reveal for the first time a rapid periodic structure in degassing from this target these gas flux modulations have considerable temporal variability in their characteristics and involve two period bands 40 250 and 500 1200s a notable correlation between gas flux fluctuations in the latter band and contemporaneous seismic root mean square values suggests that this degassing behavior may be generated by periodic bursting of rising gas bubble trains at the magma air interface citation tamburello g a aiuppa a j s mcgonigle p allard a cannata g giudice e p kantzas and t d pering 2013 periodic volcanic degassing behavior the mount etna example geophys res lett 40 4818 4822 doi 10 1002 grl 50924

oxygen and hydrogen isotopes in the hydrologic cycle changes of the isotopic composition of water within the water cycle provide a recognizable signature relating such water to the different phases of the cycle the isotope fractionations that accompany the evaporation from the ocean and other surface waters and the reverse process of rain formation account for the most notable changes as a result meteoric waters are depleted in the heavy isotopic species of h and o relative to ocean waters whereas waters in evaporative systems such as lakes plants and soilwaters are relatively enriched during the passage through the aquifers the isotope composition of water is essentially a conservative property at ambient temperatures but at elevated temperatures interaction with the rock matrix may perturb the isotope composition these changes of the isotope composition in atmospheric waters surface water soil and groundwaters as well as in the biosphere are applied in the characterization of hydrological system as well as indicators of paleo climatological conditions in proxy materials in climatic archives such as ice lake sediments or organic materials

integrated stratigraphy of the eocene oligocene deposits of the northern caucasus belaya river russia intermittent oxygen depleted episodes in the peri tethys and paratethys abstract the sedimentary succession along the belaya river north caucasus provides a record of middle eocene to miocene sediments this time interval is well known for its important climatic transitions e g middle eocene climate optimum meco and eocene oligocene transition eot and changes in basin configuration from peri tethys to paratethys the belaya section contains two intervals marked by oxygen depleted sediments the eocene kuma formation of the peri tethys and the oligocene maikop group of the paratethys both are considered important source rocks for hydrocarbon exploration in the black sea and caspian sea we present integrated stratigraphic results of the belaya river section using calcareous nannoplankton biostratigraphy magnetostratigraphy and 40ar 39ar dating furthermore we investigate the geochemical character of the sediments using x ray fluorescence xrf and stable carbon and oxygen isotopes a middle eocene age for the lower part of the succession is established from nannoplankton biostratigraphy the kuma formation is dated between 42 1 and 38 4 ma based on the assumption of constant sediment accumulation rates a negative oxygen isotope excursion in the middle part of the kuma formation could be related to the meco 40 ma the onset of the maikop group is dated around the base of chron c13n at an age of 33 7 ma close to the eocene oligocene boundary based on geochemical results we show that the kuma formation and maikop group correspond to two different episodes of intensified oceanic oxygen depletion in the succession we hypothesise that oxygen depletion as recorded in the kuma formation is linked to an increased nutrient input in the open marine peri tethys due to widespread volcanism in the neotethys subduction zone while oxygen depletion as recorded in the maikop group is linked to basin restriction caused by the eustatic sea level fall straddling the eocene oligocene boundary triggering stratified conditions in the semi isolated paratethys sea

speculations on the mesozoic plate tectonic evolution of eastern china several orogenic belts transecting eastern china are the sites of former convergent plate margins although there have been varying views on the collisional framework of individual continental blocks styles of convergence at these zones and the timing of respective collisions a tectonic study of eastern china mongolia and the southern soviet far east indicates the collision of the south china block with a combined north china northeast china fold zone block in the late triassic early jurassic their collective suturing to eurasia in the late jurassic early cretaceous followed by the sikhote alin japan block in the mid to late cretaceous the evidence is as follows 1 a linear belt of late triassic early cretaceous granites and granodiorites trends east from the qinlingshan through the dabieshan to the huaiyang massif ophiolites flysch subduction zone melange a paired metamorphic belt indicating north dipping subduction and marine strata of carboniferous to late triassic age from the qinlingshan define the suture between the north and south china blocks 2 a sinuous belt of ultramafics blueschists silicic to intermediate magmatism and west and north vergent folds and thrusts trend from the west margin of the ordos basin through central inner mongolia and along the east great khingan range to the amur river coupled with a mid jurassic early creataceous unconformity a suturing of eastern chinese blocks to eurasia along this zone is suggested 3 a fold and thrust belt with ultramafics flysch blueschists and subduction zone melange along the ussuri river in northeast china indicates the suturing of the sikhote alin japan block to eurasia along a west dipping subduction zone in the mid to late cretaceous similarly a tectonic study of southern china and southeast asia has revealed a complex regional mosaic of suture bounded terrains which nucleated about the eastern western and southern margins of the yangtze craton during the late triassic and early jurassic the evidence is as follows 4 a north south trending belt of ophiolites blueschists calc alkaline volcanics and subduction zone melange including granites granodiorites and strongly deformed marine strata all of late triassic age exposed in the longmenshan of sichuan merge with the kekexilishan ophiolite zone into the ailaoshan tengtiaohe ophiolite and blueschist belt in central yunnan along which the songban ganzi complex and the shan thai malaya block join the craton and 5 a southeastern prolongation of the ailaoshan tengtiaohe belt bifurcates into the southeast trending konvoi zone of northern vietnam and the north south trending pak lay luang prabang zone of laos and eastern thailand zones of ophiolite calc alkaline volcanics and strong late triassic deformation they separate the indosinia and shan thai malaya blocks from the craton respectively these findings differ significantly from previous interpretations of a late paleozoic consolidation of south eastern asia as well as disputing the existence of a true pangea

the tancheng lujiang wrench fault system xu jiawei editor 1993 john wiley chichester england 279 xv pp isbn 0 471 9332 5 price hardback 100

the eocene oligocene climate transition in the central paratethys abstract we studied two boreholes cserepvaralja 1 and kiscell 1 with continuous sedimentary records across the eocene oligocene climate transition from the central paratethyan area assemblages of benthic foraminifera display a shift in dominance by epifaunal taxa in the late eocene to shallow and deep infaunal taxa in the early oligocene using the benthic foraminiferal oxygen index bfoi a decreasing trend of bottom water oxygen levels is established across the eocene oligocene transition eot leading to the development of dysoxic conditions later in the early oligocene trends in 18o and 13c values measured on tests of selected benthic and planktic foraminifera roughly parallel those of the global record of stepped eot 18o increase and deviate only later in the early oligocene related to the isolation of the paratethys the overall similarity of the isotope curves and the presence of a planktic benthic ecological offset suggest that the original isotope trends are preserved despite the systematically more negative 18o values of different scenarios a quasi uniform diagenetic overprint by fluids with low 18o values during burial or uplift appears best supported we conclude that the globally established isotopic expression of antarctic ice sheet growth across the eot may be recognizable in the paratethys deviations from the global trends after the eot were caused by regional paleoceanographic changes induced by the progressing alpine orogeny and sea level change which led to a restricted connection with the open ocean freshwater influx from increased precipitation and gradual development of bottom water oxygen depletion

applying uv cameras for so2 detection to distant or optically thick volcanic plumes abstract ultraviolet uv camera systems represent an exciting new technology for measuring two dimensional sulfur dioxide so 2 distributions in volcanic plumes the high frame rate of the cameras allows the retrieval of so 2 emission rates at time scales of 1 hz or higher thus allowing the investigation of high frequency signals and making integrated and comparative studies with other high data rate volcano monitoring techniques possible one drawback of the technique however is the limited spectral information recorded by the imaging systems here a framework for simulating the sensitivity of uv cameras to various so 2 distributions is introduced both the wavelength dependent transmittance of the optical imaging system and the radiative transfer in the atmosphere are modeled the framework is then applied to study the behavior of different optical setups and used to simulate the response of these instruments to volcanic plumes containing varying so 2 and aerosol abundances located at various distances from the sensor results show that uv radiative transfer in and around distant and or optically thick plumes typically leads to a lower sensitivity to so 2 than expected when assuming a standard beer lambert absorption model furthermore camera response is often non linear in so 2 and dependent on distance to the plume and plume aerosol optical thickness and single scatter albedo the model results are compared with camera measurements made at kilauea volcano hawaii and a method for integrating moderate resolution differential optical absorption spectroscopy data with uv imagery to retrieve improved so 2 column densities is discussed

sediment chemistry and magnetic properties in an anomalously reducing core from the eastern mediterranean sea abstract in core kc19c 19 6 m long recovered in the abyssal plain between crete and cyprus in the eastern mediterranean a large number of organic rich layers sapropels occur which correlate to maxima in the insolation curve in contrast to other sites in the eastern mediterranean porewaters contain sulfide below a few meters below seafloor mbsf geochemical analyses were performed on the porewaters ammonium alkalinity sulfate manganese iron bisulfide chloride eh ph and sediments organic carbon barium total sulfur total iron manganese pyrite dithionite extractable iron in addition a series of magnetic parameters and ratios nrm arm irm in arm irm s ratio arm 20mt arm in were determined in the top of the sediments fe and mn hydr oxides occur at the oxic suboxic boundary just above the youngest sapropel si2 these hydr oxides appear to be more easily demagnetized by means of alternating fields than deeper hydr oxides which presumably are of detrital origin the transition from suboxic to anoxic sediments is located at 2 mbsf sulfide is produced possibly during sulfate reduction through anoxic methane oxidation at 17 5 mbsf from 17 5 mbsf sulfide migrates upward titrating reactive fe resulting in pyrite formation in the entire sediment column up to 2 mbsf at this depth the upward sulfide flux has been totally consumed by reaction with solid phase fe and dissolved fe ii diffusing downward from the suboxic zone above from 2 mbsf downward magnetic intensities are significantly reduced indicating reductive dissolution of fe oxide minerals and pyrite formation as a consequence no reliable nrm data can be obtained in the lower half of the core

stratigraphy and geochemical characterization of the oligocene miocene maikop series implications for the paleogeography of eastern azerbaijan abstract the oligocene miocene maikop series is a world class source rock responsible for much of the oil and gas found in the south caspian basin it is composed of up to 3 km of marine mudstone and contains a nearly continuous record of deposition during progressive tectonic closure of the basin as the arabian peninsula converged northward into eurasia historically the stratigraphy of this interval has been difficult to define due to the homogenous nature of the fine grained clay dominated strata outcrop exposures in eastern azerbaijan allow direct observation and detailed sampling of the interval yielding a more comprehensive stratigraphic context and a more advanced understanding of syndepositional conditions in the eastern paratethys sea specifically the present investigation reveals that coupling field based stratigraphic characterization with geochemical analyses e g bulk elemental geochemistry rock eval pyrolysis bulk stable isotope geochemistry yields a more robust understanding of internal variations within the maikop series samples from seven sections located within the shemakha gobustan oil province reveal consistent stratigraphic and spatial geochemical trends it is proposed that the maikop series be divided into three members based on these data along with lithostratigraphic and biostratigraphic data reported herein when comparing rupelian early oligocene and chattian late oligocene strata the rupelian age strata commonly possess higher toc values more negative 15 n tot values more positive 13 c org values and higher radioactivity relative to chattian age rocks the trace metals mo and v normalized to al are positively correlated with toc with maximum values occurring at the rupelian chattian boundary and overall higher average values in the rupelian across the oligocene miocene boundary a slight drop in v al mo al ratios is observed along with drops in s and toc these results indicate that geochemical signatures of the maikop series are regional in nature and furthermore that analogous fine grained sections may be better characterized and subdivided using similar techniques in general geochemical indicators suggest that the basin was in limited communication with the tethys sea throughout the oligocene early miocene with suboxic to anoxic conditions present during the oligocene and to a lesser extent in the miocene this increased isolation was likely due to tectonic uplift to both the south and north of the study area and greatly enhanced by global sea level fluctuations these data serve as the basis for a more detailed understanding of the tectonic evolution of the region and support a standardized chemostratigraphic division of the important petroleum source interval

glacioeustasy during the middle eocene insights from the stratigraphy of the hampshire basin uk the sedimentary strata of the hampshire basin constitute some of the best preserved palaeogene sequences worldwide and include the traditional unit stratotype for the bartonian 36 9 41 4 ma the barton clay formation at alum bay on the isle of wight iow was studied to assess the evidence for middle eocene sea level variation in records of grain size sediment properties faunal assemblage foraminiferal diversity indices and foraminiferal stable isotopes sedimentary cycles of 1 10 myr third order and 0 2 0 5 myr fourth order duration are reported and interpreted to reflect 20 60 metre variations in water depth additionally an integrated magneto bio chemostratigraphical age model for the succession at alum bay is presented and new and published litho and bio stratigraphical markers are used to correlate additional successions based on this age model it appears that during the late lutetian and early bartonian 42 38 ma water depth variation identified within the basin was synchronous sedimentary and fossil evidence supports episodic uplift in the eastern part of the hampshire basin during the bartonian which at present precludes the calculation of eustatic sea level however the amplitude and frequency of water depth variations identified in the barton clay formation and correlations to published sea level curves are consistent with a component of these changes being glacioeustatic during the middle eocene there is also evidence for a large excursion delta 18o 1 per mille sign in the mono specific benthic foraminiferal oxygen isotope record alum bay 39 9 ma which is correlated to the isotope excursion at the middle eocene climatic optimum previously reported in the southern ocean and other localities a contemporaneous water depth increase of 40 m at alum bay may indicate that a component of this global oxygen isotope excursion results from a reduction in continental ice storage

discordance of jurassic paleomagnetic data from south china and their tectonic implications abstract we have collected oriented cores in jurassic redbeds from two areas in southern guangxi province stepwise thermal demagnetization of the samples and subsequent statistical analysis show that the stable magnetization from both areas is a near primary chemical remanence that passes the fold test area 1 lies in a shear zone and is rotated 24 12 counterclockwise and insignificantly displaced 4 12 northward with respect to area 2 which lies outside the shear zone 80 km to the northwest of area 1 after adjusting for a post jurassic tectonic rotation identified in a previous paleomagnetic study the pole for area 2 is indistinguishable from an averaged early to middle jurassic reference pole for the yangtze craton suggesting that this area was joined to the yangtze craton by that time and confirming that considerable clockwise rotation of south china relative to north china remained to be accomplished before the present configuration of the two blocks was attained in combination with geological observations these data support a terrane model based on sinistral shear acting parallel to recognized structural trends in this part of southeast china during post triassic time

northern caucasus basin thermal history and synthesis of subsidence models abstract burial histories of the eastern central and western parts of the northern caucasus basin are reconstructed on the basis of well data and seismic sections subsidence began in the early triassic after the late carboniferous permian orogeny triassic sediments were mainly removed during late triassic early jurassic uplift and erosion platform cover began to form in the middle jurassic and albian sediments covered the whole territory of the basin thermal modelling shows that jurassic eocene subsidence was mainly controlled by late triassic early jurassic intrusive warming this heating event induced thermal uplift of the whole territory followed by exponentially decelerating subsidence due to cooling of the lithosphere in the southern areas adjacent to great caucasus subsidence was also affected by caucasian extensional and compressional events in the oligocene early miocene the eastern and the central basins underwent rapid long wavelength subsidence maikopian subsidence the geodynamic cause of this subsidence is probably associated with the mantle flow appearance after cessation of the tethyan subduction due to reequilibration of subducted slab while in the late miocene quaternary times the eastern and the western basins underwent foreland type asymmetrical subsidence due to loading of the great caucasus orogen the central basin was uplifted according to flexural modelling the main component of orogen loading was the lithospheric root load delamination of the latter under the central caucasus caused rapid uplift of the orogen and adjacent basin

stepwise transition from the eocene greenhouse to the oligocene icehouse the eocene oligocene transition is the largest global cooling in the cenozoic period a comparison of three independent proxies from the continental shelf and deep ocean reveals a three step transition to cold glacial conditions with ice sheets 25 larger than their present size

quantification of the gas mass emitted during single explosions on stromboli with the so2 imaging camera we performed measurements using an so2 imaging camera of the so2 gas mass emitted during five discrete explosive events on stromboli volcano on 3 october 2006 the so2 gas mass released during discrete explosions was 15 40 kg per explosion producing 3 8 of the total daily so2 gas emission demonstrating that in terms of gas flux strombolian explosions are a second order phenomenon compared with quiescent degassing using the typical gas composition measured with op ftir allows us to determine the total gas mass released during an explosion as 360 960 kg with a volume of 1500 4100 m 3 at 1 bar at the probable source pressure of gas slug formation of 75 mpa this gas amount would occupy a volume equivalent to a sphere with a radius of 0 8 1 m comparable with estimates of stromboli s conduit geometry c 2009 elsevier b v all rights reserved

real time measurement of volcanic so 2 emissions validation of a new uv correlation spectrometer flyspec a miniaturized lightweight and low cost uv correlation spectrometer the flyspec has been devel oped as an alternative for the cospec which has long been the mainstay for monitoring volcanic sulfur dioxide fluxes field experiments have been conducted with the flyspec at diverse volcanic systems including masaya nicaragua po as costa rica stromboli etna and vulcano italy villarica chile and kilauea usa we present here those validation measurements that were made simultaneously with cospec at kilauea between march 2002 and february 2003 these experiments with source emission rates that ranged from 95 to 1 560 t d 1 showed statistically identical results from both instruments so2 path concentrations ranged from 0 to 1 000 ppm m with average correlation coefficients greater than r 2 0 946 the small size and low cost create the opportunity for flyspec to be used in novel deployment modes that have the potential to revolutionize the manner in which volcanic and industrial monitoring is performed

late cenozoic burial history and dynamics of the northern caucasus molasse basin implications for foreland basin modelling abstract the collisional history of the caucasus segment of the alpine himalayan fold belt started at the end of the eocene the associated development of the northern caucasus foreland basin occurred during two syn collisional stages each displaying different subsidence patterns the 34 16 ma maikopian or pre foreland stage displays a long wavelength subsidence of a broad area whereas the 16 0 ma foreland stage displays asymmetrical foreland subsidence the first is correlated with the termination of subduction in the southern area and can be associated with mantle flow induced by the re equilibration of the subducted slab the along strike configuration of the second molasse basin stage contradicts the hypothesis in which topographical loading is considered to be the main control on foreland subsidence there is a clear anti correlation between basin depths and orogen heights the deepest parts of the basin are at the tips of the orogen where mountain heights are negligible while the area adjacent to the highest mountains central caucasus is uplifted the influence of other types of loading in foreland basin development has therefore been investigated and it has been possible to find a good fit with both gravity and basin architecture by including only two additional model parameters into the model these are crustal and lithospheric thickening thinning the results demonstrate that crustal thickening and removal of lithospheric roots are responsible for supporting the high central caucasus mountains and uplift of adjacent areas the subsidence of the basins at the orogen tips is explained by loading of lithospheric roots both effects are important in the geographically intermediate areas in general it is concluded that topography should not be considered as the main control on foreland subsidence but only as one of several counterbalancing mechanisms the existing flexural model therefore needs improvements such that it can be related directly to subsurface loading by real structures and processes during collision

ifit a simple method for measuring volcanic so2 without a measured fraunhofer reference spectrum abstract accurate quantification of the emission rate of sulphur dioxide so2 from volcanoes provides both insights into magmatic processes and a powerful monitoring tool for hazard mitigation the primary method for measuring magmatic so2 is differential optical absorption spectroscopy doas of uv scattered sunlight spectra in which a reference spectrum taken outside the plume is used to quantify the so2 slant column density inside the plume this can lead to problems if the reference spectrum is contaminated with so2 as this will result in a systematic underestimation of the retrieved so2 slant column density and therefore emission rate we present a new analysis method named ifit which retrieves the so2 slant column density from uv spectra by directly fitting the measured intensity spectrum at high spectral resolution 0 01 nm using a literature solar reference spectrum and measured instrument characteristics this eliminates the requirement for a measured reference spectrum providing a point and shoot method for quantifying so2 slant column densities we show that ifit retrieves correct so2 slant column densities in a series of test cases finding agreement with existing methods we propose that ifit is suitable for both traverse measurements and permanent scanning stations and could be integrated into volcano monitoring networks at observatories finally we provide an open source software implementation of ifit with a user friendly graphical interface to allow users to easily utilise ifit

using so 2 camera imagery and seismicity to examine degassing and gas accumulation at kīlauea volcano may 2010 abstract so 2 camera measurements at k lauea volcano hawaii in may of 2010 captured two occurrences of lava lake rise and fall within the halema um au crater summit vent during high lava stands we observed diminished so 2 emission rates and decreased seismic tremor similar events at k lauea have been described as the result of sporadic degassing following gas accumulation beneath a mostly impermeable lava lake surface incorporation of so 2 camera data into a multi parameter dataset gives credence to the likelihood of shallow gas accumulation as the cause of these high stand events with accumulated gas release upon lake level drop compensating for the gas deficit reached during accumulation

ductile deformation and regional strain field in the southern segment of the tancheng lujiang fault zone eastern china studies in a segment of the tancheng lujiang fault zone show that it is a major transcurrent ductile shear zone with a considerable sinistral displacement the formations pt t1 2 at depths of 5 to 15 km may have cropped out in this area during subsequent erosion many ductilely deformed structures are in it the deformed zone was formed during the indo sinian orogeny on the basis of measurements and analyses of many deformed pebbles within the shear zone it is suggested that the deformation in the zone studied may be catagorized as a variation of simple shear and plane strain with a constant volume the intensely deformed belt is generally 40 to 50 km wide with the average strain ratio 27 68 and the maximum greater than 87 37 from analysis of elongation strain we estimate that the deformed belt has been elongated by 164 23 km and narrowed by 222 5 km the internal belt was formed by a high shear strain calculated to be more than 11 34 the deformed belt is associated with syntectonic dynamothermal metamorphism represented by greenschist facies and retrogressive metamorphism on previous amphibolite facies

volcanological applications of so2 cameras ground based volcanic gas and ash imaging has the potential to revolutionise the way in which volcanoes are monitored and studied the ability to track and quantify volcanic emissions in space and time with unprecedented fidelity opens the door to integration with geophysical measurements allowing breakthroughs in our understanding of the physical processes driving volcanic activity in may 2013 a european science foundation funded plume imaging workshop was conducted in strombolutaly with the objective of bringing the ground based volcanic plume imaging community together in order to examine the state of the art and move towards a best practice for volcanic ash and gas imaging techniques a particular focus was the development of so2 imaging systems or so2 cameras with six teams deploying and testing various designs of ultraviolet and infrared based imaging systems capable of imagining so2 one conclusion of the workshop was that the term so2 camera should be applied to any so2 imaging system regardless of wavelength of radiation used this special issue on volcanic plume imaging is the direct result of the stromboli workshop and together the papers presented here represent the state of the art of ground based volcano plume imaging science and technology in this work we examine in detail the volcanological applications of the so2 camera reviewing previous works and placing the new research contained in this special issue in context the development of the so2 camera and future developments extending imaging to other volcanic gases is one of the most exciting and novel research frontiers in volcanology today c 2014 published by elsevier b v

shallow and deep controls on lava lake surface motion at kīlauea volcano abstract lava lakes provide a rare window into magmatic behavior and lake surface motion has been used to infer deeper properties of the magmatic system at halema uma u crater at the summit of k lauea volcano multidisciplinary observations for the past several years indicate that lava lake surface motion can be broadly divided into two regimes 1 stable and 2 unstable stable behavior is driven by lava upwelling from deeper in the lake presumably directly from the conduit and is an intrinsic process that drives lava lake surface motion most of the time this stable behavior can be interrupted by periods of unstable flow often reversals driven by spattering a shallowly rooted process often extrinsically triggered by small rockfalls from the crater wall the bursting bubbles at spatter sources create void spaces and a localized surface depression which draws and consumes surrounding surface crust spattering is therefore a location of lava downwelling not upwelling stable i e deep upwelling driven and unstable i e shallow spattering driven behavior often alternate through time have characteristic surface velocities flow directions and surface temperature regimes and also correspond to changes in spattering intensity outgassing rates lava level and seismic tremor these results highlight that several processes originating at different depths can control the motion of the lava lake surface and long term interdisciplinary monitoring is required to separate these influences these observations indicate that lake surface motion is not always a reliable proxy for deeper lake or magmatic processes from these observations we suggest that shallow outgassing spattering not lake convection drives the variations in lake motion reported at erta ale lava lake

automated paleomagnetic and rock magnetic data acquisition with an in line horizontal 2g system today s paleomagnetic and magnetic proxy studies involve processing of large sample collections while simultaneously demanding high quality data and high reproducibility here we describe a fully automated interface based on a commercial horizontal pass through 2g dc squid magnetometer this system is operational at the universities of bremen germany and utrecht netherlands since 1998 and 2006 respectively while a system is currently being built at ngu trondheim norway the magnetometers are equipped with in line alternating field af demagnetization a direct current bias field coil along the coaxial af demagnetization coil for the acquisition of anhysteretic remanent magnetization arm and a long pulse field coil for the acquisition of isothermal remanent magnetization irm samples are contained in dedicated low magnetization perspex holders that are manipulated by a pneumatic pick and place unit upon desire samples can be measured in several positions considerably enhancing data quality in particular for magnetically weak samples in the bremen system the peak of the irm pulse fields is actively measured which reduces the discrepancy between the set field and the field that is actually applied techniques for quantifying and removing gyroremanent overprints and for measuring the viscosity of irm further extend the range of applications of the system typically c 300 paleomagnetic samples can be af demagnetized per week 15 levels in the three position protocol the versatility of the system is illustrated by several examples of paleomagnetic and rock magnetic data processing

major palaeoproterozoic shear zones of the central fennoscandian shield abstract employing two recently studied crustal scale shear zones as type examples this paper summarizes the major palaeoproterozoic svecokarelian shear tectonics of the central fennoscandian shield and demonstrates that this part of the shield was not as stable during the svecokarelian orogeny as commonly assumed the collision of the svecofennian island arc with the karelian continent first created numerous nw se trending folds and thrusts of stages d1 and d2 which were then modified by successive shearing during stages d3 and d4 stage d3 built up a system of n s trending shear zones here named the savolappishearsystem the type example of which is the hirvaskoski shear zone this is a dextral strike slip shear zone at least 150 km long and 10 30 km wide characterized by blastomylonitic fault rocks and various structures such as hook folds z folds and sheath folds associated with the principal displacement zone synthetic riedel shears and pinnate shears the traces of the axial planes of f3 en echelon folds deviate 15 30 anticlockwise from the plane of the principal displacement zone other members of the savolappi shear system are the pajala shear zone in northern sweden and the russian north karelia shear zone in the east stage d4 created a conjugate shear system called the finlandia shear system the type example of which is the oulujarvi shear zone this is a ne sw trending sinistral strike slip shear zone more than 250 km long and 20 30 km wide across its southwestern end it is composed of a ne sw trending principal displacement zone synthetic riedel shears and pinnate shears with antithetic riedel shears in a nw se direction typical fault rocks within these shears are s c mylonites the axial plane traces of f4 folds of all scales diverge by 20 40 clockwise from the plane of the principal displacement zone the kuopio shear zone is a conjugate nw se trending counterpart of the oulujarvi shear zone as a whole the finlandia shear system forms a conjugate network of nw se and ne sw trending shear zones which occupies most of the northern and central fennoscandian shield

a global synthesis of lava lake dynamics abstract active lava lakes represent a variety of open vent volcanism in which a sizable body of lava accumulates at the top of the magma column constrained by the vent and or crater geometry the longevity of lava lakes reflects a balancing of cooling and outgassing occurring at the surface and input of hot and gas rich magma from below due to their longevity and relative accessibility lava lakes provide a natural laboratory for studying fundamental volcanic processes such as degassing convection and cooling this article examines all seven lakes that existed at the time of writing in 2018 located in the pacific antarctica africa and south and central america these lakes span all tectonic environments and a range of magma compositions we focus on analysis of the lake surface motion using image velocimetry which reveals both similarities and contrasts in outgassing and lake dynamics when comparing the different lakes we identify two categories of lake behavior organized erta ale nyiragongo k lauea after 2011 and erebus and chaotic villarrica masaya marum this division does not map directly to lake size viscosity gas emission rate or temperature instead when examined together we find that the lakes follow a linear relationship between average surface speed and the ratio of total gas flux to lake surface area this relationship points to the combined importance of both flux and lake size in addition to the total volume of gas emission and suggests that a shared deep mechanism controls the supply of heat and gas to all lakes on the other hand the differences between chaotic and organized lakes highlight the important role of the geometry of the conduit lake transition which superimposes a shallow signal on that of the deep circulation the spatial patterns of surface motion we document suggest that the release of gas bubbles at chaotic lakes is more efficient i e bubbles are less likely to be retained and recycled compared with organized lakes in addition the data presented here indicate that the solidified crust of organized lakes plays a role in regulating convection and outgassing in lava lakes

neogene volcanism and holocene earthquakes in the tanlu fault zone eastern china abstract in this paper we study the relationship between neogene volcanism and holocene earthquakes in the tanlu fault eastern china we find that fault segments through which neogene and quaternary magma have extruded do not show holocene slip because they are covered by unfaulted basalts in contrast fault branches that are away from the quaternary volcanic centers display quaternary faulting and are responsible for earthquakes as recorded both historically and geomorphologically therefore magma intrusion appears to modify fault activity in two different ways 1 within the faults the cooling magma serves as a cohesion or barrier welding the faults so that they become stronger in resisting slip 2 beneath the faults the upwelling magma promotes slip of faults above the magma body and hence generation of earthquakes physically the first case results from contraction of the cooling magma which causes a relative increase in fault normal stress so that the fault failure resistance is enhanced the second case results from the upward dynamic force and the heat brought in by the magma body both of which cause the effective fault normal stress to decrease so that the fault failure resistance is reduced that could explain why earthquakes occur on faults bypassing the volcanic centers as typified in the yishu fault zone and in the regions where heat flows are relatively high as shown in the bohai bay area

the so2 camera a simple fast and cheap method for ground based imaging of so2 in volcanic plumes 1 so2 flux is widely monitored on active volcanoes as it gives a window into the hidden subsurface magma dynamics we present here a new approach to so2 flux monitoring using ultraviolet imaging of the volcanic plume through carefully chosen filters to produce images of so2 column amount the so2 camera heralds a breakthrough in both our ability to measure so2 flux at unprecedented frequencies 2 hz and at unprecedented accuracy thanks to the application of correlation techniques to determine wind speed directly from the images and the ability to measure the whole profile simultaneously in this paper we detail the commercially available pieces required to construct the so2 camera introduce a retrieval scheme to determine so2 amounts from the images and present results from a field campaign in november 2005 on sakurajima volcano japan

rheology of the lithosphere selected topics we review recent results concerning the rheology of the lithosphere with special attention to the following topics 1 the flexure of the oceanic lithosphere 2 deformation of the continental lithosphere resulting from vertical surface loads and forces applied at plate margins 3 the rheological stratification of the continents 4 strain localization and shear zone development and 5 strain induced crystallographic preferred orientations and anisotropies in body wave velocities we conclude with a section citing the 1983 1986 rock mechanics literature by category

genesis of the eastern paratethys manganese ore giants impact of events at the eocene oligocene boundary abstract the giant mn ore deposits of the paratethys are located on the slopes and or margins of deep basins the eocene ocean and associated basins were strongly influenced by large scale submarine hydrothermal activity which supplied prodigious amounts of ca co2 sio2 mn and other components to the oceans this caused a substantial shift in seawater composition and resulted in the deposition of carbonates as well huge amounts of mn the giant mn ore deposits of the eastern paratethys were formed as a consequence of the early oligocene global transgression in shelf environments of marginal and epicontinental seas frequently with anoxic regime of the bottom water

retrodeforming the arabia eurasia collision zone age of collision versus magnitude of continental subduction the arabia eurasia collision has been linked to global cooling the slowing of africa mediterranean extension the rifting of the red sea an increase in exhumation and sedimentation on the eurasian plate and the slowing and deformation of the arabian plate collision age estimates range from the late cretaceous to pliocene with most estimates between 35 and 20 ma we assess the consequences of these collision ages on the magnitude and location of continental consumption by compiling all documented shortening within the region and integrating this with plate kinematic reconstructions shortening estimates across the orogen allow for 350 km of neogene upper crustal contraction necessitating collision by 20 ma a 35 ma collision requires additional subduction of 400 600 km of arabian continental crust using the oman ophiolite as an analogue ophiolitic fragments preserved along the zagros suture zone permit 180 km of subduction of the arabian continental margin plus overlying ophiolites wholesale subduction of this more dense continental margin plus ophiolites would reconstruct 400 500 km of postcollisional arabia eurasia convergence consistent with a ca 27 ma initial collision age this younger arabia eurasia collision suggests a noncollisional mechanism for the slowing of africa and associated extension

sun photometer and lidar measurements of the plume from the hawaii kilauea volcano pu u o o vent aerosol flux and so2 lifetime 1 aerosol optical depths and lidar measurements were obtained under the plume of hawaii kilauea volcano on august 17 2001 9 km downwind from the erupting pu u o o vent measured aerosol optical depths at 500 nm were between 0 2 0 4 aerosol size distributions inverted from the spectral sun photometer measurements suggest the volcanic aerosol is present in the accumulation mode 0 1 0 5 micron diameter which is consistent with past in situ optical counter measurements the aerosol dry mass flux rate was calculated to be 53 mg d 1 the estimated so2 emission rate during the aerosol measurements was 1450 mg d 1 assuming the sulfur emissions at pu u o o vent are mainly so2 not aerosol this corresponds to a so2 half life of 6 0 hours in the atmosphere

intercomparison of so2 camera systems for imaging volcanic gas plumes abstract so 2 camera systems are increasingly being used to image volcanic gas plumes the ability to derive so 2 emission rates directly from the acquired imagery at high time resolution allows volcanic process studies that incorporate other high time resolution datasets though the general principles behind the so 2 camera have remained the same for a number of years recent advances in ccd technology and an improved understanding of the physics behind the measurements have driven a continuous evolution of the camera systems here we present an intercomparison of seven different so 2 cameras in the first part of the experiment the various technical designs are compared and the advantages and drawbacks of individual design options are considered though the ideal design was found to be dependent on the specific application a number of general recommendations are made next a time series of images recorded by all instruments at stromboli volcano italy is compared all instruments were easily able to capture so 2 clouds emitted from the summit vents quantitative comparison of the so 2 load in an individual cloud yielded an intra instrument precision of about 12 from the imagery emission rates were then derived according to each group s standard retrieval process a daily average so 2 emission rate of 61 10 t d was calculated due to differences in spatial integration methods and plume velocity determination the time dependent progression of so 2 emissions varied significantly among the individual systems however integration over distinct degassing events yielded comparable so 2 masses based on the intercomparison data we find an approximate 1 sigma precision of 20 for the emission rates derived from the various so 2 cameras though it may still be improved in the future this is currently within the typical accuracy of the measurement and is considered sufficient for most applications

the shutdown of an anoxic giant magnetostratigraphic dating of the end of the maikop sea abstract paratethys the lost sea of central eurasia was an anoxic giant during oligocene early miocene maikop series times with a size matching the modern day mediterranean sea and a history of anoxic conditions that lasted for over 20 myrs the eastern part of this realm black sea caspian sea domain holds key records for understanding the build up maintenance and collapse of anoxia in marginal seas here we show that the collapse of anoxic maikop conditions was caused by middle miocene paleogeographic changes in the paratethys gateway configuration when a mid langhian badenian tarkhanian transgression flooded and oxygenated the eastern paratethys we present an integrated magneto biostratigraphic framework for the early middle miocene tarkhanian chokrakian karaganian regional stages of the eastern paratethys and date the lithological transition from anoxic black shales of the maikop series to fossiliferous marine marls and limestones of the regional tarkhanian stage for this purpose we selected two long and time equivalent sedimentary successions exposed along the belaya and the pshekha rivers in the maikop type area in ciscaucasia southern russia we show that a significant but short marine incursion took place during the tarkhanian ending the long lasting maikop anoxia of the basin our magnetostratigraphic results reveal coherent polarity patterns which allow a straightforward correlation with the time interval 15 12 ma of the geomagnetic polarity time scale the tarkhanian flooding occurred during a relatively short normal polarity interval that correlates with c5bn resulting in an age of 14 85 ma the regional tarkhanian chokrakian stage boundary is located within c5adn at an age of 14 75 ma and the chokrakian karaganian boundary is tentatively correlated with c5acn and an age of 13 9 13 8 ma our new tarkhanian flooding age reveals a paleogeographic scenario that is different from many previous reconstructions instead of envisaging marine connections to the indian ocean we show that major changes in connectivity between the eastern and central paratethys seas have caused the influx of marine waters during the tarkhanian an increase in marine connectivity with the mediterranean during a short episode of rapid sea level rise triggered mixing and ended the widespread anoxia in the eastern paratethys the mixing episode was short lived 100 kyr as the sea level rise slowed down and connectivity degraded because of tectonic uplift in the gateway area

a review of controls on lava lake level insights from halema uma u crater kīlauea volcano the height of the lava column is a fundamental measure of open vent volcanic activity but little continuous long term data exist to understand this parameter the recent 2008 2018 lava lake activity at the summit of k lauea volcano provides an opportunity to track and understand the processes that control lava level over timescales ranging from minutes to years we review recently published data as well as analyze the long term record of lava level at k lauea s summit during 2009 2017 longer timescale fluctuations over days to months have a strong positive linear correlation with ground deformation suggesting they reflect pressure changes in the summit magma reservoir shorter timescale fluctuations over minutes to hours have an inverse relationship with spattering i e outgassing intensity at the lake surface increased outgassing lowers the lake level and vice versa our analysis of the long term lava level data thus confirms that lava level at halema uma u is controlled by these two types of processes 1 those related to magma reservoir pressure changes such as magma supply rate and 2 shallow outgassing fluctuations such as gas pistoning frequency filtering can isolate pressure and outgassing driven components of lava level change time series analysis indicates that there was no large persistent periodicity in the lava level a minor fortnightly oscillation might be related to earth tides but was not continuously present the correlation between lava level and deformation of the summit indicates that the lava lake acts as a reliable piezometer tracking lava level over time may thus provide an indication of flank eruptive potential we show that long term interdisciplinary monitoring is necessary to discriminate the processes that control lava level

retrieval of volcanic ash particle size mass and optical depth from a ground based thermal infrared camera abstract volcanoes can emit fine sized ash particles 1 10 m radii into the atmosphere and if they reach the upper troposphere or lower stratosphere these particles can have deleterious effects on the atmosphere and climate if they remain within the lowest few kilometers of the atmosphere the particles can lead to health effects in humans and animals and also affect vegetation it is therefore of some interest to be able to measure the particle size distribution mass and other optical properties of fine ash once suspended in the atmosphere a new imaging camera working in the infrared region between 7 14 m has been developed to detect and quantify volcanic ash the camera uses passive infrared radiation measured in up to five spectral channels to discriminate ash from other atmospheric absorbers e g water molecules and a microphysical ash model is used to invert the measurements into three retrievable quantities the particle size distribution the infrared optical depth and the total mass of fine particles in this study we describe the salient characteristics of the thermal infrared imaging camera and present the first retrievals from field studies at an erupting volcano an automated ash alarm algorithm has been devised and tested and a quantitative ash retrieval scheme developed to infer particle sizes infrared optical depths and mass in a developing ash column the results suggest that the camera is a useful quantitative tool for monitoring volcanic particulates in the size range 1 10 m and because it can operate during the night it may be a very useful complement to other instruments e g ultra violet spectrometers that only operate during daylight

quantitative imaging of volcanic plumes results needs and future trends abstract recent technology allows two dimensional imaging of trace gas distributions in plumes in contrast to older one dimensional remote sensing techniques that are only capable of measuring total column densities the new imaging methods give insight into details of transport and mixing processes as well as chemical transformation within plumes we give an overview of gas imaging techniques already being applied at volcanoes so2 cameras imaging doas ft ir imaging present techniques where first field experiments were conducted led lidar tomographic mapping and describe some techniques where only theoretical studies with application to volcanology exist e g fabry perot imaging gas correlation spectroscopy bi static lidar finally we discuss current needs and future trends in imaging technology

continuous measurements of sif 4 and so 2 by thermal emission spectroscopy insight from a 6 month survey at the popocatepetl volcano abstract the processes linked with the emplacement and growth destruction of a lava dome are of prime importance to understand the stability of such extrusions and assess the associated risks for local populations during the last couple of decades ground and space based spectroscopic techniques have been developed to monitor such processes from a safe distance such approaches significantly improved our knowledge about the relationship between the chemical composition of the volcanic gas plumes and both the deep and shallow volcanic processes leading to the different types of explosive activity the potential of the ground based thermal emission fourier transform infrared spectroscopy ftir remained under exploited due to the difficulty to properly handle the radiative transfer phenomena despite the drawbacks in the complex analytical requirements this method enables to continuously monitor day and night with a high temporal resolution 1 meas 3 min relevant gas species such as so 2 and sif 4 in the volcanic plumes previous studies have related the temporal variations of the sif 4 so 2 ratio in volcanic plumes to the onset of vulcanian explosions this study reports a 6 month so 2 sif 4 and sif 4 so 2 time series from january to june 2015 of the popocatepetl s gas plume obtained from ftir thermal emission spectroscopic measurements the infrared spectra were analyzed using the sfit4 radiative transfer and inverse model which we have adapted for this application we obtained highly variable sif 4 so 2 ratios with a mean value of 3 6 10 4 with the highest values around 3 10 3 measured during the final phase of a lava dome growth february march 2015 the rapid sif 4 so 2 variations were more carefully explored and compared for the first time with the seismic activity a remarkable coincidence between sharp sif 4 so 2 rises and the seismic events are evidenced here

the type section of the maikop group oligocene lower miocene at the belaya river north caucasus depositional environment and hydrocarbon potential the type section of the oligocene to lower miocene maikop group considered the main source rock in the eastern paratethys has been studied using geochemical proxies to gain insights into depositional setting and hydrocarbon potential the maikop group at the type section is approximately 600 m 2000 ft thick deposition commenced after a major late eocene sea level drop and a subsequent early oligocene sea level rise the maikop group is composed mainly of carbonate free pelitic rocks calcareous rocks are limited to the lower oligocene succession including the polbian bed that forms a basin wide marker horizon deposited during a time with significantly decreased salinity solenovian event anoxic conditions prevailed and were only interrupted for longer periods during deposition of the lower part of the lower oligocene pshekha formation the polbian bed and the lower miocene olginskaya formation total organic carbon toc contents range up to 3 5 wt hydrogen index values are typically less than 300 mg hydrocarbons hc g toc but reach 420 mg hc g toc in black shales overlying the polbian bed lower morozkina balka formation organic richness of this level approximately 10 m 33 ft thick is controlled by low salinity and high bioproductivity the maikop group could generate approximately 2 0 t hc m2 surface area a significant part 0 45 t m2 comes from the lower morozkina balka formation which generates a high wax paraffinic naphthenic aromatic mixed oil the pshekha upper morozkina balka and batalpashinsk formations would generate low wax oil or condensate the hydrocarbon generation potential of the overlying formations is minor overall the generation potential of the maikop group is surprisingly low

image based correction of the light dilution effect for so2 camera measurements abstract ultraviolet so 2 cameras are increasingly used in volcanology because of their ability to remotely measure the 2d distribution of so 2 in volcanic plumes at a high frequency however light dilution i e the scattering of ambient photons within the instrument s field of view fov on air parcels located between the plume and the instrument induces a systematic underestimation of the measurements whose magnitude increases with distance so 2 content atmospheric pressure and turbidity here we describe a robust and straightforward method to quantify and correct this effect we retrieve atmospheric scattering coefficients based on the contrast attenuation between the sky and the increasingly distant slope of the volcanic edifice we illustrate our method with a case study at etna volcano where difference between corrected and uncorrected emission rates amounts to 40 to 80 and investigate the temporal variations of the scattering coefficient during 1 h of measurements on etna we validate the correction method at popocatepetl volcano by performing measurements of the same plume at different distances from the volcano finally we reported the atmospheric scattering coefficients for several volcanoes at different latitudes and altitudes

comparison of cospec and two miniature ultraviolet spectrometer systems for so2 measurements using scattered sunlight the correlation spectrometer cospec the principal tool for remote measurements of volcanic so2 is rapidly being replaced by low cost miniature ultraviolet uv spectrometers we compared two of these new systems with a cospec by measuring so2 column amounts at k lauea volcano hawaii the two systems one calibrated using in situ so2 cells and the other using a calibrated laboratory reference spectrum employ similar spectrometer hardware but different foreoptics and spectral retrieval algorithms accuracy signal to noise retrieval parameters and precision were investigated for the two configurations of new miniature spectrometer measurements included traverses beneath the plumes from the summit and east rift zone of k lauea and testing with calibration cells of known so2 concentration the results obtained from the different methods were consistent with each other with 8 difference in estimated so2 column amounts up to 800 ppm m a further comparison between the cospec and one of the miniature spectrometer configurations the flyspec spans an eight month period and showed agreement of measured emission rates to within 10 for so2 column amounts up to 1 600 ppm m the topic of measuring high so2 burdens accurately is addressed for the k lauea measurements in comparing the foreoptics retrieval methods and resultant implications for data quality we aim to consolidate the various experiences to date and improve the application and development of miniature spectrometer systems

degassing processes during lava dome growth insights from santiaguito lava dome guatemala abstract eruptions of intermediate magma may be explosive or effusive the development of open system degassing has been proposed as a pre requisite for effusion of intermediate magma however processes leading to open system degassing are poorly understood to better understand degassing processes during lava dome extrusion we report high temporal resolution so2 emission rate measurements collected with an ultra violet imaging camera at santiaguito guatemala santiaguito is an ideal case study as the dome lava is compositionally very similar to products of the 1902 plinian eruption of the parental santa maria volcano we find that degassing is weak 0 4 1 kg s 1 but continuous and explosions are associated with small increases in emission rates up to 2 3 kg s 1 continuous repose degassing occurs through a shallow cap rock which likely represents a proto crust on the block lava flow which is extruded from the same vent the continual permeability of the upper conduit argues against a mechanism of explosion triggering in which gas pressure builds beneath a viscous cap rock or plug rather we consider degassing data better consistent with a model of shear fracturing at the conduit margins using field constraints we model the viscosity of santiaguito magma as a function of depth and show that conditions for shear fracturing are met from 150 600 m to the surface this is in line with independent estimates of explosion initiation depth we show that repose timescales are orders of magnitude longer than the timescale for shear fracture and suggest that explosions are triggered when a continuous network of smaller scale fractures develops at which point decompression occurs and an explosion is triggered fracture healing occurs by viscous relaxation however near to the surface where viscosity is highest an unconsolidated gouge layer may develop our model implies that the observed explosions are a by product of extrusion shear fracturing can drive open system degassing of crystal rich intermediate magma at shallow levels in the conduit as high magma viscosity is able to overcome the low strain rates associated with slow ascent of magma

protocols for uv camera volcanic so2 measurements abstract ultraviolet camera technology offers considerable promise for enabling 1 hz timescale acquisitions of volcanic degassing phenomena providing two orders of magnitude improvements on sampling frequencies from conventionally applied scanning spectrometer systems this could for instance enable unprecedented insights into rapid processes such as strombolian explosions and non aliased corroboration with volcano geophysical data the uptake of this technology has involved disparate methodological approaches hitherto as a means of expediting the further proliferation of such systems we here study these diverse protocols with the aim of suggesting those we consider optimal in particular we cover choice and set up of hardware calibration for vignetting and for absolute concentrations using quartz so 2 cells the retrieval algorithm and whether one or two filters or indeed cameras are necessary this work also involves direct intercomparisons with narrowband observations obtained with a scanning spectrometer system employing a differential optical absorption spectroscopic evaluation routine as a means of methodological validation

coupled greenhouse warming and deep sea acidification in the middle eocene 1 the middle eocene climatic optimum meco is an enigmatic warming event that represents an abrupt reversal in long term cooling through the eocene in order to further assess the timing and nature of this event we have assembled stable isotope and calcium carbonate concentration records from multiple deep sea drilling project and ocean drilling program sites for the time interval between 43 and 38 ma revised stratigraphy at several sites and compilation of 18o records place peak warming during the meco event at 40 0 ma chron c18n 2n the identification of the 18o excursion at sites in different geographic regions indicates that the climatic effects of this event were globally extensive the total duration of the meco event is estimated at 500 ka with peak warming lasting 100 ka assuming minimal glaciation in the late middle eocene 4 6 c total warming of both surface and deep waters is estimated during the meco at the study sites the interval of peak warming at 40 0 ma also coincided with a worldwide decline in carbonate accumulation at sites below 3000 m depth reflecting a temporary shoaling of the calcite compensation depth the synchroneity of deep water acidification and globally extensive warming makes a persuasive argument that the meco event was linked to a transient increase in atmospheric pco2 the results of this study confirm previous reports of significant climatic instability during the middle eocene furthermore the direct link between warming and changes in the carbonate chemistry of the deep ocean provides strong evidence that changes in greenhouse gas concentrations exerted a primary control on short term climate variability during this critical period of eocene climate evolution

large lithium isotopic variations in minerals from peridotite xenoliths from the eastern north china craton abstractto investigate the effects of melt rock interaction on li isotope fractionation we report in situ li concentrations and 7li of olivine ol orthopyroxene opx and clinopyroxene cpx for six peridotite xenoliths from the eastern north china craton these xenoliths contain two lherzolites two cpx rich lherzolites and two wehrlites and are variably metasomatized lithium isotope zonation is observed in most peridotite minerals the majority of cpx grains display isotopically light cores with lower li concentrations than the heavy rims however the opx grains show a different style of zonation from cpx where higher li concentrations in the cores are associated with much lighter 7li olivines in most peridotites have a restricted range of li concentration and 7li within individual grains whereas the olivines in a lherzolite show isotopically light cores 10 3 with high li concentrations 2 3 ppm and heavy rims 5 5 with low li concentrations 1 7 ppm these li isotopic variations in m

a middle eocene carbon cycle conundrum a 500 000 year long period of warmth in the middle eocene was marked by high atmospheric carbon dioxide concentrations and prolonged dissolution of carbonate in the deep oceans numerical simulations attempting to capture these features identify gaps in our understanding of the causes of this and similar perturbations

relation between single very long period pulses and volcanic gas emissions at mt asama japan 1 multiple volcanic observations conducted at mt asama japan provide evidence of a link between single very long period vlp seismic pulses and volcanic gas emissions so2 flux measurements were conducted on 2 june 2009 when mt asama was producing ash free eruptions with vlp pulses gas bursts from a vent at the crater bottom following the vlp pulses provided an excellent opportunity to examine the relation directly the so2 emission for each eruption was calculated by integrating high temporal so2 flux data obtained by the so2 imaging system and subtracting the contribution from quiescent degassing from fumaroles around the crater bottom a seismic moment of vlp pulse was estimated by the waveform inversion we observed seven eruptions and obtained the proportional relation between vlp pulse moment and so2 emission the relation determined is consistent with the vlp source model these observational results are the first report of a quantitative comparison between single vlp pulse moment and volcanic gas emission

the eocene oligocene transition changes in sea level temperature or both abstract the eocene oligocene transition eot 34 ma reflects the onset of major antarctic glaciation the primary geochemical signature of the eot is two 300 kyr spaced shifts in increasing deep sea oxygen isotope values possibly reflecting both global cooling and or increasing ice volume a way to assess the respective contribution of continental ice is to quantify concomitant glacio eustatic sea level change this is usually expressed in relatively shallow marine depositional settings one potentially suitable region is in the vicentinian alps ne italy where marginal marine deposits document sea level changes during the eot by correlating stable isotope bio and magnetostratigraphic information between three distant regions we are able to relate the shallow marine sections to the pacific oxygen isotope record from ocean drilling program odp site 1218 of coxall et al 2005 microfacies sedimentological and biotic analysis suggests that associated with the first isotope shift eot 1 sea level fell 20 m and with the ultimate shift the oligocene isotope event 1 oi 1 sea level fell some 50 60 m distribution patterns of temperature sensitive dinoflagellates from a coeval central italian section reveal that the early stages of the eot were accompanied by sea surface cooling whereas no sustained cooling is noted in association with the oi 1 this suggests that the initial eot shift s reflect a mixed signal of ice volume and temperature whereas the oi 1 primarily reflects expansion of the antarctic cryosphere

shallow degassing events as a trigger for very long period seismicity at kīlauea volcano hawai i the first eruptive activity at k lauea volcano s summit in 25 years began in march 2008 with the opening of a 35 m wide vent in halema uma u crater the new activity has produced prominent very long period vlp signals corresponding with two new behaviors episodic tremor bursts and small explosive events both of which represent degassing events from the top of the lava column previous work has shown that vlp seismicity has long been present at k lauea s summit and is sourced approximately 1 km below halema uma u by integrating video observations infrasound and seismic data we show that the onset of the large vlp signals occurs within several seconds of the onset of the degassing events this timing indicates that the vlp is caused by forces sourced at or very near the lava free surface due to degassing transmitted down the magma column and coupling to the surrounding rock at 1 km depth

the quantification and application of handheld energy dispersive x ray fluorescence ed xrf in mudrock chemostratigraphy and geochemistry abstract traditionally analytical techniques such as wavelength dispersive x ray fluorescence wd xrf inductively coupled plasma icp and mass spectrometry icp ms instrumental neutron activation analysis inaa or stationary bench top energy dispersive x ray fluorescence ed xrf have been used to generate quantitative geochemical results however a more efficient means of data collection using portable ed xrf instrumentation now allows the investigator to acquire rapid non destructive quantitative measurements on drill core and clean flat rock surfaces in addition to pressed powder pellets typically used in wd xrf analysis similar to traditional xrf methods quantification using the handheld ed xrf requires a matrix specific calibration unfortunately very few internationally accepted mudrock or shale reference materials exist and their elemental ranges provide inadequate coverage for the geochemical diversity of mudrocks in order to return reliable calibrated results a unique set of reference materials has been developed that incorporates a wide range of mudrock elemental compositions the current method provides elemental calibrations for major elements heavier than sodium and the following trace elements ba v cr ni cu zn rb sr y zr nb mo th and u a comparison of handheld energy dispersive and wavelength dispersive x ray fluorescence ed xrf and wd xrf results from pressed powder pellets of mississippian age barnett shale of north central texas usa is presented in order to evaluate the reliability of the reference calibration and the quantification of unknown samples using two different instrument platforms it will be demonstrated that calibrated results from the handheld ed xrf effectively define chemostratigraphic changes in real time as a consequence quantified results can be used immediately to assess changes in bulk mineralogy paleo redox conditions and to link down core geochemical changes to stratigraphic sedimentological and paleoenvironmental observations

fragmentation of asia in the permian asia is a composite continent formed by the accretion of crustal blocks1 3 a likely sequence of events is that siberia collided with a kazakhstan block which together then collided with europe along the urals in permo triassic times2 this was followed by the sucessive accretion of various blocks of south and east asia to siberia culminating in the collision of india with asia during the cenozoic palaeomagnetic data have already demonstrated that the kolyma and sikhote alin blocks of eastern asia collided with the main continent along the late mesozoic fold belts of verkhoyansk and sikhote alin4 furthermore results from the malay peninsula5 and japan6 suggest that south east asia and japan were situated near the equator in permian times and were therefore separated from the asian continent we report here some palaeomagnetic results from the permian of the sino korean and yangtze blocks of china that show they were also situated near the equator were not in their present relationship to one another and were widely separated from siberia

an oligocene sink for organic carbon upwelling in the paratethys a synoptic review of the organic carbon content kerogen type biogenic siliceous sediments and planktonic remains is attempted for the often anoxic oligocene early miocene sediments of the paratethys covering a large area between the rhine valley and the aral sea on this basis stratification of the sea and intensity of planktonic productivity are discussed for different parts of the paratethys the eastern parathethys and some parts of the central and western paratethys show a black sea like stable stratificatin while the bulk of the anoxic sediments in the carpathian flysch basin are interpreted to have an upwelling origin the supposed flysch ocean upwelling regime has no good recent analogue although it shows similarities with the bay of california high rate of corg burial laminated diatomaceous sediments and turbiditic intercalations and offshore nw africa abundant fresh water discharge sediments of a brackish water incursion are widespread on the bottom of the np 23 zone from earliest oligocene to early miocene a continuous narrowing of the anoxic sedimentary belt towards the east european platform is observed

spatially resolved so2 flux emissions from mt etna we report on a systematic record of so2 flux emissions from individual vents of etna volcano sicily which we obtained using a permanent uv camera network observations were carried out in summer 2014 a period encompassing two eruptive episodes of the new south east crater nsec and a fissure fed eruption in the upper valle del bove we demonstrate that our vent resolved so2 flux time series allow capturing shifts in activity from one vent to another and contribute to our understanding of etna s shallow plumbing system structure we find that the fissure eruption contributed 50 000 t of so2 or 30 of the so2 emitted by the volcano during the 5 july to 10 august eruptive interval activity from this eruptive vent gradually vanished on 10 august marking a switch of degassing toward the nsec onset of degassing at the nsec was a precursory to explosive paroxysmal activity on 11 15 august

seismic profiles across the middle tan lu fault zone in laizhou bay bohai sea eastern china the stratigraphic architecture structure and cenozoic tectonic evolution of the tan lu fault zone in laizhou bay eastern china are analyzed based on interpretations of 31 new 2d seismic lines across laizhou bay cenozoic strata in the study area are divided into two layers separated by a prominent and widespread unconformity the upper sedimentary layer is made up of neogene and quaternary fluvial and marine sediments while the lower layer consists of paleogene lacustrine and fluvial facies in terms of tectonics the sediments beneath the unconformity can be divided into four main structural units the west depression central uplift east depression and ludong uplift the two branches of the middle tan lu fault zone differ in their geometry and offset the east branch fault is a steeply dipping s shaped strike slip fault that cuts acoustic basement at depths greater than 8 km whereas the west branch fault is a relatively shallow normal fault the tan lu fault zone is the key fault in the study area having controlled its cenozoic evolution based on balanced cross sections constructed along transverse seismic line 99 8 and longitudinal seismic line 699 0 the cenozoic evolution of the middle tan lu fault zone is divided into three stages paleocene eocene transtension oligocene early miocene transpression and middle miocene to present day stable subsidence the reasons for the contrasting tectonic features of the two branch faults and the timing of the change from transtension to transpression are discussed crown copyright c 2008 published by elsevier ltd all rights reserved

development of an ultra violet digital camera for volcanic so2 imaging abstract in an effort to improve monitoring of passive volcano degassing we have constructed and tested a digital camera for quantifying the sulfur dioxide so 2 content of volcanic plumes the camera utilizes a bandpass filter to collect photons in the ultra violet uv region where so 2 selectively absorbs uv light so 2 is quantified by imaging calibration cells of known so 2 concentrations images of volcanic so 2 plumes were collected at four active volcanoes with persistent passive degassing villarrica located in chile and santiaguito fuego and pacaya located in guatemala images were collected from distances ranging between 4 and 28 km away with acceptable detection up to approximately 16 km camera set up time in the field ranges from 5 10 min and temporal resolution of up to 6 images per minute is possible which combined with the camera s field of view makes a continuous so 2 dataset attainable variable in plume concentrations can be observed and accurate plume speeds or rise rates can readily be determined by tracing individual portions of the plume within sequential images initial fluxes computed from camera images require a correction for the effects of environmental light scattered into the field of view at fuego volcano simultaneous measurements of corrected so 2 fluxes with the camera and a correlation spectrometer cospec agreed within 25 experiments at the other sites were equally encouraging and demonstrated the camera s ability to detect so 2 under variable background meteorological and environmental conditions this early work has shown great success in imaging so 2 plumes and offers promise for volcano monitoring due to its rapid deployment and data processing capabilities relatively low cost and improved interpretation afforded by synoptic coverage from a range of distances