active high resolution compressional wave attenuation tomography at newberry volcano central cascade range in this study we use the seismic data from a previous study at newberry to compute its three dimensional compressional wave attenuation structure the data consist of eight explosions recorded on an array of about 120 seismograph stations the shots are located on two concentric circles centered on the caldera with radii of 39 and 85 km attenuation is estimated using spectral ratios to compute t at each station for each shot the data are inverted using a least squares technique our results indicate that regions of inferred boiling water i e two phase pore fluid are correlated spatially with regions of high attenuation not corresponding to low velocities two regions are of particular interest one is underneath the newberry ii drill hole in the central part of the caldera where results from a flow test suggest that two phase fluid conditions existed in the bottom of the hole before the flow test the other region is beneath the west flank of the volcano which has been interpreted as an attractive geothermal prospect because of a shallow conductive anomaly our results are consistent with the suggestion made in an earlier paper by us that two phase geothermal reservoirs can be located within complex three dimensional structures by using jointly interpreted compressional wave velocity and attenuation images

electrical structure of newberry volcano oregon from the interpretation of magnetotelluric transient electromagnetic and schlumberger resistivity soundings the electrical structure of newberry volcano in central oregon is found to consist of four units from the surface downward the geoelectrical units are 1 very resistive young unaltered volcanic rock 2 a conductive layer of older volcanic material composed of altered tuffs 3 a thick resistive layer thought to be in part intrusive rocks and 4 a lower crustal conductor this model is similar to the regional geoelectrical structure found through the cascade range inside the caldera the conductive second layer corresponds to the steep temperature gradient and alteration minerals observed in the usgs newberry 2 test hole drill hole information on the south and north flanks of the volcano test holes ges n 1 and geo n 3 respectively indicates that outside the caldera the conductor is due to alteration minerals primarily smectite and not high temperature pore fluids on the flanks of newberry the conductor is generally deeper than inside the caldera and its deepens with distance from the summit

reconstructing twentieth century sea surface temperature variability in the southwest pacific a replication study using multiple coral sr ca records from new caledonia 1 coral based climate reconstructions typically have not used multiple cores from a region to capture and replicate a climate signal largely because of concerns of coral conservation analytical expense and time constraints coral sr ca reproducibility through the twentieth century was investigated using three intracolony and three intercolony coral records from the reefs offshore of amedee island new caledonia different sampling resolutions were examined in coral sr ca fortnightly and monthly and 18o fortnightly monthly and seasonally as well as similar scale subsampling of the daily in situ sea surface temperature sst record the mean coral sr ca 18o and sst values do not change as a function of sampling resolution the coral sr ca signal is highly reproducible the average absolute offset between coeval monthly sr ca determinations between any two coral time series is 0 035 0 026 mmol mol 1 0 65 c which is less than twice the analytical precision of the coral sr ca measurements the stack average of the monthly coral sr ca variations and monthly anomalies are significantly correlated with monthly in situ sst 1967 1992 r 0 96 and 0 64 respectively p 0 05 and n 302 and 1 grid monthly sst data product 1900 1999 r 0 95 and 0 56 respectively p 0 05 and n 1198 the coral sr ca sst reconstruction exhibits interannual and decadal timescale fluctuations that exceed those observed in the gridded sst record which may reflect true differences between sst at a shallow reef site and those averaged over a 1 grid box or inadequacies in the methodology used to create the gridded sst product when few observations are available a warming trend of 0 6 c is observed in the twentieth century coral sr ca sst record

a stalagmite record of holocene indonesian australian summer monsoon variability from the australian tropics oxygen isotopic data from a suite of calcite and aragonite stalagmites from cave kni 51 located in the eastern kimberley region of tropical western australia represent the first absolute dated high resolution speleothem record of the holocene indonesianeaustralian summer monsoon iasm from the australian tropics stalagmite oxygen isotopic values track monsoon intensity via amount effects in precipitation and reveal a dynamic holocene iasm which strengthened in the early holocene decreased in strength by 4 ka with a further decrease from w2 to 1 ka before strengthening again at 1 ka to years to levels similar to those between 4 and 2 ka the relationships between the kni 51 iasm reconstruction and those from published speleothem time series from flores and borneo in combination with other data sets appear largely inconsistent with changes in the position and or organization of the intertropical convergence zone itcz instead we argue that the el nino southern oscillation enso may have played a dominant role in driving iasm variability since at least the middle holocene given the muted modern monsoon rainfall responses to most el nino events in the kimberley an impact of enso on regional monsoon precipitation over northwestern australia would suggest non stationarity in the long term relationship between enso forcing and iasm rainfall possibly due to changes in the mean state of the tropical pacific over the holocene

coupled north atlantic slope water forcing on gulf of maine temperatures over the past millennium to investigate ocean variability during the last millennium in the western gulf of maine gom we collected a 142 year old living bivalve arctica islandica l in 2004 and three fossil a islandica shells calibrated 14cams 1030 78 ad 1320 45 ad 1357 40 ad for stable isotope and growth increment analysis a statistically significant relationship exists between modern gom temperature records shell isotope derived 30 m r 0 79 p 0 007 prince 5 50 m r 0 72 p 0 019 boothbay harbor sst r 0 76 p 0 011 and labrador current lc transport data from the eastern newfoundland slope during 1993 2003 in all cases as lc transport increased gom water temperatures decreased the following year decadal trends in the north atlantic oscillation nao and the atlantic multidecadal oscillation amo influence gom water temperatures in the most recent period with water temperatures decreasing during nao and amo negative modes most likely linked to lc transport and gulf stream interaction mean shell derived isotopic changes 18oc during the last 1 000 years were 0 47 and likely reflect a 1 2 c cooling from 1000 ad to present based on these results we suggest that observed cooling in the gom during the last millennium was due to increased transport and or cooling of the lc and decreased gulf stream influence on the gom

hydrogeology of karst aquifer systems in sw turkey and an assessment of water quality and contamination problems the aim of this research is to determine the relationship between groundwater flow and water quality of different ground and surface water basins in the southwest turkey in addition groundwater vulnerability is assessed taking into consideration groundwater flow and quality the autochthonous beydaglari limestone is the major karstic aquifer in the region according to the groundwater level map of alluvium aquifers in the basins groundwater discharge toward the carbonate aquifer is direct and indirect the hydrogeological connection between ground and surface water basins occurs via the karstic aquifer located at the bottom of the alluvium bottom in egirdir lake water also discharges in the karstic aquifer via karstic sinkholes at the western border of the lake in the research area general groundwater discharge is toward the mediterranean sea by means of autochthonous carbonate system according to hydrogeological investigations research of lineament and hydraulic conductivities this result is supported by the locations of lineaments and shore springs discharging from the limestone in addition spreading of contaminants via karstic aquifer to great distance has been clearly identified

effects of micromilling on δ18o in biogenic aragonite 1 extraction of small aliquots g mg from aragonite samples such as corals sclerosponges bivalves and otoliths is required for bulk oxygen isotope analyses however aragonite is a metastable polymorph of calcium carbonate that undergoes transformation to calcite which is the more thermodynamically stable polymorph of caco3 this polymorph transformation occurs via heating and or stress and such conditions may occur during drilling during this polymorph transition exchange with atmospheric or organic c and o is possible therefore extracting aliquots during drilling without modification or contamination via isotope exchange is imperative for accurate isotopic analysis using a micromill aliquots were taken from aragonite cod otoliths that had been grown in the laboratory under stable temperature conditions x ray diffraction analysis showed that although 6 of the sample converts to calcite during drilling there is no significant effect on 18o

climate records from a bivalved methuselah arctica islandica mollusca iceland we measured annual shell growth rates of a 374 year old radiometrically confirmed bivalve mollusk specimen of arctica islandica linnaeus this bivalve represents the oldest ever reported individual animal in addition we analyzed 1051 individual powder samples from ontogenetic years two to 40 80 of the entire shell height for isotope analyses oxygen and carbon isotopes exhibit clear intra annual cycles the highest measured carbon isotope values on average 2 73x occurred during summer i e during maximum primary productivity the d 18 oaragonite derived temperature time series cover the period of ad 1496 1533 temperatures calculated from oxygen isotopes ranged from 4 5 to 9 3 8c and exhibit a mean value of 6 2 8c the latter coincides well with the 1854 2003 mean value of 6 81 8c for sea surface temperature between february and september growing season of a islandica neither oxygen nor carbon isotopes exhibit age related unidirectional trends however d 13 caragonite and d 18 oaragonite values fluctuated at decadal periods of four six and eight to nine years nao type periods as well as 12 14 years which may represent teleconnections to cycles in the tropical atlantic annual shell growth is positively correlated to intra annual d 18 oaragonite minima i e warm summer temperatures r 2 0 34 and to intra annual d 13 caragonite minima higher food supply r 2 0 42 using a linear multiregression model 65 of the variation in annual shell growth can be explained by summer temperature and food supply the formation of extremely narrow annual increments coincides with major volcanic eruptions e g tambora 1815 a period of extremely variable growth occurred during the culmination of the little ice age in iceland between ca ad 1550 and 1620 shell growth during ad 1765 1780 however was characterized by very little year to year variability probably as the result of extremely mild climate near the end of the little ice age this study demonstrates that shells of a islandica provide

the chemical and hydrologic structure of poa s volcano costa rica comparison of the chemical characteristics of spring and river water draining the flanks of poa s volcano costa rica indicates that acid chloride sulfate springs of the northwestern flank of the volcano are derived by leakage and mixing of acid brines formed in the summit hydrothermal system with dilute flank groundwater acid chloride sulfate waters of the rio agrio drainage basin on the northwestern flank are the only waters on poa s that are affected by leakage of acid brines from the summit hydrothermal system acid sulfate waters found on the northwestern flank are produced by the interaction of surface and shallow groundwater with dry and wet acid deposition of so2 and h2so4 aerosols respectively the acid deposition is caused by a plume of acid gases that is released by a shallow magma body located beneath the active crater of poa s no evidence for a deep reservoir of neutral ph sodium chloride brine is found at poa s the lack of discharge of sodium chloride waters at poa s is attributed to two factors 1 the presence of a relatively volatile rich magma body degassing at shallow depths 1 km into a high level summit groundwater system and 2 the hydrologic structure of the volcano in which high rates of recharge combine with rapid lateral flow of shallow groundwater to prevent deep seated sodium chloride fluids from ascending to the surface the shallow depth of the volatile rich magma results in the degassing of large quantities of so2 and hcl these gases are readily hydrolyzed and quickly mix with meteoric water to form a reservoir of acid chloride sulfate brine in the summit hydrothermal system high recharge rates and steep hydraulic gradients associated with elevated topographic features of the summit region promote lateral flow of acid brines generated in the summit hydrothermal system however the same high recharge rates and steep hydraulic gradients prevent lateral flow of deep seated fluids thereby masking the presence of any sodium chloride brines that may exist in deeper parts of the volcanic edifice structural stratigraphic and topographic features of poa s volcano are critical in restricting flow of acid brines to the northwestern flank of the volcano a permeable lava lahar sequence that outcrops in the rio agrio drainage basin forms a hydraulic conduit between the crater lake and acid chloride sulfate springs spring water residence times are estimated from tritium data and indicate that flow of acid brines from the active crater to the rio agrio source springs is relatively rapid 3 to 17 years hydraulic conductivity values of the lava lahar sequence calculated from residence time estimates range from 10 5 to 10 7 m s these values are consistent with hydraulic conductivity values determined by aquifer tests of fractured and porous lava pyroclastic sequences at the base of the northwestern flank of the volcano fluxes of dissolved rock forming elements in rio agrio indicate that approximately 4300 and 1650 m3 of rock are removed annually from the northwest flank aquifer and the active crater hydrothermal system respectively over the lifetime of the hydrothermal system 100 s to 1000 s of years significant increases in aquifer porosity and permeability should occur in marked contrast to the reduction in permeability that often accompanies hydrothermal alteration in less acidic systems average fluxes of fluoride chloride and sulfur calculated from discharge and compositional data collected in the rio agrio drainage basin over the period 1988 1990 are approximately 2 38 and 30 metric tons day these fluxes should be representative of minimum volatile release rates at poa s in the last 10 to 20 years

gravity and magnetic studies of the subglacial grimsvotn volcano iceland implications for crustal and thermal structure the highly active subglacial grimsvotn volcano is associated with a 20 mgal bouguer gravity high and a broad magnetic low the magnetic low roughly coincides with the gravity high but short wavelength magnetic highs are superimposed on the low especially along caldera rims forward models of the gravity and magnetic fields show variable magnetization 0 12 a m 1 in the uppermost 1 2 km of the crust probably reflecting differences in the proportions of crystalline rocks and hyaloclastites and variations in hydrothermal alteration the models are consistent with but do not require a 10 km3 molten magma chamber in the shallow crust beneath the main caldera between 1 5 and 4 km depth a dense body 2 95 3 0 mg m 3 with a volume of 400 km3 is located probably composed of gabbro modeling suggests that this intrusive body is nonmagnetic which may imply that its temperature is at or above the curie point the distribution of geothermal activity at the glacier bed is consistent with heat extraction from this dense hot intrusive body it may be an important source for the presently observed geothermal heat output of 2000 4000 mw at grimsvotn this high heat transfer rate is difficult to reconcile with estimates of long term heat production in an icelandic rift zone volcano the heat flux may be a transient phenomenon caused by enhanced vertical permeability due to a recent caldera collapse and subsequent heat mining of the intrusive body

three dimensional p velocity structure of the crust below newberry volcano oregon utilizing teleseismic p residuals we have detected a column of high p velocity material extending from within 10 km of the surface below the summit of newberry volcano oregon to midcrustal depths near 25 km we interpret this column to be the expression of a swarm of predominantly subsolidus gabbroic sills and dikes which were intruded as the volcano was built the high p velocities observed below the volcano severely limit the size of magma chambers which could presently exist in the crust below newberry volcano those possible include a few percent of partial melt distributed through large volumes of a mafic intrusion zone in the midcrust a few smaller higher melt fraction zones in the midcrust with dimensions less than 6 km and whose aggregate volume is only a few percent of enclosing volumes of 200 km sup 3 small magma bodies with dimensions of a few kilometers located within the upper 10 km of the crust or a mafic crystal rich magma of arbitrary dimensions located in the upper few km the low p velocities detected in the upper 4 km beneath the center of the summit caldera may be partially caused by a magma chamber in the second ofmore these catagories less

aeromagnetic mapping of the structure of pine canyon caldera and chisos mountains intrusion big bend national park texas analysis of aeromagnetic and gravity data reveals new details of the structure igneous geology and temporal evolution of the prominent enigmatic ca 32 ma pine canyon caldera and the chisos mountains big bend national park texas the main caldera fi lling pine canyon rhyolite the oldest member of the south rim formation is reversely magnetized allowing it to be used as a key marker bed for determining caldera fi ll thickness modeling of gravity and magnetic anomalies indicates that the pine canyon rhyolite is probably thicker in the northeastern part of the caldera lineaments in the magnetic data suggest the presence of buried faults beneath the caldera that may have led to increased downdrop in the northeast versus the southwest allowing a thicker section of caldera fi ll to accumulate there the pine canyon caldera has been interpreted as a downsag caldera because it lacks surfi cial faulting so these inferred faults are the fi rst mapped features there that could be responsible for caldera collapse the caldera boundary correlates well with the margins of a gravity low general features of the caldera match well with basic models of downsag calderas meaning that the pine canyon caldera may be a classic example of downsagging of which few well described examples exist in terms of a geophysical signature the source of a long wavelength magnetic high over the chisos mountains is interpreted as a previously unknown broad intrusion the long axis of which trends parallel to a major crustal boundary related to the ouachita orogeny or an even earlier precambrian margin this feature represents the largest intrusion 28 34 km diameter 1 4 km thick 700 3000 km 3 in volume in an area where relatively small laccoliths are ubiquitous the intrusion most likely represents a long lived 1 m y reservoir replenished by small batches of magma of varying composition as refl ected in the variation of eruptive products from the pine canyon and sierra quemada calderas the intrusion may represent the easternmost occurrence of voluminous tertiary magmatism in the southwestern united states

hydrogeological investigation of antalya basin concerning the future domestic water needs of antalya city turkey a hydrogeological study has been carried out in antalya travertine basin for the future domestic water supply of antalya geological formations that could be used as an aquifer have been identified and a hydrogeological map has been prepared water quality analyses show that groundwater has been and is being contaminated by sewage discharge industrial works and other activities that create an ever expending impact to the only available aquifer something should be done immediately to protect the aquifer from additional degradation

isotopic behavior during the aragonite calcite transition implications for sample preparation and proxy interpretation abstract at the earth s surface aragonite a polymorph of calcium carbonate is thermodynamically unstable and readily converts to calcite a process accelerated by heating and mechanical stress this study has investigated the behavior of the 13 c 12 c 18 o 16 o ratios and the clumped isotope temperature proxy 47 during this mineral transition aragonite samples were partially or completely converted to calcite in an oven normal atmospheric composition and pressure or in a sealed tube in the presence of a vacuum or pure co 2 of varying isotopic compositions other samples were converted from aragonite to calcite using a drill these experiments demonstrate a relationship between the 13 c and 18 o values and percent transition from aragonite to calcite the 47 value of the aragonite changed independently from the mineral transition at temperatures as low as 125 c and was accompanied by a 0 5 decrease in the 18 o value this change occurred irrespective of the presence of co 2 suggesting that water trapped in the mineral may facilitate some of this alteration results show that sampling techniques such as drilling produce sufficient heat to convert aragonite to calcite and can considerably alter 47 even small degrees of conversion 10 can increase clumped isotope derived paleotemperature estimates by nearly 10 c

a new hydrogeologically based approach to determining protected areas in drinking water supply reservoirs a case study in the aglasun sub basin burdur turkey this study covers the hydrogeologically based works taking place in the drinking water reservoir drainage basin in the aglasun sub basin to ensure water quality the geological units in the aglasun sub basin are grouped under two units as allochthonous and autochthonous autochthonous units are composed of erenler limestone yazir formation inside reef limestone the aglasun formation seen as flysch and alluvium allochthonous units are composed of akdag limestone and ophiolitic complex autochthonous positioned limestones with their dissolution cavities are classified as karstic aquifers there is no hydraulic relationship between autochthonous positioned limestones and drinking water reservoir allochthonous positioned limestones are classified as karstic aquifers having large number of spring discharges in the studied basin a groundwater vulnerability map has been prepared which is an effective tool in determining the water resource protection areas the drastic method was used when preparing the groundwater vulnerability map the groundwater depth net recharge aquifer type soil media topography vadose zone effect and hydraulic conductivity parameters were used to form thematic maps and were evaluated with the help of arcgis technology the most sensitive areas to groundwater are distinctively the areas covered with alluvium and allochthonous limestone springs discharging from these sensitive areas recharge the stream that connects to the reservoir it is therefore understood that the traditional protection areas determined after the maximum water level are inadequate in protecting the water quality in a drinking water basin in addition to existing protection zones this study suggests hydrogeologically based new protection areas which also include streams flowing into the reservoir

impact of skeletal dissolution and secondary aragonite on trace element and isotopic climate proxies in porites corals restricted zones of recent dissolution and secondary aragonite infilling were identified in a coral core collected in 1986 from a living massive porites colony from the central great barrier reef australia secondary aragonite needles 20 m long cover skeletal surfaces deposited from 1972 to late 1974 and increase bulk density by 10 dissolution is observed above this zone whereas older skeleton is pristine we investigate the impact of both types of early marine diagenesis on skeletal geochemistry and coral paleoclimate reconstructions by comparison with similar records from eight contemporary porites colonies collected at nearby reefs secondary aragonite overgrowth causes anomalies in skeletal density mg ca sr ca u ca o and c the secondary aragonite is consistently associated with a cool temperature anomaly for each of the sea surface temperature sst proxies o sst 1 6 c sr ca sst 1 7 c mg ca sst 1 9 c u ca sst 2 8 c dissolution through incongruent leaching also causes cool sst artifacts but only for trace element ratios mg ca sst 1 2 c sr ca sst 1 2 c u ca sst 2 1 c the sequence of preference with respect to dissolution of coral skeleton in seawater is mg ca sr u rigorous screening of coral material for paleoclimate reconstructions is therefore necessary to detect both dissolution and the presence of secondary minerals the excellent agreement between apparent sst anomalies generated by different modes of diagenesis means that replication of tracers within a single coral cannot be used to validate climate proxy interpretations poor replication of records between different coral colonies however provides a strong indication of nonclimatic artifacts such as dissolution and secondary aragonite copyright 2007 by the american geophysical union

oxygen isotopic composition of carbonate in the nakhla meteorite implications for the hydrosphere and atmosphere of mars abstract we have located small areas of siderite within the mesostasis of the nakhla meteorite high concentrations of mn up to 50 rhodochrosite and elevated d h ratios indicate that the siderite is not a terrestrial alteration product the isotopic composition of oxygen in the siderite has been determined with the manchester isolab 54 ion microprobe the siderite has 18 o 34 1 which is higher than any other martian carbonate yet reported if the 18 o value is the result of equilibration with water at 2 h 2 o produced during the degassing of mars and not modified subsequently isotopically formation from a water rich fluid at 60 c requires that the fluid was heavy isotope enriched relative to fluids produced during planetary degassing an enrichment of 8 15 is consistent with theoretical outgassing models that are able to account for enhancements of 17 o in martian alteration products estimated deposition temperatures would be raised to 80 170 c the effect of a global scale fixation of martian co 2 as carbonate operates in the opposite direction and could lead to a reduction in 18 o of the martian hydrosphere of a few permil

unexpected isotopic variability in biogenic aragonite a user issue or proxy problem abstract the present study seeks to investigate sources of isotopic variability in the commonly used paleoclimate archive the marine bivalve arctica islandica with an emphasis on the potential of human induced variability arising from sampling techniques stable carbon 13ccarbonate and oxygen 18ocarbonate isotopes were analyzed for split intra sample and replicate intra and inter shell samples taken from a group of laboratory reared individuals a natural population from northern norway and a natural population from the gulf of maine usa compared to analytical uncertainty of 0 17 and 0 30 for 13c and 18o respectively among the natural populations the mean difference between shell splits and shell replicates ranged from 0 12 and 0 33 for 13c and 18o respectively our data suggest that heterogeneity of the carbonate material i e large range of isotopic composition within one sample due to seasonal environmental variability may contribute to unexpected variability more than human induced error from sampling imprecision when collecting whole annual increments furthermore 13c from juvenile shells were highly variable 2 standard deviation 0 65 approximately four times more variable than analytical precision high precision among 18o measurements of the laboratory reared shells confirm the presumption that shells reliably and consistently precipitate in isotopic equilibrium with ambient seawater monte carlo simulations of measurements from this population allowed characterization of improvements in uncertainty at increasing levels of replication substantial reduction in uncertainty occurs when increasing from two to three shells however replication using a total of four shells further decreased uncertainty to within the 99 confidence level published studies sometimes compensate for uncertainties by replicating records over multiple individuals or multiple transects within the one individual oftentimes however isotope records are constructed from single individuals or transects and therefore fail to provide thorough estimates of proxy error our findings suggest that replication of carbon and oxygen isotope measurements of contemporaneously produced aragonite is necessary in order to reduce proxy derived noise furthermore population specific estimates of uncertainty related to natural variability among individuals should be investigated in order to provide more realistic representations of proxy noise when reporting isotope time series

modelling hydrostratigraphy and groundwater flow of a fractured and karst aquifer in a mediterranean basin salento peninsula southeastern italy the control exerted by the hydrostratigraphic structure on aquifer recharge groundwater flow and discharge along the coastal areas of a mediterranean basin salento peninsula about 5 000 km2 wide southern italy is assessed through the development and application of a groundwater flow model based on the reconstruction of the hydrostratigraphic architecture at the regional scale the hydrostratigraphic model obtained by processing surface and subsurface data is applied to map the top of the main aquifer which is hosted in the deep hydrostratigraphic unit corresponding to cretaceous and oligocene limestones with complex geometrical relationships with the sea it is also used to estimate the aquifer recharge which occurs by percolation through overlying younger sediments with low permeability these data are completed with information about the soil use to estimate water abstraction for irrigation and with literature data to estimate the water abstraction for drinking and industrial purposes the above sketched conceptual model is the basis for a finite difference groundwater 2d pseudo stationary flow model which assumes the following fundamental approximations the fractured and karst limestone hydrostratigraphic unit can be approximated at the model scale as a continuous medium for which the discrete darcy s law is valid the transition zone between salt and fresh water is so small with respect to the grid spacing that the ghyben herzberg s approximation for a sharp interface can be applied along the coastline different boundary conditions are assigned if the top of the limestone hydrostratigraphic unit lies either above the sea level the aquifer has a free surface and fresh water is drained or below the sea level the aquifer is under pressure and the contact with sea occurs off shore the groundwater flow model correctly predicts the areas where the aquifer is fully saturated with salt water

separation of groundwater flow components in a karstified aquifer using environmental tracers abstract groundwater discharges from the intensively karstified taurus mountains to the mediterranean sea either along the contact zone between the mountains and the travertine plateau the kirkgozler springs 15 m3 s or through the travertine e g the dudenbasi spring 18 m3 s and underneath it unnamed submarine springs unknown discharges in an attempt to identify the hydraulic connections between the various outlet points groundwater was analyzed for stable and radioactive isotopes cfcs and he the upgradient springs belonging to the kirkgozler dudenbasi system were proven to be a mixture of recent and older water on the basis of their low 14c values 12 22 4 pmc their exceptionally high he content 429 991 cc kg and 3he 4he r ra ratios 1 471 2 602 and their measurable 3h and cfc contents 1 9 5 9 tu and 0 84 to 3 27 pmoles kg respectively the older component probably contains an even lower amount of modern c however the undersaturation of the mixture with respect to calcite its high co2 content up to 83 mg l and its enriched 13c values 2 2 to 4 1 suggest intensive water rock interactions which would contribute 14c devoid bicarbonates to the solution downgradient springs discharging along the mediterranean coast contain groundwater contributions from higher altitudes as evidenced by their depleted 18o and d composition with respect to the local precipitation however a larger portion of the recent water component could be contributed from direct precipitation on the travertine this larger component is reflected in the increased 3h 3 4 to 8 4 tu and 14c 32 7 63 6 pmc contents atmospheric he 43 82 pmoles kg r ra values 1 006 1 198 and cfc contamination of the water

assessing the reproducibility and reliability of estuarine bivalve shells saxidomus giganteus for sea surface temperature reconstruction implications for paleoclimate studies studies using oxygen isotopes y 18 o of mollusk shells to determine paleotemperature need to assume water y 18 o values which could severely influence calculated temperatures we analyzed aragonitic shells of the butter clam saxidomus giganteus deshayes 1839 to determine the reproducibility of the isotopic signal between individuals and to assess how precisely temperature could be calculated given known salinity and temperature furthermore carbon isotopes are also investigated as an environmental proxy the abundance of well preserved s giganteus shells in archeological and geological deposits in northwestern north america makes them a particularly suitable species for paleoclimate studies seasonally resolved stable oxygen isotope profiles in three s giganteus shells collected from the same site in puget sound washington usa were well correlated 0 77br 2 b0 87 although there were differences up to 0 58x in high resolution y 18 o profiles of the three shells the difference between the average y 18 o of each shell was less than half of this 0 19x and half of what has been reported for between colony coral variability y 13 c profiles on the other hand were more complex with shell y 13 c being about 2 5x lower than expected equilibrium values however this roughly conforms to the idea that about 10 of the shell carbon originates from metabolic co2 both y 18 o and y 13 c indicate that s giganteus do not grow during periods of reduced salinity despite the excellent reproducibility of y 18 o between shells and the fact that salinity effects were duly considered calculated temperature still differed from instrumental temperature applying different salinity y 18 o water relationships to average shell y 18 o and considering salinity from the shell collection site and a nearby offshore station resulted in calculated average water temperatures ranging from 1 7 to 6 4 8c warmer than measured although we could not determine if s giganteus precipitate their shells in isotopic equilibrium we believe that the difficulty in predicting temperature arose from not being able to accurately determine

calc silicate mineralization in active geothermal systems detailed study of the calc silicate mineralogy in the cerro prieto geothermal system was used to demonstrate examples for thermodynamic evaluation of phase relations among minerals of variable composition and to calculate the chemical characteristics of hydrothermal solutions compatible with the observed calc silicate assemblages in general there is a close correlation between calculated and observed fluid compositions calculated fugacities of o 2 at about 320 degrees c in the cerro prieto geothermal system are about five orders of magnitude less than those at the nearby salton sea geothermal system this observation is consistent with the occurrence of fe super 3 rich epidotes and andradite garnets in the latter system and the presence of prehnite at cerro prieto modified journal abstract

geologic evidence for a magma chamber beneath newberry volcano oregon at newberry volcano central oregon more than 0 5 m y of magmatic activity including caldera collapse and renewed caldera filling volcanism has created a structural and thermal chimney that channels magma ascent holocene rhyolitic eruptions 1 have been confined mainly within the caldera in an area 5 km in diameter 2 have been very similar in chemical composition phenocryst mineralogy and eruptive style and 3 have occurred as recently as 1300 years ago with repose periods of 2000 3000 years between eruptions holocene basaltic andesite eruptions are widespread on the flanks but are excluded from the area of rhyolitic volcanism basaltic andesite in fissures at the edge of the rhyolite area has silicic inclusions and shows mixed basalt rhyolite magma relations these geologic relations and the high geothermal gradient that characterizes the lower part of a drill hole in the caldera u s geological survey newberry 2 indicate that a rhyolitic magma chamber has existed beneath the caldera throughout the holocene its longevity probably is a result of intermittent underplating by basaltic magma

the long lived mollusc arctica islandica a new paleoceanographic tool for the reconstruction of bottom temperatures for the continental shelves of the northern north atlantic ocean the carbonate shell of the bivalve arctica islandica has been recognized for more than a decade as a potentially important marine geochemical biorecorder owing to this species great longevity 200 years and wide geographic distribution throughout the northern north atlantic ocean a region vital to global climate and ocean circulation however until now this potential has not been realized owing to the difficulty of precisely sampling the shell of this slow growing species using newly available automated microsampling techniques combined with micromass stable isotope mass spectrometry a stable oxygen isotope record 1956 1957 and 1961 1970 has been obtained from a live captured 38 year old a islandica specimen collected near the former position of the nantucket shoals lightship 41 n 69 w the shell s 18o signal is compared with an expected signal derived from ambient bottom temperature and salinity data recorded at the lightship for the same period the results show that a islandica s 18o record 1 is in phase with its growth banding confirming the annual periodicity of this species growth bands 2 is in oxygen isotopic equilibrium with the ambient seawater 3 shows a consistent shell growth shutdown temperature of 6 c which translates into an 8 month may december shell growth period at this location and 4 records the ambient bottom temperature with a precision of 1 2 c these results add important information on the life history of this commercially important shellfish species and demonstrate that a islandica shells can be used to reconstruct inter and intra annual records of the continental shelf bottom temperature

strontium magnesium and barium incorporation in aragonitic shells of juvenile arctica islandica insights from temperature controlled experiments abstract in order to constrain spatial and temporal temperatures and environmental conditions in the north atlantic ocean during the holocene high resolution seasonal to annual marine proxies with excellent chronological constraints are needed the long lived ocean quahog arctica islandica which has the potential to provide a precise annually dated record via crossdating techniques is a fairly well developed and tested marine proxy archive in particular oxygen isotopes derived from a islandica shell carbonate have provided a wealth of information on marine climate and ocean circulation dynamics however shell derived oxygen isotopes are influenced by both the isotopic source water signature covarying with salinity and seawater temperature if seawater isotopic signature is not known temperature reconstructions become challenging thus an independent technique to estimate past seawater temperatures is highly desired however based on previous studies on adult and juvenile clams the utility of elemental ratios in a islandica shell material as environmental proxies remains questionable to further evaluate the influence of seawater temperature on elemental and isotopic incorporation during biomineralization a islandica shells were grown at constant temperatures under two regimes during a 16 week period from march 27 to july 21 2011 at the darling marine center in walpole maine individual juvenile clams were stained with calcein and cultured at 10 30 0 30 c for six weeks after this the clams were again stained with calcein and cultured at 15 00 0 40 c for an additional 9 5 weeks average salinity values were 30 20 0 70 and 30 70 0 70 in the first and second phases of the experiment respectively continuous sampling within and across the temperature conditions from 10 30 c to 15 00 c coupled with the calcein markings provided the ability to place each sample into a precise temporal framework and to establish exact average growth rates for the shells sampled after accounting for changes in the isotopic composition of seawater oxygen isotopes from one sampled shell effectively recorded seawater temperatures during the study and also gave confidence to the temporal fit of the data elemental ratios sr ca mg ca ba ca from five aragonitic shells were determined via laser ablation inductively coupled plasma mass spectrometry sr ca and mg ca data showed little coherence with temperature during the culture experiment including the rapid 5 c increase in seawater temperature however ba ca ratios showed an inverse relationship with seawater temperatures although this relationship was noisy additionally salinity interactions were present during the 15 00 c treatment further highlighting complex incorporation of elements during biomineralization incorporation of sr mg and ba were strongly and variably impacted by growth rates combined the results from these culture experiments demonstrate that sr ca mg ca ba ca ratios in juvenile a islandica shell material are dominated by physiological processes and thus not reliable as environmental proxies

high resolution seismic tomography of compressional wave velocity structure at newberry volcano oregon cascade range compressional wave velocity structure is determined for the upper crust beneath newberry volcano central oregon using a high resolution active source seismic tomography method newberry volcano is a bimodal shield volcano east of the axis of the cascade range it is associated both with the cascade range and with northwest migrating silicic volcanism in southeast oregon high frequency 7 hz crustal phases nominally pg and a midcrustal reflected phase travel upward through a target volume beneath newberry volcano to a dense array of 120 seismographs this arrangement is limited by station spacing to 1 to 2 km resolution in the upper 5 to 6 km of the crust beneath the volcano s summit caldera the experiment tests the hypothesis that cascade range volcanoes are underlain only by small magma chambers a small low velocity anomaly delineated about 3 km below the summit caldera supports this hypothesis for newberry volcano and is interpreted as a possible magma chamber of a few to a few tens of km3 in volume a ring shaped high velocity anomaly nearer the surface coincides with the inner mapped ring fractures of the caldera it also coincides with a circular gravity high and we interpret it as largely subsolidus silicic cone sheets the presence of this anomaly and of silicic vents along the ring fractures suggests that the fractures are a likely eruption path between the small magma chamber and the surface

the influence of karst features on environmental studies in turkey the carbonate rocks of turkey which underlie about one third of the country possess major water resources with great potential for electricity generation and water supplies the ongoing development of karst features especially in the southern part of turkey demonstrates specific environmental problems that occur in many karst water supply projects karst aquifers springs sinkholes dolines poljes and other karst features are of great importance from the standpoint of karst water resources and environmental research studies in karst regions conservation and protection of groundwater resources for both qualitative and quantitative evaluations is possible only when the catchment area is determined accurately since the catchment area in karst terrains is not limited by the surface drainage boundaries and the groundwater flows through well developed coduits or fissures the equations used in non karstic areas cannot be applied to such karstic regions studies on the development of karst features and its environmental impacts in turkey are of recent origin therefore many unreliable methods are being applied in karstic areas for example the use of shallow holes or sinkholes and fault zones for septic water waste disposal or as sewage by those who are not familiar with karst sometimes causes very serious problems of extensive groundwater pollution this paper discusses the development of different karstic features in turkey and case studies on its environmental impacts

linking large scale climate variability with arctica islandica shell growth and geochemistry in northern norway the lack of high resolution geographically diverse proxy records from the marine realm limits our understanding of climate dynamics in the north atlantic ocean and arctic during recent centuries we investigate the impact of large scale climate variability on the marine bivalve arctica islandica linnaeus 1767 from northern norway 71 n we evaluate the use of annual shell growth and geochemical records as proxies for north atlantic and arctic climate variability over centennial scales by developing a continuous 113 yr master shell growth chronology and an oxygen isotope record 18o from live caught shell material a relatively strong inverse relationship is observed between both the shell growth and isotopic proxies and large scale north atlantic sea surface temperatures in modern times r 0 54 to 0 90 p 0 05 this relationship is strengthened when using a combined shell growth oxygen isotope multiproxy index r 0 72 to 0 90 p 0 01 the regional spatial pattern of correlation resembles that of the north atlantic current as it bifurcates around 55 n indicating that large scale ocean surface current dynamics play an important role in regulating local ecosystem processes and thus shell growth in northern norway a combined proxy index created using multiple linear regression exhibits a relatively strong and time stable relationship with the atlantic multidecadal oscillation amo r 0 622 p 0 001 since ad 1900 variability in the relationship between the shell based records and the north atlantic oscillation coincide with variations in the amo index suggesting a complex relationship between atmospheric forcing on hydrographic variability and ecosystem dynamics in northern norway

isotope geochemistry of minerals and fluids from newberry volcano oregon isotopic compositions were determined for hydrothermal quartz calcite and siderite from core samples of the newberry 2 drill hole oregon the 15o values for these minerals decrease with increasing temperatures the values indicate that these hydrothermal minerals precipitated in isotopic equilibrium with water currently present in the reservoirs the 18o values of quartz and calcite from the andesite and basalt flows 700 932 m have isotopic values which require that the equilibrated water 18o values increase slightly 11 3 to 9 2 with increasing measured temperatures 150 265 c the lithic tuffs and brecciated lava flows 300 700 m contain widespread siderite calculated oxygen isotopic compositions of waters in equilibrium with siderite generally increase with increasing temperatures 76 100 c the 18o values of siderite probably result from precipitation in water produced by mixing various amounts of the deep hydrothermal water 10 5 with meteoric water 15 5 recharged within the caldera the 13c values of calcite and siderite decrease with increasing temperatures and show that these minerals precipitated in isotopic equilibrium with co2 of about 8 the 18o values of weakly altered 5 alteration of plagioclase whole rock samples decrease with increasing temperatures above 100 c indicating that exchange between water and rock is kinetically controlled the water rock mass ratios decrease with decreasing temperatures the 18o values of rocks from the bottom of newberry 2 show about 40 isotopic exchange with the reservoir water the calculated 18o and d values of bottom hole water determined from the fluid produced during the 20 hour flow test are 10 2 and 109 respectively the d value of the hydrothermal water indicates recharge from outside the caldera

assessment of geochemical processes in the unconfined and confined aquifers in the eastern ganges basin a geochemical approach groundwater quality is gaining more importance in groundwater management due to rapid growth in population agriculture and industrial sectors worldwide the goal of the present study is to evaluate the groundwater chemistry and to identify the geochemical processes governing the water chemistry in the shallow unconfined and deeper confined aquifers in the eastern ganges basin using geochemical methods groundwater samples were analysed for major ions and metals fe mn zn cu pb and as shallow wells are found to have high ph ec tds ca mg cl and so4 and low hco3 cl ratio compared to the deep wells however the average concentration of na hco3 no3 po4 f and mn is not significantly varied with depth which indicates that the variation in the water chemistry between unconfined and confined aquifers is not only due to the natural processes but also indicates that surface contamination sources could have affected the water chemistry in the unconfined aquifer in the unconfined aquifer processes like wastewater infiltration denitrification reverse ion exchange and mineral weathering govern the water chemistry the water chemistry in the confined aquifer is regulated by weathering of silicate and carbonate minerals and regional flow

biological and climate controls on north atlantic marine carbon dynamics over the last millennium insights from an absolutely dated shell based record from the north icelandic shelf given the rapid increase in atmospheric carbon dioxide concentrations pco2 over the industrial era there is a pressing need to construct long term records of natural carbon cycling prior to this perturbation and to develop a more robust understanding of the role the oceans play in the sequestration of atmospheric carbon here we reconstruct the past biological and climate controls on the carbon isotopic 13cshell composition of the north icelandic shelf waters over the last millennium derived from the shells of the long lived marine bivalve mollusk arctica islandica variability in the annually resolved 13cshell record is dominated by multidecadal variability with a negative trend 0 003 0 002 yr 1 over the industrial era 1800 2000 common era this trend is consistent with the marine suess effect brought about by the sequestration of isotopically light carbon 13c of co2 derived from the burning of fossil fuels comparison of the 13cshell record with contemporaneous proxy archives over the last millennium and instrumental data over the twentieth century highlights that both biological primary production and physical environmental factors such as relative shifts in the proportion of subpolar mode waters and arctic intermediate waters entrained onto the north icelandic shelf atmospheric circulation patterns associated with the winter north atlantic oscillation and sea surface temperature and salinity of the subpolar gyre are the likely mechanisms that contribute to natural variations in seawater 13c variability on the north icelandic shelf contrasting 13c fractionation processes associated with these biological and physical mechanisms likely cause the attenuated marine suess effect signal at this locality

gravity model studies of newberry volcano oregon newberry volcano a large quaternary volcano located about 60 km east of the axis of the high cascades volcanoes in central oregon has a coincident positive residual gravity anomaly of about 12 mgals model calculations of the gravity anomaly field suggest that the volcano is underlain by an intrusive complex of mafic composition of about 20 km diameter and 2 km thickness at depths above 4 km below sea level however uplifted basement in a northwest trending ridge may form part of the underlying excess mass thus reducing the volume of the subvolcanic intrusive a ring dike of mafic composition is inferred to intrude to near surface levels along the caldera ring fractures and low density fill of the caldera floor probably has a thickness of 0 7 0 9 km the gravity anomaly attributable to the volcano is reduced to the east across a north northwest trending gravity anomaly gradient through newberry caldera and suggests that normal perhaps extensional faulting has occurred subsequent to caldera formation and may have controlled the location of some late stage basaltic and rhyolitic eruptions significant amounts of felsic intrusive material may exist above the mafic intrusive zone but cannot be resolved by the gravity data

long term stability of δ13c with respect to biological age in the aragonite shell of mature specimens of the bivalve mollusk arctica islandica the stable carbon isotope ratio in bivalve shells 13cs is an enigmatic geochemical archive whose interpretation is often frustrated by the intrusion of variable and unpredictable vital effects which can influence the mix of metabolic and dissolved inorganic carbon dic in the shell material the impacts of vital effects and rapid changes in calcification rates on the variability and value of 13cs have been described in a number of studies and in many bivalve species with typical lifespans between a few years and a few decades 13cs has been observed to change usually decreasing with biological age very long lived animals by contrast spend most of their lives in the mature slow growing phase and it might be expected that in these instances the effect of changes in calcification rates on 13cs would be less marked or even absent analysis of 13cs in mature 40years old arctica islandica reported here indicates that this is the case 13cs in shell samples with biological ages between 42 and 391 years from four distinct sites in the north atlantic shelf seas gulf of maine north icelandic shelf irish sea and north sea shows no age related trend this suggests that metabolic vital effects in mature a islandica may be reasonably stable at the population level if the drivers of isotopic disequilibrium between shell and ambient environment can be identified and quantified it may be feasible to adjust for them and use 13cs in mature a islandica to investigate long term changes in nutrient sources and as a robust proxy for 13c of environmental dic

experimental evidence of resistivity frequency dispersion in magnetotellurics in the newberry oregon snake river plain idaho and campi flegrei italy volcano geothermal areas abstract we show that magnetotelluric measurements carried out in volcano geothermal areas can be significantly affected by the resistivity frequency dispersion phenomenon the polarization effects are recognized by comparing magnetotelluric and dc geoelectrical deep soundings performed in the same station indeed the conventional separate analysis of the two data sets sometimes gives unconformable results especially as it regards the resistivity and thickness of the conductive layers ascribable to the geothermal fluid filled rocks these apparent discrepancies can be overcome by admitting the occurrence of intense induced polarization effects inside the rocks having extensive alterations due to hydrothermal paragenesis the basic theory of the induced polarization effects over magnetotelluric measurements is at first briefly recalled then three impressive field examples taken from previous experiments performed in the newberry volcano snake river plain and campi flegrei geothermal areas are presented and discussed

upper crustal structure of newberry volcano from p wave tomography and finite difference waveform modeling 1 seismic tomography combined with waveform modeling constrains the dimensions and melt content of a magma body in the upper crust at newberry volcano we obtain a p wave tomographic image by combining travel time data collected in 2008 on a line of densely spaced seismometers with active source data collected in the 1980s the tomographic analysis resolves a high velocity intrusive ring complex surrounding a low velocity caldera fill zone at depths above 3 km and a broader high velocity intrusive complex surrounding a central low velocity anomaly at greater depths 3 6 km this second upper crustal low velocity anomaly is poorly resolved and resolution tests indicate that an unrealistically large low velocity body representing 60 km3of melt could be consistent with the available travel times the 2008 data exhibit low amplitude first arrivals and an anomalous secondary p wave phase originating beneath the caldera two dimensional finite difference waveform modeling through the tomographic velocity model does not reproduce these observations to reproduce these phases we predict waveforms for models that include synthetic low velocity bodies and test possible magma chamber geometries and properties three classes of models produce a transmittedp phase consistent with the travel time and amplitude of the observed secondary phase and also match the observed lower amplitude first arrivals these models represent a graded mush region a crystal suspension region and a melt sill above a thin mush region the three possible magma chamber models comprise a much narrower range of melt volumes 1 6 8 0 km3 than could be constrained by travel time tomography alone

overview of the structure and geothermal potential of newberry volcano oregon evidence from a broad range of geological and geophysical investigations of newberry volcano in centeral oregon suggests the presence of a small magma body beneath the summit caldera drilling has encountered temperatures indicative of a hydrothermal system above the hypothesized magma body on the basis of hydrothermal mineralogy the temperature of the hydrothermal system is at or near its maximum value indicating that the hydrothermal system is young basaltic underplating is postulated to replenish the magma body the results of interdisciplinary studies at newberry volcano document that young silicic volcanism in the cascade range can have geothermal potential these results should be applied with caution to the rest of the cascade range because of the strong influence of basin and range extensional tectonics on newberry volcano s style of volcanism

an aquaculture based method for calibrated bivalve isotope paleothermometry to quantify species specific relationships between bivalve carbonate isotope geochemistry 18oc and water conditions temperature and salinity related to water isotopic composition 18ow an aquaculture based methodology was developed and applied to mytilus edulis blue mussel the four by three factorial design consisted of four circulating temperature baths 7 11 15 and 19 c and three salinity ranges 23 28 and 32 parts per thousand ppt monitored for 18ow weekly in mid july of 2003 4800 juvenile mussels were collected in salt bay damariscotta maine and were placed in each configuration the size distribution of harvested mussels based on 105 specimens ranged from 10 9 mm to 29 5 mm with a mean size of 19 8 mm the mussels were grown in controlled conditions for up to 8 5 months and a paleotemperature relationship based on juvenile m edulis from maine was developed from animals harvested at months 4 5 and 8 5 this relationship t c 16 19 0 14 4 69 0 21 18oc vpbd 18ow vsmow 0 17 0 13 18oc vpbd 18ow vsmow 2 r2 0 99 n 105 p 0 0001 is nearly identical to the kim and o neil 1997 abiogenic calcite equation over the entire temperature range 7 19 c and it closely resembles the commonly used paleotemperature equations of epstein et al 1953 and horibe and oba 1972 further the comparison of the m edulis paleotemperature equation with the kim and o neil 1997 equilibrium based equation indicates that m edulis specimens used in this study precipitated their shell in isotopic equilibrium with ambient water within the experimental uncertainties of both studies the aquaculture based methodology described here allows similar species specific isotope paleothermometer calibrations to be performed with other bivalve species and thus provides improved quantitative paleoenvironmental reconstructions

role of an impermeable layer in controlling groundwater chemistry in a basaltic aquifer beneath an agricultural field jeju island south korea abstract hydrochemical data major cations and anions and trace metals such as fe mn and v of groundwater n 144 were collected from 15 pre existing wells in the gosan area along the southwestern coast of jeju island south korea between january and october 2010 these were used to investigate the spatio temporal variability of groundwater quality in a basaltic aquifer beneath an agricultural field in the western part of the study area an impermeable clay rich layer gosan formation overlies the basaltic aquifer prohibiting direct recharge from rainwater infiltration and allowing a shallow perched aquifer to form above the formation robust principal component analysis robpca was performed to investigate the hydrochemical characteristics twenty seven outlying samples were separated from the total dataset among these 17 samples reflected seawater effects and seven samples reflected abnormally high impacts from agricultural contamination for the rest regular observations n 117 and a good leverage point robpca showed that principal component pc 1 effectively distinguishes uncontaminated water from those samples reflecting agricultural contamination variables with positive pc 1 loadings tds ca mg no 3 so 4 and cl indicate agricultural contamination while negative pc 1 loadings ph na k hco 3 and v possibly indicate basalt weathering samples with chemistry controlled by agricultural contamination are restricted to the eastern part of the study area while uncontaminated water is predominantly observed in the western part where the gosan formation occurs such a distinct spatial pattern indicates that overall groundwater quality is regulated by the occurrence of the impermeable formation groundwater samples from wells near the edge of the gosan formation show seasonal fluctuations in water quality with factor scores that indicates uncontaminated water in the dry season january to april and agricultural contamination in the wet season may to october this suggests that groundwater below the marginal part of the impermeable layer is seasonally contaminated by a temporal extension of the pollution front during the wet season even though the impermeable layer plays a role as a natural barrier to protect groundwater from the infiltration of surface contaminants this study also shows the advantage of robpca to successfully identify spatio temporal variation of groundwater quality in an area where diverse hydrochemical processes are coexisting and anormalous samples occur

the relationship between kestel polje system and the antalya tufa plateau their morphotectonic evolution in isparta angle antalya turkey abstract this paper focuses on the relation between two significant geomorphic features of the western taurides the antalya tufa plateau and the structural kestel polje system revealing morphotectonic records of the formation and evolution of karst hydrology between the two features data were obtained by detailed mapping of faults rocks and geomorphic features the evolutionary history of the area begins with a nearly e w trending drainage system which flowed on the erosional surfaces formed during late langhian early messinian under the compressional tectonic regime the running waters comprising the major drainage system incised the valleys during the messinian salinity crisis and partly in the pliocene by over 200 m depth across the study area from the beginning of the quaternary a tensional tectonic regime became prominent and a series of graben horst structures were formed the kestel polje system consisting of five sub poljes developed within the graben structures which emerged in the upper basin of rivers during this period and the middle part of the river valleys were transformed into hanging valleys on the horsts thus drainage of the kestel polje system and horsts mountainous area that bordered the polje to the east was enabled through underground karst conduits consequently caco3 precipitating from waters coming out of the rich karst springs that fed the polje system and aquifers to the east formed the antalya tufa plateau

a strontium isotopic study of newberry volcano central oregon structural and thermal implications abstract ratios of 87 sr 86 sr were determined in twenty seven basaltic rocks from newberry these ratios range from 0 70330 to 0 70414 most fall between 0 7035 and 0 7038 covariance of al 2 o 3 feo ratio tio 2 content and th content with 87 sr 86 sr suggests that some isotopic ratios reflect shallow crustal contamination but the data also suggest that two mantle sources a prominent one at 0 7036 and a less prominent one at 0 7033 or less are represented the hypothesis of crustal contamination is supported by variations in 87 sr 86 sr ratios with locations of the vents from which these rocks erupted sr tends to be more radiogenic in rocks from vents either close to a silicic complex such as the caldera of the volcano or the amota butte sugar pine ridge complex or close to axes of the fault zones that underlie the edifice presumably local heating of the upper crust facilitates contamination of basaltic magma rising through it

modelling and management of a mediterranean karstic coastal aquifer under the effects of seawater intrusion and climate change the study and management of the groundwater resources of a large deep coastal karstic aquifer represent a very complex hydrogeological problem here this problem is successfully approached by using an equivalent porous continuous medium epcm to represent a karstic apulian aquifer southern italy this aquifer which is located on a peninsula and extends to hundreds of metres depth is the sole local source of high quality water resources these resources are at risk due to overexploitation climate change and seawater intrusion the model was based on modflow and seawat codes piezometric and salinity variations from 1930 to 2060 were simulated under three past scenarios up to 1999 and three future scenarios that consider climate change different types of discharge and changes in sea level and salinity the model was validated using surveyed piezometric and salinity data an evident piezometric drop was confirmed for the past period until 1999 a similar dramatic drop appears to be likely in the future the lateral intrusion and upconing effects of seawater intrusion were non negligible in the past and will be considerable in the future all phenomena considered here including sea level and sea salinity showed non negligible effects on coastal groundwater

corals paleotemperature records and the aragonite calcite transformation oxygen isotopic records from corals play an increasing role in paleoclimatic research and climatic modeling proxy records of sea surface temperature are produced by isotopically analyzing samples drilled from aragonitic caco 3 coral skeletons however drilling aragonite causes a polymorphic inversion to calcite accompanied by 18 o enrichment the isotopic enrichment may occur through atmospheric exchange co 2 degassing or fractionation during digestion regardless of the mechanism dry drilling produced isotopic shifts as large as 0 8 corresponding to an erroneous temperature decrease of 3 c this error is larger than the global temperature rise since the industrial revolution and a substantial part of the global temperature variation over the past 10 ka because the isotopic shift is inconsistent and can occur without the production of measurable calcite detecting and correcting the isotopic shift may be difficult

gulf of maine shells reveal changes in seawater temperature seasonality during the medieval climate anomaly and the little ice age article i nfo in this study we use subannually resolved oxygen isotope values of fossil dead collected and modern live caught bivalve shells arctica islandica l from the northwestern atlantic gulf of maine usa to reconstruct past seasonal changes in seawater temperature our results indicate decreased seasonal temperature amplitude of about 1 6 c or 21 during medieval times ca ad 1033 1062 compared to shells from the early little ice age ca ad 1321 1391 and during the late 19th century ad 1864 1886 additionally seasonal oxygen isotope data suggest that summers were cooler and winters were warmer in the gulf of maine during the 11th century compared to summers and winters in the 14th century and the late 19th century the inferred decreased seasonality during medieval times likely resulted from increased stratification of the coastal waters due to warmer seawater temperatures as seawater cooled during the little ice age we suggest that increased vertical mixing of the coastal surface waters was a major driving factor for the observed increase in the amplitude of the seasonal seawater temperature cycle