Geochemistry

Two samples from the augite syenite unit of the 1.13 Ga alkaline to peralkaline Ilimaussaq intrusion in South Greenland contain olivine (Fa 75-85 ) with micrometer-sized exsolution lamellae of intergrown augite and magnetite. The exsolved olivine contains only about 0.6 wt% CaO, whereas the reintegrated magmatic composition contained about 1.4% CaO corresponding to about 3 mol% of a larnite (La) component. The exsolved olivine bears no measurable Na, Al, or Ti, but the reintegrated magmatic olivine contained up to 0.4 wt% Na 2 O, 0.2 wt% Al 2 O 3, and 0.3 wt% TiO 2 . Magmatic baddeleyite in the same samples indicates an extremely low silica activity of below 0.4 during the early stages of magmatic crystallization at > 900 °C and 1 kbar. According to the equilibrium Ca 2 SiO 4 (La in Ol) + SiO 2 = 2 CaSiO 3 (Wo in Cpx), the low silica activity is thought to be responsible for the unusually Ca-rich compositions of the primary olivines, which, in these samples, formed at 875 ± 15 °C and at oxygen fugacities between 1.2 and 2.3 log units below the QFM buffer. The composite exsolution lamellae formed during cooling due to an overstep of the schematic reaction Fa + Kst (Ca-rich component in olivine) + 1/3 O 2 = Hd + 2/3 Mt. Phase equilibria indicate temperatures between 300 and 750 °C and oxygen fugacities close to QFM for this exsolution process. The lamellae only developed in samples where the olivines were both especially high in Ca and presumably rapidly cooled (although not chilled!), as the lamella-bearing samples were collected at the outermost rim of the augite syenite unit and close to the top of the Ilimaussaq intrusion. Schreinemakers analysis shows that Ca-rich olivine of the kirschsteinite-monticellite solid solution series [Ca(Fe,Mg)SiO 4 ] would exsolve from Ca-bearing olivine of the fayalite-forsterite series only at unusually low silica activities, whereas at higher silica activities, the observed exsolutions of clinopyroxene with magnetite are more stable. Hence, both cooling history and evolution of intensive variables during cooling are important for the formation of olivine exsolution textures.

The concentration of halogens in apatite, biotite and amphibole is investigated for a large variety of mantlederived plutonic rocks (gabbros, diorites, monzonites, olivine-and pyroxene-bearing monzonitic to granitic rocks, syenites, carbonatites and a phoscorite). In all rocks studied, apatite occurs as an early magmatic phase, whereas biotite and amphibole may occur either as a late magmatic phase or as late-stage, potentially hydrothermal product replacing precursor olivine, pyroxene and Fe-Ti oxides (ilmenite and magnetite). Based on electron microprobe analyses for F and Cl and detailed textural observations, we test existing models of halogen partitioning between apatite and biotite. Bromine concentration data for apatite, biotite and amphibole are used to further refine our understanding of the geochemical similarities and differences between Cl and Br during magmatic and hydrothermal processes. Our data suggests that F and Cl contents in apatite, biotite and amphibole can indeed be useful monitors of the halogen systematics in magmas, but they may also be subject to post-magmatic changes to variable extents. The relatively small radius and compatible F cation seems to be less prone to post-magmatic alteration and is likely to best reflect the original magmatic halogen abundancesespecially in apatite. However, the larger and probably more incompatible Cl anion, is more easily re-mobilized as reflected by strong redistribution of Cl in biotite and amphibole which have been clearly overprinted by hydrothermal fluids. In certain cases, the ability of halogens to re-distribute themselves after magmatic equilibrium partitioning (as emphasized by our data) suggests that observed partitioning (especially between apatite and biotite) may also be used as a very sensitive indicator for post-magmatic hydrothermal processes.

The halogen contents of granitoid rocks and their distribution between apatite, biotite, muscovite and amphibole from two different localities (German part of the Bohemian Massif and Central Aegean, Greece) are investigated in detail. Whole rock F and Cl contents and F/Cl mass ratios vary systematically with the magmatic halogenbearing mineral assemblage in which biotite and apatite are present in all rock samples: muscovite-bearing granites are F-rich (mostly 1100-2000 μg/g, but up to 3100 μg/g) and are relatively Cl-poor (50-130 μg/g). In contrast, amphibole-bearing rocks reach high Cl contents (50-900 μg/g) and are relatively F-poor (500-1400 μg/g). Only biotite-and apatite-bearing granites show intermediate F (750-1100 μg/g) and Cl (120-350 μg/g) contents. Bromine contents of all rock samples are below the detection limit of about 0.6 μg/g. In general, F and Cl are preferentially incorporated in apatite over biotite and biotite usually contains higher amounts of F and Cl than muscovite. Similarly, biotite prefers F over amphibole, but the distribution of Cl between biotite and amphibole varies between different rock samples. Bromine contents in muscovite are below the detection limit of 0.4 μg/g, but can reach up to 0.8 μg/g in biotite and up to 2.5 μg/g in apatite and amphibole. Near-solidus effects such as fluid exsolution, diffusive re-equilibration and hydrothermal overprint may change the initial halogen distribution in the rock. Importantly, significant amounts of the whole rock's F (up to 60%) and Cl (up to 90%) may be accommodated in post-magmatic alteration phases (fluorite and Na-K-Ca-bearing sheet silicates) and fluid inclusions. Therefore, great care has to be taken when interpreting halogen contents of whole rocks and the influence of post-magmatic halogen-carriers needs to be taken into account.

We use thallium (Tl) concentrations, K/Rb, K/Tl and Rb/Tl ratios and Tl isotopes in minerals from the alkaline to peralkaline Ilimaussaq complex (South Greenland) to trace magmatic differentiation, crustal assimilation, magmatic degassing, ore precipitation and hydrothermal metasomatism. Closed-system magmatic differentiation is marked by a coherent decrease of K/Tl-and K/Rb-ratios, whereas crustal assimilation results in a strong Tlenrichment, causing low K/Tl-ratios compared to K/Rb-ratios. Thallium isotopes show only slight changes during orthomagmatic differentiation and the assimilation of crustal material cannot be traced, since the isotopic composition of the average crust is within the range of the mantle and mantle-derived rocks. Magmatic degassing, however, increases Rb/Tl-ratios and changes the isotopic composition of Tl. The released fluids are enriched in Tl, characterized by high 205 Tl/ 203 Tl ratios and can precipitate Tl-rich sulfide and silicate minerals as indicated by some late-magmatic hydrothermal veins, which contain a conspicuous assemblage of Tl-Fe-Cu-sulfides (thalcusite, djerfisherite, chalcothallite). The oxidative alteration of these assemblages at high pH results in small-scale redistribution of Tl. Thallium released by this process is entrained into late-stage Tl-enriched astrophyllite.

In this work, we present an improved method for the semi-quantitative determination of sulfur species in S-bearing minerals by electron microprobe analysis. For calibration, we analyzed several sulfate and sulfide standard minerals such as baryte, celestine, chalcopyrite, and pyrite, and correlated the results with theoretical calculations retrieved from density functional theory (DFT). We applied this method to natural sodalite-group minerals from various localities. In addition, we applied the more common Raman spectroscopy to some samples and show that this method cannot be applied to sodalite-group minerals to determine their sulfur speciation. We show that even though sodalite-group minerals have a complex crystal structure and are sensitive to the electron beam, electron microprobe analysis is a reliable tool for the analysis of their sulfur speciation. The natural sodalite-group minerals show systematic variations in sulfur speciation. These variations can be correlated with the independently determined oxidation state of the parental magmas thus making S-bearing sodalitegroup minerals good redox proxies, although we show that the electron microprobe analysis of the sulfur speciation is matrix-dependent, and the sulfur speciation itself depends on crystal chemistry and structure, and not only on f O 2 .

The supergene alteration of cobalt arsenides produces various characteristic mineral assemblages including erythrite, pharmacolite, and other Ca±Mg±Co-bearing arsenates, which upon precipitation remove Co and As from natural waters. Their paragenetic relationships and stability conditions have not been investigated in detail. We present a detailed study on these assemblages, their successions and coexisting fluid compositions from the mining area of Wittichen, southwest Germany, where primary skutterudite and safflorite in granite-hosted barite-calcite veins are undergoing oxidation. Water analyses from the old mines, a semi-quantitative stability diagram and quantitative reaction path modeling are used to constrain their conditions of formation. Cobalt-and arsenate-bearing solutions invariably precipitate erythrite first and hence buffer Co concentrations to very low values. Both during skutterudite or safflorite dissolution and erythrite precipitation, the fluid's Co/As ratio decreases rapidly. Therefore, spherocobaltite (Co carbonate) is unstable in the presence of arsenate ions under most conditions. The formation of various mineral assemblages precipitating after or simultaneously with erythrite strongly depends on Ca 2+ and Mg 2+ activities and pH. Small changes in one of these parameters lead to different mineral assemblages. These small changes are partly governed by fluid-host rock or fluid-vein mineral reactions and partly by the precipitation of the secondary arsenate minerals themselves. This complex interdependence produces the rich variety of mineral assemblages observed, which effectively serves as a very sensitive monitor of fluid compositions. Furthermore, the assemblages themselves are able to buffer the Ca-Mg-Co-As concentrations in the fluid to some extent and effectively immobilize both As and Co in close proximity to the ore deposit.

The geological mapping, petrographic and ground magnetic Survey in Gidan-Doya, Lokoja, North Central, Nigeria was carried out. The geomagnetic data were acquired along 8 traverses using 3 axes MCL6 Proton Precession Magnetometer and Magnetic Susceptibility Meter. The data were processed using Surfer 11 software, corrected for variations in geomagnetic fields as well as upward continuation and residual magnetic field. The anomaly patterns identified in the upward continued map revealed distinct structural zones. The North Eastern and South Western zones have the maximum magnetic intensity values ranging from 700 nT to 1100 nT suggesting shallow basement while the North Western zone is characterized by relatively low magnetic intensity values ranging from -300 nT to 700 nT suggesting a deeper basement. The direct measurement of magnetic susceptibility varies between 0.36 x 10 -3 SI to 39.00 x 10 -3 SI. The contour map shows the relative thickness of the overburden to be between 15 to ...

Information about diagenetic processes and temperatures during burial of sediments entering the subduction zone is important for understanding changes in physical properties and seismic behavior during deformation. The geochemistry of authigenic carbonates from accretionary prisms can serve as proxies for conditions during carbonate cementation and resultant lithification. We report results from the Nankai accretionary prism recovered from Integrated Ocean Drilling Program (IODP) Sites C0011 and C0012 and we document continued cementation of deep sediment sections prior to subduction. Elemental and isotope data provide evidence for complex mixing of different isotopic reservoirs in pore waters contributing to carbonate chemical signatures. Carbon stable isotope values exhibit a broad range (δ 13 C V-PDB = +0.1 to -22.5‰) that corresponds to different stages of cement formation during burial. Carbonate formation temperatures from carbonate-clumped isotope geochemistry range from 16° to 63°C at Site C0011 and 8.7° to 68°C at Site C0012. The correspondence between the clumped-isotope temperatures and extrapolations of measured in situ temperatures indicate the carbonate is continuing to form at present. Calculated water

The drilling during Ocean Drilling Program Leg 146 at the accretionary margin complexes off Vancouver Island, Canada (VIM), and Oregon, U.S.A (COM), addressed specific geochemical relationships and phenomena associated with fluid, gas, and heat fluxes generated by the compressive forces. Of particular importance were the occurrence of hydrates and formation of thermogenic hydrocarbons. In most cases, the geochemistry of the hemipelagic sediments is dominated by steady-and nonsteady-state diagenetic reactions, including sulfate reduction (Sites 888 and 891), and methanogenesis and methanotrophy (Sites 888-892). However, these shallow (<600 mbsf) sediments are also clearly and extensively influenced by pervasive and active fracture COM migration of deeper seated thermogenic hydrocarbons at the VIM and COM, respectively. The origin of bacterial and thermogenic gases is confirmed by their molecular and stable carbon isotope signatures. In many cases, the occurrence of C 2 + hydrocarbons delineates the fault zones. Only disseminated macrocrystalline hydrate, not massive hydrate, was encountered during Leg 146. Based on the carbon isotope signature, the hydrate is of bacterial origin and identical to that of the surrounding sediment free gas. Thermogenic gas hydrates were not encountered. The discrepancy between the location of the bottom-simulating reflector (BSR) and the base of hydrate stability may be caused by the presence of other gases or fluid constituents in the hydrate lattice. The amount of free gas inferred by the vertical seismic profiler (VSP) below the BSR may be due to the incomplete upward cryo-distillation of gases. This vertical shift could be created by (1) the change in bottom-water temperatures between glacial and interglacial, and (2) a pressure drop caused by sea-level change and accretionary uplift. The presence of hydrogen sulfide in the methane hydrates at Site 892 was unexpected and results from the rapid incorporation of H 2 S into hydrates, protecting them from reaction, (e.g., formation of iron monosulfides.)

An oil-bearing sandstone unit within the Monterey Formation is exposed in the Los Angeles Basin along the Newport-Inglewood fault zone in southern California. The unit preserves structures, some original fluids, and cements that record the local history of deformation, fluid flow, and cementation. The structures include two types of deformation bands, which are cut by later bitumen veins and sandstone dikes. The bands formed by dilation and by shear. Both types strike on average parallel to the Newport-Inglewood fault zone (317°-332°) and show variable dip angles and directions. Generally the older deformation bands are shallow, and the younger bands are steep. The earlier set includes a type of deformation band not previously described in other field examples. These are thin, planar zones of oil 1-2 mm thick sandwiched between parallel, carbonatecemented, positively weathering ribs. All other deformation bands appear to be oil-free. The undeformed sandstone matrix also contains some hydrocarbons. The oil-cored bands formed largely in opening mode, similar to dilation bands. The oil-cored bands differ from previously described dilation bands in the degree of carbonate cementation (up to 36% by volume) and in that some exhibit evidence for plane-parallel shear during formation. Given the mostly oil-free bands and oil-rich matrix, deformation bands must have formed largely before the bulk of petroleum migration and acted as semi-permeable baffles. Oil-cored bands provide field evidence for early migration of oil into a potential reservoir rock. We infer a hydrofracture mechanism, probably from petroleum leaking out of a stratigraphically lower overpressured reservoir. The deformation bands described here provide a potential field example of a mechanism inferred for petroleum migration in modern systems such as in the Gulf of Mexico.

Two sediment cores retrieved at the northern slope of Sakhalin Island, Sea of Okhotsk, were analyzed for biogenic opal, organic carbon, carbonate, sulfur, major element concentrations, mineral contents, and dissolved substances including nutrients, sulfate, methane, major cations, humic substances, and total alkalinity. Down-core trends in mineral abundance suggest that plagioclase feldspars and other reactive silicate phases (olivine, pyroxene, volcanic ash) are transformed into smectite in the methanogenic sediment sections. The element ratios Na/Al, Mg/Al, and Ca/Al in the solid phase decrease with sediment depth indicating a loss of mobile cations with depth and producing a significant down-core increase in the chemical index of alteration. Pore waters separated from the sediment cores are highly enriched in dissolved magnesium, total alkalinity, humic substances, and boron. The high contents of dissolved organic carbon in the deeper methanogenic sediment sections (50-150 mg dm À3 ) may promote the dissolution of silicate phases through complexation of Al 3+ and other structure-building cations. A non-steady state transport-reaction model was developed and applied to evaluate the down-core trends observed in the solid and dissolved phases. Dissolved Mg and total alkalinity were used to track the in-situ rates of marine silicate weathering since thermodynamic equilibrium calculations showed that these tracers are not affected by ion exchange processes with sediment surfaces. The modeling showed that silicate weathering is limited to the deeper methanogenic sediment section whereas reverse weathering was the dominant process in the overlying surface sediments. Depth-integrated rates of marine silicate weathering in methanogenic sediments derived from the model (81.4-99.2 mmol CO 2 m À2 year À1 ) are lower than the marine weathering rates calculated from the solid phase data (198-245 mmol CO 2 m À2 year À1 ) suggesting a decrease in marine weathering over time. The production of CO 2 through reverse weathering in surface sediments (4.22-15.0 mmol CO 2 m À2 year À1 ) is about one order of magnitude smaller than the weathering-induced CO 2 consumption in the underlying sediments. The evaluation of pore water data from other continental margin sites shows that silicate weathering is a common process in methanogenic sediments. The global rate of CO 2 consumption through marine silicate weathering estimated here as 5-20 Tmol CO 2 year À1 is as high as the global rate of continental silicate weathering.

Ekonomik önemi olan Erciş/Van yöresi obsidyenleri Anadolu plakasının kuzeydoğusunda Van ilinin 20 km kuzeyinde yer almaktadır. Bölgede bulunan volkanik kayaçlar stratigrafik olarak (i) Paleozoik yaşlı metamorfik seri (klorit-muskovit, kuvars şist, fillit) ile üzerinde bulunan (ii) bazalt (iii) obsidyen, (iv) perlit ve (v) tüf serisinden meydana gelmektedir. Bazaltlar inceleme alanında ve Doğu Anadolu bölgesinde, diğer volkanik kayaçlara benzer şekilde, oluşum yönünden subalkalin tür bir köken sunmakta olup, bir okyanus tabanı toleyitine karşılık gelmektedir. Tüf serisi ise, jeokimyasal olarak aynı magmatik ayrımlaşmanın farklı jeokimyasal özellikteki andezitik ve riyolitik bir türünü yansıtmaktadır. Perlit ve obsidyenler ise, jeokimyasal açıdan, riyolitlerle benzer kimyasal bileşime sahiptir. Perlitler jeokimyasal olarak, yüksek K 2 O, Rb ve Nb değerleriyle riyolitlerden kolaylıkla ayrılabilirken, obsidyenler ise yüksek SiO 2 değerleriyle her iki tür volkanik kayaçtan açık bir şekilde ayırt edilmektedir. Erciş yöresi perlit ve obsidyenleri oluşum modu açısından, Sarıkamış yöresi obsidyenleriyle ve perlitleriyle karşılaştırıldığında benzer jeokimyasal değerler sunmaktadır. Obsidyenler, jeokimyasal açıdan magmanın soğuması sırasında, volkanik camların bünyesine bir miktar H 2 O alması ve hidratlanma yoluyla ana magmadan oluşmuştur. İnceleme sahasının araştırılmasında, yörenin 1/25 000 ölçekli jeolojik haritası temel alınarak, obsidyen zonunun uzunluğu 1250 m, genişliği 250 m. ve kalınlığı 8 m olarak belirlenmiştir. Obsidyenlerle alakalı olarak yapılan rezerv hesaplamalarında, 5 850 000 tonluk obsidiyen miktarı ortaya konmuştur. Van Erciş Ulupamir Köyü yakınındaki obsidyen araştırma sahasındaki obsidyenler ham yarı değerli süstaşları niteliğindedir. Bu çalışma da Erciş obsidyenlerinin süstaşı olarak değerlendirilmesinde; taşın rengi, parlaklığı, ışığı geçirmesi, taşın kristallografik özelliği, görünümü, taşın kırılması, taşın sertliği, yoğunluğu, çizgi rengi, bulunuşu ve arazide tanınması gibi bir takım temel parametreler ölçüt olarak alındı. Söz konusu süstaşları yörede madencilik çalışması yapan firmalar tarafından ocaklardan çıkarılarak, süstaşları üretmek için atölyelere taşınmakta, ilgili atölyelerde işlenmekte, istihdam kaynağı oluşturulmakta ve üretilen bu ürünleri ihraç edilerek ulusal ekonomiye önemli miktarda ekonomik girdi sağlamaktadır.

Ekonomik önemi olan Erciş/Van yöresi obsidyenleri Anadolu plakasının kuzeydoğusunda Van ilinin 20 km kuzeyinde yer almaktadır. Bölgede bulunan volkanik kayaçlar stratigrafik olarak (i) Paleozoik yaşlı metamorfik seri (klorit-muskovit, kuvars şist, fillit) ile üzerinde bulunan (ii) bazalt (iii) obsidyen, (iv) perlit ve (v) tüf serisinden meydana gelmektedir. Bazaltlar inceleme alanında ve Doğu Anadolu bölgesinde, diğer volkanik kayaçlara benzer şekilde, oluşum yönünden subalkalin tür bir köken sunmakta olup, bir okyanus tabanı toleyitine karşılık gelmektedir. Tüf serisi ise, jeokimyasal olarak aynı magmatik ayrımlaşmanın farklı jeokimyasal özellikteki andezitik ve riyolitik bir türünü yansıtmaktadır. Perlit ve obsidyenler ise, jeokimyasal açıdan, riyolitlerle benzer kimyasal bileşime sahiptir. Perlitler jeokimyasal olarak, yüksek K 2 O, Rb ve Nb değerleriyle riyolitlerden kolaylıkla ayrılabilirken, obsidyenler ise yüksek SiO 2 değerleriyle her iki tür volkanik kayaçtan açık bir şekilde ayırt edilmektedir. Erciş yöresi perlit ve obsidyenleri oluşum modu açısından, Sarıkamış yöresi obsidyenleriyle ve perlitleriyle karşılaştırıldığında benzer jeokimyasal değerler sunmaktadır. Obsidyenler, jeokimyasal açıdan magmanın soğuması sırasında, volkanik camların bünyesine bir miktar H 2 O alması ve hidratlanma yoluyla ana magmadan oluşmuştur. İnceleme sahasının araştırılmasında, yörenin 1/25 000 ölçekli jeolojik haritası temel alınarak, obsidyen zonunun uzunluğu 1250 m, genişliği 250 m. ve kalınlığı 8 m olarak belirlenmiştir. Obsidyenlerle alakalı olarak yapılan rezerv hesaplamalarında, 5 850 000 tonluk obsidiyen miktarı ortaya konmuştur. Van Erciş Ulupamir Köyü yakınındaki obsidyen araştırma sahasındaki obsidyenler ham yarı değerli süstaşları niteliğindedir. Bu çalışma da Erciş obsidyenlerinin süstaşı olarak değerlendirilmesinde; taşın rengi, parlaklığı, ışığı geçirmesi, taşın kristallografik özelliği, görünümü, taşın kırılması, taşın sertliği, yoğunluğu, çizgi rengi, bulunuşu ve arazide tanınması gibi bir takım temel parametreler ölçüt olarak alındı. Söz konusu süstaşları yörede madencilik çalışması yapan firmalar tarafından ocaklardan çıkarılarak, süstaşları üretmek için atölyelere taşınmakta, ilgili atölyelerde işlenmekte, istihdam kaynağı oluşturulmakta ve üretilen bu ürünleri ihraç edilerek ulusal ekonomiye önemli miktarda ekonomik girdi sağlamaktadır.

Large quantities of marble blocks are produced from many new marble quarries which were opened around Isparta (Turkey) and its surrounding region. The opened quarries are also affected negatively by weathering as a result of karstification. Therefore, block efficiency of the quarries is low which results in a lot of waste materials that can be used in cultured marble production. The production of artificial marble from marble waste materials around Isparta is the main purpose of the study. The cultured marble is an attractive, healthy and homogenous building material. It has a wide application in the building construction sector. Artificial marble which is composed of mineral dusts and polyesters has high mechanical strength and they are durable to various chemical and high temperature environmental conditions. Based on physico-mechanical properties, cultured marbles are accepted by Turkish Standards (TS). The materials used for the production of qualified cultured marble are directly related to the hardness of the minerals used as filler in the polyester resin. Physico-mechanical properties of cultured marble depend on the physical properties of the filler minerals. The compressive strength of the cultured marble material is controlled by the physical properties of the filler minerals, therefore, the hardness of the cultured marble is determined by the hardness of the filler mineral. The following analyses were carried out: wet unit volume analysis, dry unit volume analysis, compressive strength of the materials, capillary water absorption analysis, analysis of ultrasound velocity (P-wave) and the marble wastes bulk chemical analyses were investigated and the results of the data were evaluated and discussed. In addition, natural and artificial marbles were compared with respect to physico-mechanical properties.

Stratigraphy is the science that studies the strata, or beds, of (mainly) sedimentary rocks in order to extract from them the history of the earth’s surface. By grouping the bed successions in stratigraphic units and by studying their geometrical relationships with some simple rules, it creates the fundamental temporal relative framework necessary to understand the origin of the rock units themselves. Several sub-disciplines or methodological approaches (especially biostratigraphy and paleontology) cooperate in the fundamental task of Stratigraphy, which is the correlation, that is, the recognition of the time equivalence of two different sedimentary successions. In this way a standard chronostratigraphic table, or geologic timescale, has been constructed whose divisions are continuously calibrated in terms of absolute age.

The structural and optical modifications of polysulphone polymer under swift heavy ion (SHI) irradiation have been compared. Polysulphone films were irradiated with 45 MeV Li +3 ions and 120 MeV Ni +9 ions with fluence varying from 3×10 10 to 3×10 12 ions/cm 2 . Optical and structural modifications were characterized by UV-visible spectroscpy and X-ray diffraction (XRD) method. It is observed that optical absorption increases with increasing fluence and the absorption edge shifts towards the red end of the spectrum. The value of band gap shows a decreasing trend with increasing ion fluences of both the ions but a sharp decrease in band gap was observed in case of Ni ion. XRD analysis shows the decrease in peak intensity with increasing fluence.

Numerous studies have shown that urban soils can contain elevated concentrations of heavy metals (HMs). Christchurch, New Zealand, is a relatively young city (150 years old) with a population of 390,000. Most soils in Christchurch are sub-urban, with food production in residential gardens a popular activity. Earthquakes in 2010 and 2011 have resulted in the re-zoning of 630 ha of Christchurch, with suggestions that some of this land could be used for community gardens. We aimed to determine the HM concentrations in a selection of suburban gardens in Christchurch as well as in soils identified as being at risk of HM contamination due to hazardous former land uses or nearby activities. Heavy metal concentrations in suburban Christchurch garden soils were higher than normal background soil concentrations. Some 46% of the urban garden samples had Pb concentrations higher than the residential land use national standard of 210 mg kg À1 , with the most contaminated soil containing 2615 mg kg À1 Pb. Concentrations of As and Zn exceeded the residential land use national standards (20 mg kg À1 As and 400 mg kg À1 Zn) in 20% of the soils. Older neighbourhoods had significantly higher soil HM concentrations than younger neighbourhoods. Neighbourhoods developed pre-1950s had a mean Pb concentration of 282 mg kg À1 in their garden soils. Soil HM concentrations should be key criteria when determining the future land use of former residential areas that have been demolished because of the earthquakes in 2010 and 2011. Redeveloping these areas as parklands or forests would result in less human HM exposure than agriculture or community gardens where food is produced and bare soil is exposed.

Accretion models of planet formation and the early cratering history of the solar system suggest that planet formation is accompanied by a cloud of debris resulting from accumulation and fragmentation. A rough estimate of the infrared luminosities of debris clouds is presented for comparison with measured 10-#m luminosities of young stars. New measurements of 13 F, G, and K mainsequence stars of the Ursa Major Stream, which is thought to be about 2.7 x l0 s years old, place constraints on the amount of debris which could be present near these stars.

The reported infrared (IR) emission spectra from 1999 Leonid fireballs show a 3.4pm C-H emission band and unidentified bands at longer wavelengths. Upon atmospheric entry, the Leonid meteorites were flash-heated to temperatures around 2400K, which would destroy any organics on the surface of the meteorite grains. We propose that the UCH emission band in the Leonid emission spectra arises from matrix-embedded C,-H-0 entities that are protected from instant pyrolysis. Our model is based on IR absorption UCH bands, which we observed in laboratory-grown MgO and natural olivine single crystals, where they arise from C,-H-0 units imbedded in the mineral matrix, indicative of aliphatic -CH2-and -CH3 organics. Instead of being pyrolyzed, the C,,-H-0 entities in the Leonid trails become vibrationally excited to higher levels n = 1, 2, 3 etc. During de-excitation they emit at 3.4pm, due to the (0 => 1) transition, and at longer wavelengths, due to hot bands. As a first step toward verifying this hypothesis we measured the C-H vibrational manifold of hexane (CcH14). The calculated positions of the (2 => l ) , (3 => 2), and possibly (4 => 3) hot bands agree with the Leonid emission bands at 3.5, 3.8 and 4.lpm.

We measured the infrared (IR) VCH absorption bands around 3.4mum (2800 - 3000cm-1) in large laboratory- grown magnesium oxide (MgO) and natural olivine single crystals that crystallized from CO/C02/H20 saturated melts. These bands are very similar to those from many astronomical sources, such as from dust in the diffuse interstellar medium (ISM) , from the outflow of evolved stars, etc.,

Pre-irradiation defects in insulators may be activated or decorated through the effects of ionizing radiation. In order to understand these reactions it is important to have a detailed understanding of the nature of the defects which existed prior to the exposure. We shall take a close lock at defects which are introduced by omnipresent trace impurities such as Hz0 and CO, in a model-type oxide structure like MgO. Dissolved Hz0 not only forms OH-ions but also H, molecules and peroxy ions, O;-. The Hz molecules may diffuse away leaving excess 0, *-ions behind. Above 800 K the Oi-dissociate into two paramagnetic defects: V-centers (O-state bound to a cation vacancy) and unbound positive holes, i.e. O-states free to move through the 02-sublattice. If two unbound holes recombine at the surface, atomic oxygen is released. In the bulk the unbound holes cause redox reactions with transition metal impurities. Dissolved CO, does not form carbonate ions, CO:-, but Ot-plus CO;-both of which are diamagnetic. The C atoms can either occupy cation vacancy sites (at low temperatures) or enter interstitial sites (above 800 K) where they are very mobile and subject to subsurface segregation. Above 800 K the CO;-configuration dissociates into the V-center and the equally paramagnetic COspecies. Between 500-800 K a transient paramagnetism is observed probably caused by the carbon atoms of the COf-configuration fluctuating between the cation vacancy sites and the next-nearest interstitial sites.

Carbon su~u~ace ~on~ntmtion profiles in ohvine single crystals from San Carlos, Arizona, and the Sergebet Island. Red Sea, containing total carbon between 60-180 wt.-ppm, were analyzed by means of the '*C(d. p)')C nuclear reaction and by x-ray induced photoelectron spectroscopy (XPS) in combination with acid etching and with Art ion sputtering respectively. between 200-930 K. The (d, p) analysis reveals equilibrium subsurface C profiles extending l-2 pm or more into the bulk. Their steepness is a function of temperature. Typical mean C concentrations at 300 K in the resolvable layers, O-0.6. 0.6-1.2, and 1.2-1.8 hrn. are 1.8, and 0.6 wt.-%, corresponding to enrichment factors over the mean bulk C con~ntmtion of the order of 100. 40 and 30 respectively. in the topmost atomic layers analyzed by XPS the carbon is enriched by a factor of the order of 1000, decreasing with increasing temperature. The results suggest that the carbon is in a truly dissolved state and highly mobile, subject to a reversible subsurface segregation. Most probably local lattice strain associated with the solute C species provide the driving force for this diffusional process. The C diffusion coefficient was determined from the (d, p) data below 300 K: D = lO-'3 exp(-7.8/RT) lm'-set-'; K.l.mole-'1 and from XPS data between 450-925 K: D = lo-l4 exp(-6fRT) [m's set-': Kl-mole-'] The estimated error of the preexponential factors is 2 one order of magnitude. that of the activation energies t3.5 and &2 KJ mole-" respectively.

To survive in deep subsurface environments, lithotrophic microbial communities require a sustainable energy source such as hydrogen. Though H 2 can be produced when water reacts with fresh mineral surfaces and oxidizes ferrous iron, this reaction is unreliable since it depends upon the exposure of fresh rock surfaces via the episodic opening of cracks and fissures. A more reliable and potentially more voluminous H 2 source exists in nominally anhydrous minerals of igneous and metamorphic rocks. Our experimental results indicate that H 2 molecules can be derived from small amounts of H 2 O dissolved in minerals in the form of hydroxyl, OH 2 or O 3 Si-OH, whenever such minerals crystallized in an H 2 O-laden environment. Two types of experiments were conducted. Single crystal fracture experiments indicated that hydroxyl pairs undergo an in situ redox conversion to H 2 molecules plus peroxy links, O 3 Si/ OO \SiO 3 . While the peroxy links become part of the mineral structure, the H 2 molecules diffused out of the freshly fractured mineral surfaces. If such a mechanism occurred in natural settings, the entire rock column would become a volume source of H 2 . Crushing experiments to facilitate the outdiffusion of H 2 were conducted with common crustal igneous rocks such as granite, andesite, and labradorite. At least 70 nmol of H 2 /g diffused out of coarsely crushed andesite, equivalent at standard pressure and temperature to 5,000 cm 3 of H 2 /m 3 of rock. In the water-saturated, biologically relevant upper portion of the rock column, the diffusion of H 2 out of the minerals will be buffered by H 2 saturation of the intergranular water film. Key Words: Hydrogen in rocks-Deep microbial communities-Solute water in minerals-Redox conversion of hydroxyl pairs-Peroxy in minerals. Astrobiology 2, 83-92.

In July 1992 a 30 MeV high current (maximum proton current: 400 micro A) H - -ion medical cyclotron Cyclone30 (IBA Belgium) has been installed at Royal Prince Alfred Hospital (RPAH), the prime teaching hospital of University of Sydney, jointly operated by ANSTO (Australian Nuclear ...

The Pacific Centre for Isotopic and Geochemical Research (PCIGR) at the University of British Columbia has undertaken a systematic analysis of the isotopic (Sr, Nd, and Pb) compositions and concentrations of a broad compositional range of U.S. Geological Survey (USGS) reference materials, including basalt (BCR‐1, 2; BHVO‐1, 2), andesite (AGV‐1, 2), rhyolite (RGM‐1, 2), syenite (STM‐1, 2), granodiorite (GSP‐2), and granite (G‐2, 3). USGS rock reference materials are geochemically well characterized, but there is neither a systematic methodology nor a database for radiogenic isotopic compositions, even for the widely used BCR‐1. This investigation represents the first comprehensive, systematic analysis of the isotopic composition and concentration of USGS reference materials and provides an important database for the isotopic community. In addition, the range of equipment at the PCIGR, including a Nu Instruments Plasma MC‐ICP‐MS, a Thermo Finnigan Triton TIMS, and a Thermo Finnigan El...

The differential cross sections of the 9 Be( 3 He, p i ) 11 B reactions for i = 0-6 were determined within the laboratory energy range 1.24-2.87 MeV and for backward angles from 107 °to 164 °with 2 °steps using two double sided silicon strip detectors. The obtained cross sections covered the angle and energy ranges typically used for the analysis of beryllium targets with the nuclear reaction analysis technique. The experiments were carried out at the Ruđer Bošković Institute and the determined cross sections were benchmarked with the measurement of thick target reaction yields from a pure beryllium target at two beam energies, 1.8 and 2.7 MeV. The results are presented in graphical form and for 134 °and 164 °are also given as tables in the Appendix. The correctness of the data, verified through the comparison of thick target spectra as well as the observed discrepancies with previous data are discussed and analyzed.

The present study aims to identify promising oil and gas bearing objects in the eastern part of the Gulf of Suez. Three-dimensional (3D) modelling of the study area using Petrel software was carried out. The basement layer was created using airborne magnetic data through 3D modelling using GM-SYS-3D software. The sedimentary succession was generated using interpreted seismic sections and well data, and then the data was localised and digitised using Petrel software to be used in the building of the model. The lithology and age of each layer were accurately determined to be used in building the petroleum system model. Data about the temperature gradient and thermal conductivity were obtained for different wells along the Gulf of Suez and the eastern shoulder of the Gulf. In addition to that, heat flow values of the study area have been computed and the heat flow map was created to be used in predicting oil and gas accumulation in the study area. Information about hydrocarbon masses and volumes generated and expelled from the source rocks as well as the amount that has migrated and accumulated in reservoirs were computed through running forward simulation using PetroMod software. Accumulations of oil and gas are modelled in the different reservoir layers in the study area. New accumulations of oil and gas were generated within the study area; these accumulations have not been discovered yet. The study area needs more detailed 2D and 3D investigation in the predicted promising locations, where the probability of the existence of hydrocarbon is high. In the southeastern part of the area no activity has been done and according to the results of the petroleum system model, hydrocarbon accumulation area could be discovered in this area in different reservoirs.

Hydrocarbon generation and expulsion simulations of multiple organic-rich intervals with diverse kerogen types in the Khatatba Formation were performed. Generally, the organofacies exhibit an excellent generation potential for liquid hydrocarbons, gas plus oil and/or gas. The 1D forward approaches have been executed for the complex tectonic and basin-fill history. The spatial distribution of the Khatatba organofacies and allocation of significant discoveries from the Khatatba Formation are aligned perpendicular to the NE-SW Jurassic Fault System. The organic-rich intervals underwent several heating episodes throughout its burial history predominantly during the Cretaceous Rifting phase. Likewise, the organofacies underwent episodic expulsion of gas derived from either primary cracking (kerogen type III) or secondary cracking of oil (kerogen type II). The oil prone type II kerogen entered the oil window at JD-4 well close to the Albian whilst the wet-gas window since late Albian. Conversely, gas prone type III kerogen attained the dry-gas window from the time of early Oligocene at the JD-4 well prior to the wet-gas window of the JG-2 well (late Oligocene). Nevertheless, gas prone type III kerogen never reached the dry gas window at JG-2 well due to its low thermal maturation level. The burial effect, attributable to the thick basin-fill sediments (Masajid, Alam El Bueib, Abu Roash and Khoman formations), accelerated the thermal maturation at the JD-4 well. However, the organofacies revealed neither thermogenic gas generation nor gas secondary cracking at the JG-2 well and nix expulsion. The expelled hydrocarbon assumed to migrate laterally and near vertically from the southeastern part towards the north western part.

The petroliferous province of the Western Desert comprises several sedimentary basins with different hydrocarbon potentiality and production capability. The middle Jurassic Khatatba Formation was proved a potential source rock in some basins and active/effective in others. The current study aims to give a comprehensive assessment and evaluation of the potential organic-rich intervals of the Khatatba Formation across JG and JD fields, northeast Abu Gharadig Basin (NEAG). The hydrocarbon generating capability and sourcing of the Khatatba Formation studied through organic geochemistry calibrated with well logging. However, the efficiency of some widely used plots of geochemistry is re-evaluated according to their accuracy and consistency. Forty cuttings, thirteen cores and two oil samples obtained from three wells (JG-2, JG-3 and JD-4) were evaluated. The samples revealed total organic carbon (TOC) values ranging from 1 to 9 wt%, exhibiting a good-excellent potential source rock. A single sample in the JD-4 well attained a TOC value of 21.3 wt% with a generating potential (represented by S2 parameter) exceeding 146 mgHc/g rock required a special evaluation. Most of the samples (mainly in the JD-4 well) attained a sufficient level of thermal maturity for hydrocarbon generation with a T max up to 449 C. The vitrinite reflectance (%Ro) values (a common maturity-related indicator) acquired from the JD-4 well ranging between 0.76% and 0.92%. These values are tediously increasing with depth indicating a uniform geothermal regime. The Khatatba organofacies, with wide variety of kerogen types (I, II, II-S and II/III), contain marine organic matter with a slight terrigenous input, exhibiting anoxic-suboxic environmental conditions. Oil-source correlations define the organic-rich intervals responsible for charging the accumulated hydrocarbon in the NEAG concession.

Various substituted 3-{6-fluoro-7-(substituted)-1,3-benzothiazol-2-yl-1- [(4-acetyl-5-methyl-5phenyl-4,5-dihydro-1,3,4-oxadiazol-2-yl) containing different functional groups have been synthesized by condensing anthranilic acids with substituted 2-aminobenzothiazoles in dry pyridine and then by condensing with ethylchloroacetate in presence dry acetone and K 2 CO 3 . The identity of compounds were confirmed on the basis of their spectral (UV, IR, 1 H NMR and MASS) data. Further, they have been screened for their antimicrobial activities.

Water column winter nutrient profiles were evaluated of 250 m especially oxic/anoxic interface layer in Southeastern Black Sea. Although nutrient concentrations according to the depth are difference, density profiles are similar. Silicate concentrations were increased depending on depth while maximum phosphate concentration observed with the boundary of the 16,2 density. Ammonium concentrations increased depending on depth below 16.2 density layer. Minimum temperature of the CIL were measured at 100 meter depth of TY, OM and OF statiton while were measured at 75 meter of AA and SB stations. Nitrite maximas were usually observed bottom boundary of oxic layer except for AA station. Nitrate maximas were showed differences on stations according to depth and concentration. Chlorophyll-a maxima, usually at a depth of 30 m and 13.8 sigma-t.

Osmanlıların Irak'taki topraklarla ilgili politikası, işgal ettikleri ve askeri fetih kurallarına tabi olan Avrupa bölgelerindeki topraklarla ilgili politikalarından farklıydı, yani tüm bu topraklar devletin (Miri) mülkü olarak kabul edilirken, Irak'taki durum, kontrolün zorla gerçekleşmesine rağmen farklıydı. Elimizdeki kaynaklar, Osmanlıların Irak'ın kontrolünü ele geçirdiklerinde feodal ve vakıf toprakları ile özel mülkiyeti miras aldıklarını, ancak aynı zamanda önlerinde harap köyler ve bozulmuş tarım bulduklarını göstermektedir. Osmanlı İmparatorluğu yeni bölgelerin kontrolünü ele geçirdiğinde, her köyün topraklarını ve ondalık ithalatını, ayrıca sakinlerinin sayısını ve içindeki ev sayısını kaydetti. Yani, arazinin tahririni yapıyor, nüfusun ve mülklerinin genel bir sayımını gerçekleştiriyor ve buna göre vergileri hesaplıyordu. Bu, (defterimi düzenliyorum) olarak bilinen arazi tahrir defterlerine, yani kurtuluş defterlerine kaydedilir.

The Mg isotope compositions of weathering profiles developed on granite and granodiorite bedrock have been analyzed to investigate Mg isotope behavior during the weathering of felsic rocks in a continental environment. δ 26 Mg generally exhibits a small increase from the bedrock values, which range from -0.17 ± 0.06 ‰ to +0.07 ± 0.06 ‰, until the upper two meters in which a decrease is observed, producing near surface values between -0.14 ± 0.06 ‰ and +0.09 ± 0.06 ‰. The small observed increase in isotopic composition below 2 m is likely due to Mg loss to the hydrosphere during biotite weathering and in situ illite production, while the decrease at depths less than 2 m is likely due to illite weathering near the surface, with a possible minor contribution from downslope deposition of less weathered material. One hydrothermally altered profile shows more extreme fractionation, reaching δ 26 Mg values as heavy as +0.55 ± 0.06 ‰ in the near surface component of the section. The fractionation associated with Mg loss during weathering can be modeled by Rayleigh distillation with fractionation factors between the residual rock and fluid ranging from α = 1.00001 to 1.00040. The Mg isotope composition is primarily controlled by the behavior of illite in the weathering profile, as Mg isotope composition is positively correlated with the illite fraction of major Mg-bearing minerals. A thorough understanding of Mg isotope systematics in these complex clay minerals may permit the use of Mg isotopes in paleosols as paleoclimate indicators.

Triton is one of the most peculiar satellites of the Solar System, for several reasons. First of all, for its retrograde orbit that makes of Triton a plausibly captured satellite. Moreover, Triton is synchronously rotating, so we can speak of leading and trailing sides. The analysis of the Voyager images showed remarkable differences between the two hemispheres, being the leading side much more cratered that the trailing one. The origin of this huge asymmetry is still not clearly understood. We think that some hints can arise from a spectral investigation of Triton&#x27;s two faces. To this end, we obtained new observations of Triton with the ESO New Technology Telescope (La Silla, Chile) in October 2002. We discuss here the spectra and the differences between the two faces, and the implications of these findings for a better understanding of the surface composition of Triton.

The OSIRIS cameras on the Rosetta spacecraft observed Comet 9P/Tempel 1 from 5 days before to 10 days after it was hit by the Deep Impact projectile. The Narrow Angle Camera (NAC) monitored the cometary dust in 5 different filters. The Wide Angle Camera (WAC) observed through filters sensitive to emissions from OH, CN, Na, and OI together with the associated continuum. Before and after the impact the comet showed regular variations in intensity. The period of the brightness changes is consistent with the rotation period of Tempel 1. The overall brightness of Tempel 1 decreased by about 10% during the OSIRIS observations. The analysis of the impact ejecta shows that no new permanent coma structures were created by the impact. Most of the material moved with ~200 ms -1 . Much of it left the comet in the form of icy grains which sublimated and fragmented within the first hour after the impact. The light curve of the comet after the impact and the amount of material leaving the comet (4.5-9 x 10 6 kg of water ice and a presumably larger amount of dust) suggest that the impact ejecta were quickly accelerated by collisions with gas molecules. Therefore, the motion of the bulk of the ejecta cannot be described by ballistic trajectories, and the validity of determinations of the density and tensile strength of the nucleus of Tempel 1 with models using ballistic ejection of particles is uncertain.

This paper aims to give a brief description of the Wide Angle Camera (WAC), built by the Centro Servizi e Attività Spaziali (CISAS) of the University of Padova for the ESA ROSETTA Mission to comet 46P/Wirtanen and asteroids 4979 Otawara and 140 Siwa. The WAC is part of the OSIRIS imaging system, which comprises also a Narrow Angle Camera (NAC) built by the Laboratoire d'Astrophysique Spatiale (LAS) of Marseille. CISAS had also the responsibility to build the shutter and the front cover mechanism for the NAC. The flight model of the WAC was delivered in December 2001, and has been already integrated on ROSETTA.

In this work, we have measured the angular distribution of photons scattered (scattering signature) by five tissueequivalent materials used in mammography and conventional radiology and four samples used in bone densitometry at the photon energy 17.44 keV using a X-ray tube equipped with a graphite monochromator, a goniometer system and a NaI detector. Results from the tissue-equivalent materials scattering signatures have been compared with previous results for human tissues (adipose, glandular, muscle and bone). The scattering profiles obtained with tissue-equivalent materials are different from those obtained with human tissue. These differences are due to intermolecular correlation on the elastic scattering. Some tissue-equivalent materials present some very sharp peaks, absent in real soft human tissue. These results suggest that a careful analysis of the scattering properties must be done in order to use tissueequivalent material to simulate human tissues.

In this study, we analyze the recent (1990 -1997) seismicity that affected the northern sector (Sannio -Benevento area) of the Southern Apennines chain. We applied the Best Estimate Method (BEM), which collapses hypocentral clouds, to the events of low energy (M d max = 4.1) seismic sequences in order to constrain the location and geometry of the seismogenetic structures. The results indicate that earthquakes aligned along three main structures: two sub-parallel structures striking NW -SE (1990 -1992, Benevento sequence) and one structure striking NE -SW (1997, Sannio sequence). The southernmost NW -SE structure, which dips towards NE, overlies the fault that is likely to be responsible for a larger historical earthquake (I o max = XI MCS, 1688 earthquake). The northernmost NW -SE striking structure dips towards SW. The NE -SW striking structure is sub-vertical and it is located at the northern tip of the fault segment supposed to be responsible for the 1688 earthquake. The spatio-temporal evolution of the 1990 -1997 seismicity indicates a progressive migration from SE (Benevento) to NW (Sannio) associated to a deepening of hypocenters (i.e., from about 5 to 12 km). Hypocenters cluster at the interface between the major structural discontinuities (e.g., pre-existing thrust surfaces) or within higher rigidity layers (e.g., the Apulia carbonates). Available focal mechanisms from earthquakes occurred on the recognized NW -SE and NE -SW faults are consistent with dip-slip normal solutions. This evidences the occurrence of coexisting NW -SE and NE -SW extensions in Southern Apennines.