Yellow fluorescence from baghdadite and synthetic Ca3(Zr,Ti)Si2O9

Baghdadite from Fuka, Okayama Prefecture, Japan shows a bright yellow fluorescence under UV (Hg 253.7 nm) excitation. The photoluminescence (PL) spectrum at 300 K consists of one large band near 580 nm and two small UV bands at 318 and 397 nm. The optical excitation spectrum of the bright yellow fluorescence consists of two bands near 220 and 250 nm. The temperature dependence of the PL intensity exhibits linear thermal quenching. To reveal the origin of the bright yellow fluorescence from baghdadite, powder Ca₃(Zr,Ti)Si₂O₉ crystals are synthesized. Synthetic Ca₃(Zr,Ti)Si₂O₉ shows luminescence spectra similar to those of baghdadite, and the intensity of the yellow fluorescence is markedly increased by titanium addition. The origin of the bright yellow fluorescence from baghdadite is ascribed to the existence of titanium.     

Iron Isotopic Compositions of Geological Reference Materials and Chondrites

High‐precision iron isotopic compositions for Fe‐bearing geological reference materials and chondrites with a wide range of matrices (e.g., silicates, oxides, organic‐bearing materials) are reported. This comprehensive data set should serve as a reference for iron isotopic studies across a range of geological and biological disciplines for both quality assurance and inter‐laboratory calibration. Where comparison is available, the iron isotopic compositions of most geological reference materials measured in this study were in agreement with previously published data within quoted uncertainties. Recommendations for the reporting of future iron isotopic data and associated uncertainties are also presented. Long‐term repeat analyses of all samples indicate that highly reproducible iron isotopic measurements are now obtainable (± 0.03‰ and ± 0.05‰ for δ⁵⁶Fe and δ⁵⁷Fe, respectively).     

Software Dedicated for the Curation of Geochemical Data Sets in Analytical Laboratories

Software designed for analytical laboratories to guarantee traceability and accessibility of rocks with their geochemical properties has been developed. The software documents the sample origin, current sample location and the location of any sample subsets (e.g., thin sections, solutions, etc.), and archives all associated geochemical data sets. The software can be installed on a personal computer so is available for use in any laboratory and allows curation before and after publication. The software will be of use in integrating and sharing geological reference materials within and among institutes. In this article, the system design and implementation are detailed. All source codes for the software are available at http://dream.misasa.okayama-u.ac.jp/ .     

Determination of the Concentration of Carbonic Species in Natural Waters: Results from a World‐Wide Proficiency Test

The results of an international interlaboratory proficiency test for the determination of carbonic species are presented. Eight laboratories analysed twelve water samples (four synthetic waters, one lake water, four geothermal waters, one seawater and two petroleum waters) by two methods: (a) individual laboratory analytical procedure and (b) acid–base titration curves in tabular form following a standardised protocol. In case (b), the concentrations of carbonic species were calculated by the organiser using the (1) Hydrologists9; method, (2) Geochemists9; method and/or (3) initial pH and total alkalinity method. For synthetic waters, the averaged % trueness and precision of measurement of the two methods were (trueness = 7.6, precision = 9.4) and (9.0, 3.4) for total alkalinity, and (6.6, 31.0) and (7.8, 6.1) for carbonic alkalinity, respectively. This indicates that the total alkalinity calculation procedure is in general correct in the individual laboratory method, but the carbonic alkalinity calculation procedure has serious problems. The measurements of total alkalinity for lake and seawaters were in agreement in both the methods; however, the individual laboratory measurement method for geothermal and petroleum waters was conceptually incorrect. Thus, the analytical procedures for the determination of carbonic species were reviewed. To apply the Hydrologists9; and/or Geochemists9; methods, the location of NaHCO₃EP and H₂CO₃EP is necessary, even for samples with pH lower than that of NaHCO₃EP, and a backward titration curve after complete removal of CO₂ must be performed. The initial pH and total alkalinity method is appropriate where a complete analysis of species that contribute to the alkalinity is known.     

Determination of Fluoride Ions in Iron Ores by UV–VIS Spectrophotometry after Matrix Removal Using Diphonix® Resin

A modification of the spectrophotometric method for the determination of fluoride ions in iron‐rich materials is proposed. In this method the iron matrix was successfully removed using Diphonix^® resin. The studied sample was a ferruginous mineral which contained about 38% of iron. The Euronorm certified reference material (ECRM) 676‐1 (Iron Ore Sinter), as a commercially available material having a similar matrix (39.76% w/w Fe) and fluoride level (0.1% w/w), was used to validate the method. After partial digestion in concentrated hydrochloric acid the samples were diluted and passed through Diphonix^® resin. The concentration of fluoride ions was determined by a spectrophotometric method using a Zr:ER complex (λ = 540 nm). The result obtained for the ECRM was in good agreement with the certificate specification and thus proved the method to be applicable for the determination of fluoride ions in iron‐rich materials. Due to the easy digestion step and simple requirements for equipment, this method can be used in most laboratories.     

Offneria arabicanov. sp. (rudiste, Caprinidae) de l''Aptien inférieur du Jebel Madar (Sultanat d''Oman)

Offneria arabicanov. sp. (rudiste, Caprinidae) est caract9;ris9; par la simplicit9; de l'architecture de la valve sup9;rieure, bien exprim9;e par la forme subrectangulaire des canaux o9; les planchers sont relativement rares, et le faible d9;veloppement des tabulae. La valve inf9;rieure est beacoup plus complexe, ce qui traduit un taux d'evolution diff9;renci9; des deux valves. L'espèce a 9;t9;) trouv9;e dans l'Aptien inf9;rieur (Formation Shuaiba) du Jebel Madar, dans l'avant pays des nappes des Montagnes d'Oman. Son organisation la rattache au groupe des formes arabo-africaines. A côt9; de ses caractères 9;volutifs, elle est int9;ressante par son potentiel biostratigraphique et pal9;obiolog9;ographique.

Abstract

Offneria arabicanov. sp. (rudist, Caprinidae) is characterized by the simplicity of the upper valve, well expressed by the subrectangular shape of the canals where horizontal partitions are relatively rare, and the weak development of the tabulae. The lower valve is far more complex, which means distinctive evolutionary rates for the two valves. The species was found in the Lower Aptian (Shuaiba Formation) of the Jebel Madar, in the foreland of the Oman Mountain nappes. By its overall organisation it belongs to the Arabo-African group of species. Besides its evolutionary characters this form is interesting because of its biostratigraphic and palaeobiogeographic potential.     

基于MapGIS与Oracle的地质数据库建立

与普通的数据相比,地质数据有着多源、多量、多类、多元、多维、多主题等特点。由于地质数据自身的特点,如何有效地存储管理海量地质成果资料和相关信息要素,已经成为当前的热门研究课题。以矿产资源潜力评价数据为例,在Oracle 10G、MapGIS K9平台基础上完成全国矿产资源潜力评价数据的数据库建设工作。在原有软件的基础上,对海量地质数据进行统一管理,为地质数据的应用提供基础保障,从而提高地质数据的信息化服务能力。     

鄂尔多斯盆地长9烃源岩发育与排烃效率

鄂尔多斯盆地长9优质烃源岩主要集中在志丹—英旺地区,但目前仅在志丹地区发现了典型长9源岩所生原油。对源岩排烃效率的定性和定量研究表明,英旺地区长9烃源岩排烃效率明显低于志丹等其他地区,仅为44%,其余地区平均为82%。排烃效率低应是英旺地区长9原油勘探未能取得突破的重要原因。沉积埋藏史和测井资料研究证实,与其他地区相比,英旺地区地质时期所经历的最大埋深明显较小,由此造成源岩孔隙度较高,残留烃量较大,导致英旺地区排烃效率低。另外,与志丹地区相比,英旺地区单位源岩生烃量较小,由此会造成其残烃量相对较高,这也是造成英旺地区排烃效率较低的一个原因。     

Exploring the spreading layer of GX 9+9 using RXTE and INTEGRAL

We have fitted ∼200 RXTE and INTEGRAL spectra of the neutron star (NS) low-mass X-ray binary (LMXB) GX 9+9 from 2002 to 2007 with a model consisting of a disc blackbody and another blackbody representing the spreading layer (SL), i.e. an extended accretion zone on the NS surface as opposed to the more traditional disc-like boundary layer. Contrary to theory, the SL temperature was seen to increase towards low SL luminosities, while the approximate angular extent had a nearly linear luminosity dependency. Comptonization was not required to adequately fit these spectra. Together with the ∼ 70° upper bound of inclination implied by the lack of eclipses, the best-fitting normalization of the accretion disc blackbody component implies a distance of ∼10 kpc, instead of the usually quoted 5 kpc.     

The paleoclimate of the eastern desert of Jordan during marine isotope stage 9

Two Cardium horizons from the topmost Azraq Formation in the eastern desert of Jordan were investigated and dated by U/Th at 330 ka; MIS 9. Fossil diversity and abundance, especially for Charophytes and gastropods with the absence of palygorskite, dolomite and evaporites, suggest the presence of a fresh water lake changing to a brackish environment at certain time intervals. A lake or possibly several smaller and shallower lakes occupied an area of about 50 km wide within the Azraq Basin. The present-day arid climate cannot support the presence of lakes in the eastern desert of Jordan, and thus MIS 9 in Jordan must have been much wetter. The source of humidity was most probably more intense Mediterranean cyclones associated with warmer than present MIS 9. However, the possibility of summer monsoon rain from the south cannot be fully excluded.