Permian high-temperature metamorphism in the Western Alps (NW Italy)     

Kunz  Barbara E.  Manzotti  Paola  von Niederhäusern  Brigitte  Engi  Martin  Darling  James R.  Giuntoli  Francesco  Lanari  Pierre 《International Journal of Earth Sciences》2018,107(1):203-229

International Journal of Earth Sciences - During the late Palaeozoic, lithospheric thinning in part of the Alpine realm caused high-temperature low-to-medium pressure metamorphism and partial...  相似文献   

Geostandards and Geoanalytical Research Bibliographic Review 2019     

Ulrike Weis  Brigitte Stoll  Jodok Arns  Michael W. Frster  Viktoria Kaiser  Laura M. Otter  Lea Reichstein  Klaus Peter Jochum 《Geostandards and Geoanalytical Research》2021,45(1):29-35

This bibliographic review gives an outline of publications in 2019 focusing on reference materials (RMs) used in geochemistry and related fields, such as palaeoclimate and environmental research.  相似文献   

Dense infaunal assemblages on the continental slope off Cape Hatteras, North Carolina     

James A. Blake  Brigitte Hilbig 《Deep Sea Research Part II: Topical Studies in Oceanography》1994,41(4-6)

Unusually dense assemblages of benthic infaunal invertebrates have been discovered in continental slope sediments off Cape Hatteras, North Carolina. Densities were highest on the upper slope, ranging from 24,055 to 61,244 (X¯=46,255) individuals m⁻² in nine samples taken at a 600-m site in 1984 and 1985, and from 15,522 to 89,566 (X¯=37,282) individuals m⁻² in single samples at 15 stations over a wider depth range of 530 to 1535 m in 1992. A lower slope station at 2000 m sampled six times in 1984–1985 and again in 1992, had densities consistently higher than 8500 individuals m⁻². Species richness and diversity are consistently lower on the Cape Hatteras slope than at other locations off North Carolina and elsewhere in the western North Atlantic. The 1992 studies indicated that the upper slope infaunal assemblages (600m) were dominated by oligochaetes, while the middle slope assemblages (800–1400 m) were dominated by the polychaeteScalibregma inflatum. This latter depth range could be defined into two assemblages based upon suites of less abundant species. At depths of 1500–2000 m, a lower slope assemblage dominated by various deposit feeding polychaetes and oligochaetes was found. Results from the 1984–1985 studies suggest seasonal or year-to-year patterns in the dominance ofS. inflatum andCossura longocirrata. Unusually high sedimentation rates and organic carbon flux have been recorded from the slope off Cape Hatteras and may account for the high infaunal productivity in the area. Most of the dominant infaunal organisms are species more typical of shallow, coastal habitats rather than deep-sea species that dominate other areas of the U.S. Atlantic continental slope. Parallel investigations regarding the nature of organic matter in the Cape Hatteras sediments have revealed a mixture of both marine and terrestrially derived carbon, only a small percentage of which is composed of the smaller molecular weight polyunsaturated fatty acids more typical of continental slope sediments. It is likely that the high percentage of refractory organic matter would favor the survival of preadapted shelf species over those from adjacent slope environments.  相似文献   

An Automated Iridium-Strip Heater for LA-ICP-MS Bulk Analysis of Geological Samples   总被引：1，自引：0，他引：1  

Brigitte Stoll  Klaus Peter Jochum  Kirstin Herwig  Marghaleray Amini  Michael Flanz  Berthold Kreuzburg  Dmitry Kuzmin  Matthias Willbold  Jacinta Enzweiler 《Geostandards and Geoanalytical Research》2008,32(1):5-26

In this paper we describe a flux‐free fusion technique for the highly precise LA‐ICP‐MS bulk analysis of geological samples. For this purpose we have developed an automated iridium‐strip heater with temperature and melt time control. To optimise the homogeneity of the fused glasses and to reduce possible depletion of volatile elements during melting, we undertook experiments with basaltic rock and glass powders using different melting temperatures (1300–1700 °C) and melting times (5‐80 s). Major and trace element microanalysis was performed using EPMA and LA‐ICP‐MS. Homogeneous glasses were obtained for temperatures ≥ 1500 °C and melting times ≥ 10 s. High loss (20‐90%) of highly volatile elements (e.g., Cs, Ge, Sn, Pb) was observed for high melting temperatures (≥ 1600 °C) and long melting times (80 s). Standard melting conditions (1600 °C, 10 s) represent a compromise, as the glasses were homogeneous with respect to major and trace elements and, at the same time, were not depleted in elements with condensation temperatures (at a pressure of 10^?4 bar) higher than about 900 K (e.g., Zr, Hf, Ba, Sr, REE, U, Mo, Ni, Rb, Ga). Several international geological reference materials with SiO₂ ranging between 47% m/m and 59% m/m were prepared using our standard melting conditions (1600 °C, 10 s) and subsequently analysed by LA‐ICP‐MS. These samples also include the new Brazilian basaltic reference material BRP‐1. Matrix‐matched calibration of the LA‐ICP‐MS data was performed using the basaltic reference glasses KL2‐G, ML3B‐G, BCR‐2G and BHVO‐2G. Most analytical data agreed within uncertainty at the 95% confidence level with the GeoReM preferred values published in the GeoReM database for reference materials of geological and environmental interest. To demonstrate routine bulk LA‐ICP‐MS analyses of geochemical and cosmochemical samples using the whole rock fusion technique, we also present trace element data for ocean island basalts from Lanai (Hawaii) and of Martian meteorites.  相似文献   

Geothermal control on flow patterns in the Last Glacial Maximum ice sheet of Iceland     

Olivier Bourgeois  Olivier Dauteuil  Brigitte Van Vliet‐Lanoë 《地球表面变化过程与地形》2000,25(1):59-76

Because it is located both on the Mid‐Atlantic Ridge and on a mantle plume, Iceland is a region of intense tectonics and volcanism. During the last glaciation, the island was covered by an ice sheet approximately 1000 m thick. A reconstruction of the ice flow lines, based on glacial directional features, shows that the ice sheet was partly drained through fast‐flowing streams. Fast flow of the ice streams has been recorded in megascale lineations and flutes visible on the currently deglaciated bedrock, and is confirmed by simple mass balance considerations. Locations of the major drainage routes correlate with locations of geothermal anomalies, suggesting that ice stream activity was favoured by lubrication of the bed by meltwater produced in regions of high geothermal heat flux. Similar control of ice flow by geothermal activity is expected in ice sheets currently covering tectonically and volcanically active area such as the West Antarctic ice sheet. Copyright © 2000 John Wiley & Sons, Ltd.  相似文献   

Fate of Lignin in the Process of Aerobic Biological Treatment of Paper Mill Wastewater     

Brigitte Helmreich  Christian Schlegl  Peter A. Wilderer 《洁净——土壤、空气、水》2001,29(5):296-300

Although lignin is known to be not readily biodegradable the concentration of dissolved lignin decreased during aerobic biological treatment of paper mill wastewater performed in sequencing batch reactors (SBR). Systematic lab scale batch tests were conducted to clarify whether the observed removal of lignin was the result of biodegradation or adsorption onto the activated sludge. For the batch tests, sludge samples were taken from sequencing batch reactors operated at solid retention times (SRT) of 10, 15, 20, 30, and 40 days, respectively. The amount of lignin present in the bulk liquid and in the sludge samples was quantified by an analytical procedure comprising pyrolysis, gas chromatography and mass spectrometry (py‐GC/MS analysis). It was found that lignin adsorbs onto the activated sludge by up to 30%[TH]w/w. This demonstrates the sludge excellent adsorption properties. The ultimate removal of lignin is achieved by sludge wasting. The highest overall removal rate was found when sludge was used from the SBR run at SRT of 20 days.  相似文献   

Geostandards and Geoanalytical Research Bibliographic Review 2018     

Ulrike Weis  Jodok Arns  Viktoria Kaiser  Anna Reichstein  Lea Reichstein  Brigitte Stoll  Klaus Peter Jochum 《Geostandards and Geoanalytical Research》2020,44(1):51-56

  相似文献   

High-Resolution LA-ICP-MS for Accurate Determination of Low Abundances of K, Sc and Other Trace Elements in Geological Samples   总被引：1，自引：0，他引：1  

Julia Regnery  Brigitte Stoll  Klaus Peter Jochum 《Geostandards and Geoanalytical Research》2010,34(1):19-38

Laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) was used to determine K, Sc, Ti, V, Cr, Mn, Co, Ni and Zn in geological samples. Because the isotopes of these elements and the internal standard element (Ca) often have interferences from molecular ions when determined using quadrupole or sector-field ICP-MS in low mass resolution mode, ion intensities were measured at a high mass resolution of 4000. We investigated dynamic element fractionation, type and abundance of molecular ions using different geological reference materials. Highly resolved mass spectra were especially important for accurate low-abundance measurements. As a result, maximum "critical" concentration limits for each isotope were obtained, where a mass resolution of 4000 was necessary for reliable LA-ICP-MS analysis. To test the LA-ICP-MS technique, different international reference material glasses and powdered rock reference materials were analysed. Rock powders were fused to glass beads using an Ir-strip heater. Nearly all concentration values for the reference materials agreed with the reference values at the 95% confidence level. To demonstrate routine LA-ICP-MS analysis at a mass resolution of 4000, trace element data for Hawaiian basalts are also presented.  相似文献   

Refinement of the age of the Middle Miocene Fort Ternan Beds,Western Kenya,and its implications for Old World biochronology     

Martin Pickford  Yoshihiro Sawada  Ryoichi Tayama  Yu-ko Matsuda  Tetsumaru Itaya  Hironobu Hyodo  Brigitte Senut 《Comptes Rendus Geoscience》2006,338(8):545-555

It has become increasingly obvious over the past two decades that the fossiliferous strata at Fort Ternan, Kenya, are probably somewhat younger than 14 Ma, an age which has long been attached to the deposits. This realisation flows from geological and biochronological observations. In order to test the hypothesis, resampling of all the lava flows in the region of Fort Ternan was undertaken in 2003, especially those underlying the Fort Ternan Beds in the Kipchorion Gorge where the sequence is the most complete. Samples obtained from lava flows underlying and overlying the fossil beds were analysed for anorthoclase K/Ar and ⁴⁰Ar/³⁹Ar and biotite ⁴⁰Ar/³⁹Ar age determinations. The results reveal that the age of the fossiliferous sediments is ca $13.7\pm 0.3\text{Ma}$. Since Fort Ternan yielded the ‘core fauna’ that defines Faunal Set IV of the East African biochronological sequence this refinement of its age will impact on age estimates of neighbouring Faunal Sets, as well as on other faunas correlated to Fort Ternan, including those in Europe belonging to MN Zones MN 5, MN 6 and MN 7/8. To cite this article: M. Pickford et al., C. R. Geoscience 338 (2006).  相似文献   

Distribution and chronology of Pleistocene permafrost features in France: Database and first results     

Pascal Bertran  Eric Andrieux  Pierre Antoine  Sylvie Coutard  Laurent Deschodt  Philippe Gardère  Marion Hernandez  Claude Legentil  Arnaud Lenoble  Morgane Liard  Norbert Mercier  Olivier Moine  Luca Sitzia  Brigitte Van Vliet‐Lanoë 《Boreas: An International Journal of Quaternary Research》2014,43(3):699-711

Numerous periglacial features (polygons, nets, soil stripes, ice‐wedge pseudomorphs and sand‐wedge casts, involutions) have been recorded in France by examining bibliographical sources and aerial photographs. These data show that a large part of France was affected by permafrost during the Pleistocene and only the southern Aquitaine Basin and Languedoc seem to have been beyond its maximum extent. The first OSL ages obtained from the aeolian infill of wedge structures indicate that at least two phases of thermal contraction cracking occurred in southwestern France between ～25 and 36 ka. Chronostratigraphical data from loess in northern France indicate that these episodes correspond to the formation of ice‐wedge networks associated with tundra gleys. In the latter region, two additional permafrost episodes probably occurred during the Last Glacial, the older one corresponding to the end of Marine Isotope Stage (MIS) 4 around 60 ka and the more recent one to MIS 2 around 19–16 ka. Although stratigraphical data indicate that these episodes were relatively short (about one millennium), relict permafrost may have existed for longer periods in northern France.  相似文献