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71.
Friedemann Baur Matias Di Benedetto Thomas Fuchs Carolyn Lampe Simone Sciamanna 《Marine and Petroleum Geology》2009
For the first time, a new approach to petroleum systems analysis is presented which allows full integration of tectonic and palinspastic restoration with three-dimensional (3D), PVT-controlled, multi-component, three-phase petroleum migration analysis through time. A systematic modeling study has been applied to a study area dominated by fold and thrust belts located in the Sub Andean orogeny near Tarija, Bolivia. The project has been performed with a special focus on the simulation technique and on the correct distribution of temperature, source-rock maturity and pressure development through time with reference to its input data. This is the first pilot project presenting a 3D numerical model in a compressional structural regime to which the basin modeling approach has been applied to explain the observed distribution of temperature, pressure, maturity and petroleum accumulations in general. 相似文献
72.
Eleonora Ammannito M. Cristina De Sanctis Fabrizio Capaccioni M. Teresa Capria F. Carraro Jean‐Philippe Combe Sergio Fonte Alessandro Frigeri Steven P. Joy Andrea Longobardo Gianfranco Magni Simone Marchi Thomas B. McCord Lucy A. McFadden Harry Y. McSween Ernesto Palomba Carle M. Pieters Carol A. Polanskey Carol A. Raymond Jessica M. Sunshine Federico Tosi Francesca Zambon Christopher T. Russell 《Meteoritics & planetary science》2013,48(11):2185-2198
We present global lithological maps of the Vestan surface based on Dawn mission's Visible InfraRed (VIR) Spectrometer acquisitions with a spatial sampling of 200 m. The maps confirm the results obtained with the data set acquired by VIR with a spatial sampling of 700 m, that the reflectance spectra of Vesta's surface are dominated by pyroxene absorptions that can be interpreted within the context of the distribution of howardites, eucrites, and diogenites (HEDs). The maps also partially agree with the ground and Hubble Space Telescope observations: they confirm the background surface being an assemblage of howardite or polymict eucrite, as well as the location of a diogenitic‐rich spot; however, there is no evidence of extended olivine‐rich regions in the equatorial latitudes. Diogenite is revealed on the Rheasilvia basin floor, indicating that material of the lower crust/mantle was exposed. VIR also detected diogenites along the scarp of Matronalia Rupes, and the rims of Severina and a nearby, unnamed crater, and as ejecta of Antonia crater. The diogenite distribution is fully consistent with petrological constraints; although the mapped distribution does not provide unambiguous constraints, it favors the hypothesis of a magma ocean. 相似文献
73.
Simone Recchi Francesca Matteucci Annibale D'Ercole Monica Tosi 《Astrophysics and Space Science》2003,284(2):623-626
We study the effect of different star formation regimes on the dynamical and chemical evolution of Blue Compact Dwarf galaxies.
To do that, we adopt a 2-D hydrocode coupled with detailed chemical yields originating from SNeII, SNeIa and from intermediate-mass
stars. We apply this kind of simulation to a model of galaxy resembling IZw18.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
74.
75.
M. Cristina Fossi Letizia Marsili Giancarlo Lauriano Caterina Fortuna Simone Canese Stefania Ancora Claudio Leonzio Teresa Romeo Ruben Merino Esteban Abad Begoa Jimnez 《Marine environmental research》2004,58(2-5):269
Various studies have revealed high concentrations of contaminants such as organochlorines (OCs) and heavy metals in Mediterranean cetaceans. A geographical trend of contamination (PCBs and DDTs) has been found for striped dolphin (Stenella coeruleoalba). In this study we used a non-lethal approach (skin biopsy) to investigate bioaccumulation of OCs, including polychlorobiphenyls (PCBs), DDTs, polychlorodibenzo-p-dioxins (PCDDs), polychlorodibenzofurans (PCDFs), trace elements (Hg, Cd, Pb) and CYP1A activity (BPMO) in nine striped dolphins sampled in the Aeolian area (Sicily – Italy) in summer 2002. The arithmetic mean value of BPMO activity in this group was 43.46 AUF/g tissue/h. This value is approximately 3 times and 5 times lower, respectively, than the value found in the Ionian and in the Ligurian groups. Skin biopsies of striped dolphins emerged as a suitable material for assessing the toxicological status of the various Mediterranean groups. 相似文献
76.
Andrew S. Cohen Manuel R. Palacios-Fest James McGill Peter W. Swarzenski Dirk Verschuren Robert Sinyinza Tharcisse Songori Bombi Kakagozo Mutanga Syampila Catherine M. O’Reilly Simone R. Alin 《Journal of Paleolimnology》2005,34(1):1-18
We investigated paleolimnological records from a series of river deltas around the northeastern rim of Lake Tanganyika, East Africa (Tanzania and Burundi) in order to understand the history of anthropogenic activity in the lakes catchment over the last several centuries, and to determine the impact of these activities on the biodiversity of littoral and sublittoral lake communities. Sediment pollution caused by increased rates of soil erosion in deforested watersheds has caused significant changes in aquatic communities along much of the lakes shoreline. We analyzed the effects of sediment discharge on biodiversity around six deltas or delta complexes on the east coast of Lake Tanganyika: the Lubulungu River delta, Kabesi River delta, Nyasanga/Kahama River deltas, and Mwamgongo River delta in Tanzania; and the Nyamuseni River delta and Karonge/Kirasa River deltas in Burundi. Collectively, these deltas and their associated rivers were chosen to represent a spectrum of drainage-basin sizes and disturbance levels. By comparing deltas that are similar in watershed attributes (other than disturbance levels), our goal was to explore a series of historical experiments at the watershed scale, with which we could more clearly evaluate hypotheses of land use or other effects on nearshore ecosystems. Here we discuss these deltas, their geologic and physiographic characteristics, and the field procedures used for coring and sampling the deltas, and various indicators of anthropogenic impact. 相似文献
77.
Quantitative and qualitative diatom analyses from the north Nile Delta lakes sediments of Egypt were used to evaluate the
paleoenvironmental development of the lakes and climatic changes during the late Holocene. We analyzed 565 samples taken from
19 cores from Manzala, Burullus and Edku lakes. A total of 263 diatom species and varieties were identified. Multivariate
statistical analyses distinguished 17 ecological groups that reflect changes in water salinity, lake-level and trophic state
of the lakes, which in turn are mainly related to climatic changes and anthropogenic impacts. Manzala and Burullus lakes experienced
a series of alternation between fresh, brackish and marine episodes, which were associated with wet and dry climates. Edku
Lake cores, however, contained only three ecological groups that are characteristic of brackish water conditions. The general
depositional regime in the lakes indicated five environmental phases: (a) a deep freshwater phase when the Nile flood water
reach the lakes during humid warm climate; (b) a shallow freshwater phase with some macrophytes during a dry climate; (c)
a shallow brackish water phase when Nile floodwater ceased during a dry climate and the lakes shifted to brackish conditions;
(d) a mixed environmental phase when the seawater mixed with freshwater from drains and canals (water salinity fluctuated
widely from freshwater to estuarine and full marine conditions); (e) a fully marine phase when seawater entered the lakes
at all stages of the tide. 相似文献
78.
Boron and Oxygen Isotope Composition of Certified Reference Materials NIST SRM 610/612 and Reference Materials JB-2 and JR-2 总被引:1,自引:0,他引:1
Simone Kasemann Anette Meixner Alexander Rocholl Torsten Vennemann Martin Rosner Axel K. Schmitt Michael Wiedenbeck 《Geostandards and Geoanalytical Research》2001,25(2-3):405-416
We present data on the concentration, the isotope composition and the homogeneity of boron in NIST silicate glass reference materials SRM 610 and SRM 612, and in powders and glasses of geological reference materials JB-2 (basalt) and JR-2 (rhyolite). Our data are intended to serve as references for both microanalytical and wet-chemical techniques. The δ11 B compositions determined by N-TIMS and P-TIMS agree within 0.5% and compare with SIMS data within 2.5%. SIMS profiles demonstrate boron isotope homogeneity to better than δ11 B = 2% for both NIST glasses, however a slight boron depletion was detected towards the outermost 200 μm of the rim of each sample wafer. The boron isotope compositions of SRM 610 and SRM 612 were indistinguishable. Glasses produced in this study by fusing JB-2 and JR-2 powder also showed good boron isotope homogeneity, both within and between different glass fragments. Their major element abundance as well as boron isotope compositions and concentrations were identical to those of the starting composition. Hence, reference materials (glasses) for the in situ measurement of boron isotopes can be produced from already well-studied volcanic samples without significant isotope fractionation. Oxygen isotope ratios, both within and between wafers, of NIST reference glasses SRM 610 and SRM 612 are uniform. In contrast to boron, significant differences in oxygen isotope compositions were found between the two glasses, which may be due to the different amounts of trace element oxides added at ten-fold different concentration levels to the silicate matrix. 相似文献
79.
Moratti G. Benvenuti M. Santo A. P. Laurenzi M. A. Braschi E. Tommasini S. 《International Journal of Earth Sciences》2018,107(7):2491-2515
International Journal of Earth Sciences - This study is based upon a stratigraphic and structural revision of a Middle Jurassic–Upper Cretaceous mostly continental succession exposed between... 相似文献
80.
Lithospermum (Boraginaceae) belongs to a small group of plant taxa that accumulate biogenic carbonate in their fruits. In this genus, carbonate incrustations form in the cells of the epidermis and sclerenchyma of the pericarp. Fossil Lithospermum fruits (nutlets) with well-preserved calcified tissues commonly occur in Quaternary sediments and cultural layers. We tested the suitability of biogenic carbonate of Lithospermum fruits for radiocarbon dating using a total of 15 AMS measurement results from four modern and 11 fossil samples. The 14C data from modern samples suggest that Lithospermum utilises only atmospheric carbon to synthesise calcite in the nutlets. In general, the ages determined through 14C dating of fossil fruitscorresponded well with the absolute-age intervals for archaeological sites over the last 5000 yr. Biogenic carbonate of Lithospermum fruits, like that of Celtis, represents a new source of chronological information for late Quaternary studies. 相似文献