Direct determination of the aliphatic carbon content of individual macerals in petroleum source rocks by near-infrared microspectroscopy     

A.K. Blob  J. Rullktter  D.H. Welte 《Organic Geochemistry》1988,13(4-6)

In order to determine the aliphatic carbon content in sedimentary organic particles near-infrared (NIR) microscope spectroscopy has been employed for the first time. An ordinary lens microscope photometer common for vitrinite reflectance measurements has been modified to detect hydrocarbon absorbance differences with a spatial resolution of about 30 μm.Microscopic studies of natural and artificial samples under reflected light condition were shown to be unsuitable for quantitative aliphatic C--- determination. Transmitted light measurements ofliptinites in polished thin sections, however, could be calibrated against synthetic polymer blends without exact knowledge of the sample thickness. In contrast to the established microscopic techniques for characterizing coal and petroleum source rocks NIR microspectroscopy is able to follow the chemical alterations of liptinites directly with comparatively low cost.  相似文献   

Debris from the basal ice of the Agassiz ice cap,Ellesmere Island,arctic Canada     

A. M. D. Gemmell  M. J. Sharp  D. E. Sugden 《地球表面变化过程与地形》1986,11(2):123-130

This article describes the characteristics of debris obtained from the basal ice in a borehole in the Agassiz ice cap, Ellesmere Island, Northwest Territories by the Canadian Polar Continental Shelf Project in 1979. The debris appears to have been incorporated by basal freezing at a time when the base of the glacier upstream was near the pressure melting point and some 19°C warmer than at the present site. Such an occurrence may be explained by a different flow regime, by a thicker ice sheet, by the influence of irregular bedrock topography on basal ice conditions at some stage in the past, or by a combination of these factors.  相似文献   

A quantitative scanning electron microscope study of evidence for lichen weathering of limestone,Mendip Hills,Somerset     

Heather Viles 《地球表面变化过程与地形》1987,12(5):467-473

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Analytical electron microscope studies of size-segregated particles collected during AGASP-II,flights 201–203     

Patrick J. Sheridan 《Journal of Atmospheric Chemistry》1989,9(1-3):267-282

Cascade impactor samples were collected over the Alaskan Arctic during the first three research flights of AGASP-II. These samples were analyzed using analytical electron microscopy to determine the morphology, mineralogy and elemental composition of individual particles. For analytical considerations, a typical impactor sample was run for approximately 20 min, thus giving excellent time resolution of discrete events.Samples collected during flights 201 and 202 consisted of stratospheric aerosol and lower-altitude haze samples. Stratospheric samples were characterized by moderate loadings of H₂SO₄ droplets with relatively few particles of other types. Samples collected in tropospheric haze layers generally exhibited light-to-moderate particle loadings. H₂SO₄ was again the most prevalent species, with crustal and anthropogenic particles also observed. One sample taken over south-central Alaska near the end of flight 203 showed high concentrations of solid crustal particles, with relatively little associated H₂SO₄. Giant particles larger than 5 m were occasionally observed in this aerosol. The composition of this material closely matches that of bulk ash from the Mt. Augustine volcano, which erupted 9–13 days before collection of this sample. This brings forth the possibility that pockets of ash-rich aerosol existed over parts of south and central Alska during the AGASP-II field mission. There is no evidence that these volcanic aerosols were present in the AGASP study area north of the Brooks Range.  相似文献   

Further studies on torbanites and coorongite using transmission electron microscopy and C-isotope analysis     

Miryam Glikson 《Organic Geochemistry》1984,7(2):151-160

Transmission electron microscopy of torbanites from various localities in eastern Australia has revealed micro-organisms of possible methanogenic affinity. Botryococcus remains in the torbanites displayed close resemblance to the rubbery B. braunii accumulations deposited in recent bodies of freshwater origin. Compaction and collapse of structure seem to be the major visible alteration to the algal colonies. C-isotope compositions of the torbanites favour methanogenic activity. Comparison with recent botroyococcal accumulations support diagenetic alteration at a very early stage of deposition.  相似文献   

A simple accelerated rock weathering method to predict acid generation kinetics     

David M. Kargbo  Jiren He 《Environmental Geology》2004,46(6-7):775-783

The development of effective, and economical pre-development waste rock management plans requires an accurate estimate of the quality of drainage generated during mining. This study was conducted to determine if a simple accelerated rock weathering method with lower capital and personnel costs can be used in lieu of the elaborate and costly ASTM method to predict the quality of drainage generated. It involves subjecting rock samples to a constant relative humidity and temperature for 7 days and leach flooding the weathered samples on the 7th day. The acid production rate from the new weathering method correlates quite well with the net neutralization potential generated from the standard acid-base accounting procedure (R²=0.940) which has been demonstrated to be correct 90% of the time in assessing overburden quality, and a mineralogical method (R²=0.924). For investigators interested in generating weathering kinetic parameters, the simple and less costly accelerated weathering method is proposed.  相似文献   

Effect of depositional method on the undrained behavior and microstructure of sand with silt     

Jerry A. Yamamuro  Fletcher M. Wood 《Soil Dynamics and Earthquake Engineering》2004,24(9-10):751

It has been known for many years that depositional method plays an important part in the results of laboratory testing of clean sands. In this paper, undrained triaxial compression tests were performed on specimens composed of Nevada sand with 20% non-plastic silt content using a variety of depositional methods that include slurry deposition, water sedimentation, air pluviation, mixed dry deposition, and dry funnel deposition. It was found that there was a marked difference in the undrained behavior even though the density and stress conditions were identical. The conclusion was that the soil fabric was responsible for this result. Using the scanning electron microscope, a method was developed to examine and quantify the microstructure of silty sand. These results appear to indicate that there are internal particle structures in sand with silt and their relative quantities correlate with the observed macroscopic undrained behavior.  相似文献   

中国煤和烃源岩镜质组的激光诱导荧光显微特征及其应用   总被引：1，自引：1，他引：1  

刘祖发  肖贤明  刘德汉  申家贵  张轶男  米敬奎 《地球化学》2003,32(4):382-386

应用自行组装的激光诱导荧光显微光度计(LIFM)系统地研究了中国煤和烃源岩中镜质组的荧光强度及荧光变化，建立了镜质组的荧光变化与成熟度之间的相关模式图(R-I-VRo)，该图可解决镜质组反射率抑制问题，并将烃源岩成熟度评价范围扩展到VRo达2．0％左右，该方法对于正确评价烃源岩成熟度具有广泛的应用前景。  相似文献   

Genetic Mechanism of Mineral Inclusions in Zircons from the Khondalite Series, Southeastern Inner Mongolia     

LIU Fulai  SHEN Qihan Institute of Geology  Chinese Academy of Geological Sciences  Beijing 《《地质学报》英文版》2003,77(1):28-35

The early Precambrian khondalite series is widely distributed in the Jining-Zhuozi-Fengzhen-Liangcheng area, southeastern Inner Mongolia. The khondalite series mainly consists of sillimanite garnet potash feldspar (or two-feldspar) gneiss and garnet biotite plagioclase gneiss. These gneissic rocks have commonly experienced granulite-facies metamorphism. In zircons separated from sillimanite garnet potash feldspar gneisses, many mineral inclusions, including Sil, Grt, Ky, Kfs, Qtz and Ap, have been identified by the Laser Raman spectroscopy. Generally, prograde metamorphic mineral inclusion assemblages such as Ky + Kfs + Qtz + Ap and Ky + Grt + Kfs + Qtz are preserved in the core of zircon, while peak granulite-facies metamorphic minerals including Sil + Grt + Kfs + Qtz and Sil + Grt + Kfs + Qtz + Ap are identified in the mantle and rim of the same zircon. However, in some zircons are only preserved the peak metamorphic minerals such as Sil + Grt + Kfs + Qtz and Sil + Grt + Kfs + Qtz + Ap from core to ri  相似文献   

Genesis of a mottled horizon by Fe-depletion within a laterite cover in the Amazon BasinGenèse d'un horizon tacheté par déferruginisation dans une couverture à latérite du Bassin amazonien     

Vania Rosolen  Mathieu Lamotte  René Boulet  Jean Trichet  Olivier Rouer  Adolpho José Melfi 《Comptes Rendus Geoscience》2002,334(3):187-195

A mottled horizon in a laterite cover (without any duricrust) was studied by microscopy and quantitative chemical microanalysis. Apart from the voids, light red spots consisting of Fe-rich particles (≈2 μm) are set in clayey plasma. Dark red spots consisted of concentrations of Fe-rich particles. These patterns are inherited. On the border of structural or biological voids, where Fe-depletion features are systematic, gray or yellow spots result from dissolution of the Fe-rich particles and impregnation of the plasma by iron, respectively. The present Fe-depletion is the dominant process that explains the mottled differentiation and the absence of lateritic duricrust. To cite this article: V. Rosolen et al., C. R. Geoscience 334 (2002) 187–195.  相似文献