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1.
Chemical structure of Jurassic vitrinites isolated from the coals in basins in NW China have been checked using solid state 13C NMR and flash pyrolysis-GC/MS. Study shows some Jurassic collodetrinites are rich in aliphatic products in pyrolysates, consisting with the high amount of methylene carbon in 13C NMR spectra. In contrast, pyrolysates of Jurassic collotelinites are rich in phenols and alkylbenzenes. Also one Pennsylvanian and one Permian vitrinite selected from the Ordos basin, NW China have been checked for comparison. The proportion of aliphatics is low in pyrolysates, and aliphatic carbon peak in 13C NMR spectrum of Permian vitrinite is mostly composed of gas-prone carbons compared with collodetrinites in those Jurassic basins. But both pyrolysis and 13C NMR data shows the Pennsylvanian vitrinite is not only gas-prone but also oil-prone. Relatively high proportion of long chain aliphatic structure of some Jurassic vitrinite in Junggar, Turpan-Hami basins may be due to the contribution of liptodetrinites, which may be included during the formation of vitrinites. And it seems that suberinite is the most possible precursor of long chain aliphatics in the structure of Jurassic collodetrinite. 相似文献
2.
Combined subsidence and thermal 1D modelling was performed on six well-sections located in the north-western Mid-Polish Trough/Swell
in the eastern part of the Central European Basin system. The modelling allowed constraining quantitatively both the Mesozoic
subsidence and the magnitude of the Late Cretaceous–Paleocene inversion and erosion. The latter most probably reached 2,400 m
in the Mid-Polish Swell area. The modelled Upper Cretaceous thickness did not exceed 500 m, and probably corresponded to 200–300 m
in the swell area as compared with more than 2,000 m in the adjacent non-inverted part of the basin. Such Upper Cretaceous
thickness pattern implies early onset of inversion processes, probably in the Late Turonian or Coniacian. Our modelling, coupled
with previous results of stratigraphic and seismic studies, demonstrates that the relatively low sedimentation rates in the
inverted part of the basin during the Late Cretaceous were the net result of several discrete pulses of non-deposition and/or
erosion that were progressively more pronounced towards the trough axis. The last phase of inversion started in the Late Maastrichtian
and was responsible for the total amount of erosion, which removed also the reduced Upper Cretaceous deposits. According to
our modelling results, a Late Cretaceous heat-flow regime which is similar to the present-day conditions (about 50 mW/m2) was responsible for the observed organic maturity of the Permian-Mesozoic rocks. This conclusion does not affect the possibility
of Late Carboniferous–Permian and Late Permian–Early Triassic thermal events. 相似文献
3.
用空间分辨率为1km的MODIS和MISR数据可计算16天BRDF和反照率产品,该文证明了在多数采样条件下,用MODIS/MISR角度采样的BRDF和反照率反演精度在5到10个百分点以内。 相似文献
4.
5.
Saturated and aromatic biomarker ratios continue to change systematically through the oil window and into the gas-condensate window to high vitrinite reflectances (Ro = 1.16%) in mature marine and lacustrine Mesozoic clastic samples from a South African basin. Two of the ratios reverse above Ro = 0.9%. These unusual maturation effects result from isolated periods of high rates of maturation increase. The basin cooled regionally after the break-up of Gondwana but high heating rates prevailed during the late Cretaceous-early Tertiary, as Africa moved across a hotspot, and again in the late Tertiary as a result of a possible hotspot and hydrothermal event. 相似文献
6.
植被冠层多角度遥感研究进展 总被引:7,自引:0,他引:7
综述了近年来关于植被冠层多角度遥感研究的最新成果,分别讨论了二向性反射的正向模型和参量反演问题在理论和实际应用中的新进展。分析了卫星平台多角度遥感的应用前景及面临的困难,指出了未来多角度遥感研究的新方向。 相似文献
7.
YAN Shouxun Laboratory of Remote Sensing Information Sciences Institute of Remote Sensing Applications Chinese Academy of Sciences Beijing China 《中国科学D辑(英文版)》2004,47(9)
To examine the application potential of hyperspectral remote sensing techniques in classifying very low-grade metamorphic belts, the composition of clay minerals and the cyrstallinity of illite from mudstones were measured using XRD and VIS-SWIR (400-2500 nm) reflectance spectroscopy. Based on the illite cyrstallinity, Kubler Index (KI), the Early Triassic LuoLou Group and the Middle Triassic lower Baifeng Formation were classified as the lower Epizone with KI△2θ° ranging from 0.22 to 0.25, the upper Baifeng Formation as upper anchizone with KI△2θ°ranging from 0.26 to 0.33, and the Hekou Formation as lower anchizone with KI△2θ° ranging from 0.38 to 0.40. According to a KI△2θ° value of 0.43, it is possible that there may exist a local diagenetic zone in the upper strata. The illite cyrstallinity Kubler index and the metamorphic grade increase from the bottom to the top of the stratigraphic sequence. The metamorphic grade boundaries nearly match the stratigraphic boundaries, indicating a burial metamorphism nature for the stratigraphic sequence. From the bottom to the top of the sequence, the spectral absorption band center of clay minerals from fresh rocks is around 2200 nm. The absorption band centers change towards shorter wavelengths: the Luolou Group being at 2220 nm, the Baifeng Formation at 2217-2213 nm, the lower member of the Hekou Formation at 2214-2206 nm, and the upper member of the Hekou Formation at 2205-2197 nm. The spectral absorption band center of illite shows the same change pattern. These results indicate that very low-grade metamorphic belts can be subdivided using spectral indices of clay minerals, which are measured by using field portable spectroradiometers. However, it may not work well with satellite and airborne sensors. 相似文献
8.
9.
动物碎屑反射率作为源岩成熟度指标的有效性和局限性探讨 总被引:2,自引:0,他引:2
综述了笔石,几丁虫,虫牙等动物碎屑的时空分布、光性特征及影响动物碎屑反射率的因素。由于下古生界源岩中缺乏能表征成熟度指标的镜质体,使得动物碎屑反射率无法与目前国际上公认的成熟度指标--镜质体反射率直接进行对比,而得利用CAI、红外参数及沥青反射率等中间媒介质间接地与镜质体反射率进行对比,由此建立起的动物碎屑反射率与镜质体反射率的对应关系的准确程度就受到一定影响。同时由于动物碎屑分布层位有限及本身光 相似文献
10.
利用漫反射光谱鉴定红粘土中针铁矿和赤铁矿 总被引:5,自引:0,他引:5
针铁矿(Gt)和赤铁矿(Hm)是广泛存在于土壤和沉积物中的重要铁矿物。这两种矿物在土壤和沉积物中含量很低,常规的测试手段很难有效地测定其含量。利用反射光谱联合加热处理的方法,可对土壤及沉积物样品中针铁矿和赤铁矿进行定性或半定量测定。实验结果显示,样品加热到300℃后,针铁矿的反射光谱的一阶导数特征峰发生了变化,赤铁矿的一阶导数特征峰却没有明显的变化。因此加热前后样品反射光谱一阶导数的变化取决于针铁矿和赤铁矿的含量。利用这种方法估计黄土高原第三纪红粘土样品中的赤铁矿含量约为0.3%~0.4%,针铁矿含量约为0.5%~1%。 相似文献