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61.
高光谱成像作为目前遥感领域最先进的技术,在地质应用中取得了巨大成功。岩石和矿物由于电子过程和分子振动可以产生特征的光谱吸收,因此可以利用高光谱技术进行岩矿填图,快速且准确地获取区域内岩石和矿物的分布情况,进而圈定有潜力的找矿靶区。岩矿高光谱通过对岩矿信息的提取可获得矿物类别和矿物丰度分布甚至矿物化学成分的填图结果,识别方法包括光谱匹配、模式识别和人工智能方法3大类。GF-5卫星上搭载的高光谱成像仪覆盖度宽、光谱分辨率和信噪比高,满足矿物精细识别和大比例尺、大面积岩性填图的要求,应用前景广阔。青藏高原地区矿产资源丰富、岩体裸露但地势偏远,有利于高光谱遥感蚀变矿物填图,开展区域找矿工作。同时,高光谱遥感凭借其空间尺度优势,可以方便快捷地获取区域整体信息,结合地球化学的时间信息,可为青藏高原关键地质科学问题的解决提供新的视角。提升岩矿高光谱遥感的定量化和智能化水平,将传统地质学方法获得的地下深部资料与遥感手段获取的地表数据结合,是促进地质遥感和地球系统科学发展的重要途径。 相似文献
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姬塬油田长4+5砂岩储层孔隙类型与成岩作用 总被引:9,自引:1,他引:9
通过常规物性、岩石及铸体薄片、重矿物、X射线衍射、扫描电镜等多项测试方法,对鄂尔多斯盆地姬塬油田长4 5含油砂体的岩石学特征、成岩作用、储集类型进行了分析和研究。长4 5储层孔隙主要以粒间孔和长石溶孔为主,粒间溶孔次之,孔隙组合一般以粒间孔和溶孔-粒间孔为主。本区破坏性成岩作用包括机械压实作用、石英及长石的次生加大、碳酸盐胶结作用等,其中压实作用是造成本区砂岩原生孔隙大量丧失的主要原因。建设性成岩作用为溶蚀作用、绿泥石粘土膜形成作用,但溶蚀作用产生的次生孔隙对储层物性的改善不足。 相似文献
64.
《地学前缘(英文版)》2022,13(3):101367
New samples returned by China Chang’e-5 (CE-5) mission offer an opportunity for studying the lunar geologic longevity, space weathering, and regolith evolution. The age determination of the CE-5 samples was among the first scientific questions to be answered. However, the precious samples, most in the micrometer size range, challenge many traditional analyses on large single crystals of zircon developed for massive bulk samples. Here, we developed a non-destructive rapid screening of individual zirconium-containing particle for isotope geochronology based on a Micro X-ray fluorescence analysis (µXRF). The selected particles were verified via scanning electron microscopy (SEM), 3D X-ray microscopy (XRM), and focused ion beam scanning electron microscopy (FIB-SEM) techniques, which showed that zirconium-bearing minerals with several microns were precisely positioned and readily suitable for site-specific isotopic dating by second ion mass spectrometry (SIMS). Such protocol could be also applicable in non-destructively screening other types of particles for different scientific purposes. We therefore proposed a correlative workflow for comprehensively studying the CE-5 lunar samples from single particles on nanometer to atomic scales. Linking various microscopic and spectromicroscopic instruments together, this workflow consists of six steps: (1) single-particle selection with non-destructive µXRF technique, (2) 2D/3D morphological and structural characterization with a correlative submicron 3D XRM and nanoscale resolution FIB-SEM imaging methods, (3) SEM analysis of the surface morphology and chemistry of the selected particle, (4) a series of microscopic and microbeam analyses (e.g., SEM, electron probe microanalysis, and SIMS) on the cross-section of the selected particle to obtain structural, mineralogical, chemical, and isotopic features from the micron to nanometer scale, (5) advanced 2D/3D characterization and site-specific sample preparation of thin foil/tip specimens on a microregion of interest in the selected particle with FIB-SEM technique, and (6) comprehensive analyses on the FIB-milled specimens at nanometer to atomic scale with synchrotron-based scanning transmission X-ray microscopy, analytic transmission electron microscopy, and atom probe tomography. Following this technical roadmap, one can integrate multiple modalities into a uniform frame of multimodal and multiscale correlated datasets to acquire high-throughput information on the limited or precious terrestrial and extraterrestrial samples. 相似文献
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Malorie Dierick Éric Pili Nelly Assayag Pierre Agrinier 《Geostandards and Geoanalytical Research》2017,41(3):397-409
A new method for accurate determination of oxygen isotopes in uranium oxides encountered in the nuclear fuel cycle was developed using the conventional BrF5 fluorination technique. Laser‐assisted fluorination was tested for comparison. We focused on fine powders of triuranium octoxide (U3O8), uranium dioxide (UO2±x with 0 ≤ x ≤ 0.25), uranium trioxide (UO3.nH2O, with 0.8 ≤ n ≤ 2) and diuranates (M2U2O7.nH2O, with M = NH4, Na or Mg0.5 and 0 ≤ n ≤ 6). Fluorination at room temperature and heating under vacuum at 150 °C are shown to eliminate both adsorbed and structural water from the powder samples. Precision fit for purpose of δ18O values (± 0.3‰, 1s) and oxygen yields (close to 100%) were obtained for U3O8 and UO2 where oxygen is only bound to uranium. A lower precision was observed for UO3.nH2O and M2U2O7.nH2O where oxygen is both present in the structural H2O and bonded to uranium and where the extracted O2(g) can be contaminated by NF3 and NOx compounds. Laser‐assisted fluorination gave shifted δ18O values between +0.8 and +1.4‰ for U3O8, around ?0.8‰ for UO3.nH2O and between ?3.9 and ?4.5‰ for M2U2O7.nH2O (± 0.3‰, 1s) compared with the conventional method. 相似文献
66.
SPOT-5影像的高分辨率和高信息量的性质,使其得到了广泛的应用,特别是在全国第二次土地利用调查中得到了更加深入的应用。而数字正射影像的制作是SPOT-5遥感影像应用的关键所在。本文在介绍DOM制作的基础上,依据当前获取GCP主要的三种途径采用ERDAS遥感图像处理软件进行了实验,并对最终的结果精度进行分析,总结了DOM制作过程的相关问题。 相似文献
67.
Shuhuan Du Baosheng Li Dongfeng Niu David Dian Zhang Xiaohao Wen Deniu Chen Yi Yang Fengnian Wang 《Chemie der Erde / Geochemistry》2011,(1):87-95
The MGS5 segment of the Milanggouwan stratigraphical section in China's Salawusu River Valley records 8.5 sedimentary cycles consisting of dune sands alternating with fluviolacustrine facies or/and paleosols. Based on a comprehensive analysis of the distribution of Rb and Sr within the segment and paleoecological evidence (fossils), it appears that the observed sedimentation cycles mainly resulted from fluctuations between dry-cold and warm-humid climates, which indicates that the MGS5 segment experienced at least eight cold-dry and nine warm-humid climatic fluctuations. Of these, 12 cold–warm climate fluctuations correspond to DO20–DO25 and stadia 21–26 recorded by the NGRIP ice cores. Another five cold–warm climatic fluctuations that occurred during MGS5e correspond to five substages (5e1–5e5) recorded by the GRIP ice cores from Greenland. This kind of high-frequency climatic fluctuation on a kiloyear scale was mainly subject to variations in the strength of the East Asian winter and summer monsoons. 相似文献
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MM5三维变分系统在北京地区冷暖季背景场误差的对比分析 总被引:2,自引:2,他引:2
NMC方法是目前较广泛采用的一种对模式背景场误差协方差进行统计分析的一种方法。本文根据积累的2002年8月份和2003年2月份各一个月模式预报结果,采用NMC方法,计算了中尺度模式MM5V3在北京地区的冷暖季背景场误差,详细给出其气候统计特征。通过对比分析发现,背景场误差特征对于不同的模式变量、水平分辨率、垂直层各不相同,冷暖季背景场误差也有不同的特征,其差别主要表现在风场。这些特征与模式模拟区域的平均天气状况相对应,同化应该在各模式区域分别进行。MM5三维变分系统在北京地区的实际应用中,应发展根据实际季节变换背景场误差协方差矩阵的方法。 相似文献
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