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Li Q.,Xian University of Science and Technology | Li Q.,Changan University | Li Y.,China Academy of Geological science
Geophysical Prospecting for Petroleum | Year: 2014

To improve the precision and identification capacity of anisotropic parameter spectrum extracted from seismic data, based on traveltime-distance equation of reflection wave in anisotropic media, selective correlation method is introduced. The selected-correlation method is used to improve the mapping of anisotropic parameter spectrum and the extraction precision of anisotropic parameters spectrum. Model test with synthetic data indicates that the resolution of seismic anisotropic parameters spectrum with selected-correlation method is greatly improved and thin layers can be identified. The application to seismic gathers from real data in weak anisotropic area demonstrates that stretching distortion of seismic event with large-offset data is reduced after conventional NMO correction. The quality of seismic imaging in complicated geologic area is improved.

Wang D.,China University of Geosciences | Li B.,China Academy of Geological science | Ji J.,Peking University | Liu Y.,China University of Geosciences
Yanshi Xuebao/Acta Petrologica Sinica | Year: 2014

The metamorphic rock series located in the southern Lancang River tectonic zone was distributed as sporadic scattered due to large area of the Lincang granite batholiths outcrops. In the study area, several scientific problems are still not very clear such as the Precambrian crystalline basement exists or not, the age of the ancient metamorphic rocks, the metamorphic time of metamorphic rocks in the Lancang River tectonic zone, and so on. In this paper, the metamorphic rocks were taken as the study objects and yielded the U-Pb ages of 1802Ma, 1404Ma, 1092Ma, 1054Ma, 906 ∼961Ma, 812Ma and 727-623Ma using the zircon U-Pb SHRIMP dating method. These ages belong to Early Proterozoic, Mesoproterozoic and Neoproterozoic era and also reveal the existence of Precambrian crystalline basement in the study area, and the Precambrian crystalline basement was destroyed or transformed by a period regional Triassic magmatic event (∼230Ma). The granitic gneiss of Changning-Goujie section cross the Lancang River yielded the zircon U-Pb SHRIMP concordia age of 73.9 ± 1.8 Ma (MSWD = 1.3, N = 6), which was the record of Late Cretaceous metamorphic event in the Lancang River tectonic zone. Based on this study and combined with the other research data, it is suggested that the southern Lancang River area had the Precambrian crystalline basement existence and the metamorphic time of the Lancang River tectonic zone began in Late Cretaceous (85 ∼74Ma). This metamorphic event probably continued until 36Ma, and the strike-slip movements started from ∼32Ma. So the metamorphic structural event was earlier than the strike-slip geological event in the Lancang River tectonic zone.

Wang X.,Nanjing University | Chou I.-M.,U.S. Geological Survey | Hu W.,Nanjing University | Burruss R.C.,U.S. Geological Survey | And 2 more authors.
Geochimica et Cosmochimica Acta | Year: 2011

Raman spectroscopy is a powerful method for the determination of CO2 densities in fluid inclusions, especially for those with small size and/or low fluid density. The relationship between CO2 Fermi diad split (Δ, cm-1) and CO2 density (ρ, g/cm3) has been documented by several previous studies. However, significant discrepancies exist among these studies mainly because of inconsistent calibration procedures and lack of measurements for CO2 fluids having densities between 0.21 and 0.75g/cm3, where liquid and vapor phases coexist near room temperature.In this study, a high-pressure optical cell and fused silica capillary capsules were used to prepare pure CO2 samples with densities between 0.0472 and 1.0060g/cm3. The measured CO2 Fermi diad splits were calibrated with two well established Raman bands of benzonitrile at 1192.6 and 1598.9cm-1. The relationship between the CO2 Fermi diad split and density can be represented by: ρ=47513.64243-1374.824414×Δ+13.25586152×Δ2-0.04258891551×Δ3 (r2=0.99835, σ=0.0253g/cm3), and this relationship was tested by synthetic fluid inclusions and natural CO2-rich fluid inclusions. The effects of temperature and the presence of H2O and CH4 on this relationship were also examined. © 2011 Elsevier Ltd.

Li J.H.,University of Science and Technology of China | Chi Z.Q.,China Academy of Geological science | Chen H.F.,National Taiwan Ocean University
Advanced Materials Research | Year: 2011

NaY zeolite molecular sieves have been synthesized using diatomite as a main starting material via a hydrothermal method. In this approach, the mixture of diatomite and Na2CO3 in mass ratio of 1.0/1.46 was first calcined at temperature of 830 °C for about 1.5 h. The calcined materials were then dissolved in water to obtain a solution and the composition is 15.1 Na2O : 1 Al2O3 : 11.5 SiO2 : 832 H2O. The solution was used to synthesize NaY zeolite by the crystals seeds (27.76Na2O·1.00Al2O 3·25.07SiO2·305.66H2O) via hydrothermal treatment. The hydrothermal temperature is 100 °C and the percentage of added crystal seeds is 10% (volume) relative to calcined materials. The obtained zeolite was identified by X-ray diffraction (XRD), and was characterized by scanning electron microscope (SEM), transmission electron microscope (TEM) and nitrogen sorption analysis, which showed that a high yield of NaY type with a high crystalinity was obtained. © (2011) Trans Tech Publications.

Qu H.-Y.,China Academy of Geological science | Qu H.-Y.,Chinese Academy of Geological Sciences | Qu H.-Y.,Nanjing University | Pei R.-F.,China Academy of Geological science | And 2 more authors.
Jilin Daxue Xuebao (Diqiu Kexue Ban)/Journal of Jilin University (Earth Science Edition) | Year: 2010

In order to study the magmatic evolution and relationship between magmatism and mineralization, the SHRIMP U-Pb dating of zircon in Fenghuangshan quartz monzodiorite and granodiorite in Tongling area, Anhui Province are carried out. The SHRIMP U-Pb age of zircon from the quartz monzodiorite changes from (136.0 ± 2.0) to (143.0 ± 2.4) Ma, and the weighted mean age is (139.4 ± 1.2) Ma (n=15, MSWD=0.76). Results of SHRIMP U-Pb zircon dating of granodiorite is from (136.7 ± 2.0) to (145.3 ± 2.4) Ma, and the weighted mean age is (141.0 ± 1.1) Ma (n=17, MSWD=1.5). The emplacing age of the Fenghuangshan intrusion is the Late Jurassic. Moreover, the molybdenite Re-Os isochrone age is accordant with that of the granodiorite and older than the age of quartz monzodiorite. The copper mineralization has the closer relationship with the granodiorite and they are formed contemporaneously. Isotopic data indicate that the mineralization is related to the deep fluids derived from mantle magma differentiation. The extensional process resulted from the whole lithosphere thickening and the basaltic magma approaching, caused by from the aesthenosphere mantle and upper crust decompression and melting, played an important role in forming of the Fenghuangshan intrusion.

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