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Magnetic mineralogy of the Hongqiling Cu-Ni sulphide deposit: Implications for ore genesis

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Progress in Natural Science:Materials International 2007年第10期17卷 1192-1198页

作者： Xi Aihua1,2, Ge Yuhui1, Cai Yuanfeng2 and Zhang Xuefeng3(1. Faculty of Resources & Environment, Southwest petroleum university, Chengdu 610500, china 2. State Key Laboratory for Endogenic Metal Deposit Research, Nanjing university, Nanjing 210093, china 3. department of Natural Resources & Technology Information, china university of petroleum, beijing 102249, china) Faculty of Resources and Environment Southwest Petroleum University Chengdu 610500 China State Key Laboratory for Endogenic Metal Deposit Research Nanjing University Nanjing 210093 China department of Natural Resources and Technology Information China University of Petroleum Beijing 102249 China

Pyrrhotite is one of the common ore minerals in Cu-Ni sulphide deposits, but only monoclinic pyrrhotite is ferromagnetic at room temperature. X-ray and EPA analyses reveal that most pyrrhotite forming sideronitic texture in the Hongqiling Cu-Ni sulphide deposit is monoclinic, but that in the massive ore is a mixture of monoclinic and hexagonal pyrrhotites. Differential thermal and magnetic- thermogravimetric analyses of massive ore indicate a magnetic transition and heat absorption at 323℃, suggesting that this temperature is the thermomagnetic and phase transition point of pyrrhotite. For massive pyrrhotite ores heated at 400oC for 30 h and then quenched by cool water, the monoclinic pyrrhotite (mpo) transforms completely into the hexagonal pyrrhotite (hpo). However, all the pyrrhotites resulting from slow cooling of the sample in air are mpo. These results indicate that transformation between hpo and mpo depends upon the cooling rate. Therefore, massive ores in this deposit might have been formed via rapid cooling of ore melts. On the other hand, it is significant to study the effect of the ratio of the magnetite in total ores on the genesis of magmatic Cu-Ni suphide deposits.

关键词： pyrrhotite magnetite genesis of Cu-Ni sulphide deposit Hongqiling.

A physical model study of effect of fracture aperture on seismic wave

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Science china earth sciences 2008年第S2期51卷 233-240页

作者： WEI JianXin & DI BangRang CNPC Key Physical Exploration Laboratory,china university of petroleum,beijing 102248,china CNPC Key Physical Exploration Laboratory China University of Petroleum Beijing China

Based on Hudson’s theoretical hypothesis of equivalent fracture model,inserting aligned round chips in solid model can simulate fractured media. The effect of fractures on the propagation of P and S waves can be observed by changing the fracture thickness. The base model is made of epoxy resin,and the material of fractures is a kind of low-velocity mixture containing silicon rubber. With constant diameter and number of fractures in each model,one group of models can be formed through changing the thickness of fracture. These models have the same fracture density. By using the ultrasonic pulse transmission method,the experiment records time and waveform of P and S waves in the direction parallel and perpendicular to the fracture orientation. The result shows that,with the same fracture density,changing fracture aperture will affect both velocity and amplitude of P and S waves,and the effect on P-wave amplitude is much greater than that on the velocity. Moreover,the variation in velocity of S wave is more obvious in the slow shear wave (S2),while the variation in amplitude is more obvious in the fast shear wave (S1). These properties of wave propagation are useful for seismic data processing and interpretation.

关键词： fracture aperture Hudson’s fracture theory fractured model P-and S-wave velocity amplitude

Study on forward modeling of through-casing resistivity logging

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Science china earth sciences 2008年第S2期51卷 207-211页

作者： GAO Jie1,LIU FuPing2,BAO DeZhou3,CHENG Xi3 & ZHANG YuLing4 1 china university of petroleum,beijing 102249,china 2 beijing Institute of Graphic Communication,beijing 102600,china 3 china petroleum Logging CO. LTD.,Xi’an 710021,china 4 china National Logging Corporation,beijing 100101,china china university of petroleum Beijing China beijing Institute of Graphic Communication Beijing China china petroleum Logging CO. LTD. Xi’an China china National Logging Corporation Beijing China

Through-casing resistivity logging (TCRL) is a new kind of logging method for formation evaluation,reservoir monitoring and saturation changes tracking. In this paper,the basic principle of TCRL is de-tailed,and the modified transmission line equation method (MTLEM) is first proposed in china. The MTLEM has been employed to simulate the responses of TCRL,on the basis of which,the effects of formation resistivity,cement and casing on the responses of TCRL are analyzed,and the signals in-duced in different formations are also calculated,which can help the design of TCRL tool and data processing and interpretation in china.

关键词： through-casing resistivity logging (TCRL) modified transmission line equation method (MTLEM) casing cement sheath

Petrogenesis of Songshugou dunite body in the Qinling orogenic belt, Central china: Constraints from geochemistry and melt inclusions

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Science china earth sciences 2005年第8期48卷 1146-1157页

作者： SU Li1,2, SONG Shuguang3 & ZHOU Dingwu1 1. Key Laboratory of Continental Dynamics of the Ministry of Education, department of Geology, Northwestern university, Xi’an 710069, china 2. The Geological Lab Center, china university of Geosciences (beijing), beijing 100083, china 3. Key Laboratory of Orogenic Belts of the Ministry of Education, department of Geology, Peking university, beijing 100871, china Key Laboratory of Continental Dynamics of the Ministry of Education Department of Geology Northwestern University Xi’an China The Geological Lab Center China University of Geosciences (Beijing)Beijing China Key Laboratory of Orogenic Belts of the Ministry of Education Department of Geology Peking University Beijing China

The Songshugou dunite body, which occupies an area of about 20 km2, is the largest ultramafic massif in the eastern Qinling orogenic belt, Central china. The major compo-nent of this body is dunitic rocks including mylonitic dunite and coarse-grained dunite; they oc-cupy about 95 vol% of the total body. Petrography, mineral composition, major and trace ele-ments and primitive melt inclusions have been investigated in this paper; all revealed that this dunite body is the product of melt-rock interaction by porous percolation flow. In comparison with dunite sills or veins in harzburgite from the basal part of Oman ophiolite, this dunite body is characterized by lower contents of Al2O3, CaO and HREE but higher content of highly incom-patible elements and Zr and Hf. The LREE enriched patterns and primitive mantle normalized spidergrams of trace elements are also different from the Oman dunite. Combining with melt in-clusions observed in olivines, we conclude that this dunite body is the product of large- scale porous percolation flow of high-MgO melts within depleted mantle peridotites. The high-MgO magma, in essence, was most probably produced at the hot head of an upwelling mantle plume. The occurrence of the Songshugou dunite body is closely associated with the activity of mantle super-plume in Neo-Proterozoic era in the Yangtze Craton.

关键词： Songshugou dunite body, geochemistry, melt inclusion, mantle plume, Qinling orogenic belt.

Existence of the solutions and the attractors for the large-scale atmospheric equations

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Science china earth sciences 2006年第6期49卷 650-660页

作者： HUANG Haiyang1 & GUO Boling2 1. department of Mathematics, beijing Normal university, beijing 100875, china 2. Institute of Applied Physics and Computational Mathematics, beijing 100080, china department of Mathematics Beijing Normal University Beijing China Institute of Applied Physics and Computational Mathematics Beijing China

In this paper, firstly, the proper function space is chosen, and the proper expression of the operators is introduced such that the complex large-scale atmospheric motion equations can be described by a simple and abstract equation, by which the definition of the weak solution of the atmospheric equations is made. Secondly, the existence of the weak solution for the atmospheric equations and the steady state equations is proved by using the Galerkin method. The existence of the non-empty global attractors for the atmospheric equations in the sense of the Chepyzhov-Vishik’s definition is obtained by constructing a trajectory attractor set of the atmospheric motion equations. The result obtained here is the foundation for studying the topological structure and the dynamical behavior of the atmosphere attractors. Moreover, the methods used here are also valid for studying the other atmospheric motion models.

关键词： atmosphere equations, weak solution, trajectory attractor, global attractor, equilibrium.

The control of syndepositional faulting on the Eogene sedimentary basin fills of the Dongying and Zhanhua sags, Bohai Bay Basin

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Science china earth sciences 2004年第9期47卷 769-782页

作者： LIN Changsong1, ZHENG Herong2, REN Jianye1, LIU Jingyan1 & Qiu Yigang1 1. department of Energy Geology, china university of Geosciences, beijing 100083, china 2. petroleum Exploration and Production Institute, Sino-petroleum and Chemistry Cooperation, beijing 100083, china department of Energy Geology China University of Geosciences Beijing China petroleum Exploration and Production Institute Sino-Petroleum and Chemistry Cooperation Beijing China

The Dongying and Zhanhua sags are the major hydrocarbon exploration and produc- tion subbasins in the Bohai Bay Basin. Integrated analysis of the sedimentary basin fills has shown that the syndepositional faults and their arrangement styles exerted an important influ- ence on the development and distribution of the Eogene depositional systems. The sedimentary filling evolution of the subbasins reflects the general control of the episodic rifting process. The major long-term active normal faults formed a series of paleogeomorphic accident or slopebreak zones that commonly delineated the subsidiary palaeostructural units and the depositional facies tracts and constrained the general distribution of sedimentary facies zones. The central sag boundary fault slopebreak zones usually determined the distribution of the depocenters of ter- restrial clastic depositional systems, particularly the lowstand fans or deltaic depositional sys- tems, and have proven to be the economically important targets for the exploration of subtle sandstone reservoirs. A variety of syndepositional fault arrangement patterns, including the par- allel, en echelon, combo-like, broom-like fault systems and the fault overlap or transfer zones, have been recognized in the subbasins. They generated distinctive geomorphic features and exerted a direct influence on sediment dispersal and sandbody distribution during the Eogene synrift stage. It is the key for the prediction of depositional systems tracts and reservoir sand- stones to investigate the activity and distribution of the fault slopebreak zones and reconstruct the structural paleogeomorphy in different basin filling stages of the basin evolution.

关键词： episodic rifting, fault slopebreak zone, depositional pattern, Bohai Bay Basin.

Amplitude Squeezing of a Weakly Interacting Bose System with Spontaneous U(1) Symmetry Breaking

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Communications in Theoretical Physics 2007年第12期48卷 1047-1050页

作者： JIAO Zhi-Yong department of Applied Physics,china university of petroleum(East china),Dongying 257061,chinaYU Zhao-Xian department of Physics,beijing Information Science and Technology university,beijing 100101,chinaWANG Ji-Suo department of Physics,Liaocheng university,Liaocheng 252059,china department of Applied Physics China University of Petroleum (East China) Dongying 257061 China department of Physics Beijing Information Science and Technology University Beijing 100101 China department of Physics Liaocheng University Liaocheng 252059 China

We study the quantum fluctuations and the amplitude squeezing of a weakly interacting Bose system withspontaneous U(1) symmetry *** is found that this system can exhibit amplitude squeezing.

关键词： Bose system amplitude squeezing

Progress and review of the studies on the end-Triassic mass extinction event

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Science china earth sciences 2005年第12期48卷 2049-2060页

作者： DENG Shenghui1,2, LU Yuanzheng1,2,3 & XU Daoyi4 1. Research Institute of petroleum Exploration and Development, beijing 100083, china 2. Key Laboratory of Oil and Gas Reservoir of Petrochina, beijing 100083, china 3. china university of Geosciences, beijing 100083, china 4. Institute of Geology, china earthquake Administration, beijing 100029, china Research Institute of petroleum Exploration and Development Beijing China Key Laboratory of Oil and Gas Reservoir of Petrochina Beijing China china university of Geosciences Beijing China Institute of Geology China Earthquake Administration Beijing China

The mass extinction at the end-Triassic is one of the five biggest in the Phanerozoic. However,it is the least well understood among these five events, and only till last decade it became a great academic interesting subject to geologists. The evidences for this event come obviously from bivalves, brachiopods, ammonites, corals, radiolaria, ostracods and foraminifera of marine habitats, and plants and tetrapods of terrestrial realm. By contrast, for some of other groups, such as marine gastropods and marine vertebrates, no mass extinction has been recog-nized yet. The extinction event is strongly marked at specific level but shown a complicated situa-tion at generic and family levels. Dramatic changing of the environment, such as the temperature raise due to the greenhouse effect, the marine anoxic habitats caused by a sudden transgression after the regression at the end of Triassic, has been claimed to be the main cause of the extinction. Many hypotheses have been suggested to demonstrate the mechanisms of the environment changing, among which two popular ones are the bolide impact and volcanic eruption. The Triassic-Jurassic (Tr-J) boundary mass extinction event is still poorly understood because no enough data have been obtained from the Tr-J boundary successional sections of both marine and terrestrial sediments, and most of these studies were regionally restricted. The basic aspects of the event and its associated environmental conditions remain poorly characterized and the causal mechanism or mechanisms are equivocal. Some authors even doubt its occurrence. china has many successionally developed terrestrial and marine Tr-J sections. Detailed studies of these sections may be important and significant for well understanding of the event.

关键词： progress, review, end-Triassic, mass extinction, mechanism, Tr-J boundary.

Composition of substituents on pyrrole ring of high-carbon-number geoporphyrins and its dealkylation

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Chinese Science Bulletin 1999年第3期44卷 267-269页

作者： ZHANG Chunming and LIN Renzi Geochemistry Research Center, Jianghan petroleum Institute, Jingzhou 434102, china department of Geoscience, university of petroleum , beijing 100083, china Geochemistry Research Center Jianghan Petroleum Institute Jingzhou China department of Geoscience University of Petroleum Beijing China

Geoporphyrins, isolated from source rock, were analyzed on electron ionization mass spectrometry （EIMS） and Tandem mass spectrometry （MS/MS）. The spectrum of ElMS shows that the geoporphyrins are mainly composed of two types: DPEP and eito. Most of the porphyrin carbon numbers are greater than C32. The daughter spectra of the molecular ions (C34-36DPEPs) display the loss of methyl and ethyl groups, which indicate there are ethyl and propyl groups in the mother ions. The average condensed structural formulae, derived from the data of the spectra on MS/MS, have clearly shown the composition of the substituents on the porphyrin pyrrole ring, and the regular changes of the substituents reveal the characteristics of the dealkylation of the porphyrins in the geosphere.

关键词： Tandem mass spectrometry geoporphyrins condensed structural formula dealkylation.