Characteristic Features of REE and Pb–Zn–Ag Mineralizations in the Na Son Deposit,Northeastern Vietnam

The Na Son deposit is a small‐scale Pb–ZnPb–Zn–Ag deposit in northeast Vietnam and consists of biotite–chlorite schist, reddish altered rocks, quartz veins and syenite. The biotite–chlorite schist is intruded by syenite. Reddish altered rocks occur as an alteration halo between the biotite–allanite‐bearing quartz veins and the biotite–chlorite schist. Allanite occurs in the biotite–allanite‐bearing quartz veins and in the proximal reddish altered rocks. Rare earth element (REE) fluorocarbonate minerals occur along fractures or at rim of allanite crystals. The later horizontal aggregates of sulfide veins and veinlets cut the earlier reddish altered rocks. The earlier Pb–Zn veins consist of a large amount of galena and lesser amounts of sphalerite, pyrite and molybdenite. The later Cu veins cutting the Pb–Zn veins include chalcopyrite and lesser amounts of tetrahedrite and pyrite. The occurrences of two‐phase H₂O–CO₂ fluid inclusions in quartz from biotite–allanite‐bearing quartz veins and REE‐bearing fluorocarbonate minerals in allanite suggest the presence of CO₂ and F in the hydrothermal fluid. The oxygen isotopic ratios of the reddish altered rocks, biotite–chlorite schist, and syenite range from +13.9 to +14.9 ‰, +11.5 to +13.3 ‰, and +10.1 to +11.6 ‰, respectively. Assuming an isotopic equilibrium between quartz (+14.6 to +15.8 ‰) and biotite (+8.6 ‰) in the biotite–allanite‐bearing quartz vein, formation temperature was estimated to be 400°C. At 400°C, δ¹⁸O values of the hydrothermal fluid in equilibrium with quartz and biotite range from +10.5 to +11.7 ‰. These δ¹⁸O values are consistent with fluid that is derived from metamorphism. Assuming an isotopic equilibrium between galena (+1.5 to +1.7 ‰) and chalcopyrite (+3.4 ‰), the formation temperature was estimated to be approximately 300°C. The formation temperature of the Na Son deposit decreased with the progress of mineralization. Based on the geological data, occurrence of REE‐bearing minerals and oxygen isotopic ratios, the REE mineralization is thought to result from interaction between biotite–chlorite schist and REE‐, CO₂‐ and F‐bearing metamorphic fluid at 400°C under a rock‐dominant condition.     

A new approach to earthquake prediction: The Load/Unload Response Ratio (LURR) theory

The response to loading is different from that to unloading when the focal media is approaching instability. The ratio of the response rate during loading to that during unloading, called Load/Unload Response RatioY (LURR), could be a measure of the closeness degree to instability and is used in a new approach to earthquake prediction. Retrospective examination of some one hundred earthquake cases (fromM 4 toM 8.6) indicates that for more than 80% of the examined ones, the value ofY is much higher than 1 for a period before the main shock, but theY value always fluctuates slightly about 1 during two decades for seven stable regions, so that the parameterY value always fluctuates slightly degree of an impending earthquake. Several earthquakes occurring on the Chinese mainland in recent years as well as the Northridge California, U.S.A. earthquake (Jan. 17, 1994,M _w 6.7) have been predicted beforehand with this method.     

闽北麻源群变质岩的流体包裹体研究：岩石抬升过程的p－T－t

根据闽北麻源群变质岩流体包裹体的世代关系和显微测温研究，获得了麻源群变质峰期之后抬升过程ｐ－Ｔ－ｔ轨迹，推测岩石遭受剪切变形事件的温压条件为ｐ＝８５￣１００ＭＰａ，Ｔ＝２６５￣２８５℃。本区流体演化早期以ＣＯ２为主，晚期以水溶液为主。     

Investigation of structures in the Alabanda Bouleuterion by electrical resistivity method

The workspace as Bouleuterion (parliament house) is located in the ancient city of Alabanda far approximately 7 km from Aydin, Çine. The works on the city plan are still continued by the Department of Archeology in Adnan Menderes University. In this work, a geophysical study based on electrical resistivity tomography (ERT) approach is used to bring out the existence of the buried structures and situations of ruins in Bouleuterion. This study is a good example of implementation of the electrical resistivity method to the archeology in a specific area (Bouleuterion). Furthermore, the paper shows to researchers practically advantages and disadvantages of Wenner and dipole-dipole arrays that widely used in archeological prospection. Also with this work, a Bouleuterion has been subject of a geophysical article for the first time. By archeology and geophysics evaluations, it is proved that these ruins such as the cavea, stage, orchestra, and entrances are parts of the Bouleuterion.     

北秦岭构造带断裂遥感解译及其构造意义

秦岭造山带位于华北板块与扬子板块之间,造山带内发育若干条近平行的韧性剪切带和夹持其间的岩块,它们和次级断裂组成特有的构造图案。虽有后期脆性断裂的叠加,但依然可以看出这些断裂组成了具有规律性的构造图案,反映出不同的构造型式和构造活动。由于秦岭造山带山高林密,有些地段很难人力进行考察,给该区的构造研究增加了难度。为此,本文利用Google Earth软件获取高分辨率的卫星图像,对其进行影像处理和构造解译,分析了北秦岭地区的断裂构造的变形特征及组合样式,从造山带尺度研究大型断裂带的变形特征、样式图案,探求其运动方式和演化规律。     

A synthesis: Late Cenozoic stress field distribution at northeastern corner of the Eastern Mediterranean,SE Turkey

Fault kinematic analysis and inversion of focal mechanisms of shallow earthquakes reveal significant evolution of the regional stress regime in the northeastern most corner of the Eastern Mediterranean region since the Mio-Pliocene to the present time. This study was carried out in the interaction area between the Arabian/African plates and the Anatolian block. The evolution of stress regimes consists of a change from older transpression to younger transtension. Both strike-slip stress regimes having a NNW- to northwest-trending σ_Hmax (σ₁) and ENE- to northeast-trending σ_Hmin (σ₃) axes induce a sinistral component of displacement on the major intra-continental Karatas–Osmaniye and Misis–Ceyhan faults elongated with the northeast-trending Misis Range between Adana and Osmaniye provinces (sub-area i) and by a NNE-trending plate boundary Amanos fault running along Amanos Range between Antakya and Kahramanmaras provinces (sub-area ii). The inversion results show that the transtensional stress regime is dominantly strike-slip to extension, with an ENE- to northeast-trending σ_Hmin (σ₃) axis for sub-areas (i) and (ii), respectively. The inversions of earthquake focal mechanisms indicate that the transtensional stress regime is still active in the whole study area since probably recent Quaternary time. To cite this article: S. Over et al., C. R. Geoscience 336 (2004).     

基于黏弹滑移界面理论揭示套管中模式波的传播特征

目前固井质量评价主要是利用套管中模式波的幅度或衰减变化判断套管与水泥间的胶结状况.在超声测量频段（70~500 kHz）,现有声波测井仪器工作时在套管中激发的模式波类似薄板中的对称兰姆波（拉伸波）或反对称兰姆波（弯曲型兰姆波）.本文将黏弹滑移界面理论应用到套管和水泥的耦合界面,探讨了套管中的准兰姆波（包括拉伸波和弯曲型兰姆波）与套管后物质的耦合方式,拉伸波与套后物质主要以剪切刚度耦合,即便是0.01 mm的微环也会使得拉伸波的衰减明显降低,接近套后是流体时的响应特征;而弯曲型兰姆波与套管后物质主要以法向刚度耦合,这使得在套后胶结轻质水泥时弯曲型兰姆波对微环不敏感,在套后耦合常规水泥时微环的存在又会使得弯曲型兰姆波的衰减明显增强,衰减的增加说明其与套后物质的声耦合更紧密,也表明微环与常规水泥的等效声阻抗适当降低,更有利于弯曲型兰姆波传播时与套后介质实现法向刚度的匹配.拉伸波和弯曲型兰姆波对同一胶结状况的不同响应特征也为固井质量综合评价时区分不同的水泥胶结状况提供了可能.     

双层套管井中单极子声波测井的响应特征

目前,在深井中采用多层套管实现层间封隔的方法已非常普遍,对多层套管井固井质量评价的需求越来越迫切,目前还未有针对外层套管与地层之间水泥胶结评价的有效手段.本文利用三维有限差分仿真了单极声波测井在双层套管井中的响应特征,探讨了利用套管波幅度和斯通利波频散特征识别外层套管与地层之间环空是否胶结水泥的可行性.数值计算结果显示在两层套管之间胶结水泥时,套管波的幅度或衰减对外层套管和地层之间是否胶结水泥非常敏感,外层环空若充填水泥则全波中的套管波幅度降低明显;在两层套管之间充填泥浆时,全波波形中首先到达的套管波幅度较大,其对外层套管的胶结状况不再敏感,通过对接收的阵列波形做频率-慢度相关分析发现,在外层套管和地层之间胶结水泥后,井孔内接收到的低于10 kHz的外斯通利波慢度明显增大,仿真波形的处理结果与解析计算的斯通利波的频散曲线吻合较好,进一步验证了可尝试利用内层环空激发的外斯通利波判断外层套管与地层之间是否胶结水泥.     

《巴黎协定》下的国际碳市场机制：基本形式和前景展望

《巴黎协定》第6条建立的两种国际碳市场机制受到广泛关注,将在2020年后的气候制度中发挥至关重要的作用。文中识别了覆盖范围、交易指标类型和管理模式等3个构成国际碳市场机制的关键要素及其不同设计选项,并以此为基础阐明国际碳市场机制的基本形式。梳理并识别谈判中有关国际碳市场机制的焦点问题及其不同规则设计,并在此基础上分析中国参与国际碳市场机制的机遇和挑战。结合中国气候融资、提升减排力度、推动绿色“一带一路”和气候变化南南合作的内在需求以及国内有关市场机制的现有能力,分析提出两种国际碳市场机制在中国近期、中期和远期的发展前景及其所需的能力建设。