论甘孜丘洛成矿带微细浸染型金矿的成矿条件   总被引：2，自引：0，他引：2  

王小春 《矿物岩石》1993,13(1):68-75

甘孜丘洛成矿带微细浸染型金矿的成矿热液来自大气降水。矿化作用发生于燕山期的下渗雨水加热环流体系中。包裹体研究和热力学计算表明,成矿温度为93—306℃,成矿深度小于1km。矿化热液呈弱碱性,还原性较强,含盐度中等,贫氯富硫。Au以Au(HS)_2~-形式进行迁移,并在扩容减压带中沉淀富集。温度、压力降低和总硫活度减小是矿质沉淀的重要因素。  相似文献   

Polycyclic aromatic hydrocarbons in dated sediments from Green Bay and Lake Michigan     

Xiaochun Zhang  Erick R. Christensen  Michael F. Gin 《Estuaries and Coasts》1993,16(3):638-652

Sediment cores from two locations in Green Bay and two in lake Michigan were analyzed for 12 polycyclic aromatic hydrocarbons (PAHs), loss-on-ignition (LOI),²¹⁰Pb,¹³⁷Cs, and⁷Be to study differences in deposition patterns between the freshwater estuary Green Bay, with several local sources, and the open Lake Michigan, dominated by atmospheric inputs. We found that the remote sites receive relatively less high-molecular weight PAHs such as ideno(1,2,3-cd)pyrene and dibenz(ah)anthracene and are more depleted in anthracene and pyrene. This may be related to a low Henry’s law constant for the high molecular compounds and to selective photo-oxidation of anthracene and pyrene during transport. While sedimentation rates are higher in Green Bay than in the open lake, the PAH levels are generally comparable (0.3–8.5 μg g^?1) in the two areas. However, the highest PAH levels are found in a core from Green Bay (GB88G). The two Green Bay cores have total PAH concentration maxima in 1985, which appear to be related to the combustion of petroleum. Also, one Green Bay core (GB88G) and the two from Lake Michigan exhibit PAH maxima in the early 1950s in agreement with observations from other study areas. There is a significant correlation between total PAH and LOI, and thus total organic carbon, for the Green Bay cores, but little or no such correlation for the Lake Michigan cores. This may indicate that PAHs in Green Bay are effectively scavenged by settling detritus.  相似文献   

Geology of the Grove Mountains in East Antarctica   总被引：2，自引：0，他引：2  

Xiaohan?LiuEmail author  Yue?Zhao  Xiaochun?Liu  Liangjun?Yu 《中国科学D辑(英文版)》2003,46(4):305-319

Grove Mountains consists mainly of a series of high-grade (upper amphibolite to granulite facies) metamorphic rocks, including felsic granulite, granitic gneiss, mafic granulite lenses and charnockite, intruded by late tectonic gneissic granite and post-tectonic granodioritic veins. Geochemical analysis demonstrates that the charnockite, granitic gneiss and granite belonged to aluminous A type plutonic rocks, whereas the felsic and mafic granulite were from supracrustal materials as island-arc, oceanic island and middle oceanic ridge basalt. A few high-strained shear zones disperse in regional stable sub-horizontal foliated metamorphic rocks. Three generations of ductile deformation were identified, in which D₁ is related to the event before Pan-African age, D₂ corresponds to the regional granulite peak metamorphism, whereas D₃ reflects ductile extension in late Pan-African orogenic period. The metamorphic reactions from granitic gneiss indicate a single granulite facies event, but 3 steps from mafic granulite, with P-T condition of M1 800°C, 9.3×10⁵ Pa; M₂ 800–810°C, 6.4 × 10⁵ Pa; and M₃ 650°C have been recognized. The U-Pb age data from representative granitic gneiss indicate (529±14) Ma of peak metamorphism, (534±5) Ma of granite emplacement, and (501±7) Ma of post-tectonic granodioritic veins. All these evidences suggest that a huge Pan-African aged mobile belt exists in the East Antarctic Shield extending from Prydz Bay via Grove Mountains to the southern Prince Charles Mountains. This orogenic belt could be the final suture during the Gondwana Land assemblage.  相似文献   

GPS共视接收机短期观测资料处理算法研究   总被引：1，自引：0，他引：1  

杨旭海  卢晓春  胡永辉  李志刚 《武汉大学学报(信息科学版)》2004,29(3):205-209

提出了一种新的基于总体最小二乘数据拟合的短期观测资料处理算法 ,同时考虑测量时刻和时差测量值的不确定性 ,可提高共视接收机输出的单站数据精度。超短基线单通道共视测量数据表明 ,使用新算法后 ,可以提高原始共视数据短期稳定度  相似文献   

Disposal of wastewater containing Congo Red by synthesizing layer double hydroxide in-situ     

朱荣崔康平  彭书传杨远盛陈天虎  安志环徐晓春 《中国地球化学学报》2006,25(4):390-394

Based on the principle of synthesis, a new method was put forward to dispose Congo Red anion-containing dyestuff from wastewater and its feasibility was also examined. The principle of the method is described as follows： Mg^2＋ and Al^3＋ are hydrolyzed to form Mg/Al-LDH by adding Mg^2＋, Al^3＋ and NaOH in wastewater containing anion dyestuff, which is selectively intercalated with the interlayer of LDH in order to balance positive structural charge. While Mg^2＋ and Al^3＋ are co-precipitated to form LDH, the anion dyestuff in wastewater will be removed by LDH synthesized in-situ, as is confirmed by X-ray diffraction analysis of settlings and chemical analysis of aqueous samples. In this work, we studied the influence of Mg/Al mole ratio, pH value, time and temperature of reaction on the removal of anion dyestuff and the use of Mg and Al. The experimental results showed the maximum removal efficiency of anion dyestuff could be attained when pH value was 9.0, and Mg/Al mol ratio was 2 ： 1, reaction duration was 2 hours, and the effect of temperature was not remarkable, and the removal efficiency could reach 100%. Meanwhile, the Mg and Al added could be made good use of. This technology has the advantage of extraordinary efficiency of wastewater disposal.  相似文献   

大气成分网络化观测结果的分析、评估和服务     

张晓春徐晓斌  孙俊英 《中国气象科学研究院年报》2006,(1):22-24

2004年起，中国气象局在北京上甸子、浙江临安和黑龙江龙凤山区域本底站先后开展了包括大气气溶胶、反应性气体等在内的业务观测。2006年初中国气象局充分利用已有站网，结合国家大气成分本底台站的建设以及大气成分预报业务的发展急需，在全国14个关键区域布设了包括7个大气本底台站在内的30个大气成分观测站，形成了全国大气成分观测网（图1）。  相似文献   

Chrome-rich clinopyroxene in orthopyroxenite from Maowu, Dabie Mountains, central China: A second record and its implications for petrogenesis   总被引：1，自引：0，他引：1  

Xiaochun Liu  Huyun Zhou  Zhesheng Ma  & Lihua Chang 《Island Arc》1998,7(1-2):135-141

A second occurrence of chrome-rich clinopyroxene has been discovered as inclusions in orthopyroxene in orthopyroxenite from Maowu, the Dabie Mountains, Central China. The average formula for chrome-rich clinopyroxene can be expressed as (Na_0.39Ca_0.54)_0.93(Mg_0.57Fe²⁺_0.06Fe³⁺_0.01Cr_0.24Al_0.15)_1.03Si_2.02O₆, with a maximum amount of kosmochlor component of 28.52 mol%. The unit cell parameters obtained from a single-crystal are a  = 9.614 Å, b  = 8.800 Å, c =  5.240 Å, β = 106.59°, space group C2 / c . The indices of refraction are α = 1.697, β = 1.704, γ = 1.726. Chrome-rich clinopyroxene, which coexists with chromite, chromian rutile and chromian pyrope, crystallized at a temperature of 1025 °C and very high pressure, and therefore represents a mantle relic. Together with the appearance of low-pressure inclusion mineral assemblage and the estimation of physical–chemical conditions for matrix minerals, the Maowu eclogite–ultramafic complex is considered to be formed during ultrahigh-pressure metamorphism from the mantle-derived protolith.  相似文献   

赣东北-浙西北登山群和松木坞群中火山岩的地球化学   总被引：1，自引：0，他引：1  

赵风清  金文山  甘晓春  孙大中 《华北地质》1997,(2)

赣东北－浙西北新元古代登山群和松木坞群主要由板岩、砂岩、流纹岩、流纹质英安岩、玄武岩和玄武质安山岩组成，火山岩的Ｒｂ－Ｓｒ和Ｓｍ－Ｎｄ等时线年龄以及流纹岩中单颗粒锆石Ｕ－Ｐｂ年龄显示其成岩时代为８００－９００Ｍａ。登山群和松木坞群火山岩呈双峰式产出，其中镁铁质火山岩在化学成分上呈现出演化程度较高的特点（ｅｖｏｌｖｅｄｎａｔｕｒｅ），高强场元素（Ｔｉ、Ｎｂ、Ｔａ等）相对于碱土元素未发生明显亏损，反映其形成于大陆裂谷环境。镁铁质火山岩具低的Ｎｄ值，表明其来源于弱亏损的地幔源，也可能遭受一定程度的地壳混染作用改造。酸性火山岩在化学成分上表现出Ｓ型火山岩特点，但其变化于－１．９～＋２８，指示其为先存的长英质基底分熔作用的产物，但存在强烈的地慢物质添加作用。  相似文献   

利用空间均匀网格对中国夏季降水异常区域特性的初步分析   总被引：24，自引：1，他引：24  

王晓春  吴国雄 《气象学报》1996,54(3):324-332

用方差极大正交转动ＥＯＦ（Ｖａｒｉｍａｘ　ＥＯＦ）及点相关图法分析了夏季总降水（６、７、８月降水之和）及逐月降水的区域特性。使用的资料为全国范围４７个５°×５°经纬度网格上的降水资料，分析时段为１９５９—１９９４年。分析结果表明，由于采用了空间均匀的格同资料，本分析除进一步证实了中国东部地区降水异常的区域特性外，也揭示了西部地区降水异常的区域特性及沿长江流域东西方向上降水异常的相互关系。夏季总降水异常最显著的区域特性是江淮流域与河套及华南反相关。另外沿长江流域，四川盆地的降水异常与青藏高原东部及江淮流域的降水异常也存在着反相关联系。西部地区的区域特性为青藏高原中东部南北两侧为负相关，并且青藏高原中东部南侧的降水异常与华北东部及东北南部为正相关。上述的空间模都有准２—３ａ及１０ａ左右的周期。逐月降水的分析表明，６月份，江淮流域、华北东部及东北大部分地区为正相关。７月，河套地区与江淮流域的降水异常呈现一定的负相关联系，８月份降水异常的区域特性与夏季总降水异常的区域特性极其一致。  相似文献   

Stability Analysis and Reinforcement Design of A High Steep Rock-soil Slope     

Zhang Guang  Li Xiaochun  Sheng Jianhao  Xu Yibao 《岩土力学》1989,10(3):77-82

Engineering geological survey, field testing of physico-mechanical parameters, and numerical analysis of stability are made for a high steep rock-soil slope. Based on this, a reinforcement design scheme is proposed to keep slope stable in give period. The reinforcement method and safety coefficients presented in this paper are of reference value for similar slopes.  相似文献