Precious Fossil-Bearing Beds of the Lower Cretaceous Jiufotang Formation in Western Liaoning Province, China

Based on the subdivision into three members of the Lower Cretaceous Jiufotang Formation in western Liaoning, this paper deals mainly with the division and correlation of precious fossil bird-and reptile-bearing beds of the formation in the Dachengzi, Chaoyang, Dapingfang-Meileyingzi and Fuxin-Yixian basins. Among them, the precious fossil-bearing beds in the Dachengzi Basin may be recognized as the Xidagou Bed of the second member and the Yangcaogoudonggou Bed of the third member; those in the Chaoyang Basin may be confirmed as the Shangheshou Bed of the second member and the Dongpochi Bed of the third member; those in the Dapingfang-Meileyingzi Basin are as the Lamagou Bed of the second member, the Huanghuagou Bed of the lower third member and the Yuanjiawa Bed of the upper third member; and those in the Fuxin-Yixian Basin are listed as the Tuanshanzi Bed of the second member and the Pijiagou Bed of the third member. Since these basins are distinctly separated and the bird and reptile fossils are mostly new genera and species, we have to use the associated fossil ostracod assemblages as index to correlate the Xidagou Bed with the Shangheshou Bed and the Lamagou Bed, and to correlate the Yuanjiawa Bed with the Yangcaogoudonggou Bed and the Pijiagou Bed. Primarily, we established the sequence of the precious fossil-bearing beds of the Jiufotang Formation in western Liaoning. They are represented by, in ascending order, the Xidagou Bed of the second member, the Huanghuagou Bed of the lower third member, and the Yuanjiawa Bed of the upper third member. Obviously, this work has significance for the study on the time-space distribution and radiation of birds and dinosaurs during the period of the middle Early Cretaceous.     

滇中播卡铜矿床硫、铅同位素组成及其地质意义

滇中播卡铜矿床是著名“东川式”铜矿床的典型代表,但对其成矿物质来源和矿床成因认识存在争议。对矿区典型铜矿发育的金属硫化物进行硫和铅同位素组成分析,探讨其成矿物质来源。硫同位素测试结果表明,人占石铜矿金属硫化物的δ³⁴S值为1.6‰~10.7‰,指示硫以岩浆(火山喷发)作用为主要来源,并受到沉积作用影响。铅同位素测试结果则表明人占石铜矿、天生塘铜矿、竹箐凹子铜矿和白石岩铜矿中的铅主要来源于壳幔混合物质。综合前人研究和本次硫、铅同位素分析结果,认为播卡铜矿床成矿物质主要来自地幔,且受到地壳物质的混染。     

近50年山西高温日的时空分布及环流特征

利用1958-2008 年高低空气象观测资料以及山西省气象信息中心归档的109 站原始气象记录月报表及其信息化产品资料,分别以最高气温≥35℃、≥37℃、≥40℃为指标, 研究山西高温日的时空分布、变化趋势及环流特征,结果表明：①山西高温日最早出现在4 月中旬,最晚出现在9 月中旬,≥35℃、≥37℃和≥40℃的高温日均是6月下旬最多。②高温日数具有随纬度、随海拔的升高而减少,西部多于东部、南部多于北部、盆地多于山区的空间分布特征。≥40℃的高温区域主要集中在运城和临汾地区。③1984-2008 年,35℃以上的高温日数整体呈上升趋势;1979-2008 年,30a 间高温站次以153 站次/10a 的趋势增多;进入90 年代以后,不仅高温日数增多,而且高温持续时间、强度、范围都有增强趋势。④影响山西高温的500 hPa 环流形势主要有：副高纬向性、副高经向型以及大陆高压（脊）控制型3 类。在特定的流型配置下,T850≥25℃、T700≥13℃,T850≥26℃、T700≥14℃,T850≥28℃、T700≥15℃,T850≥32℃、T700≥16℃是山西省不同区域、不同风向影响时,≥35℃、≥37℃、≥40℃高温天气预报的临界值。     

Electrical conductivity of alkali feldspar solid solutions at high temperatures and high pressures

The electrical conductivities of alkali feldspar solid solutions ranging in chemical composition from albite (NaAlSi₃O₈) to K-feldspar (KAlSi₃O₈) were measured at 1.0 GPa and temperatures of 873–1,173 K in a multi-anvil apparatus. The complex impedance was determined by the AC impedance spectroscopy technique in the frequency range of 0.1–10⁶ Hz. Our experimental results revealed that the electrical conductivities of alkali feldspar solid solutions increase with increasing temperature, and the linear relationship between electrical conductivity and temperature fits the Arrhenius formula. The electrical conductivities of solid solutions increase with the increasing Na content at constant temperature. At 1.0 GPa, the activation enthalpy of solid solution series shows strong dependency on the composition, and there is an abrupt increase from the composition of Or₄₀Ab₆₀ to Or₆₀Ab₄₀, where it reaches a value of 0.96 eV. According to these results in this study, it is proposed that the dominant conduction mechanism in alkali feldspar solid solutions under high temperature and high pressure is ionic conduction. Furthermore, since the activation enthalpy is less than 1.0 eV for the alkali feldspar solid solutions, it is suggested to be a model where Na⁺ and K⁺ transport involves an interstitial mechanism for electrical conduction. The change of main charge carriers can be responsible for the abrupt increase in the activation energy for Or₆₀Ab₄₀. All electrical conductivity data were fitted by a general formula in order to show the dependence of activation enthalpy and pre-exponential factor on chemical composition. Combining our experimental results with the effective medium theory, we theoretically calculated the electrical conductivity of alkali feldspar granite, alkali feldspar quartz syenite, and alkali feldspar syenite with different mineral content and variable chemical composition of alkali feldspar at high temperatures at 1.0 GPa, and the calculated results are almost in agreement with previous experimental studies on silicate rocks.     

“人口与地理环境”教学中需关注的问题

人口问题是高中地理必修的重要内容之一,也是高考考查的重点。在教学中适时关注一些疑难易混问题,及时补充拓展相关知识,既有助于开阔学生视野,更好理解所学知识,又能提升学生答题速度和正确率,起到事半功倍的效果。     

连续Schaefer产量模型在三种模拟渔业评估中的应用

剩余产量模型具有形式简单和所需数据少的特点，使其在许多渔业资源评估中已经成为非常有吸引力的工具。本文主要分析了连续Shaefer产量模型在三种模拟渔业中的应用效果。蒙特卡罗模拟分析表明：模型对在高产量和低产量之间波动的渔业三的评估效果好于其他两种模拟渔业。这可能由于渔业三经历了过度捕捞和恢复两个阶段，所以其数据中含有更多的信息，而其他两种渔业仅仅经历了其中的一个阶段。当白色噪音小于10％时，估计的产量接近于观测产量，误差百分比小于5％；当白色噪音大于30％时，误差百分比接近40％。     

济阳坳陷区页岩气资源储存可能性浅析

页岩气作为一种非常规能源,一般主要产于空隙率渗透率极低且富含有机质的暗色页岩地层系统中,是近期可实现经济规模勘探开发、资源丰富的非常规天然气资源。山东省页岩气资源调查评价工作已起步实施,战略选区为:济阳坳陷区和临清坳陷区、胶莱坳陷区、鲁西南潜隆起区,现已先后施工多眼参数井,该次结合具体工程,针对济阳坳陷页岩气参数井施工,浅析济阳坳陷页岩气资源存在可能。     

西藏改则东地区第四纪泥火山的首次发现

青藏高原作为印度板块和欧亚板块碰撞造山的产物,新生代以来构造活动强烈,构造样式和类型复杂,新构造运动成为了研究的热点问题。而南羌塘地区河流、湖泊及其构造阶地、泥火山广泛发育,对研究羌塘地区的新构造和青藏高原隆升问题来说都是得天独厚的优越条件。依托中国地质调查局《改则东四幅1∶5万区域地质调查》项目,在青藏高原羌塘盆地南部改则东益杰错地区首次发现了泥火山,对益杰错地区泥火山的规模、构成以及发育部位进行了调查,并结合高精度遥感影像的分析结果,阐述了泥火山的发育特征,确定了益杰错泥火山是由于地下富含有机质的沉积物受到地壳运动的影响,随高压的气体和水喷出地表所形成,并指出益杰错泥火山的发育指示了新生代以来康托-日俄东断裂依旧活动。     

Sound velocities of Na0.4Mg0.6Al1.6Si0.4O4 NAL and CF phases to 73 GPa determined by Brillouin scattering method

The sound velocities of two aluminum-rich phases in the lower mantle, hexagonal new Al-rich phase (NAL) and its corresponding high-pressure polymorph orthorhombic Ca-ferrite-type phase (CF), were determined with the Brillouin scattering method in a pressure range from 9 to 73 GPa at room temperature. Both NAL and CF samples have identical chemical composition of Na_0.4Mg_0.6Al_1.6Si_0.4O₄ (40 % NaAlSiO₄–60 % MgAl₂O₄). Infrared laser annealing in the diamond anvil cell was performed to minimize the stress state of the sample and obtain the high-quality Brillouin spectra. The results show shear modulus at zero pressure G ₀ = 121.960 ± 0.087 GPa and its pressure derivative G’ = 1.961 ± 0.009 for the NAL phase, and G ₀ = 129.653 ± 0.059 GPa and G’ = 2.340 ± 0.004 for the CF phase. The zero-pressure shear velocities of the NAL and CF phases are obtained to be 5.601 ± 0.005 km/sec and 5.741 ± 0.001 km/sec, respectively. We also found that shear velocity increases by 2.5 % upon phase transition from NAL to CF at around 40 GPa.     

潮汐对高精度重力测量的改正分析

分析了固体潮和海洋负荷潮对沿海基准站绝对重力测量的影响,以及利用不同海潮模型计算后的精度统计,结果表明全球海潮模型对我国沿海绝对重力测量的改正不是十分精确。并简要分析了海洋负荷潮对相对重力测量的影响。