沉积物粒度分析在厦门市第四纪环境研究和地层划分对比中的应用   总被引：6，自引：0，他引：6  

张璞  陈建强  田明中  朱金芳  黄宗林  江春亮 《地球科学与环境学报》2005,27(1):88-94

采用MS2000型激光粒度分析仪进行测试，利用计算机粒度分析软件对数据进行整理和计算，绘制出样品的频率曲线、概率累积曲线以及粒度众数位值曲线等图件并进行沉积环境分析。厦门地区第四纪环境演化经历了中更新世同安组(含泥中粗砂、含泥细中砂、砂为主)海积一冲积一更新统上部龙海组(含泥粗中砂、含泥细中砂、含泥粗砂、粗砂、细中砂、含细砾中粗砂、中细砂等)冲积一洪冲积一更新世上部东山组(砂、砂砾、含泥中粗砂、粗砂、泥质中细砂、细砂、中粗砂等)冲洪积及部分海积(粉砂、细粉砂、含碳质泥、粘土、淤泥质粘土、粉砂质粘土等)一全新世长乐组(粉砂，淤泥质粘土、粉砂质粘土、碳质粘土、含砂淤泥质粘土，粉砂质亚粘土、粉细砂亚粘土等)海湾沉积。在解释环境变化的同时，说明粒度变化曲线在一定程度上可以作为地层划分的依据之一，并以此对研究区地层进行了详细划分。  相似文献   

菏泽市地质灾害现状与防治          下载免费PDF全文

张本进  徐淑和  黄文峰  张洪波 《山东国土资源》2003,19(5):26-27,31

菏泽市地质灾害类型主要为地震、地面塌陷、地面沉降、地裂缝、砂土液化、土地盐渍化及地氟病等，其发育与分布受地质构造、水文地质条件的控制以及气象、人类活动等因素的影响。就其分布、危害、致灾原因等做了分析，并提出了防治建议和对策。  相似文献   

恒星内部电荷屏蔽对β衰变率的影响     

孙庆强  黄增光  朴红光  罗志全 《天文学进展》2006,24(4):380-386

针对低能反应和共振跃迁,分析了在恒星内部电荷屏蔽对β衰变率的影响．对共振跃迁的分析是基于核的壳层模型．作为例子,详细计算了电荷屏蔽对56Cr的β衰变的影响．结果表明:在较低温度和高密度下,电荷屏蔽使β衰变率有明显的增加。这对恒星晚期演化和超新星爆发研究可能会有重要的影响。  相似文献   

Sensitivity experiments with the spectral HIRLAM and its adjoint     

NILS GUSTAFSSON  XIANG-YU HUANG 《地球，A辑:动力气象学与海洋学》1996,48(4):501-517

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电感耦合等离子体质谱法同时测定地下水中硼溴碘   总被引：6，自引：4，他引：2  

黄光明  窦银萍  张静梅  张培新  高孝礼 《岩矿测试》2008,27(1):25-28

建立了电感耦合等离子体质谱法同时测定地下水中B、Br、I的方法。选定φ=2%(体积分数)的稀NH3.H2O介质消除碘的记忆效应。采用干扰较少的10B和79Br同位素。B、Br、I在0~10 000 ng/mL呈良好的线性关系。方法的检出限为10B 0.176 ng/mL,79Br 0.876ng/mL,127I 0.132 ng/mL;精密度(RSD,n=12)为10B 2.86%,79Br 3.36%,127I 2.69%;10B的阶梯加标回收率为94.6%~101.5%,79Br为98.3%~104.9%,127I为96.5%~102.0%。  相似文献   

赣南淘锡坑钨多金属矿床花岗岩和云英岩岩石特征及云英岩中白云母40Ar/39Ar定年     

guochunli 《地质学报》2008,82(1):1274-1284

赣南崇义县淘锡坑钨矿位于南岭东西向构造带东段,属于以黑钨矿石英脉型为主的钨多金属矿床。矿床形成与燕山期中酸性岩浆作用有密切关系,石英矿脉受一组北西向断裂控制,穿切新元古界。本文在淘锡坑钨矿区3个揭露到花岗岩体顶部的中段（206、106、56中段）采集到岩体顶部云英岩样品,利用40Ar/39Ar同位素定年测得云英岩中的白云母的坪年龄分别为152.7 ± 1.5 Ma（206中段）,153.4 ± 1.3 Ma（106中段）,155.0 ± 1.4 Ma（56中段）。与前人用其他方法测定的花岗岩成岩和成矿年龄几乎一致。花岗岩和云英岩全岩稀土元素均具有M型四分组效应和强烈的Eu亏损特征,反映出花岗质岩浆经历了高度分异演化及其岩体结晶晚期流体/熔体相互作用。综合前人在南岭地区同类矿床的研究资料,可知南岭地区160～150Ma成岩成矿作用主要分布于南岭中-东段,可能为大陆边缘弧后岩石圈伸展的构造动力学背景的产物。  相似文献   

辽河断陷大民屯凹陷静北潜山孢粉化石新发现     

吴炳伟张巨星  江建虹陈家敏黄淑芳  薛尚义 《地质学报》2008,82(2):165-168

静北潜山的油气勘探始于上世纪70年代初,并将钻井揭示的未见化石的碳酸盐岩和石英砂岩沉积划归中元古界长城系,沿用至今.2002年在对该区的地层研究中,首次发现了晚古生代孢粉化石,从而证实静北潜山存在晚古生代地层.本文以孢粉化石为主要依据,对潜山地层进行了重新划分,并与邻区进行对比.在此基础上对本区的构造和沉积作一讨论.  相似文献   

Experimental investigation on thermochemical sulfate reduction by H₂S initiation   总被引：1，自引：0，他引：1  

Tongwei Zhang  Alon Amrani  Qisheng Ma 《Geochimica et cosmochimica acta》2008,72(14):3518-3530

Hydrogen sulfide (H₂S) is known to catalyze thermochemical sulfate reduction (TSR) by hydrocarbons (HC), but the reaction mechanism remains unclear. To understand the mechanism of this catalytic reaction, a series of isothermal gold-tube hydrous pyrolysis experiments were conducted at 330 °C for 24 h under a constant confining pressure of 24.1 MPa. The reactants used were saturated HC (sulfur-free) and CaSO₄ in the presence of variable H₂S partial pressures at three different pH conditions. The experimental results showed that the in-situ pH of the aqueous solution (herein, in-situ pH refers to the calculated pH of aqueous solution under the experimental conditions) can significantly affect the rate of the TSR reaction. A substantial increase in the TSR reaction rate was recorded with a decrease in the in-situ pH value of the aqueous solution involved. A positive correlation between the rate of TSR and the initial partial pressure of H₂S occurred under acidic conditions (at pH ∼3-3.5). However, sulfate reduction at pH ∼5.0 was undetectable even at high initial H₂S concentrations. To investigate whether the reaction of H₂S_(aq) and occurs at pH ∼3, an additional series of isothermal hydrous pyrolysis experiments was conducted with CaSO₄ and variable H₂S partial pressures in the absence of HC at the same experimental temperature and pressure conditions. CaSO₄ reduction was not measurable in the absence of paraffin even with high H₂S pressure and acidic conditions. These experimental observations indicate that the formation of organosulfur intermediates from H₂S reacting with hydrocarbons may play a significant role in sulfate reduction under our experimental conditions rather than the formation of elemental sulfur from H₂S reacting with sulfate as has been suggested previously (Toland W. G. (1960) Oxidation of organic compounds with aqueous sulphate. J. Am. Chem. Soc.82, 1911-1916).Quantification of labile organosulfur compounds (LSC), such as thiols and sulfides, was performed on the products of the reaction of H₂S and HC from a series of gold-tube non-isothermal hydrous pyrolysis experiments conducted at about pH 3 from 300 to 370 °C and a 0.1-°C/h heating rate. Incorporation of sulfur into HC resulted in an appreciable amount of thiol and sulfide formation. The rate of LSC formation positively correlated with the initial H₂S pressure. Thus, we propose that the LSC produced from H₂S reaction with HC are most likely the reactive intermediates for H₂S initiation of sulfate reduction. We further propose a three-step reaction scheme of sulfate reduction by HC under reservoir conditions, and discuss the geological implications of our experimental findings with regard to the effect of formation water and oil chemistry, in particular LSC content.  相似文献   

Formation and abundance of doubly-substituted methane isotopologues (CH₃D) in natural gas systems     

Qisheng Ma 《Geochimica et cosmochimica acta》2008,72(22):5446-5456

Formation of the Carbon-13 (¹³C) and deuterium (D) doubly-substituted methane isotopologues (¹³CH₃D) in natural gases is studied utilizing both first-principle quantum mechanism molecular calculation and direct FTIR laboratorial measurements of specifically synthesized high isotope concentration methane gas. For ¹³CH₃D, the symmetrically breathing mode A₀ emerges as IR-detectable attributed to the molecular symmetry lowering to C_3v from T_d of the non-isotopic methane (CH₄), along with a large vibrational frequency shift from ∼3000 to ∼2250 cm⁻¹. Our studies also indicate that the concentration of ¹³CH₃D is dependent on the environmental temperature through isotope exchanges among methane isotopologues; and the Gibbs’ Free Energy difference due to Quantum Mechanics Zero-Point vibrational motions has the major contribution to this temperature dependency. Potential geologic applications of the ¹³CH₃D measurement to natural gas exploration and assessments are also discussed. In order to detect the ¹³CH₃D concentration change of each 50 °C in the natural gas system, a 10⁻⁹ resolution is desirable. Such a measurement could provide important add-on information to distinguish natural gas origin and distribution.  相似文献   

针式微萃取结合GC-IRMS测定水溶液中甲酸、乙酸的稳定碳同位素组成     

李心清  黄代宽  章炎麟  江伟  安宁  胡璐  徐刚 《地球化学》2008,37(6)

甲酸和乙酸稳定碳同位素组成（δ^13C）的分析对环境、食品、制药和自然产品等的研究具有重要的应用价值。但目前尚缺乏有效的测定方法。本研究利用最近出现的针式固相微萃取技术（NeedlEX）,以吹扫．捕集方式对水溶液中的有机酸进行了萃取,然后利用气相色谱．同位素比值质谱联用仪（GC—IRMS）对所萃取的有机酸分子进行了占δ^13C的测定。结果显示,质谱计的信号强度与水溶液中有机酸的浓度存在显著的线性相关关系（R^2〉0．99,P〈0．05）,表明Needl EX对水溶液中有机酸具有稳定的萃取能力。在甲酸与乙酸含量分别不低于300μg／mL与200μg／mL的水溶液中,1000mL的吹扫体积可以使两者δ^13C多次分析结果的相对误差分别保持在3％和1％左右,且整个实验流程没有造成可检测的碳同位素分馏作用。低于这两个浓度界线,则分析误差随浓度的降低迅速增加。本研究虽然是针对水溶液中有机酸δ^13C的测定,其萃取方法对其他水溶性挥发和半挥发有机物δ^13C的分析也同样具有应用价值。  相似文献