中地壳的地球化学动力学和矿石成因   总被引：7，自引：0，他引：7  

张荣华  胡书敏  张雪彤 《地球学报》2006,27(5):460-470

笔者重点进行了大于300℃——在近临界区至超临界区条件下的硅酸盐矿物与水反应动力学实验。矿物(钠长石Ab、透辉石Di、阳起石Act和磁铁矿Mt)的溶解反应动力学实验是使用流体通过叠层反应器的开放体系在25～400℃和22MPa下完成的。实验发现矿物在300℃至400℃范围,在跨越水临界点时出现反应速率的涨落。各种多金属氧化物硅酸盐与水反应时,各个元素溶解到溶液里的释放速率一般不一样,常称为一致溶解作用。但是,在近300℃变为一致溶解作用。实验发现在22MPa时硅酸盐矿物的最大溶解反应速率多是在300℃,如硅的最大释放速率是在300℃。其余元素如Na、K、Mg、Ca、Fe、Al等释放速率在<300℃22MPa时都高于硅的释放速率,在>300℃时硅的释放速率要高于其它元素的释放速率。确切地说,金属与氧之间的键的性质决定了它们(金属氧化物)与水之间反应速率。在一般情况下,Na-Obr,Ca-Obr,Mg-Obr,Al-Obr和Si-Obr的键桥(br),它们之间相对地由具有离子键性质逐步变为具有极性键的性质。由常温常压到亚临界区(300～374℃22MPa),再到大于临界点374℃、22MPa进入超临界区,水的性质随温度、压力变化。水由容易溶解离子键逐渐变为容易打破极性键。笔者还研究了黑钨矿、锡石(玄武岩、花岗闪长岩)与水在250～400℃条件下的反应动力学过程,得出了相同的结果。实验均发现在跨越水临界点时矿物(或岩石)与水反应的动力学涨落。这些实验结果可以用于说明中地壳上部的水/岩相互作用的特征。发生于中地壳的水、岩相互作用大多是在300～450℃和20～50MPa条件下进行的。各地区的地壳厚度不一,中地壳温度压力并不完全相同。模拟中地壳条件下水/岩相互作用实验,目的主要是研究矿物(或岩石)在300～450℃条件下反应动力学过程。已有热液矿床矿物流体包体数据表明:有一批矿床的主要矿石形成于300～500℃,低于NaCl H2O溶液临界线的条件。中地壳的流体处于由亚临界态跨越临界态,进入超临界流体太的演化过程。这种流体的性质变化会引起水/岩相互作用的反应动力学涨落和矿石大量沉淀。  相似文献   

硒对华贵栉孔扇贝碱性磷酸酶的酶动力学及理化性质研究     

余群  王重刚  陈荣  郁昂  郑微云 《海洋科学》2008,32(10):56-61

探讨了微量硒(Se~(4+))对华贵栉孔扇贝(Chlamys nobilis(Reeve))碱性磷酸酶(AKP)的作用。以催化动力学原理研究了不同缓冲系统中微量硒时AKP的影响。结果表明,Se~(4+)对谈酶的作用与酶所处的环境有关。在0.05 mol/L Na_2CO_3-NaHCO_3(pH 9.0)缓冲溶液中Se~(4+)浓度小于12.5 mmol/L时呈现出激活作用;Se~(4+)浓度大于12.5 mmol/L时呈现出非竞争性的抑制作用,其抑制常数为6.81×10~(-2)mol/L。在0.05 mol/L Tris-HCl缓冲系统(pH 9.0)中,微量Se~(4+)对AKP具有强烈竞争性抑制作用,其抑制常数为3.79×10~(-1)mol/L。经紫外吸收光谱、荧光发射光谱和圆二色谱的实验表明,微量Se~(4+)与AKP作用后,该酶的构象已发生了变化。研究发现海水环境中若含有微量Se~(4+)(SeO_3~(2-)),可以促进扇贝AKP的水解。利于贝类的生长发育和外壳的形成,并有益于贝类的繁殖。  相似文献   

不同水温下儿茶素EGCG在黄颡鱼(Pelteobagrus vachelli)体内代谢动力学和肝消除研究     

葛建  刘洋  李明揆  赵进  韩宝瑜 《海洋与湖沼》2012,43(5):938-942

采用反相高效液相色谱-紫外检测法测定了黄颡鱼血浆、肝脏中儿茶素EGCG含量,并研究了不同水温(10℃和20℃)下EGCG在黄颡鱼体内代谢动力学和肝组织消除特征。结果表明,高温下黄颡鱼腹腔注射EGCG后体内吸收较快,T1/2ka为0.21h,T1/2α为2.07h,T1/2β为22.89h,AUC为5195.41μg·h/ml,Tp为0.95h,Cmax为257.75μg/ml;低温下分别为5.67h、9.53h、207.49h、17283.03μg·h/ml、12.56h和117.16μg/ml。同时在0.5、1、2、4、8、12、24、48、96h各时间点检测了肝脏组织中EGCG浓度,并计算得出高温下EGCG在肝组织中的T1/2β为24.15h,低温下肝组织中T1/2β为64.17h。对不同水温下代谢动力学和肝组织消除规律的研究表明,EGCG在黄颡鱼体内吸收、分布和消除速度与水温关系密切,高温下均较低温下迅速。  相似文献   

Hydrogeology of desert springs in the Panamint Range,California, USA: Geologic controls on the geochemical kinetics,flowpaths, and mean residence times of springs     

Carolyn L. Gleason  Marty D. Frisbee  Laura K. Rademacher  Donald W. Sada  Zachary P. Meyers  Jeffrey R. Knott  Brian P. Hedlund 《水文研究》2020,34(13):2923-2948

Over 180 springs emerge in the Panamint Range near Death Valley National Park, CA, yet, these springs have received very little hydrogeological attention despite their cultural, historical, and ecological importance. Here, we address the following questions: (1) which rock units support groundwater flow to springs in the Panamint Range, (2) what are the geochemical kinetics of these aquifers, and (3) and what are the residence times of these springs? All springs are at least partly supported by recharge in and flow through dolomitic units, namely, the Noonday Dolomite, Kingston Peak Formation, and Johnnie Formation. Thus, the geochemical composition of springs can largely be explained by dedolomitization: the dissolution of dolomite and gypsum with concurrent precipitation of calcite. However, interactions with hydrothermal deposits have likely influenced the geochemical composition of Thorndike Spring, Uppermost Spring, Hanaupah Canyon springs, and Trail Canyon springs. Faults are important controls on spring emergence. Seventeen of twenty-one sampled springs emerge at faults (13 emerge at low-angle detachment faults). On the eastern side of the Panamint Range, springs emerge where low-angle faults intersect nearly vertical Late Proterozoic, Cambrian, and Ordovician sedimentary units. These geologic units are not present on the western side of the Panamint Range. Instead, springs on the west side emerge where low-angle faults intersect Cenozoic breccias and fanglomerates. Mean residence times of springs range from 33 (±30) to 1,829 (±613) years. A total of 11 springs have relatively short mean residence times less than 500 years, whereas seven springs have mean residence times greater than 1,000 years. We infer that the Panamint Range springs are extremely vulnerable to climate change due to their dependence on local recharge, disconnection from regional groundwater flow (Death Valley Regional Flow System - DVRFS), and relatively short mean residence times as compared with springs that are supported by the DVRFS (e.g., springs in Ash Meadows National Wildlife Refuge). In fact, four springs were not flowing during this campaign, yet they were flowing in the 1990s and 2000s.  相似文献   

吐哈盆地丘东次凹低熟气的生成与动力学研究     

张长春  陶伟  张馨  王晓峰  邹艳荣 《沉积学报》2008,26(5):857-863

采用黄金管—高压釜封闭体系,对吐哈盆地艾试1井的泥岩和煤岩进行了低温热解实验。根据实验结果,分别求取了干气（C1）、湿气（C2～C5）生成过程的初始动力学参数,然后将单一活化能的动力学参数进一步优化为具有高斯分布的活化能,优化后的动力学参数能较好拟合实验数据。利用优化后的动力学模型模拟了吐哈盆地丘东凹陷八道湾组天然气早期生成过程,并将模拟结果与实际地质资料进行了对比。结果表明,经过优化后的低温恒温热解动力学,能有效评价早期生气过程;在丘东次陷发现的天然气,与八道湾组源岩关系密切。  相似文献   

Application of zeolitic volcanic rocks for arsenic removal from water     

F. Ruggieri  V. Marín  D. Gimeno  J.L. Fernandez-Turiel  M. García-Valles  L. Gutierrez 《Engineering Geology》2008,101(3-4):245-250

Natural zeolitic rocks consisting mainly of chabazite-phillipsite, clinoptilolite, and volcanic glass have been evaluated by means of batch methods to remove arsenic from waters with different mineralization degree (from deionized water to natural water with a specific conductivity of 1,600 μS cm^− 1). Arsenic was previously spiked in the studied waters at concentrations of about 100 µg l^− 1 to simulate actual cases. The compositional range of natural waters is representative of large hydrogeochemical regions around the world. The experiments were focussed on the application of natural common zeolitic rocks to water treatment for human consumption. The removal efficiency observed rises, in the better cases, 60–80% for chabazite-phillipsite raw materials whereas is 40–60% for clinoptilolite-bearing ones. The arsenic removal tends to increase with water mineralization degree, independently of the zeolitic rock type. A large zeolitic content in the chabazite-phillipsite raw materials increase the removal. Instead, the inverse situation is observed in the clinoptilolite-bearing rocks. The relevance of the quantitative mineralogical analysis, determining also the content of volcanic glass, as well as the use of natural waters in the removal tests has been demonstrated.  相似文献   

应用生烃动力学法定量评价碳酸盐岩的二次生烃:以朱家墩气藏为例   总被引：3，自引：0，他引：3  

徐立恒  陈践发  薛海涛  马广宇  李玲 《地球化学》2008,37(3):251-257

针对碳酸盐岩发育区烃源岩普遍存在二次生烃的问题,以苏北盐城凹陷朱家墩气藏源岩二叠系栖霞组灰岩为目标,应用化学动力学方法定量研究该源岩的二次生烃(气).在模拟实验基础上,选取动力学模型,求取动力学参数,再结合朱家墩地区的埋藏史和热史,最终求取了源岩生气史曲线.得出在距今240-190 Ma(三叠纪-早侏罗世)时二叠系灰岩第一次生气,随后地层抬升,生气过程中止;在距今54 Ma(始新世)时该烃源岩埋藏条件达到了第一次生气终止时的条件,开始第二次生气,生气过程一直持续到现今,第一次生气量(10%)远无法与第二次生气量(80%)相比.并通过储层包裹体的均一化温度判断朱家墩气藏流体注入期次,结果显示,二次生气的生气高峰与流体注入期相匹配,验证了用动力学方法评价二次生烃、多次生烃的合理性,同时也佐证了二叠系灰岩对朱家墩气藏的贡献.  相似文献   

Calcite Dissolution in Deionized Water from 50℃ to 250℃ at 10 MPa： Rate Equation and Reaction Order     

GONG Qingjie DENG Jun WANG Qingfei YANG Liqiang SHE Min 《《地质学报》英文版》2008,82(5)

Carbonate minerals and water (or geofluids) reactions are important for modeling of geochemical processes and have received considerable attention over the past decades.The calcite dissolution rates from 50℃to 250℃at 10 MPa in deionized water with a flow rate varying from 0.2 to 5 mL/min were experimentally measured in a continuous flow column pressure vessel reactor.The dissolution began near the equilibrium with c/c_(eq)>0.3 and finally reached the equilibrium at 100℃-250℃,so the corresponding solubility was also determined as 1.87,2.02,2.02 and 1.88×10~(-4)·mol/L at 100℃,150℃,200℃and 250℃respectively,which was first increasing and then switching to decreasing with temperature and the maximum value might occur between 150℃and 200℃.The experimental dissolution rate not only increased with temperature,but also had a rapid increase between 150℃and 200℃at a constant flow rate of 4 mL/min.The measured dissolution rates can be described using rate equations of R=k(1-c/c_(eq))n or R=kc~(-n).In these equations the reaction order n changed with temperature,which indicates that n was a variable rather than a constant,and the activation energy was 13.4 kJ/mol calculated with R=k(1-c/c_(eq))~n or 18.0 k J/mol with R=kc~(-n),which is a little lower than the surface controlled values.The varied reaction order and lower activation energy indicates that calcite dissolution in this study is a complex interplay of diffusion controlled and surface controlled processes.  相似文献   

A Study of the Migration and Accumulation Efficiency and the Genesis of Hydrocarbon Natural Gas in the Xujiaweizi Fault Depression   总被引：1，自引：1，他引：0  

LI Jijun  LU Shuangfang  XUE Haitao  HUO Qiuli  XU Qingxia 《《地质学报》英文版》2008,82(3):629-635

In order to investigate the migration and accumulation efficiency of hydrocarbon natural gas in the Xujiaweizi fault depression, and to provide new evidence for the classification of its genesis, a source rock pyrolysis experiment in a closed system was designed and carried out. Based on this, kinetic models for describing gas generation from organic matter and carbon isotope fractionation during this process were established, calibrated and then extrapolated to geologic conditions by combining the thermal history data of the Xushen-1 Well. The results indicate that the coal measures in the Xujiaweizi fault depression are typical ＂high-efficiency gas sources＂, the natural gas generated from them has a high migration and accumulation efficiency, and consequently a large-scale natural gas accumulation occurred in the area. The highly/over matured coal measures in the Xujiaweizi fault depression generate coaliferous gas with a high δ^13C1 value （〉 -20‰） at the late stage, making the carbon isotope composition of organic alkane gases abnormally heavy. In addition, the mixing and dissipation through the caprock of natural gas can result in the negative carbon isotope sequence （δ^13C1 〉δ^13C2 〉δ^13C3 〉δ^13C4） of organic alkane gases, and the dissipation can also lead to the abnormally heavy carbon isotope composition of organic alkane gases. As for the discovery of inorganic nonhydrocarbon gas reservoirs, it can only serve as an accessorial evidence rather than a direct evidence that the hydrocarbon gas is inorganic. As a result, it needs stronger evidence to classify the hydrocarbon natural gas in the Xujiaweizi fault depression as inorganic gas.  相似文献   

环境矿物界面反应动力学   总被引：3，自引：1，他引：3       下载免费PDF全文

吴大清  刁桂仪  彭金莲  王林江  袁鹏 《岩石矿物学杂志》2001,20(4):395-398

环境矿物界面反应动力学主要探讨地表中各种有毒、有害离子或分子与矿物表面之间的反应速率与反应机制。矿物表面存在一组化学活性很强的表面功能基，当它们与环境中毒害物质发生作用时，会因其极性、荷电性和Lewis酸碱性不同而表现出不同的作用力和反应速率，进而控制有毒、有害物质在大气、水体和沉积物中的赋存形态，稳定性及迁移转化速率。本文简要介绍了环境矿物界面反应动力学理论，并给出几个应用实例。  相似文献