滇西大理地区部分温泉溶解CO2及碳同位素组成特征研究

温泉溶解CO_2的来源成因研究,有利于判断与甄别研究区温泉溶解CO_2异常信息。对2016年10月至2017年7月大理地区3个温泉的水化学常量离子和δ~(13)C_(HCO_3~-)进行了10次重复取样观测,对3个温泉的水文地球化学及CO_2来源进行分析。结果表明:3个温泉均属于HCO_3·SO_4-Na型水,地下水补给都来自于大气降水,CO_2主要来自于深部的地幔成因和变质成因的CO_2;2017年漾濞M_S5.1地震发生前,3个温泉的δ~(13)C_(HCO_3~-)值与HCO_3~-正相关关系发生改变,表明温泉δ~(13)C_(HCO_3~-)值与地震有一定的相关性。     

滇西实验场区温泉碳同位素地震地球化学特征

引言最近若干年来,中、苏、美、日等一些多地震国家广泛开展了水文地球化学地震前兆的观测和研究。目前已经明确,水文地球化学综合观测在地震预报工作中具有十分重要的地位。要实现地下水预报地震,一方面要建立广泛的科学的监测台网,另一方面必须深入开展各类地球化学前兆异常的机理的研究。研究前兆机理最重要的是要搞清形成前兆异     

滇西地区二氧化碳的释放与地震

作者在研究了滇西地区碳酸泉的分布及其同位素组成特征后提出,该区存在五种不同成因机制的CO2释放.其中,深源CO2混合成因和热动力变质成因CO2的释放与地壳深部应力状态的变化关系密切,因而具有较好的映震效能.对下关、江干等典型泉点的CO2释放的连续观测表明,在该区发生五级左右地震前,地热流体的溶解CO2总量有明显的异常变化,其中短临前兆变化十分引人注目.因此,监测这类碳酸泉的CO2释放有可能是一种有效的地震前兆观测方法.     

大别山双河地区超高压变质岩流体包裹体成分及二氧化碳碳同位素研究

分步加热实验结果表明大别山超高压岩流体包裹体成分 (不计入水 )主要是CO2 ,其次为CO及少量的N2 和CH4;变质高峰期流体CO2 碳同位素值 ( - 2 5‰～- 30‰ )与地幔流体相差较大 ,说明其是原岩自身含碳物质在高温高压之下演化的结果 ,反映了超高压变质岩石虽然可能俯冲到地幔深度 ,但并未受到地幔流体的大规模作用 ,岩石中的流体系统是活动有限的、较为封闭的体系 .这可能与地壳岩石快速插入地幔、并又迅速折返至地表的动力学机制有关     

温泉气体氦碳同位素在云南地区重危区年度跟踪中的应用

正为跟踪_2017年度云南地区的震情发展,对滇南滇西南、滇东北、滇西北3个重点危险区14个温泉进行了现场测量和气体样品采集。经色谱和质谱分析测试,获得了14个温泉逸出气体全化学组成(He、H_2、Ar、O_2、N_2、CH_4、CO_2)及He、Ne同位素和CH_4、CO_2的C同位素组成数据。利用氦氖比,对氦同位素组成进行了大气污染校正和幔源比例百分比计算。利用CH_4、     

云南大理地区温泉CO2释放与地震预报研究

通过对大理地区鹤庆、洱源、下关、弥渡等温泉水CO2释放特征及与区域地震活动的相关性研究，提炼出单项地震预报指标，从而进行系统合成，找出大理地区CO2的综合预报指标。     

滇西永胜地区地震地质特征

本文研究了永胜1515年8级大震震区的新构造活动,发现控制该区的南北向构造带与之交汇的东西向构造新活动十分强烈。断裂活动是多期的,各期的活动方式也不同,反映的应力场在輓近时期发生过多次变化,而永胜地震则发生在上述两组构造的交汇处。永胜地震在基岩上形成两条东西向裂缝带。它们以力学性质特殊(是主压应力方向与东西向发震构造平行情况下形成的典型张破裂型裂缝)和单条裂缝宽度最大(最宽处在8米以上)而在国内外罕见。作为本区控震构造的南北向金河——永胜——宾川断裂中常被文献提到并被监测的程海压扭性逆断层是一条新活动很弱、感受构造应力作用很轻的断层,而改为加强监测其东西两侧其它几条新活动强烈的断层为宜。     

滇西地区小地震群特征

根据滇西地区（23°．8－28°N;97°．0－101°．5E）1966年1月－1996年7月89个ML≤4．7的小地震震群资料分别总结出滇西地区H,K,U,η,b,△M参数的判别指标和地区特征。着重讨论了小地震震群与云南及邻区中强震关系,以及综合利用上述参数尝试预报未来中强震。     

滇西地区及邻区构造单元划分及其特征

依据板块构造学说划分大地构造单元的原则和构造亲缘关系,将滇西及邻区划分为８个一级构造单元Ｉ印度板块、Ⅱ冈底斯中间板块、Ⅲ拉萨地块、Ⅳ顷甸板块、Ⅴ滇顷泰板块Ⅵ印度板块、Ⅶ杨子板块、Ⅷ松潘一甘孜活动带。并且对其主要构造单元的地质特征进行阐述。     

四川乡城然乌温泉水化学与同位素特征

<正>1研究背景乡城然乌温泉位于川滇菱形块体西北边界附近。川滇菱形块体是川滇地区活动地块中受到关注的重要组成部分,是青藏高原物质东南流的重要通道(李其林等,2019)。该块体东边界(鲜水河—安宁河—则木河断裂带)出露的大量温泉,对周围强震,如汶川M_S8.0、芦山M_S7.0和康定M_S 6.3等地震的孕育起到了重要作用(Zhou et al,2017)。德钦—中甸—大具断裂与金沙江断裂共同构成了川滇菱形块体的西北边界,德钦—中甸—稻城一带地热横向梯度变化较大且历史强震稀少,需关注其未来地震危险性(李其林等,2019),乡城然乌温泉即位于该地热异常区域内。温泉化学成分的变化对川滇菱形块体构造活动具有较好的指示意义,对相关区域的地震活动具有前兆指示意义。     

Correlations between13C and ΣCO2 in surface waters and atmospheric CO2

¹³C and ΣCO₂ data from the North and South Atlantic, the Antarctic, and the North and South Pacific are given. The δ¹³C of the ΣCO₂ in the deep water (～3000m) decreases from 1.7‰ in the North Atlantic to ?0.10‰ in the North Pacific. This change is attributed to the addition of about 158 μmoles of CO₂ per kg of seawater. The in-situ oxidation of organic matter accounts for 83% of this increase in ΣCO₂, while the remainder is attributed to dissolution of calcium carbonate.The δ¹³C of the dissolved CO₂ in mid-latitude surface water samples is controlled by a quasi-steady-state equilibrium with atmospheric CO₂ at a mean temperature of 16°C. The δ¹³C and ΣCO₂ values of Antarctic surface water samples suggest that these waters are derived from a mixture of North Atlantic deep water and equilibrated surface water.     

CO2/CaCl2 solution interfacial tensions under CO2 geological storage conditions: Influence of cation valence on interfacial tension

The effectiveness of CO₂ storage in deep saline aquifers and hydrocarbon reservoirs is governed, among other factors, by the interfacial tension between the injected CO₂ and formation water (brine). Experimental data on CO₂/water and CO₂/NaCl solution have revealed that the interfacial tension depends on the pressure, temperature and water salinity. However, there is still a lack of data for other salts (such as MgCl₂ and CaCl₂) which are also present in aquifers and carbonate reservoirs.     

Stability of forsterite + CO2 and its bearing on the role of CO2 in the mantle

An experimental determination of the reaction MgCO₃ + MgSiO₃ = Mg₂SiO₄ + CO₂ between 20 and 40 kbars and in the range 1000–1500°C yields an average pressure effect on the equilibrium of 44 bars/°C. This result shows that the assemblage forsterite and carbon dioxide is not stable under most pressure and temperature conditions expected in the upper mantle. Hypotheses requiring the presence of free CO₂ in the low-velocity zone, CO₂ as a drive mechanism for kimberlite emplacement, or action of a free CO₂ phase in ultramafic rocks may need considerable revision.     

Shock-induced CO2 loss from CaCO3; implications for early planetary atmospheres

We report new results of shock recovery experiments on single crystal calcite. Recovered samples are subjected to thermogravimetric analysis. This yields the maximum amount of post-shock CO₂, the decarbonization interval, ΔT, and the energy of association (or vaporization), ΔEV, for the removal of remaining CO₂ in shock-loaded calcite. Comparison of post-shock CO₂ with that initially present determines shock-induced CO₂ loss as a function of shock pressure. Incipient to complete CO₂ loss occurs over a pressure range of 10to 70GPa. The latter pressure should be considered a lower bound. Comparable to results on hydrous minerals, ΔT and ΔEV decrease systematically with increasing shock pressure. This indicates that shock loading leads to both the removal of structural volatiles and weakening of bonds between the volatile species and remainder of the crystal lattice.Optical and scanning electron microscopy (SEM) reveal structural changes, which are related to the shock-loading. Comparable to previous findings on shocked antigorite is the occurrence of dark, diffuse areas, which can be resolved as highly vesicular areas as observed with a scanning electron microscope. These areas are interpreted as representing quenched partial melts, into which shock-released CO₂ has been injected.The experimental results are used to place bonds on models of impact production of CO₂ during accretion of the terrestrial planets.     

北京城区二氧化碳浓度和通量的梯度变化特征——I浓度与虚温

根据北京塔7层涡动系统2012年5月至2013年12月的湍流观测数据,分析了北京城区二氧化碳浓度在不同高度层次的日变化和月变化特征,并初步给出不同季节和日变化时间段内二氧化碳的浓度垂直廓线.结果表明:二氧化碳浓度整体随高度而下降;各观测层均有浓度的明显日变化,夏季最为明显,冬季相对平缓;近地层浓度直接受城市供暖、地表植被、交通运输等碳源影响,更高观测层浓度则受对流输送和天气过程影响较大;垂直方向上,冬季浓度变化范围最大,夏季层间浓度变化最明显;在一天中的任何时刻,近地面层二氧化碳浓度的日变化最低值一般出现在夏季,50m以上则出现在春季,浓度最高值总是出现在冬季;根据对二氧化碳浓度四季垂直廓线变化的分析可以看出,边界层二氧化碳浓度强烈受到碳源、下垫面植被、大气稳定度、环境温度和天气过程等因素的影响.     

Quantifying CO2 fluxes from soil surfaces to the atmosphere

Measurements of CO₂ fluxes from ground surface of the atmosphere (soil respiration) are needed to quantify biotic and abiotic reaction rates in unsaturated zones and to gain insight into the importance of these processes on global warming. The use of three techniques (dynamic closed chambers, static chambers, and gradient calculations) to determine soil respiration was assessed by measuring fluxes of microbially produced CO₂ from an unsaturated mesocosm (2.4 m dia.×3.2 m thick) and two unsaturated minicosms (0.58 m dia.×1.2 m thick), one maintained at 18–23 °C (HT) and the other at 5 °C (LT). By injecting known and constant CO₂ fluxes into the bottom of the HT minicosm and measuring the resulting fluxes, it was shown that the dynamic closed chamber (DCCS) technique yielded accurate measurements of fluxes over the range observed from natural unsaturated media. Over this same range, results showed that the concentration gradient method yielded reasonable estimates of fluxes but its accuracy was limited by uncertainties in both the concentration gradient and the gaseous diffusion coefficient in the soil atmosphere. The static chamber method underestimated the actual flux at higher CO₂ fluxes and when adsorption times of >24 h were used.     

Melting relationships in CaO-CO2 and MgO-CO2 to 36 kilobars with comments on CO2 in the mantle

The melting curves of CaCO₃ and MgCO₃ have been extended to pressures of 36 kb by experiments in piston-cylinder apparatus. At 30 kb, the melting temperatures of calcite and magnesite are 1610°C and 1585°C, respectively. New data for the magnesite dissociation reaction permit the location of an invariant point for the assemblage magnesite + periclase + liquid + vapor near 26 kb-1550°C. New data are also presented for the calcite-aragonite transition at 800°C, 950°C and 1100°C. At pressures above 36–50 kb, calcite and magnesite melt at temperatures lower than the solidus of dry mantle peridotite. Natural and experimental evidence suggests that carbon dioxide in the Earth's mantle could be present in a variety of forms: (a) a free vapor phase, (b) vapor dissolved in silicate magma, (c) crystalline carbonate, (d) carbonatite liquid, (e) carbon-bearing silicate analogs, or (f) carbonato-silicates (such as scapolite, spurrite, tilleyite, and related compounds).     

溶解性有机碳耦合营养状态解析河流CO2动态及驱动因素

为全面探索河流溶解性有机碳(DOC)与二氧化碳(CO₂)动态及驱动因素的相关关系,以我国三峡库区河流——澎溪河为对象,于雨季和旱季采集表层水体水样,分别通过原位和室内测定,明确水文参数(水温、pH、碱度和流速)、DOC浓度和营养元素(总氮(TN)和总磷(TP))浓度,并计算水体CO₂分压(pCO₂)、水—气界面CO₂交换通量和营养元素化学计量比(DOC:TN、DOC:TP和TN:TP)。以河流CO₂、DOC和营养状态动态变化为基础,通过对DOC、TN、TP、营养元素化学计量比和荧光峰(B、T、A、M、C、D和N)与河流pCO₂的多维分析建立及评估潜在的耦合关系,从而揭示特定区域河流CO₂的来源与驱动因素特征。结果显示,澎溪河水—气界面CO₂交换速率在3.75～22.9 m/d范围内,雨季((9.91±4.93)m/d)>旱季((6.69±4.30) m/(d),pCO₂在65.95～2...