河流泥沙输移过程中矿物风化的碳汇效应初探——以长江干流为例     

张信宝  罗景城  王小国  唐家良  彭韬  朱波 《地质学报》2023,97(7):2378-2385

本文首先提出了河流泥沙输移过程中泥沙中的钙镁矿物溶蚀消耗水体中的CO2并具有碳汇功能的观点。基于前人长江干流从源头到入海口和支流2003~2007年期间4次河流悬移质泥沙的化学元素组成和矿物组成资料,分析悬移质中CaO、MgO含量和方解石、白云石含量变化特征,定量计算了这些取样点悬移质泥沙的CO2总碳汇能力和非永久性、永久性碳汇能力,分析了不同碳汇能力沿程变化规律及其原因。碳汇计算结果表明：寸滩—大通河段1956~2000年期间泥沙输移过程中钙镁矿物溶蚀产生的总碳汇量、非永久性和永久性碳汇量分别为2572万t/a、1700万t/a和872万t/a。由于输沙量减少,寸滩站—大通站河段的总碳汇量、非永久性和永久性碳汇量2006~2019年期间较1956~2000年期间相应分别减少了1852万t、1224万t和872万t。三峡水库年均淤积量1. 145亿t,损失总碳汇量675. 6万t,相当于三峡电站减排二氧化碳8580万t的7. 9%。全球河流入海年输沙量126. 1亿t,以寸滩- 吴淞口河段碳汇功能0. 060 t/t计,总碳汇量7. 57亿t相当于全球岩石风化碳汇总量10. 56亿t CO2的71. 6%。河流泥沙输移过程中钙镁矿物溶蚀的碳汇量具有重要的作用,其溶蚀速率大于原地风化。  相似文献   

基于傅里叶变换质谱的烃源岩成熟度评价方法及地质意义     

韩双彪  谢林丰  唐致远  李剑  王成善  Brian HORSFIELD 《地质学报》2023,97(5):1717-1721

<正>伴随非常规油气资源的勘探开发,油气资源开采的广度和深度进一步扩大,一定程度上缓解了我国油气供需矛盾、保障了我国能源安全,同时有力推动了能源结构战略转型。但同时也对能源地质研究工作提出了新的挑战。有机质成熟度是油气评价的重要参数之一,不同成熟阶段的有机质会对应产出不同成因、不同性质、不同质量的油气,如何准确评价沉积有机质成熟度是当前油气资源勘探开发工作的关键问题之一。前人在科研实践工作中从光学、化学、谱学等角度提出了适用条件各异的成熟度评价方法,在部分地质环境中获得了良好的应用效果,但已有的成熟度指标多受测定方法原理的制约导致其适用性不同程度受限(肖贤明等,2020),制约了油气资源的高质量勘探开发。  相似文献   

河北矾山超钾质岩浆氧逸度及含水性特征的磷灰石地球化学记录     

舒小超  孟凡巍  陶瑞  王坤 《地质学报》2023,97(12):4101-4116

产于华北克拉通北缘的晚三叠世矾山超钾质碱性岩杂岩体主要由单斜辉石岩和辉石正长岩等组成,以发育内生磷灰石-磁铁矿矿床而闻名。本文选取矾山杂岩体中的磷灰石为研究对象,通过测试磷灰石的主微量元素及原位Sr-Nd同位素组成以探讨母岩浆的氧逸度及含水性特征。研究表明,矾山磷灰石以轻稀土元素富集、重稀土元素亏损为特征,显示出缺乏显著Ce异常的“右倾”的稀土配分型式,且具有较低的Ga含量及较高的δEu值,暗示杂岩体具有较高的岩浆氧逸度,这也得到了磷灰石Mn氧逸度计的支持。所有磷灰石以高Sr、低Y为特征,具有较高的Sr/Y(>30)和La/Yb(>90)比值,且Sr/Y与La/Yb存在明显的正相关关系,表明矾山超钾质岩浆具有较高的含水量。矾山磷灰石的原位Sr-Nd同位素投点位于地幔序列,明显偏离地壳趋势。母岩浆的“氧化且富水”特征是矾山杂岩体得以发生磷灰石-磁铁矿矿化的重要因素,其主要与板片俯冲过程中蚀变洋壳对岩石圈地幔的交代作用有关。通过对比矾山杂岩体与全球范围内其他地质环境中磷灰石的成分数据,发现具有“高Sr、低F、少Cl”特征的磷灰石可作为识别超钾质碱性岩杂岩体(及其相关金属矿床)的...  相似文献   

裂隙岩体变形模量尺寸效应研究Ⅱ:解析法   总被引：1，自引：1，他引：0  

杨建平  陈卫忠  戴永浩 《岩土力学》2011,32(6):1607-1612

通过分开考虑岩块和裂隙对岩体变形的贡献,研究了任意裂隙分布岩体等效变形模量的解析计算方法,并用正交裂隙岩体对该方法进行了验证,得到的结果和经典解析解完全一致。此外,通过该方法对锦屏Ⅱ级电站辅助洞中段随机裂隙岩体进行不同尺寸、不同方位下等效变形模量的计算,计算结果显示,随着岩体尺寸的增大,不同方位的变形模量值趋于稳定,该裂隙岩体变形模量的特征单元对(REV)尺寸为8 m,和有限元计算结果一致。结果表明该方法可以用来研究裂隙岩体等效变形模量尺寸效应和各向异性特性,研究成果对于裂隙岩体等效变形参数取值具有重要意义。  相似文献   

地层渗透性对岩石强度及机械钻速影响因素分析     

杨谋  孟英峰  李皋  李永杰  徐翔  唐思洪  孙敏 《地质科技情报》2011,30(3):127-131

分析了地层渗透性对井底围压及破岩效率产生的影响,并对地层渗透性进行了分类,在此基础上建立了围压下岩石强度模型;基于压持效率制约了井底净化环境,修正与完善了不同地层渗透性的机械钻速模型,确定了各项参数.应用聚类分析中最优分段法对测井参数与录井参数进行了分类处理并编程获得了单轴下和围压下岩石强度剖面及机械钻速剖面,分别选取...  相似文献   

Critical conditions for natural gas charging and delineation of effective gas source rocks for tight sandstone reservoirs     

Fujie Jiang  Xiongqi Pang  Fengtao Guo  Jigang Guo 《Geological Journal》2016,51(1):113-124

Although it has been shown that the potential of tight‐sand gas resources is large, the research into the mechanisms of hydrocarbon charging of tight sandstone reservoirs has been relatively sparse. Researchers have found that there is a force balance during hydrocarbon charging, but discriminant models still have not been established. Based on the force balance conditions observed during gas migration from source rocks to tight sandstone reservoirs, a calculation formula was established. A formula for identifying effective source rocks was developed with the gas expulsion intensity as the discrimination parameter. The critical gas expulsion intensity under conditions of various burial depths, temperatures, and pressures can be obtained using the calculation formula. This method was applied in the Jurassic tight sandstone reservoirs of the eastern Kuqa Depression, Tarim Basin, and it was calculated that the critical expulsion intensity range from 6.05 × 10⁸ m³/km² to 10.07 × 10⁸ m³/km². The critical gas charging force first increases with depth and later decreases with greater depths. The distribution range of effective gas source rocks and total expelled gas volume can be determined based on this threshold. This method provides new insight into and method for predicting favourable tight‐sand gas‐bearing regions and estimating their resource potentials. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   

琼东南盆地乐东凹陷烃源岩热史及成熟史模拟   总被引：1，自引：0，他引：1  

刘文超  叶加仁  雷闯  郭飞飞  张洋 《地质科技情报》2011,30(6):110-115

琼东南盆地乐东凹陷烃源岩热史及成熟史研究对乐东凹陷油气资源评价及勘探选区具有指导意义.在盆地地史和热史恢复的基础上,利用EASY％Ro模型模拟重建了琼东南盆地乐东凹陷崖城组烃源岩的成熟史.研究结果表明,琼东南盆地具有较高的古、今地温梯度,且古地温梯度多高于现今地温梯度,有利于烃源岩的成熟与天然气的生成.始新世—早渐新世...  相似文献   

新疆若羌县黑山梁地区北山岩群地质特征及构造环境   总被引：1，自引：0，他引：1  

赵如意  胡能高  陈云杰  武彬  孙江华  舒林 《新疆地质》2011,29(4):398-402

北山岩群是一套经角闪岩相主期变质作用和绿帘角闪岩相退变质作用的强变质变形地体.据岩石组合特征可划分为4个岩组:第一岩组为斜长角闪片岩夹黑云斜长片麻岩和变粒岩;第二岩组为片麻岩夹斜长角闪片岩、石英片岩、变粒岩;第三岩组为石英片岩夹大理岩、石英岩;第四岩组为石英岩夹石英片岩.经原岩恢复,第一岩组原岩主要为板内拉斑玄武岩,具向岛弧玄武岩过渡趋势;第二岩组原岩为快速沉积的碎屑岩和酸性火山岩;第三岩组原岩为碎屑岩夹碳酸盐岩;第四岩组原岩为成熟度较高的碎屑岩.据火山岩组合、碎屑组合岩特征及地球化学特征,判断其形成年代为早元古代,构造环境为早期裂谷发育速度较快,火山活动强烈,沉积物为快速沉积的碎屑岩;后期构造趋于平缓,碎屑岩成熟度升高,并夹有厚层碳酸盐岩.  相似文献   

Amplitude Variation with Offset Responses Modeling Study of Walkaway Vertical Seismic Profile Data at CO2 Geological Storage Site, Ketzin, Germany     

YANG Can  Sayed Hesammoddin KAZEMEINI  FAN Wenfang  Christopher JUHLIN  LIU Dameng 《《地质学报》英文版》2011,85(5):1118-1126

An important component of any CO2 sequestration project is seismic monitoring for tracking changes in subsurface physical properties, such as velocity and density. Different reservoirs have different amplitude variation with offset (AVO) responses, which can define underground conditions. In the present paper we investigate walkaway vertical seismic profile (VSP) AVO response to CO2 injection at the Ketzin site, the first European onshore CO2 sequestration pilot study dealing with research on geological storage of CO2. First, we performed rock physics analysis to evaluate the effect of injected CO2 on seismic velocity using the Biot-Gassmann equation. On the basis of this model, the seismic response for different CO2 injection saturation was studied using ray tracing modeling. We then created synthetic walkaway VSP data, which we then processed. In contrast, synthetic seismic traces were created from borehole data. Finally, we found that the amplitude of CO2 injected sand layer with different gas saturations were increased with the offset when compared with the original brine target layer. This is the typical class III AVO anomaly for gas sand layer. The AVO responses matched the synthetic seismic traces very well. Therefore, walkaway VSP AVO response can monitor CO2 distribution in the Ketzin area.  相似文献   

Application of bacteria-plant association in biodegradation of diesel oil pollutants in soil     

Sijin Lu  Yanguo Teng  Zongjian Sun  Jinsheng Wang 《中国地球化学学报》2011,30(2):220-225

The bacteria and plants were associated to remove diesel oil pollutants from soil.Three efficiently degrading bacteria(named strains Q10,Q14 and Q18,respectively) were isolated.Two plants(alfalfa and Indian mustard) were selected to form the association.Biodegradation of diesel oil pollutants in soil was accelerated by bacteria-plants association.The main results are summarized as follows.The plants-bacteria association was more effective in biodegradation of diesel oil pollutants in soil than in respective experiments carried out with plants or bacteria alone.Strain Q18-Indian mustard association resulted in the maximum diesel oil reduction(69.18%).The activities of catalase and polyphenol oxidase in soil were enhanced and microbial populations in soil,especially in rhizosphere,were also stimulated in the treatment of bacteria-plant association.Overall,the soil conditions might be improved by alfalfa or Indian mustard to benefit the growth of bacteria,which resulted in degradation of diesel oil pollutants more effective by the bacteria-plant association.The bacteria-plants association may be a better approach to the removal of diesel oil pollutants from soil.  相似文献