首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 93 毫秒
1.
本文探讨康定榆林宫水热区水热CO2气的来源、区内主要水热点的CO2气释放强度及释放模式。稳定同位素分析结果表明,该水热区水热CO2气为深部成因,且有60%以上为变质成因;估算得区内主要水热点的CO2气释放强度为108g/a。结合研究区地质条件做出了水热CO2气释放模式示意图。  相似文献   

2.
环境水中化学需氧量的反向流动注射分析法研究   总被引:1,自引:1,他引:0  
研究了Ce(SO4)2H2SO4体系反向流动注射分析法测定环境水中化学需氧量(COD)的试验条件。在2.5~160.0mg/L线性范围内,采样频率达到25/h,Cl-的质量浓度至2500mg/L无干扰。对60mg/L的标准试样重复测定11次,相对标准偏差为0.79%,检出下限为2.5mg/L。该法便于实际工作中COD的连续监测,用于河水、池塘水分析,获得结果与经典的重铬酸钾法相对照,相关性良好  相似文献   

3.
环境水中化学学需氧量的反向流动注射分析法研究   总被引:5,自引:0,他引:5  
陈慧  金晓塞 《岩矿测试》1999,18(3):185-188
研究了Ce(SO4)2-H2SO4体系反向流动注射分析法测定环境水中化学需氧量的试验条件。在2.5-160.0mg/L线性范围内,采样率达25/h,Cl^-的质量浓度至2500mg/L无干扰。对60mg/L的标准试样重复测定11次,相对标准偏差为0.79%,检出下限为2.5mg/L。该法便于实际工作中COD的连续监测,用于河水,池塘水分析,获得结果与经典的重铬酸钾法相对照,相关性良好。  相似文献   

4.
何明友  金景福 《矿物学报》1996,16(2):158-164
本文分析了若尔盖铀矿床含铀热液中∑CO2,碳酸盐岩脱碳化成因的CO2,热解有机碳形成的CO2的碳同位素组成,并与岩浆源碳同位素组成进行上对比,结果表明,含铀热液中∑CO2的碳同位素组成与岩浆源碳同位素组成接近,说明含矿热液中∑CO2来源于岩浆,而不是地层岩石。  相似文献   

5.
通过4个月实地和近3年的追踪观测,查明拒马矿泉水产于涞源县浮图峪铜矿区的闪长玢岩与夕卡岩接触带中。H_2SiO_3含量25~39mg/L;Sr含量0.40~0.39mg/L,还含有CO_2,I,Br,Li,Zn,Mo,Se,Cu等多种对人体有益的微量元素,是极为宝贵的矿泉水资源。  相似文献   

6.
通过4个月实地和近3年的追踪观测,查明拒马矿泉水产于涞源县浮图峪铜矿区的闪长玢岩与夕卡岩接触带中。H2SiO3含量25 ̄39mg/L;Sr含量0.40 ̄0.39mg/L,还含有CO2,I,Br,Li,Zn,Mo,Se,Cu等多种对人体有益的微量元素,是极为定贵的矿泉水资源。  相似文献   

7.
滇西羊拉铜矿床稳定同位素地球化学研究   总被引:11,自引:0,他引:11  
滇西羊拉铜矿是近年来发现的大型铜矿床。作者系统地研究了该矿床的S、Pb、C、O、Si同位素组成,研究表明该矿床不同矿石的硫同位素组成变化范围一致,其平均值靠近零值且具有塔式分布特征,表明硫来源于上地幔或岩浆作用;该矿床矿石中方解石的C、O同位素组成与矿区大理岩的C、O同位素组成明显不同,其δ^13C(PDB)为-3.27‰~-4.89‰,与土地幔射气及岩浆作用形成的CO2的碳同位素组成一致,因此矿石中方解石中碳亦来源于土地幔射气或岩浆作用;铜同位素特征表明早期热水沉积形成的块状硫化物矿石铅主要来源于上地壳,而中晚期形成的夕卡岩型矿石及蚀变破碎带型矿石的铅具有土地幔铅的特征。  相似文献   

8.
北京斋堂黄土剖面主要温室气体组分初步研究   总被引:3,自引:0,他引:3  
全球碳循环研究表明,在北半球中纬度地带可能存在一个陆地生态江(植被和土壤)。中国黄土分布在北半球中纬度,在CO2未知汇的研究中很可能具有重要作用。通过自制钻机对北京斋堂黄土剖面(L2上部 ̄L1)进行了不同层位(深度)的垂直或水平钻,利用毛细管负压原理采集到游离气体并进行了主要温室气体CO2、CH4、N2O的浓度和CO2的碳、氧同位素组成分析。此外,还分析了土样的碳酸盐含量及其碳、氧同位素组成。初步  相似文献   

9.
浙西石炭纪层状硅质岩地球化学特征及其意义   总被引:7,自引:0,他引:7  
在浙西石炭纪地层中存在与地层整合产出的层状硅质岩。硅质岩中FeO、MnO、TiO2、Al2O3、MgO、CaO、Na2O、K2O等含量相对较高,富集As、Sb、Bi、Au、Ag、Ga,Fe2O3/FeO、SiO2/Al2O3、SiO2/(Na2O+K2O)、SiO2/MgO比值较小,稀土元素总量低,Ce弱负异常,重稀土相对富集,包裹体富含气相组份CH4、CO2、N2、CO、H2,具热水沉积硅质岩的地球化学特征。在Fe—Mn—(Ni+Co+Cu)三角图及SiO2—Al2O3、SiO2—Fe2O3图上均属于热水沉积硅质岩。硅质岩中硅、氧同位素也显示其热水成因之特点。硅质岩的硅同位素和稀土元素Ce/Ce※值表明本区层状硅质岩主要是在浅海环境下沉积的。硅质岩的形成温度较高,为98℃~152℃  相似文献   

10.
研究了以咪唑为背景吸收电解质,α羟基异丁酸为络合剂,毛细管离子电泳分离,间接紫外光度法测定镍矿石中Ni、Co、Cu含量。考察了背景电解质的pH值、α羟基异丁酸(αHIBA)和咪唑浓度对Fe3+、Co2+、Ni2+、Zn2+、Cu2+分离的影响。在优化的条件下,几种离子在8min内完成分离,检测限低至0.2mg/L。以Zn作内标,改善了方法的精密度,对于20mg/L各离子峰面积的相对标准偏差(RSD,n=9)<6.5%。采用内标标准曲线法对镍矿样中Ni、Co、Cu的含量进行了测定,线性范围分别在0.5~80mg/LNi2+和Co2+,5~80mg/LCu2+,结果与其它方法一致。  相似文献   

11.
元素碳碳同位素在古环境研究中的应用   总被引:1,自引:0,他引:1  
刘恋  周鑫  葛俊毅 《地质论评》2012,58(3):526-532
元素碳几乎完全来源于植被的燃烧,长期广泛地分布于大气、土壤、沉积物、岩石、水体和冰体等自然界载体中,记录了大量的古环境信息。利用元素碳碳同位素(δ13CEC)指标来反映古气候、古植被信息是将元素碳应用到古环境研究的一个重要方面,本文通过总结国内外学者利用δ13CEC指标进行古环境研究的现状,总结出对于"直接利用δ13CEC指标进行古环境恢复"这一关键问题还存在不同认识。燃烧前后物质的碳同位素是否发生变化是利用δ13CEC进行古环境研究时需要考虑的一个重要问题,国内外学者近20年来对C3、C4植物开展了大量燃烧实验,主要结论是C3植物燃烧前后物质的碳同位素变化(Δδ13C)较小,在±1‰以内,而C4植物变化范围较大,在0‰~-9‰之间;此外,文中还讨论了元素碳外源输入等可能影响δ13CEC指标的因素。建议在利用δ13CEC指标进行古环境重建之前,有必要对δ13CEC进行详细的基础研究工作,进一步研究表土δ13CEC与地表植被相关性以及元素碳外源输入等问题。  相似文献   

12.
河北平原土壤有机碳储量及固碳机制研究   总被引:5,自引:0,他引:5       下载免费PDF全文
利用2005年多目标区域土壤地球化学调查及20世纪70年代末全省第二次土壤普查土壤有机碳数据,对河北平原土壤有机碳密度及碳储量的时空变化规律、固碳机制及固碳潜力等问题进行了研究。结果表明,全省第二次土壤普查时土壤有机碳储量124.86Mt,2005年为176.08Mt,26年中增加了41.02%,表现出“碳汇”效应。据...  相似文献   

13.
Carbonate rock outcrops cover 9%–16% of the continental area and are the principal source of the dissolved inorganic carbon (DIC) transferred by rivers to the oceans, a consequence their dissolution. Current estimations suggest that the flux falls between 0.1–0.6 PgC/a. Taking the intermediate value (0.3 PgC/a), it is equal to 18% of current estimates of the terrestrial vegetation net carbon sink and 38% of the soil carbon sink. In China, the carbon flux from carbonate rock dissolution is estimated to be 0.016 PgC/a, which accounts for 21%, 87.5%–150% and 2.3 times of the forest, shrub and grassland net carbon sinks respectively, as well as 23%–40% of the soil carbon sink flux. Carbonate dissolution is sensitive to environmental and climatic changes, the rate being closely correlated with precipitation, temperature, also with soil and vegetation cover. HCO3- in the water is affected by hydrophyte photosynthesis, resulting in part of the HCO3? being converted into DOC and POC, which may enhance the potential of carbon sequestration by carbonate rock dissolution. The possible turnover time of this carbon is roughly equal to that of the sea water cycle (2000a). The uptake of atmospheric/soil CO2 by carbonate rock dissolution thus plays an important role in the global carbon cycle, being one of the most important sinks. A major research need is to better evaluate the net effect of this sink in comparison to an oceanic source from carbonate mineral precipitation.  相似文献   

14.
山东半岛蓝色经济区土壤有机碳储量及固碳潜力分析   总被引:1,自引:0,他引:1  
土壤碳储量研究在碳循环和全球变化中具有重要意义,但以往碳储量计算结果受到数据来源的制约。山东省多目标区域地球化学调查采用双层网格化采样和分析,获取了大密度、高精度土壤有机碳数据,为土壤碳库的准确计算奠定了基础。笔者利用这些数据计算了山东半岛蓝色经济区表层(0~20 cm)、中上层(0~100 cm)及全层(0~160 cm)的土壤有机碳(SOC)密度和储量,并对其空间分布特征及固碳潜力进行了研究。结果显示,经济区内3种土壤层次的碳库组成不同,表层SOC储量占总碳(TC)储量的71.67%,随深度增加所占比例逐渐减小,而无机碳(SIC)储量所占比例逐渐增加,全层二者所占比率较为接近:表层SOC储量为132.64 Mt,碳密度为2.06 kg/m2;中上层为458.27 Mt,碳密度为7.11 kg/m2;全层为619.96 Mt,碳密度为9.61 kg/m2。各层SOC密度处于全国偏低水平,且在不同土壤类型、地貌类型、土地利用类型之间有一定差异:褐土土表层SOC密度最高(2.48 kg/m2),风沙土最低(0.91 kg/m2);灌溉水田表层SOC密度最高(3.45 kg/m2),菜地最低(1.61 kg/m2)。表层SOC密度分布总体上呈现为沿海地区低、鲁北平原和胶莱盆地中等、山地丘陵和中低山区偏高的分布格局。从第二次土壤普查和本次多目标调查数据所建立的回归方程分析发现,在今后一定时期内,本区表层土壤总体表现为“碳汇”效应,未来可净增总有机碳(TOC)量60.94 Mt,其中“碳源”量5.07 Mt,“碳汇”量65.97 Mt。  相似文献   

15.
长江口盐沼土壤有机质分布与矿化的空间差异   总被引:2,自引:0,他引:2  
在长江口崇明东滩两类植被(互花米草、土著植被)区域分别选择一条纵向剖面,在高潮滩、中潮滩及光滩取得柱状样,利用颗粒有机碳(POC)含量、碳稳定同位素组成、土壤C/N比与颗粒组成等资料,研究盐沼有机质的分布与矿化特征。结果表明,两个纵向剖面的相同高程部位柱样之间,颗粒有机碳δ13C与POC含量的深度特征均存在显著差异;两个柱样的δ13C与POC含量的平均值均相差较大。互花米草对高潮滩柱样有机质的含量与组成均产生了明显影响,对中潮滩柱样有机质组成已有一定影响;土著植被对高潮滩柱样有机质组成的影响显著。盐沼植被对土壤有机质的分布与矿化均产生了明显影响。高潮滩柱样矿化阶段不同的有机质组分混杂,中潮滩柱样有机质的组成相对简单,矿化程度较弱。柱样粘粒含量与含水量在垂向上变化频繁,盐沼原始沉积层序对柱样的物质分布特征具有本底制约。不同高程部位柱样之间,有机质的深度分布特征以及矿化程度差异显著,盐沼碳动态受到潮滩特征性动力沉积过程的显著影响。  相似文献   

16.
江西省鄱阳湖及周边经济区土壤有机碳储量分布特征   总被引:3,自引:2,他引:1  
土壤是陆地生态系统的重要组成部分,土壤碳储量研究在碳循环和全球变化中具有重要意义。本文利用江西省鄱阳湖及周边经济区多目标区域地球化学调查取得的土壤碳数据,计算了研究区表层、中层、深层土壤的全碳储量和有机碳储量,分析其有机碳储量和有机碳密度的分布特征。结果表明:研究区总体碳储量是以有机碳储量为主;表层土壤(0~0.2 m)的有机碳密度为3512 t/km2,有机碳储量为1.38亿吨;中层土壤(0~1.0 m)的有机碳密度为11156 t/km2,有机碳储量为4.39亿吨;深层土壤(0~1.8 m)的有机碳密度为15617 t/km2,有机碳储量为6.14亿吨。与全国农业地质调查数据进行对比,研究区表层土壤的有机碳密度高于全国农业地质调查区内表层土壤有机碳密度的10.86%,中层及深层土壤的有机碳密度与全国农业地质调查区平均水平接近,显示研究区土壤的有机碳储量巨大。进一步分析研究区不同土壤类型、不同土地利用类型、不同地貌单元、不同行政单元的土壤有机碳密度及有机碳储量,系统查明了土壤有机碳的分布和分配特征。研究认为,区域内各层土壤有机碳密度空间分布具有同一性特征,与所处区域的成土地质背景和植被覆盖率密切相关。土壤有机碳密度高值区均分布在山地和丘陵区,包括江西丰城市北部、高安市南部、乐平市周边地区等古生代炭质岩和煤系地层区,其中乐平市表层土壤的有机碳密度最高;低值区均分布在湖区和水系河谷地区。该成果可为江西省的碳循环和碳排放研究提供可靠的数据基础。  相似文献   

17.
范美彤  葛璐  谭红兵  陈维 《地质论评》2020,66(6):1637-1648
碳是陆地生态系统中最重要的生命元素,能够在各个圈层之间相互转换和运移。碳循环作为地球各圈层相互连接的纽带,被认为是地表系统最重要的元素地球化学循环。碳在水体中主要以溶解性有机碳(dissolved organic carbon,简称DOC)和溶解性无机碳(dissolved inorganic carbon,简称DIC)形式存在。内陆水体(包括河水、地下水、湖水和水库等)尽管只占陆地表面1%,但它们在碳循环过程中发挥了重要作用。其DIC浓度(CDIC)和DIC同位素组成(δ13CDIC)可以为碳循环研究提供线索,因此成为近年来国际研究的热点之一。本文系统总结了全球内陆水体DIC同位素的研究进展。DIC同位素具有广泛的地质应用,不同碳源具有独特的同位素特征。因此,DIC同位素被用于定性和定量地示踪碳源,指示碳循环过程以及确定河水补给端元。  相似文献   

18.
By combining the carbon cycle model with the records of carbonate and organic (kerogen) carbon isotope, this paper presents the calculation of the fraction of organic carbon burial (f org) of beds 23–40 at the global boundary stratotype section and point (GSSP) of the Permian-Triassic boundary at Meishan, Zhejiang Province. The resulting calculation produces two episodes of f org maxima observed to occur at beds 23–24 and 27–29, which respectively corresponds to the two episodic anoxic events indicated by the flourish of green sulfur bacteria. Two episodic f org minima occurred at beds 25–26 and 32–34, generally coincident with the flourish of cyanobacteria (bed 26 and upper part of beds 29 to 34) as shown by the high value of 2-melthyhopnoanes. It appears that the f org is related to the redox conditions, with greater f org values observed under the reductive condition. The relationship between f org and the total organic carbon (TOC) content was complex. The f org value was low at some beds with a high TOC content (such as bed 26), while high observed at some beds with a low TOC content (e.g. bed 27). This association infers the important contribution of primary productivity to the TOC content. The original organic burial could be thus calculated through the configuration of the function of the primary productivity and f org, which can be used to correct the residual TOC measured today. This investigation indicates that compiling the organic-inorganic carbon isotopes with the carbon cycle model favors to understand the fraction of organic carbon burial, providing information for the reconstruction of the coupling among biota, environments and organic burial. Journal of China University of Geosciences, 2007, 32(6): 767–773 [译自: 地球科学—中国地质大学学报]  相似文献   

19.
The Changjiang, Huanghe, Zhujiang and Heilongjiang are the four largest rivers in China and they transport large amount of fresh water and terrigenous materials, including both inorganic and organic carbon into the ocean. The sources of the terrestrial carbon transported in the four rivers, however, have not been well constrained and compared. In this study, we used carbon isotopes (13C and 14C) combined with concentration measurements to investigate and compare the sources and fluxes of Dissolved Inorganic Carbon (DIC), Particulate Inorganic Carbon (PIC), Dissolved Organic Carbon (DOC) and Particulate Organic Carbon (POC) in the four rivers. The contributions of the potential sources to both DIC and DOC were quantitatively calculated using a dual isotope and three end member model. The results showed that the concentrations and isotope characteristics of the carbon pools in the river depended largely on the geological setting, surrounding environment and the anthropogenic influence of the drainage basins. Compared with other large rivers in the world, the concentrations of DIC in the Changjiang, Huanghe and Zhujiang were higher, but the DIC fluxes in the Huanghe and Zhujiang were lower. The DOC concentrations in the Heilongjiang River were higher and lower in the other three rivers compared with the average value of the world largest 25 rivers. The Changjiang, Huanghe and Zhujiang all transport millennia aged carbon. The old riverine DIC reflects the influence of chemical weathering of carbonate rocks and the old DOC reflects influence mainly from pre-aged soil OC. These ancient terrestrial carbon discharged by the rivers could have significant effects on the carbon cycle and ecosystems in the China's marginal seas.  相似文献   

20.
 This study re-estimates one important component in the global carbon cycle: the modern global fluviatile organic carbon discharge- and burial rates. According to these results, approximately 430×1012 g of terrestrial organic carbon are transported to the ocean in modern times. This amount is higher than the latest estimates but takes into account new data from Oceania not previously considered in global flux studies. However, only the minor amount of 10% or approximately 43×1012 gC year–1 is most likely buried in marine sediments. This amount is similar to the burial of marine organic carbon in the coastal ocean (55×1012 gC year–1). Adding both estimates gives approximately 100×1012 gC year–1, which is the value calculated by Berner (1982) for "terrestrial" deltaic-shelf sediments. However, the results in this study suggest that on a global scale the organic carbon content in coastal ocean sediments is not solely of terrestrial origin but a mixture of nearly equal amounts of marine and terrestrial organic carbon. The major part of the terrestrial organic carbon that enters the ocean by rivers (approximately 400×1012 gC year–1) seems to be either (a) remineralised in the ocean, whereas the mechanism by which the terrestrial organic carbon is oxidised in the ocean are unknown; or (b) is dispersed throughout the oceans and accumulates in pelagic sediments. Received: 9 November 1998 / Accepted: 25 May 1999  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号