广东省电白县大放鸡岛滨珊瑚的重金属含量及其意义   总被引：2，自引：1，他引：2  

彭子成  刘军华  刘桂建  贺剑峰  聂宝符  陈特固  温孝胜 《海洋地质前沿》2003,19(11):5-12

采用等离子体质谱(ICP-MS)技术，测定了1982-2001年广东省电白县大放鸡岛(111^* 11’E、21^*21’N)滨珊瑚中的Pb、Cd、Cu、Co、Cr、Mn、Ni、Zn重金属元素的含量。结果表明，珊瑚中有高的Ni和Zn含量的平均值，且在1990和2001年Zn的含量高出平均值1．8和2．3倍；1997和1998年，Pb的含量高出平均值3．5和2．3倍；1987年Cu的含量高出平均值1．5倍。这表明珊瑚样品在上述的年段内受到了Zn、Ni、Pb和Cu较显著的污染。其他重金属元素未构成明显的影响。此外，还用多元统计分析的方法，探讨了重金属含量的年际变化率与气候环境和经济环境指标的相关性，以及重金属元素之间的相似性和差异性。  相似文献   

关于东南极拉斯曼丘陵夕线片麻岩类原岩恢复问题的讨论   总被引：2，自引：0，他引：2  

任留东  耿元生  王彦斌  赵越 《地学前缘》2007,14(1):75-84

南极拉斯曼丘陵及其邻区的(含)夕线片麻岩类的原岩可以是杂砂岩、亚杂砂岩、石英砂岩、泥质岩或页岩等。粘土岩或页岩之类的富铝沉积岩与富夕线片麻岩并没有直接对应关系。没有一种泥质岩的化学组成可以与富夕线片麻岩相对应。研究区内夕线石片麻岩的形成主要与黑云斜长片麻岩有关,影响夕线石出现的决定性因素是特定温压条件下的变形变质改造过程,而不是原岩成分。夕线石片麻岩在很大程度上是黑云斜长片麻岩经长英质组分迁移之后的滞留-残留体。夕线石化过程中岩石组分发生了改造,相关变质作用已经明显偏离等化学过程,基本上属于开放体系。原岩中Al2O3的含量也不能控制夕线石的出现与否,含夕线石的岩石未必富铝,反之亦然,岩石富铝也可以不出现夕线石;但是夕线石化过程往往是Al2O3相对增加的过程,这些认识对于夕线石片麻岩成岩环境的确定和原岩建造的重建都具有重要意义。  相似文献   

Geochemical characteristics of sediment pore water from Site XS-01 in the Xisha trough of South China Sea and their significance for gas hydrate occurrence     

Yang Tao  Jiang Shaoyong  Ge Lu  Yang Jinghong  Ling Hongfei  Wu Nengyou  Zhang Guangxue  Liu Jian  Chen Daohua 《Frontiers of Earth Science》2007,1(2):212-217

Gas hydrate is a recently-found new source of energy that mostly exists in marine sediments. In recent years, we have conducted gas hydrate exploration in the South China Sea. The Xisha trough, one of the promising target areas for gas hydrate, is located in the northern margin of the South China Sea, adjacent to several large oil and gas fields. The Xisha trough extends 420 km long with the water depth of 1 500 m in the west part and 3 400 m in the east part and deposits thick sediments with organic matter content of 0.41%–1.02%. Previous studies on topographical features, geological P-T conditions, structural geology, sedimentary geology and geophysical bottom simulating reflectors (BSR) in the Xisha trough suggest that this area is favorable for the formation and accumulation of gas hydrate. In this paper, we present geochemical analyses for the sediment and pore water from a piston core at Site XS-01 in the Xisha trough. Seven pore water samples were analyzed for their anion (Cl⁻, SO₄ ²⁻, Br⁻, I⁻) contents, cation (Na, K, Ca, Mg) contents and trace element (Li, B, Sr, Ba, Rb, Mn) contents. Eight sediment samples were analyzed for stable carbon and oxygen isotopic compositions. A number of geochemical anomalies such as anions (e.g. Cl⁻, SO₄ ²⁻), cations (e.g. Ca, Mg) and trace elements (e.g. Sr, Ba, B) were found in this study. For example, the concentrations of Cl⁻ and SO₄ ²⁻ in pore water show a decreasing trend with depth. The estimated sulfate/methane interface (SMI) is only 18 m, which is quite similar to the SMI value of 23 m in the ODP164 Leg 997 at Blake Ridge. The Ca, Mg and Sr concentrations of pore water also decrease with depth, but concentrations of Ba, and Mg/Ca and Sr/Ca ratios increase with depth. These geochemical anomalies are quite similar to those found in gas hydrate locations in the world such as the Blake Ridge and may be related to the formation and dissociation of gas hydrates. The salt exclusion effect during the gas hydrate formation will cause an increase in major ion concentrations in the pore waters that diffused upward such as Cl. The anaerobic methane oxidation (AMO) may lead to the change of SO₄ ²⁻ and other cations such as Ca, Mg, Sr and Ba in pore water. Low δ ¹³C value of authigenic carbonates is a good indicator for gas hydrate occurrence. However, the bulk sediment samples we analyzed all show normal δ ¹³C values similar to biogenic marine carbonates, and this may also suggest that no gas hydrate-related authigenic carbonates exist or their amount is so small that they are not detectable by using this bulk analytical method. In conclusion, we suggest that the Site XS-01 in the Xisha trough of the northern margin of the South China Sea is a potential target for further gas hydrate exploration. Translated from Quaternary Sciences, 2006, 26(3): 442–448 [译自: 第四纪研究]  相似文献   

含硼老卤添加芒硝卤水继续富集的控制          下载免费PDF全文

张柏顺  张淑霞 《盐湖研究》2006,14(2):26-34

探讨老卤添加芒硝(芒硝水)的方法富集硼锂原理以及各种控制手段应用的限制因素,认为老卤添加芒硝水较适合盐湖地区使用。  相似文献   

干旱内陆流域景观格局变化下的景观土壤有机碳与氮源汇变化   总被引：2，自引：2，他引：2  

王根绪  卢玲  程国栋 《第四纪研究》2003,23(3):270-279

以黑河流域中游绿洲区域为例,近10年来,在干旱内陆流域受人类活动强烈影响的区域,景观的破碎度降低,景观异质性减弱,显著的景观变化表现在:耕种景观与荒漠化景观的扩张和沼泽草甸景观与水域景观的萎缩,其中荒漠草原景观面积的10%、山地草原景观的49.8%以及沼泽草甸(包括盐化草甸)景观面积的16.8%演变为耕种景观类型;相反,17.4%的荒漠草原景观面积和20.2%的沼泽草甸退化为沙漠与戈壁景观,另有13.02%的灌耕地面积演变为荒漠草原.景观空间格局演变驱动景观土壤N、C的源汇变化,近10年来,黑河流域中游地区由于景观空间格局变化形成的景观N净排放和有机C净释放分别达到50.65×104T和530.17×104T.山地草原景观的荒漠化与耕种利用、耕种景观的荒漠草原化、沼泽草甸与山地草甸景观以及荒漠草原景观的耕种利用和这些景观的沙漠化发展是造成区域N、C损失的主要途径.  相似文献   

Modeling of tensile strength on moist granular earth material at low water content   总被引：4，自引：0，他引：4  

Tae-Hyung Kim  Changsoo Hwang 《Engineering Geology》2003,69(3-4):233-244

While most research has mainly focused on the volume change, flow, and shear strength of unsaturated earth materials, investigations of tensile strength of unsaturated earth materials especially granular materials have not received much attention except for cemented and clayey materials. Thus, direct tension experiments were carried out to quantify the actual magnitude of tensile strength induced by water in moist granular soil at especially low water contents (w<4%). The magnitudes of the measured tensile strength are significantly different from zero. A simple experimental tensile strength model is proposed. Practicing engineers can use this model for approximate estimation of the tensile strength of unsaturated granular soils without experiments and for precise design or analysis of most engineered facilities relying on the unsaturated granular soils in the vadose zone. The experimental data are also compared with a theoretical model developed for monosized spheres at low water contents, and its application for a real granular earth material having a variety of particles is discussed. The nonlinear behavior of the tensile strength for moist granular soil is appropriately simulated with a model.  相似文献   

南极菲尔德斯半岛生物体的微生物含量分析   总被引：2，自引：0，他引：2       下载免费PDF全文

陈皓文  袁峻峰  张树荣 《极地研究》1998,10(4):53-56

于１９９３／１９９４年以平板培养法用５种基本培养基对南极菲尔德斯半岛地区的生物体作了微生物含量分析。所研究的海藻、苔藓、地衣、沙蚕、小红蛤、帽贝、鱼、企鹅和鲸等的体表和体内样本计３３个。分析和比较了各类生物体内外所含的陆源性细菌、海洋性细菌、肠细菌、真菌及耐酸细菌等的含量,在一定程度上,培养温度的提高可促进样本中原有的微生物迅速大量繁殖,表明低温仍是制约南极微生物的重要因子。  相似文献   

科学钻探中的元素测井技术   总被引：10，自引：0，他引：10  

李舟波  王祝文 《地学前缘》1998,5(1):119-130

系统地介绍了科学钻探中应用自然伽玛能谱测井、活化测井、热中子俘获伽玛能谱测井和中子非弹性散射伽玛能谱测井确定元素含量的原理和方法;详细讨论了在不同的岩性条件下如何选择和建立从元素含量向矿物成分转换的模型。最后,介绍了元素测井技术在ＫＴＢ和ＯＤＰ中的应用,说明元素测井技术对重建岩性剖面、了解元素丰度和矿物成分的变化、研究矿物在高温高压下蚀变所涉及的地球化学作用、显示岩石的不均匀性和重建地球化学剖面等方面有特殊作用。此外,元素测井技术对于精确计算骨架密度、孔隙度和渗透率、井与井间相关对比,以及补足由于漏掉岩芯或岩屑而失去的有关信息,均具有重要作用。  相似文献   

氢氧化镁吸附卤水中硼的研究   总被引：9，自引：1，他引：9       下载免费PDF全文

刘玉胜  李法强  乌志明 《盐湖研究》2004,12(4):45-48

阐述了用氢氧化镁将海水及盐湖卤水中的硼、镁同时除去的方法,并对其反应条件进行了研究。  相似文献   

中国煤中的硼     

黄文辉  杨宜春 《中国煤田地质》2002,14(Z1):41-42

对中国煤中硼仍缺乏系统研究。有限的数据显示,我国多数煤中含硼介于100～200mg/kg之间,最大达500mg/kg。煤中的硼主要与有机质缔合,其次是与粘土矿物结合。含硼太高将影响植物生长。硼也是反映成煤环境的良好元素。  相似文献