广西百色盆地州景矿第三系褐煤有机地球化学与煤岩学研究　Ⅳ．单化合物碳稳定同位素推断生物标志物起源     

Schoe.  M 王铁冠 《沉积学报》1995,13(4):73-81

一个未成熟褐煤抽提物中，高等植物生源化合物的同位素值在全煤碳同位素组成（δ１３Ｃ值－２７．０‰）的±２‰范围内，表明相似成煤植物对这些化合物的贡献，或者其成煤植物经历过相似的生物合成分馏效应。所检测的萜烃类按同位素差异分为两组:二萜类（δ１３Ｃ值－２５．０±１．４‰）和倍半萜类（δ１３Ｃ值－２５．９±１．５‰）平均较全煤样富集１～２％。１３Ｃ，而奥利烷－乌散烷－羽扇烷型衍生物（δ１３Ｃ值－２９．０±０．８‰）平均比全煤样减少１～２‰１３Ｃ。Ｃ₁₅～Ｃ₃₅正烷烃δ１３Ｃ平均值－３２．４±０．６‰，据此表明Ｃ₁₇～Ｃ₂₂和Ｃ₂₂～Ｃ₃₃正烷烃的同位素值与上述平均值没有明显差异。与全煤样相比较，该煤样抽提物的藿烷衍生物１３Ｃ值则减少８～３４‰，标志在成煤过程中甲烷的细菌循环起着作用。  相似文献   

川西甲基卡308号脉的矿物学特征及其岩浆- 热液演化示踪   总被引：1，自引：0，他引：1  

王臻  陈振宇  李建康  陈毓川 《地质学报》2022,96(6):2039-2061

甲基卡稀有金属矿床是亚洲规模最大的伟晶岩型锂矿床，308号脉为其中出露面积最大的伟晶岩脉。308号脉具有完善的分带性:细粒白云母- 钠长石- 石英带（Ⅰ）、中粗粒钠长石- 石英- 微斜长石带（Ⅱ）、中粒电气石- 钠长石- 石英带（Ⅲ）、中粗粒锂辉石- 钠长石- 石英带（Ⅳ）和中细粒锂辉石- 钠长石- 石英带（Ⅴ），并且富含稀有金属矿物（如锂辉石、绿柱石、锡石和铌钽氧化物），因此是系统研究伟晶岩演化历史和成岩成矿机制的理想实验对象。308号脉的矿物学研究较为薄弱，其岩浆- 热液演化过程及该过程中熔- 流体性质的变化规律，以及稀有金属的富集过程和影响因素尚不清楚。本文选取该脉各结构带中的贯通性矿物云母、磷灰石，以及稀有金属矿物锂辉石和特征性矿物电气石，通过详细的电子探针工作，分析它们的产状、结构特征、化学组成及其变化，结果表明:① 308号脉边部Ⅰ带（高温结晶）中电气石的出现（~5%）反映伟晶岩初始熔体具有富B的特征（>2%）；锂辉石在Ⅳ和Ⅴ带内的大量结晶说明初始熔体可能具有富Li的性质；主要含氟矿物电气石、磷灰石和云母类在岩石中的含量均较低，并且原生磷灰石具有相对偏低的F浓度（<3%），仅能形成于富F环境中的锂云母矿物也十分稀少，这些特征均表明308号脉初始熔体很可能具有较低的F含量；② 伟晶岩体系演化至Ⅴ带时发生流体出溶现象，自此进入岩浆- 热液过渡阶段，出溶流体可能具有富Cs和贫F的性质；③ 原生白云母和电气石化学成分的规律性变化说明308号脉的演化过程很可能不存在外来流体的加入；④ 308号伟晶岩的成岩和锂成矿过程主要受分异结晶作用支配，有限的出溶流体规模和伟晶岩分异演化程度（仅演化至岩浆- 热液过渡阶段，未充分进入热液阶段）对锂辉石的结晶和保存都起到了重要作用。  相似文献   

辽河盆地煤系地层中特高含量的二萜类及其地质意义     

妥进才  王先彬  陈践发 《沉积学报》1999,17(2):285-290

从辽河盆地东部凹陷下第三系沙三段煤系烃源岩中检出了特高含量的海松烷,脱氢松香烷等三环二萜烷和扁枝烷等四环二萜烷类化合物,此外还检测到了奥利烯、乌散烯等罕见的三萜类。上述三类化合物尽管出现在同一套地层中,但它们的主要来源并不完全相同,其中三环二萜和四环二萜类分别以裸子植物和蕨类植物为主要来源,而五环三萜类则主要来源于被子植物。说明辽河盆地下第三系沙三段煤系地层中母质输入的多样性和复杂性。  相似文献   

甲基异丁基酮负载泡塑富集—原子吸收测定岩矿中痕量金银铊镉   总被引：4，自引：4，他引：4  

陈金武  曾法刚 《岩矿测试》1993,12(2):85-88

研究了多种负载泡塑对Au、Ag、Ti、Cd的富集行为。提出了在HCI-KI-抗坏血酸介质中用甲基异丁基酮(MIBK)负载泡塑同时萃取,然后用2％硫脲-1％HCl解脱的富集方法,并采用火焰原子吸收连续测定地质样品中痕量Au、Ag、Tl和Cd,方法的测定下限(μg/g)分别为:0.2g、0.05、0.20和0.04。  相似文献   

轮南油田原油中三甲基苯基类异戊二烯化合物的检出及其意义     

卢鸿孙永革  彭平安 《高校地质学报》2004,10(2):283-289

轮南油田不同时代储层原油中检出了丰富的三甲基苯基类异戊二烯化合物。该类化合物被普遍认为是来自于高盐度和强还原水体沉积环境中绿硫菌体内的类胡萝卜素的特征性生物标志化合物。该类化合物的检出对轮南油田烃源岩研究具有重要的指示意义，暗示了具有分层水体或高盐度的强还原环境下发育的优势烃源岩，对该区烃类的主力生烃贡献不容忽视。基于C15-3，4，5-三甲基苯基类异戊二烯异构体在轮南油田原油中的分布规律，及C15-3，4，5／C13-2，3，6-比值与Pr／Ph，Ga／C31H和Ts／Tm等常规地球化学参数的对比，说明具有生源意义、能够指示沉积相特征的三甲基苯基类异戊二烯化合物分布，在一定程度上也受烃类热演化程度的影响。  相似文献   

1-甲基咔唑的结构参数及其热稳定性     

陈传平  包建平  朱翠山 《地质科技情报》2006,25(2):57-59

利用1-甲基咔唑的分子结构参数,计算了吡咯环氮上氢原子与1-甲基间的距离,计算结果小于氢原子和1-甲基的范德华半径之和,说明氢原子和1-甲基之间存在空间位阻,这一作用迫使键角张大,或是发生扭转,使原子或基团离开芳香环平面,表明咔唑环上1-或8-甲基在化学热力学上是不稳定的,而在咔唑环可能的甲基化中,1-或8-甲基化反应速率较快,推测有更多的产物生成.  相似文献   

Mercury anthropogenic loadings vs. mercury levels in fish： Baihua Reservoir as an exemplary case study     

《中国地球化学学报》2006,25(B08):236-236

It is still disputed in the scientific community whether it is possible to trace a direct link or even proportionality between mercury （Hg） anthropogenic loadings to lake ecosystems and resulting methylmercury （MeHg） levels found in fish tissues. We present here the exemplary case of the Baihua Reservoir, located on the Maotiahoe River, near Guiyang （Guizhou, China）. Baihua was impacted for many years by Hg-contaminated effluents from industrial source. While sedimentary profiles exhibit extreme enrichment in sedimentary Hg burden, fish species harvested from the reservoir still present low Hg levels. Thus we propose here that in the case of Hg, loading does not tell it all and one must take it into account the net methylation capacity of lake ecosystems and its ability to efficiently bioaccumulate MeHg along the trophic web.  相似文献   

Mercury concentrations in a contaminated river system in Kazakhstan and biomonitoring of the local population     

Susanne M. Ullrich Huiwen HSIAO 《中国地球化学学报》2006,25(B08):238-239

The River Nura in central Kazakhstan has been heavily contaminated by mercury （Hg） from an acetaldehyde plant located in the industrial city of Temirtau. The plant released Hg-containing wastewater into the river from the 1950s until the mid 1990s and strongly contaminated the bed sediments up to 25 km downstream. In addition, a local power station released an estimated 6 million tonnes of fly-ash into the water which has adsorbed much of the Hg and has become mixed with the natural sediments. River water,fish and agricultural land in the floodplain are also contaminated by Hg. Humans are exposed to Hg primarily via the consumption of contaminated fish from the river. A survey was undertaken in June/July 2005 to investigate Hg concentrations in river water, drinking water, sediments and fish. To estimate the risk posed to the local population, approximately 300 hair samples were collected from people living in villages near the most contaminated section of the river, at a distance of between 5 and 30 km downstream of the acetaldehyde plant, and their dietary habits were recorded. Mercury concentrations in river water ranged from 2-3 ng/L upstream of the source of the pollution to 348 ng/L downstream of the factory outfall pipe. Some drinking water wells close to the river were contaminated, but deeper wells had Hg concentrations below the detection limit.  相似文献   

High exposure of Chinese mercury mine workers to elemental mercury vapor and their increased hair methylmercury levels： A preliminary report     

Mineshi Sakamoto Xinbin FENG Ping LI Guangle QIU Hongmei JIANG Minoru Yoshida Toyoto Iwata Xiaojie LIU Katsuyuki Murata 《中国地球化学学报》2006,25(B08):42-43

Objectives： To assess the exposure to elemental mercury （Hg0） vapor and methylmercury （MeHg） among mercury mine workers in an area of Guizhou Province, China. Methods： Urine total mercury （THg） and hair THg and MeHg were measured in 26 mercury miners and smelters （i.e., exposed group）, and 52 control subjects （unexposed group）. Results： The mine workers showed high geometric mean THg concentrations in urine （258 ng/mL, 226 μg/g creatinine） and hair （20.0 μg/g）. The urine Hg level of smelters, in particular, was extremely high （338 μg/g creatinine in urine）. The highest urine THg reached 4580 μg/g creatinine. THg concentrations in urine and hair showed a significant correlation in the exposed group （r=0.62）, indicating the adhesion of HgO vapor to hair. However, no such significant correlation was found in the control group.  相似文献   

Mercury levels in surface waters of six reservoirs in the Wujiang River     

《中国地球化学学报》2006,25(B08):151-151

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