东南大陆岩石圈板块地体构造

东南大陆的地质构造模型,具有欧亚大陆边缘向洋增生的独特形式。除外来地体之外,或以扩张、地幔上涌,洋壳向大陆地壳转化,并不断向洋增生;或是大陆分裂,地幔柱——热点物质不断注入变薄和破裂了的地壳,形成区域性新的生长构造层,构造岩浆地质体表现为有独特属性的“A型”花岗岩和流纹岩链。这些高DI值的富硅富碱富钠质岩石,出现在欧亚大陆边缘的重力梯度带上。裂解带的地壳结构模式是上地壳存在着重力不稳定的硅铝低速带;中地壳有洋——陆过渡型地壳的“类裂谷型”结构,P波速度为6.3～6.4km/s的中间壳层;在下地壳下部有速度为7.0～7.4km/s的壳——幔混合型高速层;随着“异常”的上地幔的形成,有大范围的热活动和壳——幔边界穹窿,穹窿的地盖比正常区为为薄。由于化学库和化学边界层的横向不连续,可划分出古老基底和后期地质发展史完全迥异的两个亚板块;和以壳层(或幔层)断裂为边界特点的八个地体;一个以分裂为主,并具热点径迹的最新生长构造层的扩张——裂解构造岩浆地体。     

中国东南大陆边缘裂解─岩浆构造模型

欧亚大陆东南边缘的中生代构造演化模式为NNE-SN构造，EW向扩张-裂解、向东增生和大洋壳大陆化。在裂解过程中有新的岩浆构造地体形成。裂解带的地壳结构：下地壳有高速层、中地壳有中速层和低速层。     

中国东部火山岩带特性与碰撞—伸展复合动力学框架

编者按大陆岩石圈、全球变化与地球深部内展研究为当代地学的三大主题。大陆动力学旨在研究大陆与地球系统之间热学、力学与化学等相互关系及其过程的学科。中同东部地处亚州大陆东部．被观为研究大陆动力学的最佳场所之一。东部火山岩带-火山系统、岩浆系统研究包括：岩浆发生、运珍、定位的方式及其构造、热机制；岩浆在何种深度上，如何与地亮相互作用？不同类型计浆可以揭示地幔依、地壳成分、结构、壳幔相互作用、地球物质循环的过程。因此，火山一岩浆系统被视为岩石围的探针、大陆动力学过供的天然记录之一．从这一意义上讲．大地动…     

中国东南大陆中、新生代岩浆作用与壳幔演化动力学

本文论述了中国东南大陆中、新生代岩浆作用的多旋回性和迁移性，构造演化与岩石系列和岩石组合的关系。前寒武纪岩石圈制约本区中、新生代岩浆作用和成矿作用，并在三种岩石围岩石学一地球物理综合模型中反映。总结了四个主要构造期岩浆作用源区特征和构造背景，并根据不同大地构造单元在碰撞造山后近南北向刊近北东向伸展裂解，从造山带挤压碰撞向伸展裂解机制转换过程探讨了中、新生代岩浆作用和壳幔演化动力学。     

中国东南沿海的地质构造特征

本文主要论述了中国东南大地构造演化特征。晋宁旋回,南北板块碰撞,形成近东西向构造格局、转换块间带及交结盆地。加里东旋回至印支旋回,东南地壳由非成熟性地壳逐渐向稳定性大陆地壳过渡。陆壳的生长是以两个外隆为中心呈环带状向外扩张。燕山旋回,大陆破坏和改造,形成大陆边缘的流纹岩链。显示了地壳生长为多旋回前进演化的特征。     

元古代到白垩纪金伯利岩中上地幔捕虏体的成分

<正> 上地幔岩石是基性、超基性及某些其他成分岩浆的来源。岩浆熔体的熔融及其由上地幔运移到地壳中,这在漫长的地球演化期间是一长期过程。毫无疑问,熔体的熔融并从上地幔岩石中分离出来,不可能在保存下来的残留物的成分中没有反映:地幔物质熔融和分离得越     

构造环境对幔源岩中稀有气体同位素比值的制约

稀有气体是地球化学研究中有效的物源示踪剂。在广泛收集资料的基础上,通过对He、Ne、Ar同位素数据的统计分析,总结、对比了不同构造环境幔源物质中轻稀有气体同位素的组成特征。统计表明,大洋中脊玄武岩(MORB)中3He/4He=7 0～10 0Ra者约占统计样品的90%;洋岛幔源物质(OIB)的3He/4He值变化范围大,但>10 0Ra者占65%;消减带幔源岩的3He/4He值总体略低于MORB;大陆幔源岩的3He/4He值主要变化于6 0～10 0Ra间,但环太平洋大陆边缘低于MORB者普遍;大陆热点地幔流体具有类似OIB的3He/4He值分布特征。MORB与OIB的40Ar/36Ar值分布范围类似(主要范围为296～12000),但低于1000者在MORB中仅24 5%,而在OIB中约43 4%;板块俯冲区幔源岩的40Ar/36Ar值总体较低,<1000者约占67%;大陆各类地幔流体的40Ar/36Ar值普遍偏低,主要在4000以下。大陆、大洋幔源岩中20Ne/22Ne值主要介于9 8～12 5间,但<9 8者在各大陆地幔普遍存在。幔源物质的上述组成特征与大气、地壳等源区对其影响有关。我国东部幔源物质稀有气体同位素组成具有大气 地幔混合源区特征。     

大陆构造及成矿作用学术讨论会采风

由中国地质学会构造专业委员会,国际地科联岩石圈委员中国委员会、国家自然科学基金委员会、湖北省地质学会、湖北省石油学会和中国地质大学发起并主办的大陆构造及成矿作用学术讨论会于1989年11月20日～20日～24日在武汉举行.73个单位的近200名代表参加了会议.会议共分4个专题:造山带构造和区域构造;沉积盆地和能源资源;断裂构造及其控矿作用;地球物理和深部构造.会议着重讨论了八十年代以来有关陆内造山带、构造岩浆活动、上地幔及下地壳特证、韧性剪切带、薄皮构造、推覆构造、伸展构     

板块与地幔的相互作用—板块内岩浆的成因和上地幔的构造(Ⅲ)

在世界范围内,板块内岩浆所表现出的系列地球化学和同位素特征看来都是通过一个与大洋岩石圈俯冲作用有关的共同成因过程所形成的。据发现,板块内岩浆的源区在大陆下岩石圈和大洋下岩石圈中的位置是截然不同的,而且在地幔中的深度也要大得多。然而,少量元素的配分关系表明,产生板块内岩浆源区的过程并非发生于下地幔中钙钛矿相条件下,而几乎可以肯定是限制在地幔内。有人提出板块内岩浆的源区最初形成于上地幔内的两个主要位置。其中一个位于俯冲岩石圈和上覆地幔的界面附近,是由于板块和地幔的相互作用(主要在150—300km深处)而形成的。在这一源区内板块的榴辉质洋壳的部分熔融是由于俯冲的前蛇纹岩体释放水所致。熔体迁移到邻近的难熔橄榄岩中,与之混染变富。这实质上是形成钙碱性源区的同一过程的延伸,并可解释这两种组合在地球化学和同位素特征方面的相似性。钙碱性组合相对贫Ti、Nb和Ta,这是因为俯冲榴辉质洋壳的上层在80—100km深处发生部分熔融时使这些元素滞留在残留金红石中所致。而在更深处(150—300km),当俯冲洋壳的下层发生部分熔融时,金红石不再是残留相,因此,Ti、Nb和Ta成为高度不相容元素,从而有效地从俯冲板块迁移到板块内岩浆源区。俯冲作用的角度可能很小,因而在大陆下延伸的水平距离     

湘东北中生代基性岩脉微量元素地球化学特征及岩石成因

湘东北中生代基性岩脉可以分为煌斑岩和辉绿岩两类 ,前者形成于 136 .6 1Ma ,后者形成于 86 .18Ma ,与华南中生代主要拉张时期相对应。岩石富集LREE ,Eu负异常不明显 ,其形成主要受地幔部分熔融作用制约。早期煌斑岩类微量元素和Sr、Nd同位素总体上具有富集地幔 (EMⅡ型 )洋岛玄武岩 (OIB)特征 ,富集Nd、P、Cs,而K、Rb、Sr、U、Th等富集程度不明显 ,Ta、Nb略有富集 ,具有软流圈地幔上涌地幔热柱玄武岩岩浆源区性质 ,表现出软流圈地幔上涌部分熔融的成岩特点。晚期辉绿岩类表现出Ta、Nb、Ti亏损 ,但LILE并不富集 ,反映地壳混染程度的增强 ,具有大陆拉张带 (裂谷初期 )形成的玄武岩岩浆源区性质 ,为岩石圈地幔部分熔融形成。二者具有不同的岩浆源区性质 ,从早期到晚期岩浆源区向上迁移并致使部分陆壳物质混入 ,反映由热点式拉张到岩石圈伸展 减薄的作用过程。     

Toxic effects of acetochlor, methamidophos and their combination on nifH gene in soil

Toxic effects of two agrochemicals on nifH gene in agricultural black soil were investigated using denaturing gradient gel electrophoresis （DGGE） and sequencing approaches in a microcosm experiment. Changes of soil nifH gene diversity and composition were examined following the application of acetochlor, methamidophos and their combination. Acetochlor reduced the nifH gene diversity （both in gene richness and diversity index values） and caused changes in the nifH gene composition. The effects of acetochlor on nifH gene were strengthened as the concentration of acetochlor increased. Cluster analysis of DGGE banding patterns showed that nifH gene composition which had been affected by low concentration of acetochlor （50 mg/kg） recovered firstly. Methamidophos reduced nifH gene richness that except at 4 weeks. The medium concentration of methamidophos （150 mg/kg） caused the most apparent changes in nifH gene diversity at the first week while the high concentration of methamidophos （250 mg/kg） produced prominent effects on nifH gene diversity in the following weeks. Cluster analysis showed that minimal changes of nifH gene composition were found at 1 week and maximal changes at 4 weeks. Toxic effects of acetochlor and methamidophos combination on nifH gene were also apparent. Different nifH genes （bands） responded differently to the impact of agrochemicals： four individual bands were eliminated by the application of the agrochemicals, five bands became predominant by the stimulation of the agrochemicals, and four bands showed strong resistance to the influence of the agrochemicals. Fifteen prominent bands were partially sequenced, yielding 15 different nifH sequences, which were used for phylogenetic reconstructions. All sequences were affiliated with the alpha- and beta-proteobacteria, showing higher similarity to eight different diazotrophic genera.     

Arsenic uptake by arbuscular mycorrhizal maize （Zea mays L.） grown in an arsenic-contaminated soil with added phosphorus

The effects of arbuscular mycorrhizal (AM) fungus (Glomus mosseae) and phosphorus (P) addition (100 mg/kg soil) on arsenic (As) uptake by maize plants (Zea mays L.) from an As-contaminated soil were examined in a glasshouse experiment.Non-mycorrhizal and zero-P addition controls were included.Plant biomass and concentrations and uptake of As,P,and other nutrients,AM colonization,root lengths,and hyphal length densities were determined.The results indicated that addition of P significantly inhibited root colonization and development of extraradical mycelium.Root length and dry weight both increased markedly with mycorrhizal colonization under the zero-P treatments,but shoot and root biomass of AM plants was depressed by P application.AM fungal inoculation decreased shoot As concentrations when no P was added,and shoot and root As concentrations of AM plants increased 2.6 and 1.4 times with P addition,respectively.Shoot and root uptake of P,Mn,Cu,and Zn increased,but shoot Fe uptake decreased by 44.6%,with inoculation, when P was added.P addition reduced shoot P,Fe,Mn,Cu,and Zn uptake of AM plants,but increased root Fe and Mn uptake of the nonmycorrhizal ones.AM colonization therefore appeared to enhance plant tolerance to As in low P soil,and have some potential for the phytostabilization of As-contaminated soil,however,P application may introduce additional environmental risk by increasing soil As mobility.     

Degradation of metabolites accumulated of benzo[a]pyrene by coupling Penicillium Chrysogenum with KMnO4

Several main metabolites of benzo[a]pyrene （BaP） formed by Penicillium chrysogenum, Benzo[a]pyrene-1,6-quinone （BP 1,6- quinone）, trans-7,8-dihydroxy-7,8-dihydrobenzo[a]pyrene （BP 7,8-diol）, 3-hydroxybenzo[a]pyrene （3-OHBP）, were identified by high-performance liquid chromatography （HPLC）. The three metabolites were liable to be accumulated and were hardly further metabolized because of their toxicity to microorganisms. However, their further degradation was essential for the complete degradation of BaP. To enhance their degradation, two methods, degradation by coupling Penicillium chrysogenum with KMnO4 and degradation only by Penicillium chrysogenum, were compared; Meanwhile, the parameters of degradation in the superior method were optimized. The results showed that （1） the method of coupling Penicillium chrysogenum with KMnO4 was better and was the first method to be used in the degradation of BaP and its metabolites; （2） the metabolite, BP 1,6-quinone was the most liable to be accumulated in pure cultures; （3） the effect of degradation was the best when the concentration of KMnO4 in the cultures was 0.01% （w/v）, concentration of the three compounds was 5 mg/L and pH was 6.2. Based on the experimental results, a novel concept with regard to the bioremediation of BaP-contaminated environment was discussed, considering the influence on environmental toxicity of the accumulated metabolites.     

Impact of atrazine and nitrogen fertilizers on the sorption of chlorotoluron in soil and model sorbents

Sorption of chlorotoluron in ammonium sulfate, urea and atrazine multi-solutes system was investigated by batch experiments. The results showed application of nitrogen fertilizers to the soil could affect the behavior of chlorotoluron. At the same concentration of N, sorption of chlorotoluron decreased as the concentration of atrazine increased on the day 0 and 6 in soil, respectively. The sorption of chlorotoluron increased from 0 to 6 d when soils were preincubated with deionized water, ammonium sulfate and urea solution for 6 d. That indicated incubation time was one of the most important factors for the sorption of chlorotoluron in nitrogen fertilizers treatments. The individual sorption isotherms of chlorotoluron in rubbery polymer and silica were strictly linear in single solute system, but there were competition sorption between pesticides or between pesticides and nitrogen fertilizers. That indicated the sorption taken place by concurrent solid-phase dissolution mechanism and sorption on the interface of water-organic matter or water-mineral matter.     

Potential of plant polyphenol oxidases in the decolorization and removal of textile and non-textile dyes

In this study an effort has been made to use plant polyphenol oxidases; potato （Solanum tuberosum） and brinjal （Solanum melongena）, for the treatment of various important dyes used in textile and other industries. The ammonium sulphate fractionated enzyme preparations were used to treat a number of dyes under various experimental conditions. Majority of the treated dyes were maximally decolorized at pH 3.0. Some of the dyes were quickly decolorized whereas others were marginally decolorized. The initial first hour was sufficient for the maximum decolorization of dyes. The rate of decolorization was quite slow on long treatment of dyes. Enhancement in the dye decolorization was noticed on increasing the concentration of enzymes. The complex mixtures of dyes were treated with both preparations of polyphenol oxidases in the buffers of varying pH values. Potato polyphenol oxidase was significantly more effective in decolorizing the dyes to higher extent as compared to the enzyme obtained from brinjal polyphenol oxidase. Decolorization of dyes and their mixtures, followed by the formation of an insoluble precipitate, which could be easily removed simply by centrifugation.     

Effects of two sludge application on fractionation and phytotoxicity of zinc and copper in the soil

The potential harm of heavy metals is a primary concern in application of sludge to the agricultural land. A pot experiment was conducted to evaluate the effect of two sludges on fractionation of Zn and Cu in soil and their phytotoxicity to pakchoi. The loamy soil was mixed with 0%, 20%, 40%, 60% and 80% (by weight) of digested sewage sludge (SS) and composted sludge (SC). The additions of both sludges caused a significant raise in all fractions, resulting in that exchangeable (EXCH) and organic bound (OM) became predominance of Zn and organic bound Cu occupied the largest portion. There was more available amount of Zn and Cu in SS treatments than SC treatments. During the pot experiment, the concentration of Zn in EXCH, carbonate (CAR) and OM and Cu in EXCH and OM fractions decreased in all treatments, so their bioavailability reduced. Germination rate and plant biomass decreased when the addition rate was high and the best yield appeared in 20% mixtures at the harvest of pakchoi. The two sludges increased tissue contents of Zn and Cu especially in the SS treatments. Zn in pakchoi was not only in relationship to ΔEXCH and ΔCAR forms but also in ΔOM forms in the sludge-soil mixtures. Tissue content of Cu in pakchoi grown on SC-soils could not be predicted by ΔEXCH. These correlation rates between Zn and Cu accumulation in pakchoi and variation of different fractions increased with time, which might indicate that sludges represented stronger impacts on the plant in long-term land application.     

Intraspecific differences in effects of co-contamination of cadmium and

A hydroponic experiment was carried out to study intraspecific differences in the effects of different concentrations of cadmium (Cd)(0-10 mg/L) and arsenate (As(V)) (0-8 mg/L) on the growth parameters and accumulation of Cd and As in six wheat varieties Jing-9428, Duokang-1, Jingdong-11, Jing-411, Jingdong-8 and Zhongmai-8. The endpoints of wheat seedlings, including seed germination,biomass, root length and shoot height, decreased with increasing the Cd and As concentrations. Significant differences in seed germination, biomass, root length, shoot height and the accumulation of Cd and As were observed between the treatments and among the varieties (p ＜ 0.05). The lethal dosage 50% were about 20, 80, 60, 60, 80 and 20 mg As/L for Jing-9428, Duokang-1, Jingdong-11,Jing-411, Jingdong-8 and Zhongmai-8, respectively, and the corresponding values for Cd were about 30, 80, 20, 40, 60 and 10 mg Cd/L, respectively. Among the six varieties, Duokang-1 was found to be the most resistant to Cd and As toxicity, and Zhongmai-8 was the most sensitive to Cd and As co-contamination. The resistance of the six varieties was found dependant on the seedling uptake of Cd and As. Duokang-1 was the most suitable for cultivation in Cd and As co-contaminated soils.     

Removal of heavy metals from sewage sludge by low costing chemical method and recycling in agriculture

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Isolation and preliminary characterization of a 3-chlorobenzoate degrading bacteria

A study was conducted to compare the diversity of 2-, 3-, and 4-chlorobenzoate degraders in two pristine soils and one contaminated sewage sludge. These samples contained strikingly different populations of mono-chlorobenzoate degraders. Although fewer cultures were isolated in the uncontaminated soils than contaminated one, the ability of microbial populations to mineralize chlorobenzoate was widespread. The 3- and 4-chlorobenzoate degraders were more diverse than the 2-chlorobenzoate degraders. One of the strains isolated from the sewage sludge was obtained. Based on its phenotype, chemotaxonomic properties and 16S rRNA gene, the organism S-7 was classified as Rhodococcus erythropolis. The strain can grow at temperature from 4 to 37℃. It can utilize several （halo）aromatic compounds. Moreover, strain S-7 can grow and use 3-chlorobenzoate as sole carbon source in a temperatures range of 10-30℃ with stoichiometric release of chloride ions. The psychrotolerant ability was significant for bioremediation in low temperature regions. Catechol and chlorocatechol 1,2-dioxygenase activities were present in cell free extracts of the strain, but no （chloro）catechol 2,3- dioxygenase activities was detected. Spectral conversion assays with extracts from R. erythropolis S-7 showed accumulation of a compound with a similar UV spectrum as chloro-cis,cis-muconate from 3-chlorobenzoate. On the basis of these results, we proposed that S-7 degraded 3-chlorobenzoate through the modified ortho-cleave pathway.     

Single and joint effects of pesticides and mercury on soil urease

The influence of two pesticides including chlorimuron-ethyl and furadan and mercury （Hg） on urease activity in 4 soils （meadow burozem and phaeozem） was investigated. The soils were exposed to various concentrations of the two pesticides and Hg individually and simultaneously. Results showed that there was a close relationship between urease activity and organic matter content in soil. Chlorimuron-ethyl and furadan could both activate urease in the 4 soils. The maximum increment of urease activity by chlorimuronethyl was up to 14%-18%. There was almost an equal increase （up to 13%-21%） in the urease activity by furadan. On the contrary, Hg markedly inhibited soil urease activity. A logarithmic equation was used to describe the relationship （P〈0.05） between the concentration of Hg and the activity of soil urease in the 4 tested soils. Semi-effect dose （ED50） values by the stress of Hg based on the inhibition of soil urease in the 4 soils were 88, 5.5, 24 and 20 mg/kg, respectively, according to the calculation of the corresponding equations. The interactive effect of chlorimuron-ethyl or furadan with metal Hg on soil urease was mainly synergic at the highest tested concentrations.