Sediment—Hosted Gold Deposits in China_geochemistry and Prospecting

Sediment-hosted gold deposits are the major type of gold resources in china,Concen trated mostly in the two“Triangle Regios“,they are generally hosted in fine-clastic turbidite,hydrothermal chet and marl ranging from cambrian to Triassic in age,structurally controlled by domes,anticlines and second-ordered faults.They are similar to the Carlin-type gold deposits in mineral assemblage and geochemical marks,with an element association closely comparable to those of modern springs and submarine hydrothermal sediments.Organic matter may have played an important role in mineralization .The ore solution may be hydrothermally altered meteoric water developed i areas of local geothermal anomaly.     

广州珠江西航道,流溪河有机污染特征与感潮作用

珠江西航道和流溪河在广州市区上游，为广州市主要水源区。由于感潮作用，受市区严重污染的水体因涨潮上溯而上游传输。严重影响上游水质。因此，弄清感潮作用对广州水源区水质的影响程度和范围，对水源保护与利用有重要意义。本研究从下游到上游，对水源区底泥中有机物特征进行了分析，结果表明：（１）从上游到上游，受感潮作用影响逐渐减小，污染程度逐渐减轻；（２）水源区有机物特征呈有规律变化。从靠近城市的下游到远离城市的     

临沧超大型锗矿床有机质与锗矿化的地球化学特征

临沧锗矿床是一产于第三系含煤岩系中的超大型矿床。矿床的最初锗源与盆地西缘的二云母花岗岩有关。主矿体产于下煤组沉积旋回的早期地层中，每一沉积阶段早期形成的褐煤和碳质泥岩中富含锗，最高含量达１４７０×１０＾－６。褐煤和碳质泥岩在矿化过程中平均富集了１６４－１６９倍。根据锗含量，褐煤和碳质泥岩可分为锗含量小于１２×１０＾－６的低锗煤（泥岩）和大于９０×１０＾－６的高锗煤（泥岩）。高锗煤中有机质富含氧官能     

The hydrocarbon generation mechanism and the three-stage type model of hydrocarbon generation for carbonate source rocks

The diagenetic mechanism and process of carbonate rocks, which is different to that of clastic rocks, decides the existence of different existing state organic matters in carbonate rocks. This has been verified by both the microscopic observation of organic petrology and the analysis of organic geochemistry of many samples. Based on the hydrous pyrolysis simulation experiment of the low-mature carbonate rocks, the contrasting study on the yield and their geochemistry characteristics of different existing state soluble organic matters of a series of various maturity samples shows that the different existing state organic matters make different contributions to hydrocarbon generation during every evolution state. So that, the hydrocarbon generation process of carbonate rocks can be summarized as the following three stages: the first is the direct degradation of biogenic bitumen macromolecules during the immature stage, the second is the thermal degradation of a large amount of kerogen at the mature stage, the last stage is the expulsion or release of inclusion organic matter owing to the increased thermal expansion pressure during the high evolution stage. Part of achievements of the Eighth Five-Year National Science-Technology Key-Task Project “85-102-02-07”.     

Organism relics or kerogens in oils as oil-source rock correlation indicator

Organism relics or kerogens in oils are first obsenred by a confocal laser scanning microscope (CLSM) and a transmission electron microscope (TEM). The complexes of kerogens in oils are characterized by the presence of a great variety of microfossils or macerals. These kerogens in oils are mainly the residues of the original organic substances from which oil formed, and minor kerogens from enclosing rocks enter the oils, therefore, the components and types of the kerogens in crude oils can serve as an indirect indicator of oil-source rock correlation. This method was applied to Jurassic oils in the Junggar Basin and the Turpan-Hami Basin, and there are two types of the kerogens in oils: one containing a lot of macerals from terrestrial plants may derive from coals, and the other, characterized by a high content of microscopic algae, fungus spores and Acritarch, may originate from Permian organic matter. In addition, the reflectance of the vitrodetrinites in oils can be used as an indicator of oil-source rock correlation.     

民和盆地中侏罗统煤-油页岩层系生油特征

本文简要论述了民和盆地中侏罗统含煤及油页岩层系的生油特征，探讨了盆地独特的石油地质和地球化学条件。原油主要地化特征为:Ｐｒ/Ｐｈ比值偏高（２.６５-３.１５）、甾烷/藿烷比值极低（０.０３）、Ｃ_２７甾烷较丰富、Ｔｓ/Ｔｍ＞１低硫芴/氧芴比值、较高含量的Ｃ_２９降新藿烷及重排藿烷类化合物及相对丰富的长链联苯及烷基四氢萘系列化合物。中侏罗统煤－泥页岩层系含生油潜力明显不同的多类型油页岩，多数油页岩属由藻类和陆生高等植物母质组成的混合型有机质，沉积环境为淡水－微咸水弱氧化条件，其地化特征也表现为高Ｐｒ/Ｐｈ比值（平均为１。９８），低甾烷/藿烷及低硫芴/氧芴比值等特征。某些油页岩富含Ｃ_２９降新藿烷及重排藿烷系列化合物，它们应为主力源岩。油页岩多含再沉积型或沉积改造型有机质。异常地热作用对源岩演化及原油地化特征有重要影响。     

杭州地区石笋稳定同位素古气候探索

用１４Ｃ测年技术和稳定同位素地球化学古温度方法，对浙江省临安瑞晶洞穴的石笋进行了１４Ｃ的测年和碳、氢、氧同位素测试，获得５～１万年间杭州地区古气候演化记录、该记录表明，在５～１万年间有三次较明显的周期性古温度变化，最高温度为１４．９℃，最低温度为６．６℃，最大温差为８℃左右，平均温差３～５℃。这段时期正处在大理冰期后期，但大理冰期并不是一个持续的低温阶段，它至少有３次温度波动。与我们获得的石笋同位素古温度相一致。另外，我们将５～１万年间杭州地区古气候变化与同期东南沿海的海平面变化进行了对比，在时间上也较为吻合，也就是温度上升、海平面也上升，温度下降、海平面也随之下降     

中国东部寒武系与奥陶系界线地层的碳氧同位素研究

对我国东部不同地层区一些代表性的寒武系-奥陶系界线层位开展了碳?氧同位素研究?结果表明,由于沉积环境差异和成岩蚀变影响,界线层位的δ18O值变化较大,规律性不明显,δ13C值变化虽小,但在界线处均发生不同程度漂移?漂移的层位与寒武纪-奥陶纪主要生物群面貌变化的界线相一致?综合各方面资料分析,笔者认为,碳同位素组成的漂移很可能由晚寒武世到早奥陶世时期内海平面的升降所引起.     

上扬子地台区晚古生代海相碳酸盐岩的碳,锶同位素研究

未经蚀变的海相碳酸盐岩的碳，锶同位素组成代表了原始海水的同位素组成，在确定样品末经显著蚀变的基础上，本文测定了上扬子地区晚古生代７条剖面２３８个海相碳酸盐岩样品的碳、锶同位素组成，分布了它们的测试结果和演化曲线，为其他相关研究提供了可利用的基础参照数据。     

不同岩溶动力系统的碳稳定同位素和地球化学特征及其意义——以我国几个典型岩溶地区为例

结合水化学的野外观测及室内计算,作者对桂林岩溶试验场、四川黄龙风景区和贵州乌江渡坝区3个岩溶动力系统的碳稳定同位素特征进行了分析,进而对系统的性质、系统中CO_2的来源、碳酸盐沉积过程中的碳同位素动力分馏、水化学和钙华的成因及热水钙华的~(14)C测年等地球化学问题作了探讨。结果表明,桂林岩溶试验场属于表层岩溶作用动力系统,其中的侵蚀动力主要来源于大气降水溶解土壤中的CO_2;四川黄龙风景区属于深部岩溶动力系统,侵蚀动力来自大气降水溶解幔源的CO_2;贵州乌江渡坝区岩溶系统,虽然属于表层岩溶动力系统,但其中一部分的同位素和水化学特征已受到人类活动的重大影响。