菌藻生物在成矿作用中的富金实验模拟

进行了菌落生物活体,死体,原油,有机质,有机淤泥和三种粘土矿物富金作用的对比实验,并研究了不同环境不同类型的菌藻生物在不同环境下的富金能力的差异,探讨了生物富金机理。结果表明活体菌藻生物富金能力比其他实验样品的强。与海水和淡水条件相比,温尔泉蓝细菌富金能力强;与常温条件相比,热水条件下的温泉蓝细菌富金能力强。     

论川西炉霍裂谷微细浸染型金矿的矿质来源

扼要介绍了川西炉霍裂谷微细浸染型金矿的地质特征, 通过地层和岩石中元素丰度特征,稀土元素、同位素、微量金的可化性实验等系统分析, 提出炉霍裂谷微细浸染型金矿的成矿物质来自三叠纪地层中的细碎屑质浊积岩建造和裂谷海底火山作用提供的深源物质。并讨论了矿质初始富集的机制。     

甘肃省阳山超大型金矿床的有机地球化学特征研究

甘肃省文县阳山金矿是我国地质勘查储量最大的卡林-类卡林型金矿床,赋矿地层为泥盆系一套碳-硅-泥质地层.矿区发育了大量碳质千枚岩,富含有机碳.本文研究了矿石和围岩可溶有机质的生物标志物、有机质的来源和成熟度、干酪根的碳同位素等,论述了阳山金矿床的有机地球化学特征及有机质与成矿的关系,查明了参与成矿的有机质主要是菌藻类等低等生物.生物标志化合物参数和干酪根的H/C-O/C原子比值指示阳山金矿有机质成熟度较高,达到了无烟煤的演化阶段.在热演化的过程中,有机质裂解产生的CH_4和C-2H_6等进入成矿流体中,参与了成矿过程.阳山金矿赋矿地层中含有生物成因的草莓状黄铁矿,显示生物-有机质参与了地层的预富集作用.有机碳含量、有机质的类型和金的丰度之间相关性不明显,说明在阳山金矿的成矿过程中有机质对金的沉淀贡献不大,但是有机质可能参与了金的预富集和运移.     

Biogenic sedimentation factors of mineralization in the Neoproterozoic strata of the Baikal–Patom region

The formation environments of stratiform ore deposits in the Neoproterozoic Baikal–Patom region (BPR) have been considered. A model for the formation of the Sukhoi Log gold ore deposit in the Bodaibo zone has been put forward. The first stage is gold concentration by a chemolithotrophic bacterial community. Independently established facts suggest that bacterial communities may also have contributed to initial metal accumulation in the sediments of the Kholodnaya Pb–Zn deposit. The ore beds occur in the high-carbon sediments of the side and trough of a back-arc basin. Sedimentation (Dal’nyaya Taiga and Zhuya regional horizons) took place during the “back-arc basin–foreland basin” transition. This transition is characterized by increased sediment bioproductivity, which is clearly evidenced from the increased biophile-element content and taxonomic diversity of organic remains. Hundreds of microfossil sites in the Neoproterozoic BPR host littoral benthos (cyanobacteria and brown algae) and plankton (green algae). Most microfossils in the outer shelf, on the basin side, and in its trough belong to chemolithotrophic bacteria. These bacteria are assumed to have accumulated metals in the vent field of the back-arc basin. Studies showed the ability of microorganisms (bacteria, algae, fungi, etc.) to accumulate Fe, Mn, Au, Pb, Zn, and other metals. Bacterial communities are particularly important for metal accumulation in the vent fields of rift zones and areas of arc volcanism. All these conditions were observed in the Neoproterozoic BPR.     

拉尔玛金矿矿源层──太阳顶群硅质岩的有机地球化学研究

拉尔玛金矿矿源层──太阳顶群硅质岩的有机地球化学研究林丽（成都理工学院，成都６１００５９）关键词有机地球化学，硅质岩，太阳顶群，拉尔玛金矿床拉尔玛金矿床赋存于寒武系太阳顶群中，该群的硅质岩是矿源层。本文探讨矿源层形成过程中与金关系密切的有机质的生物先...     

Biomineralization in the La'' erma Gold Deposit of the Western Qinling Mountains

Geological and geochemical studies and experiments on mineralization indicate that the source bed of the La' erma gold deposit in the south subbelt of the western Qinling Mountains is hydrothermal cherts in the Cambrian Taiyangding Group. Organic geochemical study of the cherts shows that the organic precursors intimately associated with gold are marine bacteria and algae. The gold content in chert,is positively correlated with the amount of bacterial and algal microfossils, and simulation experiments on biomineralization of modern bacteria and algae indicate that bacteria and algae played an important role in the formation of the La' erma gold deposit.     

广西金牙金矿床的有机地球化学特征

从矿石和围岩可溶有机质的生物标志化合物,非烃的红外光谱学特征,以及有机包裹体的光学和谱学特征等方面论述了金牙金矿的有机地球化学特征及其有机流体的成矿作用,查明了参与成矿的有机质主要来源于菌藻类等低等生物,本有机质的成分、结构、成熟度和胡成矿作用的进行而不断演化。在有机碳、金含量及藻类成矿作用模拟实验的分析基础上,认为流体有机质参与成矿的方式主要是活化萃取、还原沉淀,而干酪根则对金起集作用。     

华北太原组腐殖煤形成过程中菌藻类的贡献

从煤岩学、煤核古植物学、超微组分和分子有机地球化学４个方面证实华弱东部和南部太原组腐殖煤形成过程中有明显的菌藻类低等生源贡献，提出成煤过程中明显菌藻类低等生物贡献是太原组煤性质异常的一个重要原因。     

黔西南灰家堡金矿田有机岩相学和地球化学

灰家堡金矿田是黔西南卡林型金矿床的集中产地之一,对其中的水银洞、紫木凼、太平洞和簸箕田4个代表性金矿床进行了有机岩相学和地球化学研究。灰家堡金矿田的矿床中固体沥青主要产于矿石内,与矿化关系密切,产出形态受孔隙、构造裂隙控制;沥青与热液期矿物的共生组合关系表明其形成时间与成矿时间大致一致。矿石中普遍发育有机质包裹体。有机地球化学特征表明,金矿石和围岩中的有机质成熟度均较高,经历了类似的地质作用过程;有机质形成于强还原、中低盐度的沉积环境;有机质来源以海相菌藻类等低等生物为主,有少量陆源高等植物的输入。     

黔西南下三叠统金矿床有机地球化学特征及其成矿意义

黔西南下三叠统浸染型金矿床的形成与泥灰岩和泥岩中的有机质具有密切的关系。浅海及Ｘｉ湖相泥灰岩、泥岩中有机质较丰富，金的矿化程度较高，生物标志化合物研究表明，金的富集与菌藻类来源的有机质有关，菌藻类生物对矿源层的形成具有重要意义，而有机质演化产物不仅促使了金的活化迁移，有机质热解产物还促使金的沉淀和富集。因此，金的物源丰富和源于菌藻类的有机质较丰富的岩层分布区是金矿找矿的有利地区。