Computer simulation of Neocomian clinoform reservoirs in northern and arctic West Siberia

Neocomian reservoirs in the Mesozoic sedimentary cover of West Siberia have a complex geological structure. Their wedge-like (clinoform) geometry, with abrupt thickness changes and facies diversity (continental, shoreface, and pelagic deposits), causes difficulty in correlation between drilling- and seismics-based sand formations and clay caps. East-wedging (west-dipping) clinoforms consisting of interbedded clay and sand have the greatest reservoir potential in the West Siberian basin. Prediction of new oil and gas plays and their reservoir potential assessment require regional reconstructions in addition to local contour maps of individual zones and fields. However, the simulation technology which has been applied for years to Jurassic regional reservoirs is not fully applicable to the Neocomian clinoform sequences. Therefore we have adapted it correspondingly and suggest new tools to make due regard for the clinoform reservoir structure. The new approach has been tested through computing several structure and thickness contour maps of clinoform sequences for three largest regional Neocomian reservoirs (sub-Sarman, sub-Pim, and sub-Alymka) in northern and arctic West Siberia.     

Modelling and optimization of processes for removal of dissolved heavy-metal compounds from drinking water by microbiological methods

The results of laboratory modelling of microbiological removal of soluble compounds of Fe, Mn, and other heavy metals (Al, Cr, Zn, Co, Cu, Pb, Cd) with the use of a laboratory bioreactor. The results have shown that the main method of optimization of conditions facilitating the removal of dissolved metal compounds from drinking water consisted in creating and maintaining an oxygen aeration regime favorable for bacterial oxidation processes and, which is especially important, in preventing stagnancy in the sand filter of bioreactor during its shutoff. The latter was accompanied by an acceleration of bacterial reduction processes of precipitated heavy metals, resulting in their dissolution, hence secondary water pollution.     

LA-ICPMS原位微区面扫描分析技术及其矿床学应用实例

LA-ICPMS原位微区面扫描技术的发展对解析具有包裹体、环带结构的矿物或受多期岩浆/热液活动影响形成的溶蚀再结晶的矿物具有重要的地质意义。黄铁矿作为最普遍的硫化物种类之一,可形成于各种类型矿床中,其微量元素组份记录了矿床形成过程的重要信息。通过LA-ICPMS原位微区面扫描技术获得的黄铁矿晶体内部结构组份信息可用来限定成矿流体的性质、厘定成矿流体的演化规律、示踪成矿物质来源、约束变形变质作用过程中元素的活化和迁移行为,以及约束矿床成因等。本次研究选取了内蒙古二连盆地中巴彦乌拉大型铀矿床、辽宁青城子地区榛子沟铅锌矿、加拿大Pardo砂金矿中的黄铁矿作为研究对象,运用原位微区LA-ICPMS元素面扫描技术揭示其内部组份及结构信息,探索该技术在不同类型矿床中的应用价值。巴彦乌拉大型砂岩型铀矿床中的黄铁矿的内部组构信息显示成矿体系的p H和Eh对硫酸盐还原细菌活动均有影响,并控制与之相关的铀矿化;且成矿体系的p H和Eh受到外界不断供给的地下水的影响,呈振荡性变化。辽宁榛子沟铅锌矿中的黄铁矿的内部组构信息显示矿化过程受到了至少两期流体活动的叠加影响,包括早期同沉积时期的流体以及晚期与燕山期岩浆活动有关的热液流体。加拿大Pardo金矿中黄铁矿的内部组构信息显示矿床中半自形-自形的黄铁矿实际包含碎屑成因的磨圆状核部及后期热液活动形成的增生边;金主要呈浸染状分布在碎屑成因的黄铁矿核部,后期热液活动对金矿化影响微弱。     

雷琼地区第四纪地磁极性年表——火山岩钾-氩年龄及古地磁学证据

雷琼地区火山岩的钾-氩同位素年龄测定和古地磁极性研究表明,新生代在该地区的岩浆活动一直很强烈。火山岩的生成年代不晚于中新世晚期,至更新世岩浆活动尤为强烈。 研究也表明中新世晚期以来这里的地球磁场极性变化规律与近期发表的地磁极性年表大体相符,并肯定了数个尚有争议的短期极性事件的存在。年代为0.58±0.13Ma的反极性火山岩的资料肯定了安比拉（Emperor）事件的存在。研究还证实了布容/松山极性时界线之下和哈拉米洛极性亚时之上有一短期的极性事件,其年代约为0.78±0.03Ma.在奥尔都维和哈拉米洛极性亚时之间存在有另一正极性事件,这可能相当于吉尔萨（Gilsa）事件。