Environmental Geochemistry of Mining Activities in Panzhihua Region, Southwestern China

INTRODUCTIONMining activlties have significant envi ronmenta1 inll)ac'l ssuch as visual intrusions, dust, noise, blasting, trafflc and h}'drology (Kwolek, l999; Ripley et al., l996 ). The l)rot'csst'sof mineral extraction, processing, smelting and refinlng;1rt'never approximate to the environmental neutrality, but tht' affected areas can be ameliorated (KwoIek, l999; Klukanov;1;llltlRapant, 1999). The regions, where mining activities are I,r('sent or continuous for a long tlme, are pote…     

钻井设备老化过程及规律的探讨

本文通过对钻机老化过程及规律的探讨，找出了一种方便而有效衡量钻机老化程度的数量指标，用以定量地度量钻机老化程度，为钻机发挥最佳经济效益起到一定的作用。     

Adsorption characteristics of perchloroethylene in natural sandy materials with low organic carbon content

Laboratory batch tests were conducted to investigate the sorption isotherms and sorption kinetics of the chlorinated hydrocarbon perchloroethylene (PCE) in five natural sandy materials with an organic carbon content (f _oc) in the range 0.080–0.540%. The amended non-linear dual-mode model can describe the sorption isotherms in materials with f _oc in the range 0.080–0.090%. For a sample with a much higher f _oc of 0.54%, the absorption isotherm was found to fit a linear model. These results may indicate that organic carbon is not the main factor influencing the sorption isotherm. The sorption kinetics of PCE in samples with f _oc in the range 0.080–0.090% are not first-order and are different from those observed in the samples with higher f _oc. The sorption process in the materials with lower f _oc involves fast sorption, fast desorption and an equilibrium stage. The results may imply that the factors affecting sorption kinetics of PCE in low f _oc media are pore filling and capillary condensation rather than organic carbon content.     

黑龙江七星河含煤盆地古近纪-新近纪沉积相及层序地层特征

黑龙江省东部七星河盆地是一新生代聚煤盆地,其含煤地层为古近系宝泉岭组、新近系富锦组。宝泉岭组由各级砂岩、泥岩、炭质泥岩以及褐煤组成,发育滨浅湖相、深-半深湖相、三角洲平原相,属于湖泊沉积体系、三角洲沉积体系。富锦组主要由泥岩、粉砂岩、中砂岩、含砾粗砂岩及煤层、炭质泥岩、硅藻岩组成,发育滨浅湖相、扇三角洲平原相,分别属于湖泊沉积体系和扇三角洲沉积体系。层序SI相当于宝泉岭组,发育低位体系域、湖侵体系域和高位体系域,煤层主要发育高位体系域中后期,成煤环境以滨浅湖淤积沼泽为主。层序SII相当于富锦组,主要发育湖侵体系域、高位体系域,局部地区发育低位体系域,煤层亦主要发育高位体系域中后期,成煤环境以扇三角洲淤积沼泽和滨浅湖淤积沼泽为主。层序SI、SII的高位体系域中后期,盆地基底沉降速率和物源供给处于相对平衡状态,主要发育了扇三角洲淤积沼泽、滨浅湖和滨浅湖淤积沼泽环境,发育可采煤层。     

Iron and Sulfur Chemistry in a Stratified Lake: Evidence for Iron-Rich Sulfide Complexes

A four month study of a man-made lake used for hydroelectric power generation in northeastern Pennsylvania USA was conducted to investigate seasonal anoxia and the effects of sulfide species being transported downstream of the power generation equipment. Water column analyses show that the system is iron-rich compared to sulfide. Total Fe(II) concentrations in the hypolimnion are typically at least twice the total sulfide levels. In situ voltammetric analyses show that free Fe(II) as [Fe(H₂O)₆]²⁺ or free H₂S as H₂S/HS^- are either not present or at trace levels and that iron-rich sulfide complexes are present. From the in situ data and total Fe(II) and H₂S measurements, we infer that these iron-rich sulfide complexes may have stoichiometries such as Fe₂SH³⁺ (or polymeric forms of this and other stoichiometries). These iron-rich sulfide complexes appear related to dissolution of the iron-rich FeS mineral, mackinawite, because IAP calculations on data from discrete bottle samples obtained from bottom waters are similar to the pK_sp of mackinawite. Soluble iron-sulfide species are stable in the absence of O₂ (both in lake waters and the pipeline) and transported several miles during power generation. However, iron-sulfide complexes can react with O₂ to oxidize sulfide and can also dissociate releasing volatile H₂S when the waters containing them are exposed to the atmosphere downstream of the powerplant. Sediment analyses show that the lake is rich in oxidized iron solids (both crystalline and amorphous). Fe concentrations in FeS solids are low (<5 μmole/gr_{dry wt}) and the pyrite concentration ranges from about equal to the solid FeS to 30 times the solid FeS concentration. The degree of pyritization is below 0.12 indicating that pyrite formation is limited by free sulfide, which can react with the iron-rich sulfide complexes.     

Red clay deposits on the Chinese Loess Plateau during 11.0–2.6?Ma and its implications for long-term evolution of East Asian monsoon

Loess and red clay on the Chinese Loess Plateau have produced a detailed history of the East Asia monsoon for the past eight million years. Recently, a well-conserved red clay sequence was discovered at Shilou on the eastern edge of Chinese Loess Plateau, extending the monsoon history back to approximately 11 Ma. By comparing lithologic features, particle size distribution, magnetic susceptibility and deposition rate of Shilou red clay sequence, the paleomonsoon evolution from 11 to 2.6 Ma can be divided into four stages: largely fluctuated stage (11.0–8.0 Ma), relatively strengthened period (8.0–6.5 Ma), extremely changed stage (6.5–4.9 Ma) and further intensified period (4.9–2.6 Ma). The new evidence indicates that variation of paleomonsoon has close relationship with uplifting of the Tibetan Plateau and ongoing global cooling and the consequent expansion of ice sheets during 11.0–2.6 Ma.     

层状侵入体韵律层理形成过程的定量模拟——以四川攀枝花层状岩体为例

层状侵入体的韵律层理是一种特殊的岩石构造,长期以来其成因倍受关注,成因假说很多。本文在综合这些观点关于岩浆物理,化学性质的研究,尤其是在岩浆房地对流特征研究成果的基础上,提出了新的成因解释,认为固化带前锋处矿物的结晶,熔浆组分的扩散及固化带前锋本身的推进等３个因素的相互耦合是形成韵律层理的主要机制,这个过程是发生在一定过冷却条件下的,在这种定性认识基础上,笔者提出了旨在对韵律层理形成过程进行模拟计     

平南幔源包体中橄榄石的显微构造研究及其意义

平南玄武岩中的尖晶石二辉橄榄岩包体的平衡温度为930~980℃, 平衡深度为59~74km, 包体中橄榄石的扭折带滑移系多为(010) [100], 但也有(001) [100]的滑移系类型; 斜方辉石的滑移系为(100) [001], 它们均为高温低应变速率下的滑移系, 说明该区的上地幔主要是在高温低应变速率条件下经历了塑性变形作用.橄榄石位错组态多样, 有自由位错、位错壁、位错弓弯、缠结、{110}滑移带, 反映了上地幔的塑性变形特征.根据位错壁的大小估算, 上地幔差异流动应力为24.5~42.1MPa, 流动速率为2.93×10-17~8.36×10-16s-1, 有效粘度为1.72×1023~2.80×1024 Pa·s, 特征与中国东部新生代上地幔较为一致, 反映同处于拉张环境.      

塔里木盆地北部中生界生油岩基本特征

塔里木盆地北部地区中生界生油岩为陆相泥质生油岩，主要发育在三叠系、侏罗系。有两个生油岩发育中心，库车坳陷区和阿瓦提断陷－满加尔坳陷区。三叠系生油岩有机质丰度主要为较差一较好生油岩，侏罗系生油岩则为较差－较好－好生油岩。三叠－侏罗系生油岩干酪根类型以Ⅲ型为主，少量Ⅱ型。库车坳陷三叠－侏罗系生油岩热演化多处于成熟－高成熟阶段。阿瓦提断陷－满加尔坳陷三叠系处于初熟阶段，侏罗系则处于未成熟－初熟阶段。沙雅隆起北侧，库车坳陷南缘是寻找油气藏最为有利的地区。