Diagenesis of volcanic-rich tight sandstones and conglomerates: a case study from Cretaceous Yingcheng Formation,Changling Sag,Songliao Basin,China

Thick conglomerate and sandstone lithofacies of Yingcheng Formation in Changling Sag are tight gas reservoirs. The formation contains a fair amount of volcanic clasts and accumulated in a deltaic system that spans from delta plain to prodelta depositional setting. High-quality reservoirs are only a small fraction of these thick siliciclastic rocks. Petrographic analysis has been used to assess diagenetic processes, paragenetic sequence, and their effects on the reservoir qualities. The major loss of primary porosity is due to compaction along with grain-coating, pore-filling clay, and quartz cements. Alteration of volcanic rock fragments supplied alkali cations which favored formation of chlorite, smectite, and zeolite cements. The thickness of the chlorite coating decreases from the delta plain to the distal part of the delta front. On the contrary, the content of the zeolite cement increases toward the distal part of the delta front. Quartz and feldspar cements were ubiquitous due to high SiO₂ concentration and alkali cations. Early dissolution of volcanic rock fragments and feldspars by freshwater increased porosity but did not contribute much to the permeability because pore-throats are predominantly occluded with clay and pseudomatrix. Late-stage dissolution of the zeolite cement was caused by organic acid expelled from maturation of organic matter. Although the reservoirs with chlorite coatings have moderate porosity, the permeability in situ is very low and pore-throat sizes are small. The high-quality reservoirs are medium- to fine-grained zeolite-dissolved sandstones developed in the distal part of the delta front and shallow lacustrine.     

用全数字摄影测量系统高效获取4D数字产品的方法

以北京某地区为例,详细介绍利用JX-4C全数字摄影测量工作站制作4D（DRG、DLG、DEM、DOM）数字产品的作业方法,最后得出该地区的4D产品成果图。证明利用该方法制作4D产品的速度快、精度高,可广泛应用于测绘生产过程。     

Property insurance against debris-flow disasters based on risk assessment and the principal–agent theory

Dongchuan City is highly threatened by debris-flow disasters originating from Shengou gully, a typical debris-flow gully along Xiaojiang River in Yunnan Province (Kang et al. 2004). Shengou gully is studied, and a hazard assessment with numerical simulation is developed using ArcGIS 9.2 software. Debris-flow numerical simulation is an important method for predicting debris-flow inundation regions, zoning debris-flow risks, and helping in the design of debris-flow control works. Meanwhile, vulnerability measurement is essential for hazard and risk research. Based on the self-organized map neural network method, we combine the six vulnerability indicators to create an integrated debris-flow vulnerability map that depicts the vulnerability levels of Dongchuan City in Shengou Basin. Based on the risk assessment (including hazard assessment and vulnerability assessment), we adopt the principal–agent theory and use the risk degree of debris flows as an important index to build the insurance model and analyze the insurance premium of debris-flow disasters in Dongchuan City. This paper discusses the model and mechanism of property insurance in debris-flow risk regions and aims to provide technical support for insurance companies to participate in disaster prevention and reduction.     

胶东望儿山金矿带有限应变分析及其意义

望儿山金矿带中广泛发育变形石英颗粒。经三维有限应变分析表明,望儿山断裂曾经历过强烈的挤压作用,金矿体定位于断裂带的扩容空间,矿体附近付林参数普遍表现为拉伸型。构造岩有限应变椭球体拉伸轴,主要集中于ＮＥ—ＳＷ向,含矿热液在区域应力及岩浆热动力作用下,沿望儿山断裂带运移。成矿过程中,体系是开放的。     

A Study of Monitoring,Simulation and Climate Impact of Greenland Ice Sheet

Greenland Ice Sheet is one of the two largest ice sheets on the planet. Under the background of climate warming, the melting of the Greenland ice sheet and its contribution to sea level rise has become an international hot issue. The whole melting of the Greenland ice sheet can cause the global sea level to rise by about 7.3 meters. However, the dynamic mechanism that affects the mass balance of ice sheet is still unclear and is the greatest uncertainty source for predicting the rise in sea level in the future. The National Key Research and Development Program of China “A Study of the Monitoring, Simulation and Climate Impact of Greenland Ice Sheet” conducts monitoring and simulation studies on the key processes of instability of the “ice sheet-outlet glacier-sea ice” system, and establishes a satellite-airborne-ground integrated observation system, supporting the numerical simulation and impact research of the ice sheet and its surrounding sea ice, laying the foundation for long-term monitoring and international cooperation in Greenland. This program will work to reduce the uncertainty of sea level change projections by improving the ice sheet dynamic model forced by the ice core records, reveal the driving mechanism of sea ice changes around the ice sheet, focusing on the Northwest Passage, evaluate and forecast the navigation window period. The results of the project will deepen the understanding of the changes and impacts of the Arctic cryosphere, serve the safe navigation and operation of the Northwest Passage, and provide scientific support for the comprehensive risk prevention of coastal zones in China.     

尹赞勋先生对第四纪研究的开拓性贡献──兼论顾乡屯动物群及其时代

顾乡屯动物群是由１９３１年尹赞勋先生在哈尔滨顾乡屯发现１９种哺乳动物化石而得名,其后在东北、内蒙古一带多处发现,由于以被毛犀、猛犸象化石最为常见,一般也称为“披毛犀－猛犸象动物群”。到目前为止该动物群至少有６４种化石,分属１８科３７属。顾乡屯组代表东北地区晚更新世河－湖相沉积,与华北萨拉乌苏组有很好的对比性,属同期异地同相沉积。顾乡屯动物群化石层位仅限于顾乡屯组地表出露部分,年龄测定结果不超过６００００─７００００ａＢ．Ｐ．,表明顾乡屯动物群相当于萨拉乌苏上部动物群,时代为晚更新世晚期。顾乡屯动物群与顾乡屯组在时代上的不一致性,是东北地区第四纪研究中应引起重视的问题。对大同第四纪火山群及我国近期火山的分布,自３０年代由尹赞勋先生做了开创和倡导性研究以来,在岩石学、地球化学、树造环境和深部岩浆源及年代学等方面的研究都已取得长足的进展。     

Expansion and contraction of Hulun Buir Dunefield in north-eastern China in the last late glacial and Holocene as revealed by OSL dating

Optical stimulated luminescence (OSL) study on sand and fossil soils from Hulun Buir Dunefield in Eastern China is reported in this paper. Aeolian dune sequences responded to the climate change by alternations of aeolian sand and dark sandy soils, which corresponded to arid and humid conditions, respectively. Optical dating using the single aliquot regeneration technique with quartz was applied to the deposits. The results indicate that the soils and underlying aeolian sand correspond to the Holocene optimum (HO) and the last late glacial, respectively. Combined with studies of OSL dating of 13 profiles and grain-size, magnetic susceptibility, total organic carbon, sediment color and scanning electron microscopy measurements for two representative sections, indicate the expansion in the last late glacial sand was 10 times that of today. The dune field was not totally stabilized by vegetation cover until HO (10–5 ka BP).     

Structural pattern of eastern Himalayan syntaxis in Namjagbarwa and its formation process

The structural pattern of the eastern Himalayan syntaxis in Namjagbarwa consists of two series of structures with different styles. One series compiles the earlier ductile contrac-tional and lateral-slip deformation system, formed by nearly north-south shortening within the syntaxis, left-lateral and right-lateral slipping along its western and eastern boundaries respectively. They were possibly produced by the indentation of the Indian continent into Asian continent after India-Asia collision. The peak deformation-metamorphic ages in these structures are 62-60 Ma, -23 Ma and -13 Ma. The other series is composed of ductile-brittle normal faults distributing concentrically and dipping toward the outsides of Namjagbarwa Peak. They were probably the collapse structures caused by rapid uplift in a later time and the beginning ages for the normal faulting are about 7.3-6.3 Ma.     

The effect of long-term reclamation on enzyme activities and microbial community structure of saline soil at Shangyu, China

Reclamation of saline soil plays an important role in supporting high population growth in China. To evaluate the effects of reclamation and sustainability of salt-affected land production, soil chemical properties, enzyme activities, microbial community structure and function in sites reclaimed in 1976, 1984 and 1996 were characterized. The 2009 site was left to succession fallow and chosen as a control site. Results showed that electrical conductivity (EC) and pH decreased rapidly after the soil forming process started. An accumulation of soil organic C as a result of farming was observed. In all sites, inorganic N and available P were increased within 33 years after reclamation and commencement of agriculture. As a result of reclamation, soil enzyme activity (β-glucosidase, phosphatase, urease and arylsulfatase) was increased. There were no significant differences in soil enzyme activity between the sites reclaimed in 1976 and 1984, with the exception of phosphatase. Carbon source utilization patterns were less diverse in control soil than in treatment sites. The activities of reclamation resulted in synthesis of new phospholipid fatty acids (14:0, 17:1 c9, 16:0 2OH, 17:0 10Me, i17:0, 20:4 ω6c). Principal component analyses showed that the sites reclaimed in 1976 and 1984 clustered together and were distinct from 1996. Taken together, reclamation showed significantly increased soil quality and microbial activity. EC was the main limiting soil quality characteristic, which showed a comparative steady state after a reclamation time of 33 years. Differences in soil enzyme activity and microbial community function after long-term reclamation have potential to be reflected in soil functional integrity and ecosystem service.     

代县和繁峙2次塌陷地震的机理成因浅析

金属矿山的深部开采易引发冒落型矿震。本文对繁峙和代县两相邻铁矿区相继发生的2次塌陷地震,从其发展到发生的过程特点、形态特征和成因机理等方面进行了分析和总结,认为这两次塌陷的孕育发生与区域构造应力、降雨和人为开采等因素密切相关。2次塌陷前前兆特征现象明显,据此可充分利用测震台网记录到的塌陷数据,通过甄别,收集更多的震例,研究总结其规律,并将研究成果应用于日常监测中,以便能对较大矿震事件做到尽早预报预警,更好地服务社会,服务应急等相关部门。