黑云母花岗岩全风化层工程地质特性研究

研究目的:华东、华南地区广泛分布有黑云母花岗岩,花岗岩全风化层厚度大,工程地质特性特殊。目前有多条高速铁路在华东、华南区域兴建,针对这种地层条件下的边坡处理以及路基填筑成为极为关键的问题。为全面了解华东、华南地区黑云母花岗岩的工程地质特性,在该区域多地取样进行室内试验,对风化层的矿物风化特征、物理特性、强度特性以及膨胀性进行系统的探讨,为该区域的铁路建设提供可靠的依据。研究结论:(1)华东、华南地区黑云母花岗岩的矿物成分主要是石英、长石和黑云母,发生风化蚀变的主要是长石和云母,长石风化蚀变成高岭石、伊利石或蒙脱石,黑云母蚀变为伊利石和铁锰质物;(2)华东、华南地区黑云母花岗岩全风化层结构疏松,泥质胶结为主,塑性指数在10%左右,属于粉质黏土的范畴;(3)黑云母花岗岩全风化层原状样的摩擦角在27°左右,粘聚力均小于100 kP a,粘聚力随具体地区相差较大;(4)黑云母花岗岩全风化层均不具有膨胀性;(5)该研究成果可为穿越花岗岩地区的铁路勘察设计提供参考与借鉴。

有机硅加固材料的合成及应用

根据石质文物风化蚀变原因和故宫博物院提供的石质样品的风化状况,选用甲基三乙氧基硅烷、正硅酸乙酯为单体合成聚硅氧烷,并对产品的性能进行测试。结果表明,该材料赋予风化石质以一定强度的同时,具有优良的防护性能。

准噶尔盆地南缘侏罗系泥岩黏土矿物组合及地球化学特征

对准噶尔盆地南缘玛纳斯河剖面泥岩中黏土矿物的组合类型、微观形貌和地球化学特征进行了综合分析,讨论了侏罗纪古气候、古环境演化过程.结果表明,泥岩中主要矿物为黏土矿物、石英、长石,以及少量的方解石、赤铁矿等.黏土矿物组合类型分为两类.一类为伊利石蒙脱石混层矿物、伊利石、高岭石和绿泥石组合,主要分布在下侏罗统泥岩中;另一类为伊利石和蒙脱石组合,主要分布在上侏罗统泥岩中.扫描电子显微镜分析表明,黏土矿物结晶度较低,伊利石常呈丝状、叶片状,蒙脱石呈不规则板状分布在碎屑颗粒表面,片状伊利石/蒙脱石混层矿物存在于孔隙之中.其δCe为0.9～1.3,Eu呈负异常,La/Sc、La/Th、Th/Sc值则较高,指示源区母岩为长英质岩石类型.研究认为准南地区侏罗纪气候和沉积环境演化可划分为3个阶段：早侏罗世属于温暖湿润气候条件,以湖泊三角洲沉积为主;中侏罗世早期属于温干偏湿润气候条件,以湖泊沉积为主;中侏罗世中后期至晚侏罗世属于相对较冷干旱的气候条件,属于宽浅氧化湖盆沉积环境类型.

湘西南高涧群的地球化学特征及其意义

湘西南高涧群主要是一套浅变质沉积碎屑岩系。由变质泥岩、板岩和变质粉砂岩组成,原岩颗粒小。变质作用对岩石化学成分没有大的改变,岩石具有相近的风化蚀变指数(平均CIA=75),风化蚀变矿物主要为伊利石-白云母-蒙脱石组合。主要化学成分反映沉积物来源于中性和基性火成岩区。浅变质沉积岩中大多数微量元素亏损,元素Cu、Zn、Co、Ti、Cr等在研究区的南部和北部具有相似的共生组合。并且稀上元素的分布模式基本相同,稀土的总量与岩性有关。上述特点显示了高涧群沉积物来源相同,亲石元素共生组合相似;Au、Ag、As、Sb、Sr、Ba等存在一定的分异。Ba/Co比值、Sr/Ba比值和δCe值表明,它是主要在浅深海-深海相还原环境下的产物。

龙岩高岭土矿床地质特征及成矿作用

福建龙岩高岭土矿床是蚀变花岗岩风化残余型矿床。花岗岩风化剖面具有明显的垂直分带性，各带有特征的粘土矿物组合、含量和化学组分。矿石矿物主要有高岭石、埃洛石、水白云母、石英及少量长石。高岭石的结晶有序度较低，粒度一般大于２μｍ。埃洛石粒度多小于２μｍ．龙岩高岭土矿石具有贫铁、钛和自然白度高的特征，属优质大型高岭土矿。其成矿作用经历了内生岩浆分异、热液蚀变和表生风化三大地质作用。

探水注浆工作在北洺河铁矿的实践

通过北氵名河铁矿基建过程中探水注浆的实践 ,提出采用探水注浆方法通过风化蚀变严重、裂隙岩溶发育 ,且被泥沙充填复杂地层的技术措施 。

峰峰煤业集团公司通顺公司集贤村地区软岩支护的理论与实践

软岩是指软弱、破碎、松散、膨胀、流变、强风化蚀变以及地应力变大的岩体总称。在煤矿开掘过程中最常遇到的软岩巷道主要是在软弱泥质或泥炭质岩体、破碎带或严重蚀变带以及深度在500～800m以下开掘的巷道。随着煤矿尤其是老矿区矿井的不断延深，采深不断加大，软岩巷道势必越来越多，软岩巷道地压和支护问题日渐突出和严重，软岩巷道支护的研究从理论方面尤其是实践方面已迫在眉睫，成为针对不同具体地应力条件下所采取不同支护方式的复杂变化的长久的课题，其研究也必将融入国内外地下工程科学研究的潮流中。

花岗岩氡析出影响因素研究进展

随着对氡气危害认识的加深,花岗岩作为生产、生活上接触较多的天然辐射来源,其氡析出特征对人居环境的辐射影响得到广泛关注。本文从岩石的原生特性和次生变化两方面对花岗岩的氡析出进行文献综述,发现花岗岩氡析出与岩石化学成分、矿物成分和成因类型等原生特性以及次生风化和蚀变导致的放射性核素分布、矿物颗粒大小以及岩石微裂隙等因素密切相关。研究表明,铀镭活度与花岗岩氡析出表现出线性相关,但受铀赋存矿物类型的影响,矿物成分的具体影响还需进一步研究,可能与其构造背景或者物质来源有关。岩石次生变化对花岗岩氡析出的影响主要表现为风化和蚀变使得放射性核素迁移到颗粒表面和岩石裂隙等有利于氡析出的位置,而颗粒变小比表面积增大以及岩石内表面积和孔隙率增加使得铀镭发生富集和逃逸,从而最终促进岩石氡的析出。岩石原生特性和次生变化对花岗岩的氡析出起着重要的影响作用,铀镭活度可以作为花岗岩氡析出率潜力的预测指标,而对于矿物成分和岩石的次生变化则是研究花岗岩氡析出的重要潜在因素。故此,未来需要系统研究并定量描述岩石化学、矿物成分和次生变化,并据此建立合理有效的岩石氡析出模型,帮助更全面地掌握岩石中氡析出规律,为地下工程及人居环境的氡防护提供理论依据。

介福高岭土矿床地质特征及成矿作用探讨

永春介福高岭土矿床是蚀变花岗斑岩风化残余型矿床。花岗斑岩风化剖面具有明显的垂直分带性,且各带主要化学组分呈规律性变化。矿石具有贫铁、钛和自然白度高的特征,属优质高岭土矿。其成矿作用经历了内生岩浆分异、热液蚀变和表层风化三大地质作用。

Sediment recycling and indication of weathering proxies

As a result of recycling, the mineralogical and chemical compositions of riverine sediments may reflect the combined effects of the present-day weathering regime as well as previous weathering and diagenetic alteration history. River sediments can be interpreted as a mixture of non-weathered bedrock—of igneous, metamorphic, or sedimentary origin—and solids formed by the modern weathering system. The correlation between the weathering proxies chemical index of alteration and weathering index of Parker offers an approach to distinguish fine suspended particles, coarse bedload sediments, and recycled sediments under the influence of quartz dilution. Recycling of cation-depleted source rocks formed during past geological weathering episodes may have great impacts on the weathering indices of sediments from the Changjiang(Yangzte) and Zhuoshui Rivers. Special caution is required when using chemical weathering indices to investigate the intensity of chemical weathering registered in fluvial sediments. To minimize the effect of hydrodynamic sorting or sediment recycling, we suggest that the fine sediments(e.g.suspended particles and ﹤2 lm fractions of bedload sediments) in rivers better reflect the average of weatheredcrust in catchments and the terrigenous end-member in marginal seas.

介福高岭土矿床地质特征及成矿作用探讨

永春介福高岭土矿床是蚀变花岗斑岩风化残余型矿床。花岗斑岩风化剖面具有明显的垂直分带性,且各带主要化学组分呈规律性变化。矿石具有贫铁、钛和自然白度高的特征,属优质高岭土矿。从矿床地质特征,推断其成矿作用经历了内生岩浆分异、热液蚀变和表层风化3大地质作用。

Spatio-temporal Variation of Wind Erosion in Inner Mongolia of China Between 2001 and 2010

Using Geographic Information System(GIS), based on wind speed, precipitation, topographic, soil, vegetation coverage and land use data of Inner Mongolia between 2001 and 2010, we applied the revised wind erosion equation(RWEQ) model to simulate wind erosion intensity. The results showed that an area of approximately 47.8 × 10~4 km^2 experienced wind erosion in 2010, 23.2% of this erosion could be rated as severe, and 46.0% as moderate. Both the area and the intensity of wind erosion had decreased from 2001 to 2010, the wind erosion area reduced 10.1%, and wind erosion intensity decreased by 29.4%. Precipitation, wind speed, population size and urbanization in rural areas, and gross domestic product of primary industry(GDP1) were the main factors influencing wind erosion. Overall, these factors accounted for 88.8% of the wind erosion. These results indicated that the decrease in wind erosion over the past decade related to the increase in precipitation and the decrease in the number of windy days, while modest urban development and optimization of the economic structure might partially reduced the level of ecological pressure, highlighting the importance of human activities in controlling wind erosion.

Influence of Vegetation on Runoff and Sediment in Wind-water Erosion Crisscross Region in the Upper Yellow River of China

All characteristics of vegetation,runoff and sediment from 1960 to 2010 in the Xiliu Gully Watershed,which is a representative watershed in wind-water erosion crisscross region in the upper reaches of the Yellow River of China,have been analyzed in this study.Based on the remote sensing image data,and used multi-spectral interpretation method,the characteristics of vegetation variation in the Xiliu Gully Watershed have been analyzed.And the rules of precipitation,runoff and sediment's changes have been illuminated by using mathematical statistics method.What′s more,the influence mechanism of vegetation on runoff and sediment has been discussed by using the data obtained from artificial rainfall simulation test.The results showed that the main vegetation type was given priority to low coverage,and the area of the low vegetation coverage type was reducing year by year.On the country,the area of the high vegetation coverage type was gradually increasing.In a word,vegetation conditions had got better improved since 2000 when the watershed management project started.The average annual precipitation of the river basin also got slightly increase in 2000–2010.The average annual runoff reduced by 37.5%,and the average annual sediment reduced by 73.9% in the same period.The results of artificial rainfall simulation tests showed that the improvement of vegetation coverage could increase not only soil infiltration but also vegetation evapotranspiration,and then made the rainfall-induced runoff production decrease.Vegetation root system could increases the resistance ability of soil to erosion,and vegetation aboveground part could reduce raindrop kinetic energy and splash soil erosion.Therefore,with the increase of vegetation coverage,the rainfall-induced sediment could decrease.

国外某风化型钒钛铁矿选矿试验研究

针对国外某深度蚀变氧化型钒钛铁矿,铁矿物与钛矿物难以物理选矿实现分离,脉石矿物的比磁化系数、比重与金属矿物差异较大、易磨矿解离的特征,开展了选矿富集钒钛铁试验研究,对比了磁选回收工艺、分级-磁选回收工艺及重选回收工艺,确定磁选回收工艺为最适宜的回收工艺。磁选回收工艺获得了可市售的含钒铁精矿含Fe 60.52%、V_(2)O_(5)1.03%,回收率分别为Fe 8.12%、V_(2)O_(5)8.62%,钒钛铁混合精矿Fe 50.03%、V_(2)O_(5)0.80%、TiO_(2)16.01%,回收率分别为Fe 78.61%、V_(2)O_(5)78.45%、TiO_(2)82.88%的选别指标,混合精矿钒、钛、铁品位较高,可作为冶金进一步获取钒、钛、铁的原料。

Sand-fixing Function under the Change of Vegetation Coverage in a Wind Erosion Area in Northern China

Using meteorological and remote sensing data and changes in vegetation cover during the wind erosion season in northern China, a revised wind erosion equation was applied to evaluate spatiotemporal variation in soil erosion and conservation since the 1990s, and to reveal the effects of the change of vegetation coverage on the wind erosion control service. The results showed that average soil erosion in northern China between 1990 and 2010 was 16.01 bil ion tons and was decreasing. The most seriously eroded areas were mainly distributed in large desert areas or low cover grasslands. Most wind erosion occurred in spring, accounting for 45.93% of total wind erosion. The average amount of sand ifxation service function for northern China between 1990 and 2010 was 20.31 billion tons. Given the influence of wind erosion forces, the service function for sand fixation cannot effectively highlight the role of sand ifxation from the ecosystem itself. The retention rate of service function for sand ifxation reveals the role of the ecosystem itself. The distribution characteristics of the soil retention rate are similar to vegetation cover, which shows a gradual decrease from southeast to northwest in the study area. Improved spring vegetation cover was observed mainly on the Loess Plateau, Qinghai-Tibet Plateau, in northern Hebei, eastern Inner Mongolia and northeast China after the implementation of ecosystem projects. The soil retention rate in most areas showed a signiifcant positive relationship with grassland vegetation in spring （r＆gt;0.7, p＆lt;0.01）. The increments of ecosystem service function for various ecological systems are different. Increments for the grassland ecosystem, forest ecosystem, farmland ecosystem and desert ecosystem are 2.02%, 1.15%, 0.99% and 0.86%, respectively.