变异函数在异常空间插值中的应用

针对数据空间架构中异常点对地质数据解译过程的干扰，以协方差数学理论为基础，提出界定空间数据分布方法-变异函数。着重阐述变异函数的求取过程，对新疆贝克滩水系沉积物化探数据处理，预测误差均值为0．1032、平均预测标准差为21．12、标准均方根预测误差为0．9841。预测值与样品实测值误差较小，界定的空间数据分布与实际矿床（点）分布吻合较好。     

福建雷潭金矿地质特征及找矿预测

雷潭金矿处于华南褶皱系闽东断拗带的周宁-华安断隆带中段,成矿作用与石英闪长岩和断裂构造密切相关;矿体受NE、NW、近EW向断裂带控制;围岩蚀变以硅化、绢英岩化、黄铁矿化最为重要,它们与金矿密切相关。文章较详细地阐述了区域成矿地质背景和矿床地质特征,总结了矿床的控矿因素,指出了进一步找矿方向。     

水源井同径套、筛管封井止水工艺

水源供水井，在封井止水下艺中，始终存在封井质量、水泥固结质量及井内钻具事故等风险，为此在对准格尔旗施工的10口水源供水井施工中，制作了单向逆止阀水泥封隔器，并与Ф340套、筛管用吊卡按一定顺序下入井内。该装置的使用，有效地提高了封井止水的质量。     

C02-CH4流体与金成矿作用：以阿尔泰山南缘和穆龙套金矿为例

造山型金矿的成矿作用与H20-CO2流体有着密切的联系。然而对阿尔泰山南缘和穆龙套金矿的流体包裹体研究表明，无水的CO2-CH4流体在中亚成矿域中一些金矿床中具有同样重要意义。阿尔泰山南缘萨热阔布金矿包裹体的Xch4达0.20～0.23，穆龙套金矿的XCH4为0.07～0.23。CH4扩大了流体不混溶的范围，有利于对Au的富集沉淀。CO2流体在Au成矿中的重要作用至少包括了三方面的意义，即：缓冲流体PH值范围、提高流体中的Au含量并使其维持与还原硫的络合作用进行迁移；扩大超临界流体的温度范围；增加流体不混溶的区域。CH4的加入扩大了流体不混溶的范围，有利于对Au的富集沉淀。     

对门源盆地"红层"形成时代的新认识

门源盆地位于青藏高原东北缘北祁连山腹地,为狭长的新生代走滑拉分山间宽谷盆地。其中充填一厚约407~960 m、干旱气候条件下的河湖相沉积"红层",长期以来各项研究工作均未能于其中采获任何生物化石。因此,尽管各家均认同其属"第三纪"无疑,但仍对其确切时代存在着较大的争论,而对其时代的确定有助于正确认识门源盆地形成时的构造背景,具有较为重要的意义。通过区域地层对比、"红层"形成气候条件与南侧西宁盆地及北邻酒泉—张掖盆地古气候环境所作的对比,深入探讨认为其时代属中中新世,并初步分析了门源盆地形成的新构造运动大陆动力学机制背景。     

On the influence of stratification and tidal forcing upon mixing in sill regions

A cross-sectional non-hydrostatic model with idealized topography was used to examine the processes influencing tidal mixing in the region of sills. Initial calculations with appropriate parameters for the sill at the entrance to Loch Etive showed that the model could reproduce the main features of the observed mixing in the region. In particular, the hydraulic jump in the sill region was reproduced, as was an intense mid-water jet that was observed to separate from the lee side of the sill. Shear instabilities associated with the jet appeared to be a source of mixing within the thermocline. In addition, internal lee waves were generated on the lee side of the sill, with the observed amplification because of trapping during the flood stage. Their magnitude and hence the mixing increased with increasing Froude number (F _r). In the case of vertically varying buoyancy frequency, its value near the sill top determined the F _r number, with its value below influencing internal waves magnitude at depth. At high F _r values particularly with strong currents, short waves and overturning occurred.     

对江南-雪峰带构造属性的讨论

讨论了江南-雪峰山“隆起带”的性质问题,它既不是造山带的“厚皮构造”,也不属于沉积盖层褶皱的“薄皮构造”,而是“过渡型的基底拆离式”的构造。其发生机制是印支—早燕山运动期间由SE向NW(同时派生由S向N、由E向W)的基底拆离和推覆,成为控制整个扬子板块海相中古生界盆地改造变形的动力来源和主导因素,也控制了海相油气的形成与聚集。     

连拱隧道施工对洞口仰坡影响的三维数值分析

以江西某高速公路一浅埋偏压连拱隧道为例,采用Marc有限元程序对其出口段进行了动态施工的三维数值模拟。从施工过程中的应力集中、塑性区的分布形态和发展规律、仰坡轴向地表位移的分布特征等方面,系统研究了偏压连拱隧道施工对强风化岩体洞口仰坡的影响作用机制。结果表明:在模拟施工过程中塑性区和应力集中区只出现在洞体附近,可能的仰坡失稳往往是隧道施工失稳的累进性响应;洞口仰坡的轴向水平位移前缘大、后缘小,垂直位移后缘大、前缘小;隧道上方和近山脊一侧仰坡位移比近山谷一侧大,仰坡失稳往往从隧道上方和埋深较大一侧开始。     

川西北平武地区南一里花岗闪长岩锆石U-Pb定年及其地质意义

川西北平武地区的碧口地块中出露较多的印支期岩浆侵入岩类,但缺乏精确的年代学资料.笔者运用阴极发光技术,对碧口地块西南缘的南一里化岗闪长岩中的锆石进行了细致的内部结构分析,并在此基础上利用LA-ICP-MS锆石U-Pb原位定年技术进行了同位素年龄测定.结果表明,花岗闪长岩中锆石Th/U比值较高,阴极发光图像显示锆石内部发育振荡环带,具岩浆成因特点;南一里花岗闪长岩的结晶年龄为223.1±2.6 Ma(MSWD=1.4),表明其形成时代为晚三叠世早期、南一里花岗闪长岩侵入时代晚于勉略构造带的主碰撞期,侵位于后碰撞环境,或者至少是由同碰撞到后碰撞的转折阶段.     

Cold Air Activities in July 2004 and Its Impact on Intense Rainfalls over Southwest China

The severe rainfall events in the mid-summer of July 2004 and the roles of cold air in the forma- tion of heavy precipitation are investigated by using daily observational precipitation data of China and NCEP/NCAR reanalysis.The results show that the severe rainfalls in Southwest China are closely related to the cold air activities from the mid-high latitudes,and the events take place under the cooperative effects of mid-high latitude circulation and low latitude synoptic regimes.It is the merging of a cold vortex over mid-latitudes with the northward landing typhoon and eastward Southwest China Vortex,as well as the abrupt transformation from a transversal trough into an upright one that causes three large alterations of mid-high atmospheric circulation respectively in the early and middle ten days of this month.Then,the amplitude of long waves soon magnifies,leading to the unusual intrusion of cold air to low-latitude areas in the mid-summer.Meanwhile,the warm and humid southwest summer monsoon is quite active.The strong interactions of cold air and summer monsoon over Southwest China result in the large-scale convective rain- falls on the southern side of cold air. With regard to the activities of cold air,it can influence rainfalls in three prominent ways.Firstly,the incursion of upper-level cold air is often accompanied by partial southerly upper-level jet.The ascending branch of the corresponding secondary circulation,which is on the left front side of the jet center,provides the favorite dynamic upward motion for the rainfalls.Secondly,the southward movement of cold air contributes to the establishment of atmospheric baroclinic structure,which would lead to baroclinic disturbances.The atmospheric disturbances associated with the intrusion of cold air can destroy the potential instability strat- ification,release the convective available potential energy(CAPE)and finally cause convective activities.In addition,the advection processes of dry and cold air at the upper level along with the advection of humid and warm air at the lower level are rather significant for the reestablishment of potential instability in the precipitation area,which is one of the crucial factors contributing to persistent rainfalls.