Preliminary study on the relationship between the crust-mantle structure and the formation of Laowangzhai superlarge gold deposit

The essential shallow-crust structural factors controlling the formation of Laowangzhai gold deposit include favorable tectonic and regional structural site, the release site of a great deal of the earth energy, favorable orecontrolling structure system, abundant and favorable source rocks for gold, ductile shearing, abundant minerogenetic materials source in extensive crust and mantle. And the essential deep-seated crust-mantle structure factors dominating the formation of the ore deposit include intracrustal low-velocity len, high-velocity bodies in the lower part of middle crust and lower crust, the steps on the slope of Moho, connecting site of mantle rises, the crust-mantle transition layer, upwelling of asthenosphere and the low-velocity plume. It is concluded that the fundamental reason that controls the formation of Laowangzhai superlarge gold deposit lies in the coupling between deep and shallow crust-mantle structure factors controlling the formation of the deposit and their coupling with the lithospheric evolution and geological event. Project supported by the National Climbing Plan Programme A-30.     

论胶西北河西金矿床成因及其动力学条件

胶东河西金矿床属于典型的蚀变岩型金矿床.金矿体赋存于玲珑黑云母花岗岩体内,并受北东向断裂构造带所控制.87Sr/86Sr的初始比值表明,玲珑黑云母花岗岩和郭家岭花岗闪长岩均为壳源深熔花岗岩.地质和同位素年代学资料表明,金成矿作用发生在早白垩世.据硫、氧同位素组成判断,河西金矿床的成矿作用可能与郭家岭花岗闪长岩的流体活动有关,其成矿温度以中温为主,成矿压力为(1*!200～1*!400)×105 Pa.河西金矿床的花岗岩、蚀变岩和矿石的稀土与微量元素分布模式明显相似,说明它们有着共同的成因,与壳熔花岗岩岩浆作用有关.     

和平沟滑坡风险性评价

本文从工程可靠性出发，对和平沟滑坡可能的失稳规模、方式及其危害性进行了深入分析。初步估算出该滑坡的危险性（风险）概率，否定了该滑坡治理的必要性，从而为国家节约了可观的建设资金。这一分析思路地其他工程有一定的借鉴意义。     

福建平和铜钟坑锡异常区地质特征及找矿远景浅析

平和铜钟坑一带1：10000土壤测量圈定了锡、钼、铜、铅、锌等元素异常及5个锡矿化蚀变带。铜钟坑锡异常分布于晚侏罗世南园组第二段火山碎屑岩中,异常范围大,浓度较高。裂隙带发育,矿化贮存于裂隙带中,成矿条件好。     

新疆东天山黑白山镁铁超镁铁岩地球化学、U-Pb年代学、Hf同位素特征及地质意义

黑白山镁铁超镁铁岩位于新疆中天山地块与觉罗塔格构造带的分界断裂——阿其克库都克大断裂南侧约4 km处.该岩体主要由阳起石化橄榄辉石岩、辉橄岩、辉石岩、蚀变细粒辉长岩组成,对岩体的主微量及稀土元素地球化学特征研究表明,岩体属铁质镁铁超镁铁岩,具低钾拉斑玄武质岩的分异特征;岩石具相对较低SiO2(43.90％～52.80％...     

机载激光雷达技术在地质灾害调查中的应用——以四川九寨沟7.0级地震为例

九寨沟7.0级地震诱发的地质灾害具有高位滑坡远程灾害的特点,传统地质灾害排查手段无法有效解决隐患的早期识别问题。本文采用机载激光雷达测量技术,快速获取九寨沟地震核心景区的激光点云数据。通过构建高精度数字高程模型(DEM)、数字正射影像图(DOM),建立三维地质灾害解译场景,利用数字地形分析、地形形态学分析和计算机图像识别等技术,综合开展九寨沟高位远程区域内隐蔽性强、随机性大的地质灾害隐患早期识别与分析。应用实践表明,机载激光雷达测量技术可以提高九寨沟地震灾区地质灾害隐患的早期识别能力,对进一步提高综合防灾减灾能力提供了一些可借鉴的思路。     

A building label placement method for 3D visualizations based on candidate label evaluation and selection

Adding building labels greatly improves the recognizability of buildings and the readability of three-dimensional (3D) city scenes. However, building label placement is much more complex in 3D scenes than in two-dimensional (2D) maps. The annotation effect is influenced by the attributes of the 3D label, building visibility, and the spatial relationship between the building and viewpoint. In this context, automatically generating building labels for 3D scenes during interactions requires highly complex computations. By contrast, evaluating candidate labels and then selecting the suitable label for each building can be effectively implemented. This paper introduces an approach for labeling buildings in 3D scenes based on evaluations of label candidates. The proposed method predefines a candidate label set for each building. These candidates are then evaluated in terms of their attributes and the relationship between the labels and viewpoint at runtime. The best candidate label, or a situational alternative for each building, is then placed in order of comprehensive label priority to avoid annotation conflicts. A series of experiments demonstrate that this method effectively enhances the correlation of labels and buildings, improves interactive efficiency, and realizes a viable global label layout.     

烷烃与海水界面张力的研究

于１９９１年３月－１９９２年６月间用滴体积法较系统地测定正已烷、正庚烷、正辛烷、异辛烷、正十二烷、正十六烷和煤油与海水在不同的温度（１６－４０℃）和盐度（１０－４０）范围内的界面张力，测定值的相对误差≤０．５％。对数据进行统计处理后，归纳出所研究烷烃－海水界面张力与温度和盐度的经验关系式，计算与实验值相对误差≤０．５％。     

四川省剑门关一带晚侏罗世沉积体系与古环境演化

晚侏罗世是龙门山前陆盆地演化的关键时期, 因而沉积体系与古环境演化研究具有重要意义.运用比较沉积学的方法, 通过对沉积序列与旋回的详细研究, 将研究区晚侏罗世沉积体系分为湖泊沉积体系、三角洲沉积体系、冲积扇沉积体系以及河流沉积体系; 基于沉积背景和演化的分析, 确定龙门山推覆构造带是研究区晚侏罗世古环境演化和沉积体系空间配置的控制因素; 依据古流和物源分析, 确定西北部的龙门山是本区主要物源区      

黄河三角洲饱和粉土液化特性及孔压模型试验研究

以黄河三角洲地区可液化场地粉土为研究对象,利用室内循环三轴试验结果,分析了动荷载作用下粉土的液化特性,通过模拟地震荷载作用下粉土的孔压响应,提出了原状粉土的孔压上升模型,并与粉质粘土和粉砂的液化特性和孔压模型进行了对比,并得出一些结论。