A stepwise method for determining the number of component distributions in a mixture

This paper considers the problem of estimatingm, the number of components in a finite mixture of distributions from a parametric family. A step-up procedure using the bootstrap method is proposed. Some properties of the procedure are illustrated with simulation studies. An example of the method, applied to orientation of beach clasts, is given.     

元岭金矿蚀变破碎带特征及其找矿意义

根据对元岭金矿三条蚀变破碎带一般地质特征、微量元素特征的对比研究，并借鉴邻近矿区蚀变破碎带的矿化特征，本文阐明了元岭蚀变破碎带矿化的有利构造部位，总结了蚀变破碎带特征与矿化强度之间的关系，指出蚀变破碎带的矿化蚀变元素为中低温组合，矿化蚀变愈强则参与元素的种类愈多、数量愈大。围岩性质对矿化蚀变有一定影响，围岩中的易迁移亲铜元素和亲硫铁族无素对矿化有利。据此，为进一步成矿预测、评价蚀变破碎带的含矿性提供依据。     

Slumping and shallow faulting related to the presence of salt on the Continental Slope and Rise off North Carolina

Seismic reflection profiles and long- and medium-range sidescan sonar were used to investigate a salt diapir complex and area of slope instability near the base of the Continental Slope off North Carolina. Within the area of investigation three diapirs are bounded on their upslope side by a scarp 60 m high and 50 km long. The slope above the scarp is characterized by a series of shallow rotational normal faults. The bottom below the scarp is furrowed by slide tracks, which were probably carved by large blocks that broke off the scarp face and slid downslope leaving rubble and scree lobes.Extensive slumping in this area appears to be a result of uplift and faulting associated with salt intrusion, which has fractured and oversteepened the slope leading to instability and failure. Sharply defined slide tracks suggest that slope failure above the breached diapir complex is a continuing process, in contrast to much of the surrounding slope area where few instability features were observed.     

Study on numerical simulation to water lowering in an open coal mine digging

In view of the situation of excavation of open coal mine for the underground water disaster,we should carry out simulation studies for the numerical value of the water lowering project and improve the accuracy and the level of the water lowering project.On the basis of the hydrological geological conditions of certain open mine digging,a more reasonable seepage numerical model was built according to MODFLOW.It was simulated in advance that the process of the confined water level descending with the time,and combining with the actual observations to test the correctness of the model.The calculation showed that the results coincided well with the results of actual measurement.Based on this,different water lowering numerical simulations were built for the open coal mine digging.It could be simulated and forecast that the changes of the groundwater level in drainage process within and outside the mine pit,and it was quantitatively assessed that the possible water lowering result of the opencast water drainage process,which provide an important basis for the actual water lowering project and the possible project disposal.     

八庙—青山金红石矿床化学成分与成矿关系

本矿床是我国金红石矿床重要的成因及工业类型，为具有特定化学成分的岩石在特定变质条件下形成的。本文通过对大量数据的处理，查明了化学成分与成矿的关系：高Ａｌ２Ｏ３、ＭｇＯ、Ｆｅ２Ｏ３＋ＦｅＯ、Ｋ２Ｏ、Ｐ２Ｏ５、Ｈ２Ｏ＋、ＭｎＯ，低ＳｉＯ２、ＣａＯ、Ｎａ２Ｏ、ＣＯ２、Ｓ等，利于钛富集；高ＴｉＯ２、ＭｇＯ、Ｐ２Ｏ５、Ｓ，低ＳｉＯ２、ＣａＯ、Ｋ２Ｏ、Ａｌ２Ｏ３、Ｆｅ２Ｏ３／ＦｅＯ，利于金红石形成；高Ｓｃ、Ｚｒ、Ｎｉ、Ｚｎ及Ｌａ／Ｙｂ，低Ｙ、Ｎｂ、Ｔｈ、Ｃｄ、Ｂａ、Ｂｅ、ΣＲＥＥ，利于金红石纯度提高。对研究矿床成因及寻找新的同类矿床等有重要意义     

广西芒场锡多金属矿田稳定同位素组成对矿床成因探讨

笔者曾对广西芒场锡多金属矿田的稳定同位素进行研究。本文根据硫、铅、氢、氧、碳等稳定同位素组成和锶的初始值提供的信息.探讨了矿床成因。并结合矿田矿床地质特征、控矿条件及有关统计参数,参考前人对矿床认识的基础上,修正提出了该矿田混合热液成矿模式,可供类似矿床研究和找矿的参考。     

金矿床的热液流体特征研究

通过对中国东部金成矿区域地质特征的分析,根据氢氧同位素及流体包裹体数据特征,表明中国东部金矿床成矿流体主要来自大气降水,其次为变质作用过程释放的水和岩浆分异水;成矿金属组分主要来自太古宙变质岩系。     

Simulation of double cold cores of the 35°N section in the Yellow Sea with a wave-tide-circulation coupled model

Based on the MASNUM wave-tide-circulation coupled numerical model, the temperature structure along 35°N in the Yellow Sea was simulated and compared with the observations. One of the notable features of the temperature structure along 35°N section is the double cold cores phenomena during spring and summer. The double cold cores refer to the two cold water centers located near 122°E and 125°E from the depth of 30m to bottom. The formation, maintenance and disappearance of the double cold cores are discussed. At least two reasons make the temperature in the center (near 123°E) of the section higher than that near the west and east shores in winter. One reason is that the water there is deeper than the west and east sides so its heat content is higher. The other is invasion of the warm water brought by the Yellow Sea Warm Current (YSWC) during winter. This temperature pattern of the lower layer (from 30m to bottom) is maintained through spring and summer when the upper layer (0 to 30m) is heated and strong thermocline is formed. Large zonal span of the 35°N section (about 600 km) makes the cold cores have more opportunity to survive. The double cold cores phenomena disappears in early autumn when the west cold core vanishes first with the dropping of the thermocline position. Supported by the National Basic Research Program of China (No. G1999043809) and the National Science Foundation of China (No. 49736190).     

广西难处理金矿固化焙烧氰化提金试验

通过对广西六梅金矿、明山金矿、金牙金矿含高砷高硫难浸金矿石进行固化焙烧—氰化提金的试验研究 ,获得了砷、硫固定率分别为 99.0 3%、97.0 4 % ,金浸出率 92 .35 %的较好指标 ,为这类难浸金矿的开发 ,展示了一种经济有效的途径     

Recharge and salinization in the Madrid Basin

The purpose of this work was to reinvestigate the existing hydrogeological conceptual model of the basin of Madrid, Spain. A cumulative chemical isotopic diagram which enabled the distinction between different groups of water as well as calculation of the mode of their blending was used for this investigation. It was found that the groups of discharge were lighter in their isotopic composition than that of recharge. The previous explanation of this fact, backed by carbon-14 dating, was the long residence time due to flow lines going down to depths of more than 1000 m. This flow model assumes homogenous conditions to these depths. This assumption can not be supported by evidence from deep wells. Thus a modified model is suggested which maintains homogenous conditions only to about 300 m and a deep confined aquifer below containing paleowater. The higher degree of depletion of this water has been explained by a colder climate on top of an altitude effect. Another interesting observation was the correlation between the isotopic composition of the rains, the month of the rain event and the composition of the recharge group groundwater. It could be seen that the winter rains resemble the groundwater composition, which shows that practically all the spring and summer rains were evapotranspirated.