广东钟丘洋次火山岩型铜矿床蚀变围岩的岩石化学特征

研究发现矿床的围岩蚀变主要有绢云母化、绿尼石化、黑云母化和硅化；蚀变矿物主要交代原岩中的长石。对蚀变和矿化岩石化学组成的定量研究表明：蚀变过程中ＳｉＯ２软活泼，可以被大量带出，也可以随硅化而大量带入；Ａｌ２Ｏ３和ＴｉＯ２相对稳定；ＴＦｅＯ和ＭｇＯ随绿泥石化和黑云母化而带入；长石被交代分解后释放出的ＣａＯ、Ｎａ２Ｏ和Ｋ２Ｏ被淋滤带出，另一部分Ｋ２Ｏ可进入新生矿物云母而保留下，释放出的Ａｌ２Ｏ３则形成     

华北陆块北缘区域矿床成矿谱系探讨

区域矿床成矿谱系是区域成矿规律研究的重要内容，指一个区域内地质构造环境演化过程中成矿作用的演化及时空结构。在华北陆块北缘划分出18个矿床成矿系列，讨论了它们的分布特点。华北陆块北缘区域矿床成矿谱系证实该区域经历四个主要的地壳演化及成矿时期，依次出现太古宙克拉通矿床、元古宙陆内-陆缘裂陷带矿床、古生代陆间增生褶皱系和陆内盖层矿床、中生代构造-岩浆活动带矿床，存在三个(3000～2500Ma，1900～1400Ma和180～140Ma)成矿作用高峰。成矿谱系指示了从太古宙进入元古宙时，海水和大气的氧化还原电位明显升高的过程。成矿谱系研究意义重大。     

1906年地震的远域余震

在１９０６年４月１８日加州旧金山大地震后的２４ｈ之内,俄勒冈州的佩斯利,亚利桑那州的莫尼克斯,加州的洛杉矶,布劳利都分别感到了地震。运用概率理论,结果表明同一天内在这些散布地区的每一个地点都发生有感地震是感见的。对１９０６年地震后２４ｈ内经受过地震的４个不同区域,确定了１８９７￣１９０６年９ａ间有感地震的发生率。我们用盒子里摸球概率问题的思想模拟了余震发生的似然性。结果表明,大地震余震区至少可延伸     

羊拉地区含矿夕卡岩流体包裹体特征及其成因意义带

羊拉铜矿化集中区共有４个夕卡岩体,按成因分为喷流－沉积和接触交代夕卡岩两大类,前者呈层状,是铜的主要赋矿围岩。层状夕卡岩中包裹体以类型多、组分复杂、均一温度（１００～６２０℃,一般大于３００℃）和盐度（８．３％～５５．０％ＮａＣｌ,一般≥２０％ＮａＣｌ）高且变化范围大、密度高（一般大于１．００ｇ／ｃｍ３）、捕获压力低（１０～２５ＭＰａ）为特征;交代夕卡岩则以包裹体类型简单、组分单一、均一温度（一般小于２５０℃）和盐度中—低（９．０％～２０．０％ＮａＣｌ）、密度低（一般小于１．００ｇ／ｃｍ３）且变化范围大、捕获压力高（１５０ＭＰａ）为特征。这些包裹体特征反映了两类夕卡岩的流体来源和演化机制是不同的,其中层状夕卡岩之流体为深部源与海水源的二元混合特征;交代夕卡岩为岩浆（体）源等组分自然冷却演化趋势。     

地球物理反演在矿产勘查中的应用

借助于计算机技术和数学优化理论所产生的新算法,对各种地球物理数据,选择特定的目标函数及物性参数进行迭代反演计算,最后恢复出能够反映实际成矿条件和地质特征的一维,二维及三维图像。     

斑岩铜金矿床地地球物理的数据的反演：米利根山的一个研究案例

在本文中,我们反演了米利根山斑岩铜金矿床的磁测、直流电阻率、激发极化（ＩＰ）和航空电磁数据,并将反演结果与已有的地质和矿化资料作综合解释。反演的区域内有一个侵入岩株,称之为ＭＢＸ岩体,区域周围遍布矿化带。在地模型被离散为许多单元,每个单元的物性恒定,构建与相应数据充分拟合的模型目标函数,通过使目标函数最小救是磁化率、电导率和极化率的分布。直接反演地面总场数据求取３－Ｄ磁化率模型。反演ＤＣ／ＩＰ数据     

A geographical analysis of multiethnic households in the United States

"Using the household-level data provided by the 5% PUMS [Public Use Microdata Sample] data from the 1990 Census, this paper reports the pattern of ethnic mixing at the household level in the U.S. and also describes the geographical patterns of different types of multiethnic households at both the state level and the PUMA [Public Use Microdata Area] level. Several of the largest metropolitan areas are also examined in greater detail. The strong dominance of whites in the process of ethnic mixing is clear, as is the expected dominance of blacks in southeastern U.S. and the dominance of Hispanics in the southwest at the state level. The PUMA-level analysis reveals local clusters of ethnic mixing that are not apparent at the state-level analysis."     

Chlorohydrocarbon pesticides in the Australian marine environment after banning in the period from the 1970s to 1980s

The chlorohydrocarbon pesticides (CHPs) (principally DDT, dieldrin, hexachlorocyclohexane (HCH) including lindane, chlordane, heptachlor and heptachlorepoxide, aldrin and hexachlorobenzene (HCB)) were used extensively in Australia during the 1960s and 1970s. These were progressively banned from the 1970s with DDT being totally banned in 1987. The levels in marine waters are believed to have progressively declined as indicated by water in the Brisbane River, which consistently fell from maximum concentrations of about 1.7 μg/l in 1972–1973 to not detectable in 1986–1987. In some urban areas sediment concentrations, up to 1700 μg/kg dry weight, were recorded in the early 1990s which may reflect the reworking and exposure of older more contaminated material. Fish exhibited consistent occurrence of DDT, HCH, dieldrin and HCB through the 1970s to the 1990s. Maximum concentrations of DDT and dieldrin occurred generally in the 1970s at 40.3 and 8.8 μg/g wet weight, and minimums in the 1990s at 2.4 and 0.041 μg/g wet weight respectively. Inputs of dialdrin from sewage and DDT from the broad environment, reflected by the calculated daily human uptake in the diet, were shown to decline with half-lives of 1.1–1.5 and about 3 years respectively. This evidence suggests that banning of the CHPs has greatly reduced the inputs into the marine environment with consequent reductions in concentrations in biota but there is the occasional occurrence of relatively high concentrations.     

华南花岗岩数据库--一个在Microsoft Access中编写的实用小数据库

在Microsoft Access 2000中编辑制作的华南花岗岩数据库,由24张表格和相应的表单、部分查询组成,可以方便地实现花岗岩数据的管理和GeoKit、Mapgis等软件对数据的引用处理;界面友好,操作简单,是花岗岩类数据收录、管理与综合分析的有用工具.