黑龙江省砂金的成色特征

对黑龙江省８４个砂金样品的成色进行测定了并与７个岩金样品对比，结果表明，砂金成色变化较大，与原生岩金来源有明显继承性关系，由于受后生风化作用影响，砂金普遍具有金壳结构。砂金成色与其粒度及在河谷中产出位置呈规律性变化，由成色计算出来的溶蚀系数，可作为指导寻找原生金矿的依据之一。     

脉金矿床控矿条件及源区性质刍议

目前对脉金矿床，特别是大型金矿床的形成研究已取得重要进展，它在时间和空间上具有明显的一致性表明：大型脉金矿床的形成与特定的地质背景有密切关系，矿源具有深源性质，而与探矿岩系金的丰度值基本无关。     

冀西北东坪金矿床成矿流体的来源研究

冀西北东坪金矿床成矿流体的来源研究＊莫测辉王秀璋程景平梁华英（华南农业大学资源环境学院，广州５１０６４２）（中国科学院广州地球化学研究所，广州５１０６４０）关键词金矿床成矿流体来源岩浆热液大气降水热液侵入岩体中的金矿床乃至岩体接触带或附近地层中的金矿...     

浙江省安吉县山区竹类资源综合利用

安吉县竹类资源优势突出 ,使其综合利用已初具规模 .竹业工业已成为新兴工业门类 .竹业经济已是地方经济的一个台柱子 .但竹业结构不合理 ,竹制品雷同性大 ,增值率低 ,资源供需矛盾突出等日益明显 .对今后竹类资源综合利用和持续发展 ,提出了主要思路     

The Zihuatanejo, Mexico, earthquake of 1994 December 10 (M= 6.6): source characteristics and tectonic implications

An analysis of the Zihuatanejo, Mexico, earthquake of 1994 December 10 ( M = 6.6), based on teleseismic and near-source data, shows that it was a normal-faulting, intermediate-depth ( H = 50 ± 5 km) event. It was located about 30 km inland, within the subducted Cocos plate. The preferred fault plane has an azimuth of 130°, a dip of 79° and a rake of −86°. The rupture consisted of two subevents which were separated in time by about 2 s, with the second subevent occurring downdip of the first. The measured stress drop was relatively high, requiring a Δσ of about a kilobar to explain the high-frequency level of the near-source spectra. A rough estimate of the thickness of the seismogenic part of the oceanic lithosphere below Zihuatanejo, based on the depth and the rupture extent of this event, is 40 km.
This event and the Oaxaca earthquake of 1931 January 15 ( M = 7.8) are the two significant normal-faulting, intermediate-depth shocks whose epicentres are closest to the coast. Both of these earthquakes were preceded by several large to great shallow, low-angle thrust earthquakes, occurring updip. The observations in other subduction zones show just the opposite: normal-faulting events precede, not succeed, updip, thrust shocks. Indeed, the thrust events, soon after their occurrence, are expected to cause compression in the slab, thus inhibiting the occurrence of normal-faulting events. To explain the occurrence of the Zihuatanejo earthquake, we note that the Cocos plate, after an initial shallow-angle subduction, unbends and becomes subhorizontal. In the region of the unbending, the bottom of the slab is in horizontal extension. We speculate that the large updip seismic slip during shallow, low-angle thrust events increases the buckling of the slab, resulting in an incremental tensional stress at the bottom of the slab and causing normal-faulting earthquakes. This explanation may also hold for the 1931 Oaxaca event.     

Source investigation of a small event using empirical Green's functions and simulated annealing

We propose a two-step inversion of three-component seismograms that (1) recovers the far-field source time function at each station and (2) estimates the distribution of co-seismic slip on the fault plane for small earthquakes (magnitude 3 to 4). The empirical Green's function (EGF) method consists of finding a small earthquake located near the one we wish to study and then performing a deconvolution to remove the path, site, and instrumental effects from the main-event signal.
The deconvolution between the two earthquakes is an unstable procedure: we have therefore developed a simulated annealing technique to recover a stable and positive source time function (STF) in the time domain at each station with an estimation of uncertainties. Given a good azimuthal coverage, we can obtain information on the directivity effect as well as on the rupture process. We propose an inversion method by simulated annealing using the STF to recover the distribution of slip on the fault plane with a constant rupture-velocity model. This method permits estimation of physical quantities on the fault plane, as well as possible identification of the real fault plane.
We apply this two-step procedure for an event of magnitude 3 recorded in the Gulf of Corinth in August 1991. A nearby event of magnitude 2 provides us with empirical Green's functions for each station. We estimate an active fault area of 0.02 to 0.15 km² and deduce a stress-drop value of 1 to 30 bar and an average slip of 0.1 to 1.6 cm. The selected fault of the main event is in good agreement with the existence of a detachment surface inferred from the tectonics of this half-graben.     

滇、川、黔成矿区的铅锌矿源层（岩）

滇、川、黔铅锌成矿区的矿源层（岩）及其成矿作用，具多矿源层（岩）、多容矿层和多遮挡层共存的特点。矿源层（岩）改造成矿分海西晚期改造生成贫铅锌矿床和燕山期改造生成铅锌富矿床两个旋回，改造成矿的３个主因是：多条继承、发展了基底构造的深一道断层系统，峨眉山玄武岩浆上涌产生的高热能、喷气、矿质和广泛、多中心循环的热卤水，铅锌矿床为沉积─改造─后成成矿。     

吐哈盆地及二连盆地侏罗系煤微类脂组分的共聚焦激光扫描显微镜（CLSM）研究及油气意义

吐哈盆地产出有比较丰富的侏罗系煤成油气田，本文用共聚焦激光扫描显微镜和热解分析等手段研究了煤中类脂组及微类脂组的类型、含量、分布与煤成烃性能和产出的关系。观察分析结果表明：在一般煤岩组分观测中主要含煤的西山窑组和八道湾组煤层类脂组含量很少超过１０％，但是一些煤样的热解分析中Ｓ＿１可高达５－２３ｍｇ／ｇ，Ｓ＿２可达１５０─２００ｍｇ／ｇ，ＨＩ（烃／有机碳）可高达１５０─３５０ｍｇ／ｇ生烃、含烃性能较好。进一步用共聚焦激光显微镜观测结果表明：本区一些薄层状、条带状煤层的基质镜质体和叶结构镜质体中微类脂组含量比较丰富，微区定量统计含量在３％─１８％左右。这种富含微类脂组的基质镜质体和结构镜质体在煤成油气中有重要意义，而且由于多数微类脂体在煤中常成点线状、似层状、充填状、网络状分布，可能有利于煤成油气的运移和聚集。     

沉积盆地流体—岩石相互作用研究的现状

沉积盆地流体－岩石相互作用研究主要是通过实验地球化学和岩石学，地球化学模拟方法开展的，综述了这一领域的研究现状，主要包括有机酸来源和分布及期 对矿物稳定性的影响，地层水成因与演化、烃类与岩石间的氧化还原反应、以及储层润湿性的变化等，并展望了其 发展趋势。     

西菲律宾海沉积物稀土元素地球化学

对取自西菲律宾海区3个沉积物柱样（WP1、WP2和WP40）的32个样品的稀土元素（REE）地球化学行为进行了系统的研究。区内沉积物表现出以下特征：①稀土元素含量及总量（ZREE）较低，WP1、WP2和WP40孔的ΣREE依次为72．91×10－6，54．15×10－6和54．18×10－6，REE在粘土粒级中得到了较大富集；②REE球粒陨石标准化的分布模式曲线表现为负斜率，富集轻稀土，WP1、WP2和WP40孔LREE／HREE比值平均值为37．36，26．33和17．16，页岩标准化曲线大致呈水平；③与球粒陨石和页岩相比，Ce都表现为强烈的亏损；以球粒陨石为标准，WP40孔表现为弱的Eu正异常，其他两孔表现为弱的Eu负异常；以页岩为标准，皆显示Eu正异常；④ΣREE纵向变化曲线与CaCO3旋回曲线有良好的对应关系。上述特征表明：①沉积物的来源复杂，有陆源、火山源、生物源和自生源，在所研究的三个孔中，WP1孔含有较多的陆源物质，WP2和WP40含有较多的火山物质；②被粘土吸附是本区REE重要的存在形式；③沉积物形成环境为氧化条件；④据ΣREE的纵向变化曲线与CaCO3旋回曲线，将本区沉积物自下而上划分为末次冰期亚间冰期沉积、冰期最盛期沉积和全新世沉积。