电偶源频率电磁测深中比值视电阻率和阻抗相位的联合反演

本文论述了电偶源频率电磁测深中,利用比值视电阻率和相应阻抗相位进行联合反演的必要性和可能的应用前景及具体实施方法。理论模型和实际观测资料的反演试验表明这一联合反演是可行和有效的,且明显地优于视电阻率和阻抗相位的单参量反演。     

滇东黔西晚二叠世早期辫状河三角洲沉积体系及其聚煤特征

滇东黔西上二叠统底部发育着一套玄武岩质砾岩，本文针对云南富源和贵州盘县一带的底砾岩进行综合研究，认为这套砾岩为辫状河三角洲沉积，并进一步识别出砾质辫状河道、砂质辫状河道、砾质河口坝、砂质河口坝等沉积类型。文中还对该辫状河三角洲的沉积序列、发育背景以及与聚煤作用关系等问题做了一定分析，认为三角洲朵体之间地区以及在衰退的三角洲朵体之上成煤较好。     

矿石中金的在线固相萃取及缝管火焰原子吸收测定

介绍了将流动注射在线因相萃取预浓集与石英缝管火焰原子吸收相结合测定矿石中金的方法，用ＸＡＤ－８吸附树脂填充的微型柱（１００μｌ）在６ｍｌ／ｍｉｎ的流速下，从０．５ｍｏｌ／ＬＨＣｌ介质的试样溶液中浓集金氯络合物，再用乙醇洗脱，最后由火焰原子吸收检测，在采样频率为１０３样／ｈ的流速下灵敏度提高４７倍，分析精度为１．３％，检出限为１．０μｇ／Ｌ；在６５样／ｈ的采样频率下灵敏度提高９５倍，检出限可达０．７     

金川超镁铁质岩体矿物化学特征及矿物地质温度计、压力计研究

根据金川超镁铁质岩体主要造岩矿物和副矿物的共生组合关系及各种矿物的化学成分特点；选用５种较成熟、使用较方便的矿物地质温度计、压力计（主要是辉石温压计和角闪石压力计），对岩体形成的温、压条件进行了估算，其结果为：成岩温度为１０００～１３００℃（上限可到１４００～１５００℃），成岩压力约为５×１０￣８～１１×１０￣８ｐａ。金川超镁铁质岩体的主要岩石类型为尖晶石二辉橄榄岩，这一岩石类型在复杂体系相关系图中的稳定区域大致处于５×ｌ０￣８～１５×１０￣８ｐａ的范围，这与矿物温压计估算的成岩温压条件是一致的。     

淮北煤田早二叠世化石植物古生态

淮北煤田早二叠世化石植物丰富，其形成于炎热多雨的热带滨海三角洲沉积体系中。下三角洲平原是该区化石植物最宜生长的地方。早二叠世该区化石植物常形成四类植物群落：森林沼泽植物群落、沿岸水生植物群落、高地植物群落、三角洲平原真蕨及种子蕨混生植物群落（早期）、树蕨－大羽羊齿类雨林植物群落（晚期）。随着时间的推移，这四类植物群落的结构及面貌发生着不断的变化；其演替显示，早二叠世晚期该区气侯更加湿热，雨林气侯更为普遍。     

南极中山站固体潮观测分析

中国南极中山站位于南极拉斯曼丘陵地区（λ＝７６°２２′Ｅ，φ＝６９°２２′Ｓ），１９９１年３月至１９９３年２月，用ＬａｃｏｓｔｅＥＴ型重力仪，在这个地区进行了为期近两年的观测，取得了６００多天的有效资料，经调和分析和流变模型、海潮负荷改正后得到：δｏ１＝１．２２５３±０．００３１，Δφｏ１＝０．７３°±０．１４°；δｍ２＝１．０７８５±０．００４５，Δφｍ２＝－３．５５°±０．２９°从资料分析的精度来看，观测资料是比较好的；但由于海潮负荷改正缺少附近海域的资料，会对最终结果造成较大的影响     

A hypothesis for the seismogenesis of a double seismic zone

The seismogenesis of a double seismic zone, in particular the lower layer of a double seismic zone, has not been adequately explained in the literature. On the basis of seismic data and geothermal structures along three well-studied cross-sections in the Kuril-Kamchatka and Japan subduction zones, we investigate the temperature/pressure conditions associated with seismogenic structures of the double seismic zones. the corresponding T/P loci seem to suggest that earthquakes observed in the lower layer and in the lower part (below approximately 130 ± 20 km) of the top layer of a double seismic zone were caused by metastable phase transition-a mechanism similar to that responsible for deep-focus earthquakes only at lower temperature/pressure conditions. Under this hypothesis, the wedge-shaped configuration of a double seismic zone is interpreted to represent the loci of the kinetic boundary of the phase transition. According to theoretical/experimental studies and the constraints imposed by our observations, a likely candidate for such a phase transition is the metastable Al-rich enstatite decomposing into the assemblage of Al-poor enstatite plus garnet. Earthquakes in the upper part of the top layer were most probably due to conventional mechanisms such as dehydration of subducted materials and/or facies change from basalt to eclogite. That the top layer involves more than one seismogenic mechanism is also implied by the distinct behaviour of seismicity in the vicinity of 130 ± 20 km. Because the presence of deviatoric stress is critical to the reaction rate of a metastable phase transition, it is inferred that single seismic zones are also caused by the same mechanisms, except that the implicit layer of a supposed double seismic zone is missing, due to the insufficient amount of appropriate metastable minerals or to the lack of appropriate deviatoric stresses in the source region.