巴彦浩特盆地东部上石炭统羊虎沟组孢粉组合

钻井资料证实，内蒙巴彦浩特盆地东部保存有较完整的石炭系，其中上石炭统羊虎沟组厚达４５９．６ｍ。经７２块岩样分析鉴定，共发现６２属１１９种孢粉，含６个新种。可概括为上下两个孢粉组合，上组合称Ｄｅｎｓｏｓｐｏｒｉｔｅｓｂｅｌｕｌｕｓ－Ｃｒａｓｓｉｓｐｏｒａｌａｔｉｇｒａｎｉｆｅｒ－Ｌｙｃｏｓｐｏｒａｇｒａｎｕｌａｔａ（简称ＢＬＧ）组合，下组合称Ｃｒａｓｉｓｐｏｒａｌａｔｉｇｒａｎｉｆｅｒ－Ｃａｍｐｔｏｒｉｌｅｔｅｓｒｅｔｉｃｕｌｏｆｏｒｍｉｓ－Ｖｅｓｔｉｓｐｏｒａｃｏｓｔａｔａ（简称ＬＲＣ）组合。地质时限为晚石炭世中期羊虎沟组（维斯法期Ａ—Ｃ）。     

河北平原京津以南深层地下水资源形成规律的研究

本文应用同位素技术，结合含水岩组水文地质结构特征的分析及地下水动力方法的年龄计算，揭示了河北平原京津以南地区深层地下水的形成规律，得出深 地下水资源补给能力及承受开采能力很低的结论，这为今后深 地下不资源的合理开发利用提供了重要依据。     

贵州三都早奥陶世同高组下燕高页岩段的生物标志化合物

本文着重报道了贵州三都早奥陶世同高组下燕高页岩段生物标志化合物特征，首次在采自该层位的样品中检出丰富的正烷烃、链状类异戊二烯烷烃、萜类化合物及甾类化合物。测试结果显示:正烷烃图谱呈双驼峰形，碳数分布为ｎＣ_１５～ｎＣ_３５，以ｎＣ_１８为主峰碳，ｎＣ_２９为次主峰碳，Ｃ－_２１/Ｃ＋_２２为０.７７～１.０２，ＯＥＰ为０.９４～１.０４；植烷占优势，Ｐｒ/Ｐｈ为０.４０～０.４６；藿烷碳数为Ｃ_２７～Ｃ_３５，以Ｃ_３０占优势，Ｃ_２７＋Ｃ_２９＜Ｃ＋_３１；仅见碳数分布为Ｃ_２０～Ｃ_２９的长链三环二萜烷，以Ｃ_２８为主峰碳；甾烷丰度顺序为Ｃ_２９甾烷＞Ｃ_２７甾烷＞Ｃ_２８甾烷，同时检出了孕甾烷和４－甲基甾烷。生物标志化合物显示出还原环境特点，且可能主要来自藻类。     

关于侵入岩体中金矿床成因研究若干问题的讨论

各时代、不同类型侵入岩中的金矿床是金矿的主要类型。关于金矿床与岩体的成因关系目前尚存在不同的看法，但传统的岩浆热液成因观点仍居统治地位，其原因往往在于不少研究者把岩液热液成因当成了固定模式应用于具体矿床的研究，而不是建立在综合研究的基础之上。本文结合近年来金矿的研究进展，强调侵入岩中金矿床的研究的研究要综合考虑成岩成矿的时代与时差，成矿流体和成矿物质的来源等各方面因素。金矿床定年的进展研究表明，矿     

不同岩溶动力系统的碳稳定同位素和地球化学特征及其意义——以我国几个典型岩溶地区为例

结合水化学的野外观测及室内计算,作者对桂林岩溶试验场、四川黄龙风景区和贵州乌江渡坝区3个岩溶动力系统的碳稳定同位素特征进行了分析,进而对系统的性质、系统中CO_2的来源、碳酸盐沉积过程中的碳同位素动力分馏、水化学和钙华的成因及热水钙华的~(14)C测年等地球化学问题作了探讨。结果表明,桂林岩溶试验场属于表层岩溶作用动力系统,其中的侵蚀动力主要来源于大气降水溶解土壤中的CO_2;四川黄龙风景区属于深部岩溶动力系统,侵蚀动力来自大气降水溶解幔源的CO_2;贵州乌江渡坝区岩溶系统,虽然属于表层岩溶动力系统,但其中一部分的同位素和水化学特征已受到人类活动的重大影响。     

用地质学的观点探讨洞庭湖的治理

洞庭湖是一断陷盆地，至今仍在继续下沉，因围湖筑垸使水面减小，泥砂堆积速度大于湖区下沉速度使湖面进一步缩小，致使洪水季节常泛滥成灾。按地质规律科学治理方案，一是退垸还湖，二是垸湖置换，才能从根本上消除洞庭湖的水灾。     

益阳市矿泉水的基本特征及形成机理探讨

益阳市矿泉水是一种弱酸、弱碱性、低矿化、富含偏硅酸的ＨＣＯ３－Ｃａ天然优质饮料矿泉水。它赋存于武陵期海底裂隙式喷溢形成的基性火山岩－细碧玄武岩的构造断裂和半风化层的风化裂隙之中。矿泉水水量起源于多途，化学成分形成于多因，是多因复成的产物。     

CHARACTERIZATION AND FORMATION MECHANISM OF THE CENTRAL UPLIFT OF THE QIANGTANG BASIN

The Qiangtang basin is located between Kekexili-Jingshajiang suture belt and Bangong-Lujiang suture belt, and is divided into the north part and south part by the central uplift that has no crop out of Mesozoic strata. When the Jinshajiang Ocean was closed, the subducting plate was subducted southward. In the central part of the Qiangtang basin, the cushioning effect of the asthenosphere resulted in the thermal doming of the mantle and subsequent large-scale anatexis. Mantle source materials and antectic materials were upwelled and extruded into the middle crust, leading to the thickening of the middle crust and the heating and weakening of the middle to upper crust, and resulting in the rapid deformation (detachment) and tectonic erosion, and in the isostatic uplifting and the formation of metamorphic core complex. The upwelling of anatectic materials would further enhance the buoyant repercussion, which would combine with the side stress due from extrusion in resulting in the formation of an extension     

鄂尔多斯盆地奥陶系海相碳酸盐岩生烃性能与中部长庆气田气源成因研究

用激光 -荧光显微镜等有机岩石学方法 ,挑选样品中有明显生、排烃现象的碳酸盐岩 ,再以测定的这类碳酸盐岩的有机碳含量为依据 ,确定本区高成熟碳酸盐气源岩残余有机碳的下限指标用 0 .13%～ 0 .14 %比较合理。根据碳酸盐岩储层孔隙中充填沥青和皮膜状残余沥青的分布和含量 ,论证了陕参 1井等奥陶系碳酸盐岩地层在地质历史中 ,存在若干油气有效储层。采用连续升温 ,步进取样的热模拟实验方法 ,揭示了本区煤与碳酸盐岩干酪根随热演化作用增强 ,烃类气体产物的干燥系数增大 ,δ1 3C1 、δ1 3C2 明显变重的规律 ,并根据样品实验结果推算 ,本区石炭系—二叠系煤最大生气阶段的δ1 3C1 应为 - 2 7‰～ - 2 8‰ ,碳酸盐岩最大生气阶段的δ1 3C1 应为- 31.7‰～ - 33‰。在气源成因判识中 ,根据主生气期阶段对天然气成藏储聚的贡献最大、甲烷碳同位素较重以及长庆气田风化壳气藏天然气δ1 3C1 重值区并不与石炭系—二叠系煤的镜质组反射率高值区匹配的现象等进行气源判识 ,认为长庆奥陶系风化壳气藏 ,具有下古生界海相碳酸盐岩气与上古生界石炭系—二叠系煤成气的混源成因     

Crater formation in soils by raindrop impact

The process of crater formation by the impact of water drops on soil, sand and various other target material was studied. Craters of various shapes and sizes were observed on different target materials or conditions, ranging from circumferential depression to completely hemispherical shape. Crater shape was dependent upon target material, its ?ow stress or shear strength and the presence and thickness of water on the surface. Between 5 and 22 per cent of impact energy was spent on cratering, but the relationship between crater volume and kinetic energy of a raindrop was curvilinear, indicating a lower ef?ciency of impact energy in removing target material as the energy increases. Impact impulse, on the other hand, showed a more linear relationship with crater volume, and the ratio of impulse over crater volume (I/V) remained constant for the entire range of drop sizes, impact velocities, and surface conditions used in this study. Surface shear strength, represented by the penetration depth of fall‐cone penetrometer, appeared to be a key factor involved in this process. An equation was developed which related crater volume to cone penetration depth and impact impulse. Crater volume, which appeared to be a better indicator of the total amount of material dislodged by a raindrop than splash amount, can thus be predicted using this equation. Copyright © 2004 John Wiley & Sons, Ltd.