安徽沙溪含和不含铜(金)矿斑岩斜长石斑晶粒度统计及其岩浆结晶动力学和成矿意义     

徐文艺  傅斌  任启江  胡文暄  徐兆文 《岩石学报》1997,13(2)

通过对沙溪矿区含矿与不含矿斑岩中斜长石斑晶的粒度统计，计算出平均矿物粒度（Ｓ）、矿物分布密度（Ｄ）及矿物分布均匀度（Ｈ）；再根据晶体大小分布理论（ＣＳＤ），计算出斜长石的晶体生长速率、成核密度及成核速率等岩浆结晶动力学参数；发现含矿斑岩较无矿斑岩有高的成核密度和成核速率，而晶体生长速率则较低；指出成分相近的斑岩在岩浆结晶动力学特征上的极细差别可能造成岩体含矿性明显不同  相似文献   

Computer Modeling and Simulation of Geofluids： A General Review and Sample Description   总被引：3，自引：0，他引：3  

胡文XUAN  段振豪 《中国地球化学学报》1997,16(3):240-247

Thermodynamic properties of fluids are essential for the understanding of the geochemical behavior of various processes,The paper introduces the most updated computer modeling and simulation methods in the study of thermodynamics of geofluids,inclduing semiempirical models(such as equation of state)and molecular dynamics and Monte Carlo simulation.A well-established semi-empirical model can interpolate and extrapolate experimental data and yield much physicochemical information.Computer modeling may produce“experimental data“ yield much physicochemical information.Computer modeling may produce“experimental data“even under experimentally difficult conditions.They provide important methods for the study of geological fluid systems on the quantitative basis.  相似文献   

大运河北京段地表覆盖变化与景观格局演变     

谢文瑄  祝晓坤  张翼然  丁月  齐景怡 《北京测绘》2021,35(10):1262-1266

及时评估地表覆盖变化下景观格局演变特征,对于促进运河生态廊道建设和保障生态安全具有重要指导意义.本文以大运河北京段遗产监测区为例,分析了研究区2015—2020年的地表覆盖变化和景观格局动态特征.结果表明:(1)房屋建筑、构筑物、种植土地面积持续降低;林草覆盖、水域、铁路与道路面积持续增长.(2)人工堆掘地的破碎化程度不断增加、受人类活动影响越来越大;种植土地不断趋于成片化分布;裸露地表的分散程度急剧增加;水域景观格局稳定.(3)地表覆盖变化和景观格局演变特征与部分施行政策的预期效果基本一致.  相似文献   

云南安宁盆地上侏罗统含盐系中粘土矿物特征及其环境意义     

胡文瑄  朱井泉 《现代地质》1989,3(4):397

粘土矿物在安宁盆地含盐系中分布很广。其矿物学、结晶学及地球化学特征与成盐环境和成盐作用密切相关。石盐层序中主要含伊利石;硫酸盐层序中,除伊利石外尚有绿泥石及绿/蒙混层矿物。这是由于不同盐类沉积阶段,卤水浓度、成分及pH值不同所致。在结构上,粘土矿物以三八面体型组合为特征（伊利石除外）,反映了成盐盆地中相对富Mg²⁺的特点。此外,粘土矿物中硼和钾的含量远高于非盐系地层,因为这些元素在盐盆地中均得到了蒸发浓集。显然,粘土矿物的上述特征,很好地反映了蒸发环境的具体特点,具有良好的指相意义。  相似文献   

汶川8.0级地震前邻区远程动态触发小震活动异常特征研究          下载免费PDF全文

邹文轩  冯建刚 《地震工程学报》2023,(1):228-234

基于龙门山断裂带及邻区2000—2008年的小震目录资料,采用全球7级以上地震活动影响“叠加”的思路,系统分析震前邻区小震受远程动态触发的异常活动特征。结果表明：汶川8.0级地震前,龙门山断裂带及邻区的小震活动明显受全球7级地震活动的影响,震前1年左右龙门山断裂带及邻区小震活动受远震动态触发活动的异常特征显著。并采用随机检验方法和改变统计参数对计算结果的可靠性进行验证。该方法能够有效地突出震前发震断层上远程动态触发小震的异常活动特征,对区域强震危险性评估具有一定的参考意义。  相似文献   

叠合盆地储层油气包裹体GOI成因与应用探讨——以准噶尔盆地莫索湾地区为例   总被引：1，自引：0，他引：1  

谢小敏 曹剑胡文瑄  张义杰王绪龙  张越迁唐勇 《地质学报》2007,81(6):834-842

在准噶尔盆地莫索湾地区选取了5口具有不同油气显示级别的典型探井,通过对48块岩心样品作精细的储层油气包裹体GOI组成分析,尝试探讨了在复杂油气充注情况下,叠合盆地油气包裹体GOI组成的成因。结果表明,含油气流体的充注强度是主因。但由于油气成藏的多期复合、油气水界面的多期变迁,决定了我们在研究过程中不可以直接借鉴文献中提出的1%和5%等指标来判断油气水层,而是应该结合地质背景,首先仔细分析其成因,再深入讨论应用。文中利用GOI对莫索湾地区的油气运移进行了讨论,取得了良好效果,表明其在叠合盆地油气运移研究中具有一定应用前景。  相似文献   

胜利油区第三纪火山活动对油气生成的影响   总被引：2，自引：1，他引：1  

陆现彩  胡文宣  李佩珍  张方吼  陈致林 《地质论评》1999,45(7):594-598

本文介绍了胜利油区第三纪期间火山岩的类型和分布状况,在此基础上讨论了禹城凹陷和东营凹陷南坡火山活动对烃源岩生烃作用的影响,认为小规模的火山活动对生烃作用并没有明显的负面效应,但可能改造已形成的油藏。这一认识对含火山岩盆地的油气成藏评价有着重要意义。  相似文献   

闪锌矿交代黄铜矿形成的"黄铜矿病毒"结构     

胡文宣  张文兰  胡受奚  顾连兴 《矿物学报》2000,20(4):331-336

闪锌矿和黄铜矿交生形成的“黄铜矿病毒”结构通常被解释为由富铜热液交代闪锌矿形成。本文通过显微结构研究、电镜观察和电子探针微束分析,都证明了建德铜矿的“黄铜矿病毒”结构系闪锌矿交代黄铜矿形成。闪锌矿中“黄铜矿病毒”群仍保留着原始黄铜矿的轮廓,高倍电镜下具明显的交代残蚀结构,电子探针点、线、面成分分析都表明,无论闪锌矿中“黄铜矿病毒”含量多少,Ｆｅ：Ｃｕ原子比始终在１附近,与后期热液交代说不相符。总成分在相图上的投点还否定了固溶体成因的可能。  相似文献   

New evidence of microbe origin for ferromanganese nodules from the East Pacific deep sea floor   总被引：3，自引：0，他引：3  

HU Wenxuan  ZHOU Huaiyang  GU Lianxing  ZHANG Wenlan  LU Xiancai  FU Qi  PAN Jianming  ZHANG Haisheng 《中国科学D辑(英文版)》2000,43(2):187-192

Using a fluorescence microscope and EPMA, abundant microbe ”bodies“ and clear microbic fluorescent microstructure are determined in the ferromanganese nodules recently collected from the East Pacific deep sea floor. The microbic fluorescent structure shows a close relation to the formation of the ferromanganese nodules. According to their morphological features, the microbes are classified into two types: one is named clumpy microbe, which takes a bar-shaped manganese mineral as a pillar and grows like fasciculate coral, resulting in irregular cauliflorate nodules with rough surfaces; the other is called filamentous microbe, which grows in very thin arcuate and/or concentric circular laminae composed of a microbe layer and a metal (manganese and iron)-rich layer, leading to potato-shaped nodules with relatively smooth surfaces. It also can be seen that the two types of microbes are intergrown together, resulting in nodules complicated in compositions and shapes.  相似文献   

Impact of the Three Gorges Dam on reproduction of four major Chinese carps species in the middle reaches of the Changjiang River   总被引：1，自引：0，他引：1  

黎明政  段中华  高欣  曹文宣  刘焕章 《中国海洋湖沼学报》2016,34(5):885-893

Silver carp (Hypophthalmichthys molitrix), bighead carp (Aristichthys nobilis), grass carp (Ctenopharyngodon idella), and black carp (Mylopharyngodon piceus) are the four major Chinese carps and are commercially important aquaculture species in China. Reproduction of these carp has declined since the construction of the Three Gorges Dam (TGD) due to an altered water flow and thermal regime in the Changjiang (Yangtze) River. However, details of the changes in reproduction of the four species are not well understood. To assess the impact of the TGD on reproduction of the four carp, we investigated their eggs and larvae at Yidu City, which is 80 km below the TGD, during 2005–2012. We examined diff erences in larval abundance of the four species in the Jianli section (350 km downstream of the TGD) before (1997–2002) and after (2003–2012) construction of the TGD. Based on these observations, the first spawning date of the four species was delayed a mean of about 25 days after the dam was constructed. Mean egg abundance in the Yidu section of the river was 249 million and mean larval abundance was 464 million, which were significant decreases since the 1980s. Moreover, larval abundance in the Jianli section after the dam was constructed was significantly lower than that before construction (ANCOVA, P<0.05). The observed larval abundance accounted for only 24.66% of the predicted value in 2003 when the dam was first inundated. The present spawning grounds between the TGD and Yidu section of the river are very similar to those described in the 1980s, and some spawning grounds exist upstream of the TGD. Large free-flowing stretches upstream of the TGD and the creation of artificially flooded downstream reaches are needed to stimulate spawning and eff ectively conserve these four major Chinese carps species.  相似文献