简单剪切—中国东南地区活动构造变动机制讨论   总被引：1，自引：0，他引：1  

王业新  彭承光 《华南地震》1994,14(4):1-8

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宝鸡─彭县、天水─宝轮地区活动断裂调查与地震危险性分析     

《四川地震》1996,(1)

经过对宝鸡─彭县、天水—宝轮地区进行详细的实地调查，对重点地段开展了槽探和剥土，采集年代样及构造岩薄片样，实测河流阶地位相剖面，同时还搜集了遥感图象解译等资料和研究区前人所作工作成果．在此基础上对该区进行了地质构造背景分析、断裂活动性评价、全新世断裂发展能力与位移量评估及区内六个重点区的地震危险性分析．研究区地处川、陕、甘三省交界区，以前很少系统、统一的开展地震地质工作，本次研究成果的整理发表，可供同行讨论和有关方面参考。  相似文献   

东南季风与贵州夏季干旱的诊断分析     

杨洋  俞佚名 《贵州气象》1992,16(1):3-7

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Sm—Nd and Zircon U—Pb Isotopic Constraints on the Age of Formation of the Precambrian Crust in Southeast China   总被引：1，自引：0，他引：1  

李献华  赵振华等 《中国地球化学学报》1992,11(2):111-120

Nd model ages(TDM) of the Pre-Mesozoic crustal rock samples from Southeast China range from 1.2 to 3.5Ga.Two age peaks of 1.4Ga and 1.8 Ga are observed in the histogram of TDM model ages.Available U-Pb zircon inheritance ages are concentrated around 1.2-1.4Ga,1.8Ga and 2.5Ga,respectively.The combined use of Sm-Nd and U-Pb zircon inheritance ages suggests that the formation of the Precambrian curst is of episodic character.The oldest crustal nucleus may have been formed during the Late Archean(2.5Ga or older?).A rapid production of the crust took place 1.8 Ga ago,consistent with the global crust formation event at 1.7-1.9Ga.Another important episode of the addition of juvenile crustal material from the mantle in Southeast China took place 1.2-1.4Ga ago,during which the pre-existing crust was strongly reworked and/or remelted.  相似文献   

陕、甘、川“金三角”地区砂金富集规律及成因类型     

盛刚 《地质与资源》1993,2(1):35-40

区内砂金矿大都分布在嘉陵江、涪江、白龙江和汉水的河床、河漫滩及Ⅰ级阶地内。在河道由开阔趋向狭窄或由狭窄突变为开阔地段、河流转弯的凸岸（堆积岸）弧形拐弯偏向上游地段、支沟与主河道文汇处靠下游等地段砂金相对富集。砂金主要富集在松散沉积层近底部的含泥砂砾层中。区内砂金矿的成因类型分为冲积型河床砂金矿、冲积型河漫滩砂金矿和冲积型阶地砂金矿三种。成矿时代为全新世早期。形成砂金矿必须具备两个条件：一是必须有砂金矿质来源，即必须有含金地质体的存在；二是有适宜的外营力作用、良好的地貌条件和有利的新构造运动，两者缺一不可。据此划出琵琶寺一河口和刘家坪-椒园里两个找矿远景区。  相似文献   

川甘陕三角成矿区金矿床成矿条件与区域分布特点     

罗梅 《矿床地质》1998,17(Z1):141-144

川甘陕三角成矿区具有独特的区域成矿背景,是我国重要的金成矿区之一。文中论述了区域初始金源层为扬子型地台基底岩系,金矿化主要赋存于三叠系浅变质复理石建造及火山岩或含火山碎屑的沉积建造。本区划分为5条金矿带,阐述了各金矿带基本特征。  相似文献   

冲锋在前 为了群众     

廖燕萍  黄兴旺  刘晓 《广西地质》2010,(9):52-53

今年入汛以来,桂东南地区屡遭强降雨的袭击。灾情发生后,当地基层国土人迅速投入到抗灾救灾第一线,不畏艰险,持续作战,打响了地灾点群众转移安置与应急抢险攻坚战。从本期起,本刊将陆续刊登他们在抢险救灾中的故事,平凡的点滴,用一个个特写镜头来展现他们的风采。  相似文献   

The Characteristics of Atmospheric Ice Nuclei Measured at Different Altitudes in the Huangshan Mountains in Southeast China简   总被引：3，自引：0，他引：3  

JIANG Hui  YIN Yan  YANG Lei  YANG Shaozhong  SU Hang  and CHEN Kui 《大气科学进展》2014,31(2):396-406

The concentration of ice nuclei （IN） and the relationship with aerosol particles were measured and analyzed using three 5-L mixing cloud chambers and a static diffusion cloud chamber at three altitudes in the Huangshan Mountains in Southeast China from May to September 2011.The results showed that the mean total number concentration of IN on the highest peak of the Huangshan Mountains at an activation temperature （Ta） of-20℃C was 16.6 L-1.When the supersaturation with respect to water （Sw） and with respect to ice （Si） were set to 5％,the average number concentrations of IN measured at an activation temperature of-20℃C by the static diffusion cloud chamber were 0.89 and 0.105 L-1,respectively.A comparison of the concentrations of IN at three different altitudes showed that the concentration of IN at the foot of the mountains was higher than at the peak.A further calculation of the correlation between IN and the concentrations of aerosol particles of different size ranges showed that the IN concentration was well correlated with the concentration of aerosol particles in the size range of 1.2-20 μtm.It was also found that the IN concentration varied with meteorological conditions,such as wind speed,with higher IN concentrations often observed on days with strong wind.An analysis of the backward trajectories of air masses showed that low IN concentrations were often related to air masses travelling along southwest pathways,while higher IN concentrations were usually related to those transported along northeast pathways.  相似文献   

渝东南地区龙马溪组页岩储层非均质性控制因素     

张鲁川  卢双舫  肖佃师 《地质论评》2023,69(Z1):246-248

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渝东南地区志留系龙马溪组页岩粘土矿物特征及其地质意义     

靳雅夕  蔡潇  袁艺  吴宇 《中国煤炭地质》2015,(2):21-25

渝东南地区地处上扬子前陆盆地川中隆起与黔中隆起之间,古生界发育多套厚层黑色页岩,其中下志留统龙马溪组黑色页岩分布极为广泛,为区内重要的烃源岩。根据探井岩心X-射线衍射测试结果,页岩中粘土矿物的组合类型为伊利石、有序的伊/蒙间层和绿泥石,其中伊利石相对含量最多,平均含量为54%,伊/蒙间层次之,平均含量为36%。在纵向上粘土矿物的组合类型没有变化,但随着埋深的增加,伊/蒙间层不断向伊利石进行成岩转化,绿泥石的含量逐渐降低,埋藏加热作用在成岩过程中起主导作用。粘土矿物的组合类型也反映了干旱的古气候和富含钾、镁、铁离子的古水介质特征,盐碱性水介质在成岩过程中起到了重要的控制作用。伊/蒙间层的间层比和镜质体反射率表明龙马溪组黑色页岩已达到晚成岩阶段,有机质演化属于过成熟期。  相似文献