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1.
牟平-即墨断裂带是胶东地区一条重要的区域性断裂带。通过研究断裂带两盘不同构造层的共轭节理系、纵弯褶皱以及野外断层滑动矢量,对古构造应力场进行反演。结果表明,牟平-即墨断裂带即墨段白垩纪时期构造应力场具有以伸展为主,并与急剧的挤压作用交替进行的燕山旋回构造演化特征。断裂带经历了莱阳期、青山期的张性活动、各构造期末的左行压扭活动,以及王氏期的张性活动,最终以右行压扭性活动结束白垩纪的演化历史。伸展构造与岩石圈的减薄作用关系密切,而挤压作用则与周边板块,尤其是东部太平洋板块的运动方向和方式有着密切关系。 相似文献
2.
借助GPS数据作为边界条件,运用有限元对陇县-宝鸡断裂带及其邻区进行位移场与应力场数值模拟,分析该地区现今地壳活动与构造应力场的分布特征。结果表明：1）陇县-宝鸡断裂带与岐山-马昭断裂南端渭河盆地的张应力较弱;2）鄂尔多斯地块西南缘与陇县-宝鸡断裂带接壤的SE向条带的节点应力性质、方向与陇县-宝鸡断裂带一致,显示出平行于断裂带SE走向的张性活动特征;3）最大主应力表明,陇西地块及秦岭构造区具有较高强度的张性应力;4）第二主应力表明,陇县-宝鸡断裂带南端与秦岭构造区接壤地区南侧的SEE向压性应力显著。 相似文献
3.
建立滇西北地区三维有限元地质模型,将2009~2016年GPS速度场数据作为数值模拟的位移边界条件,模拟获取该地区的构造应力场。结果表明,在楚雄至滇西北地区整体显示张性应力区;出现由“洱源鹤庆断裂-红河断裂-程海断裂”圈起的低值张性区,区域内部张性应力明显低于外部,这种张应力低值区尤其在区域四周断裂边界处,往往是地壳断裂活动的频发区;曲江断裂北端及元谋-绿汁江断裂南端出现张性应力集中区,是今后重点关注的断裂结点。 相似文献
4.
5.
利用场区各种类型水平形变网数据，求得红河断裂中、北段的区域应力场基本特征是：（１）北区为张性左旋型，（２）中区为压性右旋型，（３）南区为张性右旋型。场区区域应力场基本以张性为主，中区的压性右旋型恰好反映转换区应力场的局部特征。北区主应变积累和速率比南区大，最大处在剑川，而高敏感区在后山定两岭。基于水平形变和应变分析，获得了场区现今主要活动构造参数。利用地震前兆形变信息和震后效应进行了地震震例分析。并对３～５年内的潜在震源区进行了预估。 相似文献
6.
对比分析石油地震剖面和高分辨浅层地震剖面,依据震源机制解、地震精定位结果,给出太康MS4.7地震区深浅断裂的展布关系。结合区域构造演化认为,晚白垩世至古近纪,太康隆起发生NWW和NE-NNE向张剪性走滑断层活动,其产生的伸展拉张作用使隆起解体,形成目前凸凹相间的构造格局;新近纪以来,在太康隆起整体接受沉积的背景下,构造活动强度有所减弱,但凸凹相间的构造变形样式得以延续,表现为控制断陷的边界断层的持续活动,同时,一系列新近纪-第四纪铲式正断层的形成也表明深部走滑伸展作用的存在;太康MS4.7地震区深部震源构造表现为沿近NW和近NE走向的高角度断层,浅部构造表现为受近NW向铲式张性断层控制的凸凹相间的构造样式,这种深浅构造展布形式共同控制了太康MS4.7地震及其余震的发生。 相似文献
7.
钟继茂 《大地测量与地球动力学》2010,30(Z1)
为了解水口水库地区次级断裂的受力性质和活动特征,选用库区15个P波初动清晰可靠的地震震源机制解,采用力轴张量计算法推算了该区构造应力场的主轴方向,进而对断裂进行了应力分析。结果表明,湾口断裂受力性质为压性,其余为张性。根据库区布设的6个跨断层短水准场地观测资料,通过线性拟合方法,发现西瓜洲断裂为正断活动,其余为逆断活动。最后对两种方法得到的结果进行了比较。 相似文献
8.
鲁西地区早前寒武纪地质研究新进展 总被引：3，自引：1，他引：2
近年来在鲁西地区早前寒武纪结晶基底进行锆石SHRIMP测年结果显示,泰山岩群形成年龄大约在2770～2750Ma。新太古代发生3期岩浆侵入活动,每期岩浆侵入活动开始都有地幔岩浆侵入。早期构造岩浆活动主要形成2740～2700Ma的英云闪长质片麻岩、条带状英云闪长质片麻岩;中期构造岩浆活动主要形成2650～2600Ma的TTG质花岗岩;晚期构造岩浆活动最强烈,从地幔岩浆侵入到地壳深熔形成大规模的钾质花岗岩,导致大规模陆壳的形成。古元古代早期和中元古代,有少量岩浆沿太古代刚性陆壳裂解形成的张性裂隙侵入。对鲁西地区前寒武纪侵入岩按岩性＋时代进行了重新划分,变质深成侵入体（片麻岩）按时代＋gn,依据其不同成分和不同结构构造的第一个英文大写字母进行表示,探讨了鲁西地区早前寒武纪陆壳演化历史。 相似文献
9.
通过对1976年7月28日唐山大震前后地壳形变资料的分析,探讨了唐山地区现今构造活动特征和应力作用方式。结果表明,区内现今构造活动主要是沿袭新华夏构造体系的构造形迹而进行,但活动方式和力学性质有所改变。大震前后的形变资料一致表明,隆起和凹陷的长轴方向,以及活动最明显的断裂均以北北东向占优势。北北东向断裂的活动方式以顺时针扭动并兼有垂直升降为特征。震区及邻区的断层微量位移和短水准等测量结果也表明.北北东——北东向断裂多表现为压顺扭,北西向显张性兼反扭,近东西向断裂呈张性。实测断裂活动方式,大震构造裂缝带的特征及摸拟实验结果均表明本区构造应力场的主压应力方向为近东西向。唐山大震的发生,就是北北东向活动断裂带的发展受到北部强大的阴山东西构造带的阻挡形成相对的“闭锁”区,在近东西向压应力作用下,逐渐积累应变能,孕育成为大的震源体,直至地应力超过岩石的抵抗强度而突破“闭锁”,产生地震。 相似文献
10.
龙山金锑矿NNE向矿脉力学性质及找矿前景分析 总被引：1，自引：0，他引：1
区内NNE向组断裂构造与NWW向组含矿断裂多期次活动历史长,力学性质变换频繁,在印支晚期至燕山早期主成矿期同具扭张性特征,深切幅度大,倾向延深大于走向延长,长深比为2:3至1:10。同处于成矿时间一致的热液运移系统,NWW向组矿脉矿体向NWW侧伏,NNE向组矿脉矿体向SSW侧伏,自地表至深部,矿体厚度增大,金锑品位变富。NNE向构造与NNW向含矿断裂构造一样,具有较大的找矿潜力,从而拓宽了以往仅局限于NWW向含矿构造带找矿空间,为矿山今后找矿提供了思路。 相似文献
11.
孙建中 《地球科学与环境学报》1993,(Z2)
这里所指示的大气圈、水圈、岩石圈、生物圈以及人类的作用千变万化,从而对人类的生存造成巨大影响,构成了一个复杂的生态环境,讨论这些问题,对人类生存至关重要。 相似文献
12.
A study was conducted on Cu, Zn, Cd, Fe, Co and Ni levels in Saanich Inlet anoxic seawater. Data on the concentration of these
trace metals and H2S, and other oceanographic parameters were obtained in four cruises.
Equilibrium models are presented together with in situ data. The results strongly support the assumption that the solubilities
of Cu, Zn, Cd, Fe, Co and Ni are controlled by bisulfide and/or polysulfide complexes. The species of Cu, Zn, Cd and Ni are
shown to be Cu(S4)
2
3−
and Cu(Sn4S5)3−, Zn(HS)
2
0
and ZnHS
2
−
, Cd(HS)
2
0
and Ni(HS)
2
0
, respectively. The solid species controlling Fe2+ and Co2+ are respectively the pyrohotites FeS and CoS. The data illustrates that thermodynamic equilibrium has been established in
the H2S-controlled seawater of Saanich Inlet, and that equilibrium has not been established in the H2S−O2-coexisted seawater of Saanich Inlet. The lack of equilibrium in the H2S−O2-coexisted seawater is a result of the flushing or mixing of oxygenated seawater with anoxic water. The new species of trace
metals are still in the processes of reduction and precipitation.
Contribution No. 1428 from Institute of Oceanology, Academia Sinica 相似文献
13.
较详细地研究了无规取向、无吸收椭球体粒子的T－矩阵收敛问题。首先，简要概括了nmax的3种收敛方案和它们的基本特性。然后，应用1993年提出的数学收敛方法（M－方法）和1998年提出和物理收敛方法（P－方法）研究收敛问题。结果表明椭球粒子收敛精度对粒子的尺度参数，纵横比以及椭球体的种类（例如，长／扁椭球）有很强的依赖性。当粒子的尺度参数不太大时，甚至在极端纵横比的条件下，P－收敛方案优于M－收敛方案。 相似文献
14.
Vitaly A.Stepanov 《世界地质(英文版)》2004,7(2)
The Bamsk gold-ore deposit is located in the Amur region, the Far East of Russia. It is confined to the Early Cretaceous volcanic-plutonic uplift of central type, located in the Stanov folded-clumpy Pre-Cambrian system. The deposit is presented by a series of gold-bearing quartz and carbonate-quartz vein-stringer zones. They are confined to the super-intrusive zone of the Nevachansk subvolcanic intrusion of sienite-porphyric composition. The mineralization is being controlled by zone of fractures developed in the autochthone ofthe Bamsk fault. Quartz, carbonates and sericite prevail in the composition of ores. The quantity of ore minerals doesn't exceed 1%～5%. Pyrite, chalcopyrite, galena and native gold are widely spread. Sheelite, gold and silver tellurides, sulphobismuthites, acanthite, sphalerite and cinnabar are less developed. Four stages of mineralization have been distinguished. Gold-sulphide-sulphosalt ore with tellurides of gold and silver is productive for gold. The following set of elements is typomorphic for the ores of the deposit: Au, Ag, Cu, Bi,Mo, Pb and Sb (W1, Pb1, Mo) -Cu- (Ag, Bi, Sb, Mn, W1, Pb2) form the vertical series of zoning. Rocks, enclosing the mineralization are exposed to the processes of listvenitization-beresitization. The processes of gumbeization and argillization are less manifested. The age of the gold mineralization, determined by Rb-Sr method on ore-accompanying minerals, is 130.6 Ma. 相似文献
15.
Dynamics and Relationships of Ca,Mg,Fe in Litter,Soil Fauna and Soil in Pinus koraiensis-Broadleaf Mixed Forest 总被引：1，自引：0，他引：1
The Liangshui Natural Reserve in Heilongjiang Province of China was selected as the study area.The authors collected the samples of forest litter (Tilia amurensis,Fraxinus mandshurica,Pinus koraiensis,Acer mono,Betula costata,and mixed litter),soil in humus horizon (0-5cm) and soil horizon (5-20cm),and soil macrofauna (Oligochaeta,Geophiloporpha and Juliformia) from 2001 to 2002.The role of soil macrofauna in the material cycle was analyzed through comparing the macro-element contents among various parts of the subsystems and using enrichment index (EI).The results indicate that dynamic changes of various litters are very complicated.The contents of Fe in each kind of litter increase firstly,and then decrease in the study period.The changes of macro-element contents are greater in the broad-leaf litter than in the coniferous litter,and the mixed litter is in the middle level,but the differences among them are not significant.The contents of Mg and Fe in humus are higher than those in soil,but the contents of Ca in soil are higher than that in humus.The dynamic changes of macro-element contents in soil and soil fauna are not consistent with those in litter.The diplopod presented obvious enrichment of Ca and Mg (EI>1),but it does not significantly enrich Fe.Earthworm has a stronger enrichment ability of Fe than diplopod and scolopendra,but EI<1.Soil fauna can make great influences on the material cycle of the subsystems. 相似文献
16.
The contents of nearly forty-elements in surface sediments in Jiaozhou Bay were determined using a Neutron Activation Analysis Technique(Grancini,et al.,1976;Li Peiquan et al.,1985,1986;Li Xiuxia etal.,1986).This paper's detailed discussion on only nine elements(Fe,Mn,Co,Cr,Sc,As,Sb,Zn andV)includes their distributions,concentrations,correlationships,material sources,background,etc.Based on Zavaristski's classification method,Fe,Mn,Co Cr and V belong to the second group;As and Sb to theeighth groups:Sc and Zn to the third and sixth groups.It was found that their notably good correla-tionship is mainly due to the similarity of their ionic structures and that their variation is controlled by theFe content(except Mn).The source of sediments is mainly terristrial material,and the composition ofsediment is similar to that of shale and shale+clay.The contents for a large number of ele-ments are within the scope of the background level,but there still is pollution of Zn and Cr,at least in a few stations. 相似文献
17.
S. S. Samant Man Singh Manohar Lal Shreekar Pant 《山地科学学报》2007,4(3):259-274
In the Indian Himalayan Region predominantly rural in character, livestock is one of the main sources of livelihood and integral part of the economy. Livestock mostly rely on fodder from wild. The diversity, distribution, utilization pattern, nativity, endemism, rarity, seasonality of availability, nutritive values, perceived economic values and pressure use index of livestock have not been studied. The present study attempts to enumerate 150 species of fodder representing trees (51 spp.), shrubs (54 spp.) and herbs (45 spp.). Poaceae (19 spp.) and Fabaceae (13 spp.) amongst families and Salix (6 spp.), Ficus, Clematis, and Desmodium (5 spp., each) amongst genera are rich in species. Maximum species were found in the 1801 ~ 2600 m zone, and the remaining two zones showed relatively low diversity. Out of the 150 species, 109 are used in summer, 5 winter and 36 throughout year. During rainy season, mostly grasses are used as fodder. Only 83 species are native to the Himalayan region, one species, Strobilanthus atropuroureus is endemic and 35 species are near endemic. The nutritive values of the fodder species were reviewed, and economic values and status of the species were also assessed. The pressure use index of the species was calculated on the basis of cumulative values of the utilization pattern, altitudinal distribution, availability, status, nativity and endemism. Amongst the species, Grewia oppositifoilia, Morus serrata, Indigofera heterantha, Quercus leucotrichphora, Ulmus villosa, U. wallichiana and Aesculus indica showed highest PUI indicating high preference and pressure. Season wise prioritization of the species for different altitudinal zones has been done. Appropriate strategy and action plan have been suggested for the conservation and management of fodder species. 相似文献
18.
Dynamics and relationships of Ca, Mg, Fe in litter, soil fauna and soil in Pinus koraiensis-broadleaf mixed forest 总被引：1，自引：0，他引：1
The Liangshui Natural Reserve in Heilongjiang Province of China was selected as the study area. The authors collected the samples of forest litter （Tilia amurensis, Fraxinus mandshurica, Pinus koraiensis, Acer mono, Betula costata, and mixed litter）, soil in humus horizon （0--5cm） and soil horizon （5-20cm）, and soil macrofauna （Oligochaeta, Geophiloporpha and Juliformia） from 2001 to 2002. The role of soil macrofauna in the material cycle was analyzed through comparing the macro-element contents among various parts of the subsystems and using enrichment index （El）. The results indicate that dynamic changes of various litters are very complicated. The contents of Fe in each kind of litter increase firstly, and then decrease in the study period. The changes of macro-element contents are greater in the broad-leaf litter than in the coniferous litter, and the mixed litter is in the middle level, but the differences among them are not significant. The contents of Mg and Fe in humus are higher than those in soil, but the contents of Ca in soil are higher than that in humus. The dynamic changes of macro-element contents in soil and soil fauna are not consistent with those in litter. The diplopod presented obvious enrichment of Ca and Mg （E1〉1）, but it does not significantly enrich Fe. Earthworm has a stronger enrichment ability of Fe than diplopod and scolopendra, but E1〈1. Soil fauna can make great influences on the material cycle of the subsystems. 相似文献
19.
Zhang Chuanling 《地球科学与环境学报》1997,(1)
文中详细地论述了新疆阿尔泰哈巴河一带古生代火山岩的地质、岩石化学、稀土元素地球化学特征。将其分为三个类型，认为火山岩是在陆缘裂陷槽的区域构造背景下发生和演化的。对各类型火山岩岩浆来源，上升模式也做了初步讨论。 相似文献
20.
Donald A. FRIEND 《山地科学学报》2005,2(3):181-192
Introduction Studies on microfabric and macrofabric are common, spanning from the sedimentology of fine grained rock to fabric analyses of glacial and periglacial deposits. These studies generally focus on one deposit that is all the same age. This study is unique in that identical measures of fabric were taken on a series of like deposits on the steep slopes (~25° to ~35°) of rhyolite domes in eastern California (Figures 1 and 2) whose maximum possible age stretches over a one-million-year… 相似文献