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1.
Wadi Qudaid is present about 120 km northeast of Jeddah, Saudi Arabia. The area includes Precambrian Arabian Shield, Tertiary sedimentary rocks, Tertiary basic volcanics (harrat), and finally Quaternary wadi deposits which represent the main aquifer of Wadi Qudaid area. The present study indicates the presence of pronounced geochemical variations in the groundwater characters along the main channel of Wadi Qudaid from the southwestern part (downstream) to the northeastern (upstream) part. The groundwater-bearing horizon is thicker in the downstream part than the upstream part. The study also revealed that the groundwater is of good quality in the upstream (NE) part than the downstream (SW) part. This is related to the addition and depletion of many elements during the groundwater trip from NE to SW and the addition and depletion of some elements. The downstream part is of high hardness and TDS when compared with the upstream part. Also, the downstream part is of high bisnous element (As, Co, Ni) than the upstream part. The groundwater of the southwestern part of Wadi Qudaid are free from the following elements: i.e., Al, Mn, Fe, Ni, Cu, Zn, and Pb. 相似文献
2.
鲜水河断裂带炉霍段具有极强的活动性,一旦发生地震,极有可能引发大量的滑坡等地质灾害。研究区发育1973年地震滑坡179个（通过现场调查识别出43个）,1973年以前地震滑坡62个。本文研究数据基于1973年179个及1973年以前62个地震滑坡,共计241个地震滑坡。利用统计分析方法研究了1973年179个地震滑坡分布与烈度及震中距的关系,分析了241个地震滑坡发育的滑动方向、地层岩性、地形坡度、相对高程及在断裂不同位置的分布特征。结果显示:（1）炉霍断裂地震滑坡规模以小型为主;（2）集中于Ⅸ～Ⅹ度烈度区内;（3）距震中0～5km及10～15km范围内密度最大;（4）滑动方向多与断裂斜交,交角介于35～75;（5）断裂南东段滑坡数量多于北西段,北东盘多于南西盘,北西段的北东盘滑坡个体面积较大;（6）滑坡多发育于T2-3r地层中;（7）主要分布于斜坡的中下部,相对高程主要介于30～60m;（8）发育坡度多介于30～45,具有规模越大,坡度越小的特点。 相似文献
3.
海底隧道围岩位移全曲线研究 总被引：1，自引：0，他引：1
限于施工现场条件,目前的隧道量测位移均是隧道实际位移的一部分,而隧道量测全位移则少有研究。以厦门海底隧道工程为依托,对隧道开挖各部拱顶下沉监测数据进行了回归分析,得出了海底隧道CRD1和CRD3部拱顶下沉未监测到位移的第1部分Y1。采用三维有限差分程序研究海底隧道各部位移全曲线,得出了掌子面到达研究断面前发生位移所占比例。根据实测资料得出海底隧道CRD1部和CRD3部拱顶下沉未监测到的位移第2部分Y0。将Y0和Y1与实测部分Ym相加,即得到隧道位移全曲线。 相似文献
4.
内蒙古正镶白旗碎斑熔岩岩石学特征及其岩相划分 总被引：4，自引：0，他引：4
白旗碎斑熔岩为不规则穹状体,可分为边缘玻质碎斑熔岩、过渡霏细碎斑熔岩、中心粒状碎斑熔岩和根部花岗斑岩四个岩性带。从玻质碎斑熔岩到粒状碎斑熔岩,斑晶碎裂度逐渐减弱,珠边结构在粒状碎斑熔岩中最发育,根部花岗斑岩与正常次火山岩相近。碎斑熔岩中钾长石有序度低,指示了岩石高温成因特征。白旌碎斑熔岩属太平洋岩系钙碱质系列,原始岩浆由来源于上地幔和下地壳熔体的混熔作用形成。 相似文献
5.
对CCSD主孔3 000 m岩心叶理、具断层擦痕的微断层及断层擦痕产状特征进行了统计分析, 并分析了脆、韧性剪切带的运动学特征, 研究表明(1) 榴辉岩类叶理产状明显较片麻岩类陡, 可能与其岩石能干性较强有关, 因而在挤压褶皱变形过程中表现出不同的变形行为.韧性变形主体表现为顺层剪切, 含断层擦痕的微断层最主要的一组产状与叶理面一致或接近一致, 部分伴随与之呈共轭关系的另一组微断层. (2) 脆、韧性变形以SEE-NWW向剪切为主, 部分为近SN向, 脆性、韧性变形域断层运动方向基本一致.但现在所保留下来的构造变形中韧性变形以SEE向NWW的逆冲型剪切为主, 部分为近SN向韧性剪切作用; 而脆性变形以NWW向SEE的正滑作用为主. (3) 主孔构造应力场初步可划分为4期, 现在所保留的主期构造为SEE-NWW向挤压构造应力场所致. 相似文献
6.
基于火山岩溢流相的高连续强振幅和火山通道相的低连续弱振幅2种截然相反的地震反射特征, 建立振幅-方差体地震属性分级-拾取-融合技术刻画火山岩时空展布的方法, 有效刻画火山岩的三维时空展布以及火山喷发期次.通过渤海湾盆地黄河口凹陷BZ34-9区带火山岩三维刻画和火山喷发期次研究, 取得以下认识: (1)研究区沙一二段火山岩零星分布, 主要发育在BZ34-9区带中部, 多为中心式喷发; 东营组火山岩广泛发育, 连片分布, 主要发育在BZ34-9区带南部缓坡带, 为中心式、裂隙-中心复合式喷发; (2)沙一二段东部火山先于西部火山喷发, 南部火山先于北部火山喷发; (3)东营组南部火山先于北部火山喷发, 且南部火山喷发期次多于北部, 北部火山多为短暂性喷发; (4)东营组火山较沙一二段活动强烈、喷发次数多、范围广. 相似文献
7.
为研究上部采用锚索框架结构、下部设置为桩板墙的组合式支挡结构的抗震性能,开展了大型振动台模型试验。通过输入不同强度大瑞波测试了组合结构的加速度响应和动土压力响应,同时将动土压力的实测值与规范法、Mononobe-Okabe法（M-O法）的计算值进行了对比研究。研究表明：（1）组合式支挡结构在不同强度地震动激励下水平向和竖直向加速度沿坡高有不同程度的放大,且输入的激振加速度幅值越大,放大效应越明显;（2）组合式支挡结构下部桩板墙墙后的动土压力强度随激振加速度幅值的增大而增大,沿着墙高呈现出上部小、下部大的分布特性;（3）动土压力强度的计算,在低烈度区使用规范法和M-O法是合理的,但在高烈度区需要对规范法和M-O法进行修正。 相似文献
8.
L. G. Bragina 《Stratigraphy and Geological Correlation》2018,26(1):62-79
In the sections from the western and eastern peaks of Ak Mountain, the Patellula selbukhraensis Zone (upper part of the lower Turonian), which is established for the first time in the southwestern Mountainous Crimea, is traced. The first data on the radiolarian distribution in the section of the eastern peak of Ak Mountain, which is stratotypical of the Phaseliforma turovi (middle Turonian, without the upper part) and Actinomma (?) belbekense (upper part of the middle Turonian–upper Turonian) zones, are presented. These zones are also traced in the parallel section of the western peak of Ak Mountain. 相似文献
9.
利用钻井、二维和三维地震资料,剖析了孟加拉湾若开海域晚新生代的构造变形特征,探讨了构造变形对油气的控制作用。区域深度地质剖面揭示,研究区南部仅发育底部滑脱层(深度10 km),而北部则发育底部滑脱层(深度12 km)和中部滑脱层(深度4 km);受滑脱层的控制,研究区南部仅发育一套构造层,而北部则发育变形不协调的上、下两套构造层;南部背斜的南北向延伸距离、波长及背斜间隔距离均明显大于北部。通过北部局部构造精细解析表明,研究区北部变形相对较复杂,上构造层主要发育近南北向的背斜和次级张扭性右旋走滑断层,二者形成时间分别为晚第四纪和晚第四纪末。若开海域晚新生代的构造变形对圈闭形成、油气运聚和保存条件具有重要的控制作用。指出研究区南部平缓褶皱带构造—岩性复合圈闭具备形成大油气田的条件,是下一步油气勘探的重要目标。 相似文献
10.
松辽盆地长岭断陷深层天然气资源潜力分析 总被引：3，自引：1，他引：2
松辽盆地长岭断陷深层具有丰富的天然气资源,应用含油气系统模拟方法重新进行了评价,深层天然气地质资源量为1.14×1012~1.71×1012m3,中值为1.42×1012m3。烃类气和CO2气具有分区分布的特点,其中断陷西部为CO2气富集区,断陷中部为CO2气和烃类气混合气区,断陷东部主要为烃类气富集区,局部为CO2气富集区。烃类气的分布主要受烃源岩分布的控制,高含CO2气的分布主要受火山岩和基底大断裂的控制。综合评价认为长岭断陷可划分5个勘探区带,Ⅰ类有利区带1个、Ⅱ类较有利区带3个、Ⅲ类非有利区带1个,其中Ⅰ类和Ⅱ类区带是下一步勘探部署的主要方向。 相似文献
11.
V. V. Sesha Sai 《Journal of the Geological Society of India》2009,74(4):509-514
Extensive field and petrological studies carried out in Kandra ophiolite complex (KOC) in the southern part of Nellore schist
belt (NSB) revealed the existence of sheeted dykes in Kandra- Kondakuru-Gollapalli section. The sheeted dykes occur in the
northern part of the complex and compositionally vary from medium-grained dolerites showing typical sub-ophitic texture to
diabase dykes that are extremely fine grained aphanitic to fine-grained cryptocrystalline parallel basic dykes (varying in
width from 4 cm to 1.25 m). These dykes show chilled margins on either side with the host dykes into which these are intruded.
Veins of oceanic plagiogranite (0.5 × 5 m) are noticed in a major sheeted dyke. Occurrence of oceanic plagiogranite as ovoid
/ semicircular patches of 6 cm diameter resembling “immiscible droplets” within basic dykes is also noticed. The southern
part of the complex is made of a major NW-SE trending cumulus gabbro that grades into olivine gabbronorite in its eastern
part. The southern gabbros represent the plutonic component and form the deeper part of the complex. In this paper an attempt
has been made to present the field, petrographic and mineral chemistry account of various lithounits that constitute the Kandra
ophiolite complex in a succinct manner. 相似文献
12.
Biopetrographic and chemical investigations carried out on the Lower Permian (Barakar Formation) coal seams encountered in two bore-holes (NCSM-3 and CMSA-111) from the Singrauli coalfield, Son Valley, reveal that they are, in general, rich in inertinite and mineral matter towards the eastern part. Whereas, towards the western part they are rich in vitrinite with subordinate amounts of inertinite and mineral matter. The Turra and Purewa Top seams, in the eastern part, consist chiefly of mixed and fusic coal types and the Turra and Purewa Merged seams, in the western part of the basin, are characterized dominantly by vitric and mixed coal types. The basin of deposition was shallower in its major part but deepened towards west. Consequently frequent oxic fluctuations are most common in the coal seams of the eastern part.The rank of these coal seams ranges between subbituminous-A to high-volatile bituminous-C stages. They show normal increase in rank with depth. The coal seams in the western part of the area are higher in rank than their counterparts in the east. The Purewa Bottom seam (NCSM-3) is petro-palynologically correlatable with the Turra seam (CMSA-111) of the western part.It has been presumed that Glossopteridophyta (a complex group of gymnospermous plants), arthrophytes and ferns were the vegetal source for the formation of Barakar coal seams. These plants during the Early Permian grew as thick forests along river valleys and as upland and subaquatic vegetation, and experienced a warm, humid and windy temperate climate. The coal seams were presumably deposited in backwater and lacustrine swamps in fluvial environment from hypoauchthonous source material.An attempt has been made to explain reasons for the high incidence of mineral matter and its apparent relationship with inertinite content in the coal seams while also discussing the depositional history. 相似文献
13.
北苏鲁荣成地区超高压变质带的形成与折返动力学 总被引：1，自引：0，他引：1
山东省荣成地区位于苏鲁高压-超高压变质带的东北部,以花岗质片麻岩、副片麻岩为主,夹有少量的榴辉岩、石榴辉石岩、麻粒岩、超基性岩、石英岩、大理岩和斜长角闪岩等,各类岩石的锆石中普遍含有柯石英包裹体,表明荣成地区岩石曾经历超高压变质作用过程。荣成地区区域构造格架表现为面理产状总体为NNE-SSW走向,向南转为由NE-SW走向,呈弧形展布,倾向SE或SSE,超高压变质岩石由一系列近平行的剪切岩片组成,岩片之间的分界线为一些韧性剪切带,是折返阶段角闪岩相-绿片岩相的产物。结合野外宏观变形现象、显微构造分析以及糜棱岩中石英的优选方位EBSD （electron backscatter diffraction,电子背散射技术）测量结果,可以判断北苏鲁荣成地区韧性剪切带主要形成于中、低温（550~350℃）条件,并具有由NW向SE“斜向正滑”的剪切指向。根据韧性剪切带中所含的榴辉岩透镜体的显微构造和绿辉石与金红石的优选方位的EBSD的研究,重塑超高压变质阶段的流变学特征：绿辉石和金红石都具有高温的滑移系组构模式。横穿苏鲁高压-超高压变质带的地震反射剖面揭示了苏鲁高压-超高压变质带呈厚10km以上的穹形板片,位于苏鲁高压-超高压变质板片下部的荣成及江苏刘山以韧性正断裂系列为主。Ar-Ar测年结果表明,发生这种伸展韧性剪切作用的时间在117~130Ma。位于板片上部的南苏鲁以韧性逆冲性断裂系列为主。基于以上各方面的研究,进一步验证了苏鲁超高压-超高压变质带折返动力学的挤出模式。 相似文献
14.
In the southern Korean Peninsula twelve quartzite strata occur in the Gyeonggi massif and Okcheon belt. Their geologic ages range from Precambrian to Upper Paleozoic. All quartzites in the Gyeonggi massif are of Precambrian in age and are characterized by high-grade metaquartzites; they are Seosan, Anyang, Yongmunsan and Uiam quartzites from west to east. Quartzite types occurring in the Okcheon belt are diverse from orthoquartzite to medium-grade metaquartzite. Orthoquartzites are all Paleozoic in age and are distributed mainly in the eastern Okcheon belt (Taebaeksan Basin) (Jangsan, Dongjeom and Jeongseon quartzites) with one in the central Okcheon belt (Mungyeong Quartzite). Low-grade metaquartzite is Hwasan quartzite in the western part and medium-grade metaquartzites are Daehyangsan and Geumsusan quatzites in the central part, and Yongamsan quartzite in the southwestern part of the Okcheon belt. Distribution of quartzite types in the southern Korean Peninsula is not related to the geologic age of quartzites. As a case study, quartzite characteristics were applied to a provenance study of quartzite clasts in the northwestern part of the Cretaceous Gyeongsang Basin. Quartzite clasts in the study area are interpreted to have been mostly derived from source quartzites in the Okcheon belt, which is consistent with the results of previous studies. 相似文献
15.
再论蛇绿岩中豆荚状铬铁矿的成因——质疑岩石/熔体反应成矿说 总被引：9，自引：0，他引：9
着重论述了蛇绿岩地幔橄榄岩中豆荚状铬铁矿的成因,并对现今盛行的岩石/熔体反应成矿说提出了质疑。世界含铬铁矿的地幔橄榄岩均显示上部偏基性、下部偏酸性的垂直熔融分带,与蛇绿岩堆晶岩中上部偏酸性、下部偏基性的岩浆分异垂直层序恰恰相反。豆荚状铬铁矿与熔融剖面上部的纯橄岩或纯橄岩-方辉辉橄岩杂岩带紧密伴生。豆荚状铬铁矿是原始地幔岩高度熔融再造的产物,高铬型铬铁矿与PPG型蛇绿岩伴生,形成于岛弧或弧前盆地环境;高铝型铬铁矿与PTG型蛇绿岩伴生,形成于扩张脊（MOR）或弧后盆地环境。玻安岩（boninite）与高铬型豆荚状铬铁矿无成因关系,铬铁矿（或富铬矿浆）的形成反而为boninite提供了其形成所需的残余地幔;高铝型铬铁矿不是地幔橄榄岩/拉斑玄武质熔体反应形成的,而是富铬矿浆与基性熔体发生再平衡的产物。豆荚状铬铁矿中超高压矿物包体的出现为其地幔深部成因提供了佐证,而boninite形成于浅部较低压的条件;豆荚状铬铁矿中富集强相容元素IPGE（Os、Ir、Ru）合金,boninite富集不相容元素PPGE (Pt、Pd)硫（砷）化物, 而亏损IPGE,显示其形成较晚。因此,boninite与铬铁矿无生因关系,两者均受岛弧（或弧前盆地）环境的制约而在空间上相伴产出。 相似文献
16.
湖盆无曝露缓坡带层序界面特征及成因——以松辽盆地他拉哈地区上白垩统为例 总被引：1，自引：0，他引：1
松辽盆地他拉哈地区在泉头组四段—嫩江组三段沉积时期为长期被湖水覆盖的缓坡带,层序地层学研究结果表明,层序界面在岩性—测井曲线特征上,有7种表现形式:(1)砂岩发育段内正反旋回的分界面;(2)砂岩发育段与含砂泥岩层（组）之间的正反旋回的分界面;(3)含砂泥岩层（组）与砂岩发育段之间的正反旋回的分界面;(4)钙质含量较高层段内正反旋回的分界面;(5)钙质含量较高的层（组）与含砂泥岩层（组）之间的正反旋回的分界面;(6)含砂泥岩层（组）与钙质含量较高的层（组）之间的正反旋回的分界面;(7)含砂泥岩层（组）内部的正反旋回的分界面。二级和三级层序界面以砂岩发育段内正反旋回的分界面为主,分别占92％和39％。四级层序,7种类型的界面出现的概率差别较小,表现形式具有真正的层序界面特征多样性。层序界面的特征取决于湖平面的升降、物源供应强度和蒸发作用的强度。 相似文献
17.
祁连山花岗岩分类及找矿方向初探 总被引：1，自引：1，他引：0
祁连山花岗岩出露广泛,主要是早古生代的,按照地球化学特征的不同可以分为3类:第1类为高Sr低Y型(埃达克岩),第2类为低Sr高Y型,第3类为A型花岗岩.高Sr低Y型花岗岩有O型(富钠)和C型的(富钾)2类,前者主要分布在北祁连的东段,后者主要分布在北祁连的西段.祁连山铜矿主要有两种类型:石居里型和黑石山型,前者与蛇绿岩有关,后者与斑岩(埃达克岩)有关.本区金矿主要分布在北祁连的西段,如寒山、鹰咀山金矿等,其成因与花岗岩的关系不清楚,但是,多数与埃达克岩有关(如车路沟、黑刺沟、贾公台金矿等).祁连山钨锡矿主要产出在祁连山西段,大多与低Sr高Y型花岗岩有关(如野牛滩岩体、小柳沟岩体、金佛寺岩体和柴达诺山岩体等).铅锌矿与低Sr高Y型花岗岩有关(如南坝),白银小铁山铅锌矿的流纹岩具A型花岗岩的特征,可能大多属于碰撞后阶段. 相似文献
18.
三峡库区奉节县三马山移民小区岩体的变形及其机制 总被引：8，自引：1，他引：8
三马山小区巴东组三段泥质灰岩由于岩溶溶蚀作用已全部发生了变形 ,根据变形程度的差别 ,可将变形区分为三个地带 ,即上部轻度溶蚀沉降地带 (Ⅰ ) ,中部溶蚀沉降地带 (Ⅱ )和下部沿江滑坡 (Ⅲ )。建筑设施主要分布在中部溶蚀沉降地带 ,应注意防水。下部沿江滑坡治理难度大 ,不适于移民迁建。 相似文献
19.
L. G. Bragina 《Stratigraphy and Geological Correlation》2016,24(2):141-166
A scheme of radiolarian zonal subdivision is proposed for the upper Albian–Santonian of the Tethyan regions of Eurasia. The upper Albian contains one zone: Crolanium triangulare; the Cenomanian contains three zones: Patellula spica (lower Cenomanian), Pseudoaulophacus lenticulatus (middle Cenomanian), and Triactoma parva (upper Cenomanian); the Turonian contains four zones: Acanthocircus tympanum (lower Turonian (with no upper part)), Patellula selbukhraensis (upper part of the lower Turonian), Phaseliforma turovi (middle Turonian (with no upper part)), and Actinomma (?) belbekense (upper part of the middle Turonian–upper Turonian); the Coniacian contains two zones: Alievium praegallowayi (lower part of the Coniacian) and Cyprodictyomitra longa (upper part of the Coniacian); the Santonian contains three zones: Theocampe urna (lower Santonian), Crucella robusta (middle Santonian–lower part of the upper(?) Santonian), and Afens perapediensis (upper part of the upper Santonian). The biostratigraphic subdivisions are correlated with biostrata in the schemes proposed previously for the Tethys and Pacific. A new species Patellula selbukhraensis Bragina sp. nov. is described. 相似文献
20.
阿尔金喀腊大湾铁矿田褶皱构造特征及找矿意义 总被引：2，自引：0，他引：2
通过对阿尔金山喀腊大湾铁矿田内构造的系统研究,确认矿田中东段为单斜层构造,南侧为较老的下部岩层,北侧为较新的上部岩层,岩层总体倾向北,在7910铁矿床局部出现倒转倾向南。铁矿田西段为陡枢纽褶皱构造,含铁层位(卓阿布拉克组第三岩性段第一岩性层,即下部玄武岩层)与其上覆的第二岩性层(大理岩层,标志层)、第三岩性层(上部玄武岩层)以及第四岩性段沉积岩系自7914铁矿床向西逐渐转向呈半圆形状弯曲(由EW向逐渐转向至SW向?NS向?SE向?SEE向)延伸,转折端及附近发育低级别"M"型及"S"型和"Z"型褶皱,构成直立陡倾伏背斜构造,轴面近直立东西走向,枢纽约71?向西陡倾。卓阿布拉克第四岩性段组成的外层也呈现同样的褶皱构造形态。褶皱南翼大部被后期中酸性侵入岩侵位吞噬,仅残留八八铁矿床一带一小部分,形成铁矿带和含矿层位呈横卧"L"状形态;该陡枢纽褶皱形成时间介于517~482 Ma之间。铁矿田东段7910铁矿床深部的铁矿体呈向形构造,不是较大规模的褶皱,而是规模有限的局部次级褶皱构造,在自东向西观察的剖面中其形态特征为"Z"形(因为岩层产状近直立,更像"N"形)。该次级褶皱的形成与剖面上南侧较老下部岩层的相对上升、北侧较新上部岩层的相对下降的层间相对运动以及铁矿南侧花岗质杂岩体侵位和隆升有关。铁矿床和铁矿层均受火山岩特定岩性和层位以及褶皱构造控制,依据次级褶皱的形态,含铁层位将继续向深部延伸,所以深部存在很大的铁矿找矿潜力。 相似文献