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971.
马家疃金矿区位于胶东著名的台前-陡崖金成矿带上盘,笏山、西陡崖金矿床东邻。笏山、西陡崖矿区已累计提交金资源储量30余吨,其主矿体倾向深部,向马家疃矿区延伸稳定。区内地层出露单一,岩浆岩发育,矿体产出于玲珑花岗岩体中,严格受NNE向压扭性断裂控制,矿石类型主要为黄铁绢英岩化碎裂岩。通过对矿床地质特征及矿床成因的分析,其深部有较大的找矿前景,在总结成矿规律的基础上,围绕有利构造部位进一步勘查,有望实现栖霞地区找矿的再次突破。  相似文献   
972.
利用钻探岩心识别断裂形变、挤压扭曲、岩心破碎带等断层标志, 有利于勘探区构造地质条件的分析。通过对钻孔岩心岩性特征、地层厚度、煤层间距等方面的研究,发现ZK13钻孔在C51与C52煤层之间地层出现明显的揉皱与破碎现象、地层厚度与煤层间距增大,同时测井曲线显示地层有重复现象,推测在C51与C52煤层之间发育一逆断层;C54与C58煤层之间地层也比较破碎、地层厚度与煤层间距减小,伽玛伽玛曲线幅值增大,推测在C54与C58煤层之间发育一正断层。  相似文献   
973.
蒙阴盆地是在库拉板块向亚洲大陆下俯冲,中国东部隆升伸展板块裂解阶段发育起来的。在中生代,盆地的成生演化经历了侏罗纪拗陷盆地发育阶段和早白垩世拗陷—裂陷阶段。在相应沉积演化过程中,形成侏罗纪湖相红色碎屑岩建造,早白垩世早期滨浅湖—半深湖相灰绿色细粒陆屑岩沉积,早白垩世中期河湖相凝灰质复陆屑岩类夹火山碎屑岩类沉积,早白垩世晚期中基性火山熔岩、火山碎屑岩组合。沉积中心在侏罗纪和早白墨世早期皆偏于西北部,此后,向东南部迁移。晚白垩世,盆地处于风化剥蚀阶段。古近纪,受新生太平洋板块向亚洲大陆下俯冲影响,盆地又处于拗陷—裂陷阶段,相应形成山间河湖相—山麓堆积相类磨拉石建造。古近纪末期,该盆地整体隆起处于长期风化剥蚀状态。  相似文献   
974.
青岛小珠山花岗岩岩石谱系单位划分及其主要特征   总被引:3,自引:0,他引:3       下载免费PDF全文
周汝国   《山东国土资源》2001,17(6):32-38
青岛小珠山花岗岩体为中生代偏碱性侵入岩,过去通称小珠山岩体,通过15万区域地质填图,将其划分为15个单元,划归为大店和崂山两个超单元.对各单元的岩石学、岩石化学、微量元素及稀土元素特征等进行了分析研究,认为应属A型花岗岩,为燕山晚期之产物.  相似文献   
975.
Solar radiation is an important energy source for plants on the earth and also a major component of the global energy balance.Variations in solar radiation incident at the earth's surface profoundly affect the human and terrestrial environment,including the climate change.To provide useful information for predicting the future climate change in China,distinctive regional features in spatial and temporal variations of the surface solar radiation (SSR) and corresponding attributions (such as cloud and aerosol) are analyzed based on SSR observations and other meteorological measurements in North and East China from 1961 to 2007.Multiple models,such as the plane-parallel radiative transfer model,empirical and statistical models,and corrclation and regrcssion analysis methods are used in the study.The results are given as follows.(1) During 1961-2007,the total SSR in North China went through a process from quickly “dimming” to slowly “dimming”,while in East China,a significant transition from “dimming” to “brightening” occurred.Although there are some differences between thc two regional variation trends,long-term variations in SSR in the two regions are basically consistent with the observation worldwide.(2) Between the 1960s and 1980s,in both North and East China,aerosols played a critical rolc in the radiation dimming.However,after 1989,different variation trends of SSR occurred in North and East China,indicating that aerosols were not the dominant factor.(3) Cloud cover contributed less to the variation of SSR in North China,but was thc major attribution in East China and played a promoting role in the reversal of SSR from dimming to brightening,especially in the “remarkable brightening” period,with its contribution as high as 70%.  相似文献   
976.
ABSTRACT The high-grade rocks (metapelite, quartzite, metagabbro) of the Hisøy-Torungen area represent the south-westernmost exposures of granulites in the Proterozoic Bamble sector, south Norway. The area is isoclinally folded and a metamorphic P–T–t path through four successive stages (M1-M4) is recognized. Petrological evidence for a prograde metamorphic event (M1) is obtained from relict staurolite + chlorite + albite, staurolite + hercynite + ilmenite, cordierite + sillimanite, fine-grained felsic material + quartz and hercynite + biotite ± sillimanite within metapelitic garnet. The phase relations are consistent with a pressure of 3.6 ± 0.5 kbar and temperatures up to 750–850°C. M1 is connected to the thermal effect of the gabbroic intrusions prior to the main (M2) Sveconorwegian granulite facies metamorphism. The main M2 granulite facies mineral assemblages (quartz+ plagioclase + K-feldspar + garnet + biotite ± sillimanite) are best preserved in the several-metre-wide Al-rich metapelites, which represent conditions of 5.9–9.1 kbar and 790–884°C. These P–T conditions are consistent with a temperature increase of 80–100°C relative to the adjacent amphibolite facies terranes. No accompanying pressure variations are recorded. Up to 1-mm-wide fine-grained felsic veinlets appear in several units and represent remnants of a former melt formed by the reaction: Bt + Sil + Qtz→Grt + lq. This dehydration reaction, together with the absence of large-scale migmatites in the area, suggests a very reduced water activity in the rocks and XH2O = 0.25 in the C–O–H fluid system was calculated for a metapelitic unit. A low but variable water activity can best explain the presence or absence of fine-grained felsic material representing a former melt in the different granulitic metapelites. The strongly peraluminous composition of the felsic veinlets is due to the reaction: Grt +former melt ± Sil→Crd + Bt ± Qtz + H2O, which has given poorly crystalline cordierite aggregates intergrown with well-crystalline biotite. The cordierite- and biotite-producing reaction constrains a steep first-stage retrograde (relative to M2) uplift path. Decimetre- to metre-wide, strongly banded metapelites (quartz + plagioclase + biotite + garnet ± sillimanite) inter-layered with quartzites are retrograded to (M3) amphibolite facies assemblages. A P–T estimate of 1.7–5.6 kbar, 516–581°C is obtained from geothermobarometry based on rim-rim analyses of garnet–biotite–plagioclase–sillimanite–quartz assemblages, and can be related to the isoclinal folding of the rocks. M4 greenschist facies conditions are most extensively developed in millimetre-wide chlorite-rich, calcite-bearing veins cutting the foliation.  相似文献   
977.
网袖扭转是单拖渔轮用网囊引纲船舷一侧起网时有发生的现象。本模拟试验,可清楚地观察到网袖扭转的角度、方向,从而采取安全、简便快捷的方法排除。操作:面向船尾,右舷收网的顺时针方向扭转一周,左舷收网的逆时针方向扭转一周,排除时连接着网囊引纲一侧的网袖和混含纲保持不动,解开连接另一网袖叉纲一端的混合纲,顺其向绕另一混合纲一周并接回原处,网袖扭转便排除。  相似文献   
978.
A mass‐balance approach was used to estimate in‐stream processes related to inorganic nitrogen species (NH4+, NO2? and NO3?) in a large river characterized by highly variable hydrological conditions, the Garonne River (south‐west France). Studies were conducted in two consecutive reaches of 30 km located downstream of the Toulouse agglomeration (population 760 000, seventh order), impacted by modification of discharge regime and high nitrogen concentrations. The mass‐balance was calculated by two methods: the first is based on a variable residence time (VRT) simulated by a one‐dimensional (1‐D) hydraulic model; the second is a based on a calculation using constant residence time (CRT) evaluated according to hydrographic peaks. In the context of the study, removal of dissolved inorganic nitrogen (DIN) for a reach of 30 km is underestimated by 11% with the CRT method. In sub‐reaches, the discrepancy between the two methods led to a 50% overestimation of DIN removal in the upper reach (13 km) and a 43% underestimation in the lower reach (17 km) using the CRT method. The study highlights the importance of residence time determination when using modelling approaches in the assessment of whole stream processes in short‐duration mass‐balance for a large river under variable hydrological conditions. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   
979.
由于地震构造的许多重要信息在卫片上显示往往比较隐晦,必须对其进行增强处理,以取得最佳的解译效果。本文以历史上曾发生过八级地震的华县地震构造带为例,讨论辐射增强、多波段频谱变换、空间变换假彩色增强、分类等计算机图象处理方法的若干功能,以及这些功能在不同背景条件下的处理效果,为分析该地区活动断裂、地质构造等提供了有意义的信息,也为这种处理手段在地震构造信息分析等方面的推广应用提供参考。  相似文献   
980.
芥川龙之介的《水虎》与果戈理的《狂人日记》、鲁迅的《狂人日记》均采用了现实主义与象征主义相结合的创作方法,一针见血地揭露了社会制度的黑暗与腐朽。但他们在创作方法上使用的象征主义和对社会现实揭露的广度与深度不完全相同,主人公的思想高度更是各不相同。作品创作的背景、历史条件,作者的思想高度、性格特点和创作风格是造成这些差别的根源。  相似文献   
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