Formation,tectonic position,and ore genesis of granitoids in the Pautovaya Horst (Northeast Russia)     

Yu. Ya. Vashchilov  N. K. Gaidai  O. V. Sakhno 《Russian Journal of Pacific Geology》2008,2(5):433-440

This paper considers the problems of the existence of unexposed Late Jurassic-Early Cretaceous Priiskatel’skii and Pautovaya granitoid massifs in the core of the Pautovaya Horst and the Late Cretaceous Orotukan-Sulukhachan Massif, which is located at depths of <2 km and projected to the surface as the Verkhnii Orotukan, Sulukhachan, and Solnechnyi granite massifs. The formation of palingenetic-anatectic granitoid magma and its migration to the surface occurred under conditions of general basification of the crust in the Late Mesozoic and led to the formation of the Pautovaya Horst. Granitization of near-surface parts of the crust was accompanied by basification at depths of 8–15 km, where granitoid magma originated in magmatic chambers. The contact-metamorphosed sedimentary cap of the uneroded granitoid core of the Pautovaya Horst is promising for tin-rare metal ore deposits and occurrences and unpromising for gold mineralization.  相似文献   

试论河南毛集--二郎坪古裂陷带演化史     

刘平河  庞振山  张照锋  王铭生  王振闽  刘学理 《华北地质》2005,28(2):87-93

毛集-二郎坪古裂陷带的形成、发展及演化,受华北、扬子两大板块活动制约。晚元古代-早古生代时期为-边缘裂陷海盆,形成了歪头山组复理石建造和二郎坪群蛇绿岩建造,与其相伴产出了金、银、铁、铜、锌、硫、重晶石等火山成因块状硫化物矿床。华力西-印支期发展演化为裂陷带,并褶皱造山使裂陷带南北向大规模收缩,形成复式倒转褶皱系。燕山期的构造叠加,使裂陷带的构造面貌更加复杂,为金、银及多金属矿产的成矿提供了有利空间。  相似文献   

渤海湾地区构造变换带及油气意义   总被引：2，自引：0，他引：2       下载免费PDF全文

余一欣  周心怀  魏刚  汤良杰  徐长贵 《古地理学报》2008,10(5):555-560

利用地震剖面解释结果和构造编图成果,分析了渤海湾地区构造变换带的特征及其油气地质意义。渤海湾地区主要发育区域横向调节带和局部变换带两类构造变换带。区域横向调节带由北西向大型走滑断裂带充当,这些断裂带同时也是强地震活动带,将渤海海域地区分为北、中、南3段。局部变换带主要发育在相互作用的分段正断层的叠置区内。根据分段正断层的倾向及其组合特征,可将局部变换带分为转换斜坡型、斜向背斜型和地垒型3类。渤海湾地区构造变换带具有重要的油气地质意义,主要表现为控制构造圈闭的形成、有利于优质储集层的发育及控制油气运移过程等。  相似文献   

东秦岭二郎坪群硅质岩地球化学特征及其沉积环境意义   总被引：3，自引：0，他引：3  

冯胜斌  周洪瑞  燕长海  彭翼  胡绍斌  任建光 《现代地质》2007,21(4):675-682

东秦岭二郎坪群硅质岩成因分析对二郎坪群形成环境和构造背景研究具有重要意义。通过对二郎坪群中3类硅质岩地质特征、岩石地球化学特征（w(SiO₂)=61.35%~96.01%、N(Si)/N(Al)=2.77~51.53）研究,认为二郎坪群硅质岩为非纯硅质岩;稀土元素的配分模式和特征值（∑REE、∑LREE、∑HREE、δCe、δEu)、常量元素含量（w(Al₂O₃)、w(TiO₂)）和微量元素含量（w(Nb)、w(Rb)、w(Th)）的分析表明研究区硅质岩是热水成因型,但受陆源物质成分影响,陆缘物源对南阳盆地西硅质岩影响较大。地球化学综合分析揭示二郎坪群硅质岩产出于不同海相沉积环境,南阳盆地西硅质岩形成于大陆边缘海环境,而盆地以东硅质岩形成于远洋盆地环境,证实了二郎坪群形成于弧后盆地构造环境。  相似文献   

Permafrost distribution and temperature in the Elkon Horst,Russia     

Mikhail Zhelezniak  QingBai Wu  Anatolii Kirillin  Zhi Wen  Aleksandr Zhirkov  Vladimir Zhizhin 《寒旱区科学》2021,13(2):107-122

The Elkon Horst is a geological structure that consists of heterogeneous strata with highly variable geocryological and temperature conditions. Gaining accurate knowledge of permafrost distribution patterns within this structure is of both scientific and practical importance. In mountainous terrain, the ground thermal regime is controlled by both surface and subsurface conditions. Surface conditions include snow cover characteristics, the presence or absence of vegetation, vegetation density, etc.. In contrast, subsurface conditions involve rock lithology or petrography, density, quantity and depth of fissures, groundwater, etc.. This article examines ground thermal regimes in various geomorphological settings based on temperature measurement data from geotechnical boreholes. The occurrence and extent of permafrost were evaluated for the entire horst area using direct and indirect methods. The maximum permafrost thickness measured in the Elkon Horst is 330 m, and the estimated maximum is 450 m at higher elevations. Thermophysical properties were determined for the major rock types, and the geothermal heat flux was estimated for the study area. The thermal conductivities were found to vary from 1.47 to 4.20 W/(m·K), and the dry bulk densities to range between 2,236 kg/m~3 and 3,235 kg/m~3. The average geothermal heat flux was estimated to be 44 mW/m~2.  相似文献   

济南千佛山断裂与文化桥断裂导水透水性研究          下载免费PDF全文

王鑫  武朝军  谢松彬  李岩  郑灿政  周雨阳 《山东国土资源》2018,34(4)

针对已有资料,推断出济南市区段千佛山断裂与文化桥断裂的构造形成过程,通过整理千佛山断裂与文化桥断裂周围分布的大量钻孔数据,从地层岩性特点,重点研究市区内千佛山断裂与文化桥断裂的导水性与透水性。研究表明,地垒处东南高、西北低的地势特点,对四大泉群的形成具有重要作用。千佛山断裂在市区内从南郊宾馆至明湖北路4km范围内具有透水性,明湖北路以北断裂EW向隔水不连通。文化桥断裂在市区内经十路至明湖北路之间3.7km范围内为EW向透水断裂;在经十路以南部分,断裂处南北向导水受阻,这是由于浅层强风化闪长岩钙华沉积所致。位于四大泉群正西方向的千佛山断裂,东西两侧透水性好,垂直方向上导水畅通,但由于上部沉积较厚粘土隔水层,因而没有出现泉水喷涌。  相似文献   

东秦岭二郎坪群地质特征及成矿规律   总被引：3，自引：0，他引：3  

汤清龙  赵志强  吉恒召  杨涛  牛磊 《华南地质与矿产》2010,(4):45-54

二郎坪群位处扬子板块和华北板块的拼合带——秦岭造山带的东段,夹持于NW向瓦穴子-乔端、朱阳关-夏馆两个区域性深大断裂之间,由于特殊的大地构造位置和成岩成矿环境,受到国内外众多地质学家的关注。本文以笔者近期开展的二郎坪群1:5万找矿填图和成矿规律研究的最新资料为依据,结合前人大量地质和科研工作的多项成果资料,着重论述二郎坪群的地质特征及成矿规律,为本区的广深找矿工作提供科学依据和理论支撑。  相似文献   

Comparison of the Typical Metallogenic Systems in the North Slope of the Tongbai‐East Qinling Mountains and its Geologic Implications   总被引：4，自引：0，他引：4  

ZHANG Jing  CHEN Yanjing  QI Jinping  GE Jun 《《地质学报》英文版》2009,83(2):396-410

The Tongbai-East Qinling Mountains, an important part of the Central orogenic belt, is one of the most important metallogenic belts in China and contains lots of orogenic-type and VMS-type (Volcanogenic Massive Sulfide type) metallogenic systems. The Dahe and Shuidongling VMS-type Cu-Zn deposits, located in the Erlangping Group in Tongbai and East Qinling Mountains, respectively, show similar geological and geochemical features. The Huoshenmiao Formation in the East Qinling region and the Liushanyan Formation in the Tongbai region are spilite-keratophyre sequences occurring in the western and eastern sides of the Nanyang Basin, respectively, and are interpreted to be equivalent to each other. The orogenic-type Au-Ag deposits can be subdivided into two styles; namely, fault- or structure-controlled (e.g. Yindonggou) and stratabound (e.g. Poshan). The Poshan and Yindongpo orogenic-type Au-Ag deposits, whose ore bodies are strictly hosted in carbonaceous strata in the Tongbai Mountains, show obvious stratabound characteristics. Their ore-fluids are enriched in K+ and SO42? and are regarded as K+-SO42? types. The Pb-isotope ratios of sulfides of the ores are extremely uniform and significantly different from those of the tectonostratigraphic terranes of the Qinling orogens except for the ore-hosting strata of the Waitoushan Formation. The Yindonggou and Xuyaogou orogenic Au-Ag deposits in the East Qinling Mountains, whose ore bodies are hosted in the faults cutting the hosting strata or granite body, show fault-controlled characteristics. Their ore-fluids belong to the Na+-Cl? type. The Pb-isotope ratios of sulfides of ores are similar to those of the northern Qinling orogenic belt. The Waitoushan Formation, dominated by carbonaceous sericite-rich schists and only occurring in Tongbai region, should be detached from the Erlangping Group, which occurs both in the western and eastern sides of the Nanyang Basin. Future ore exploration in the Tongbai-East Qinling Mountains should focus on fault-controlled Au-Ag lodes.  相似文献   

河南北秦岭古火山断陷带二郎坪群及其相关地层划分对比     

王铭生  宋峰  武新强 《河南国土资源》1997,(4)

二郎坪群及其相关地层，自７０年代以来，划分对比方案达十余种之多。笔者根据大量地质素材，将其划分为：上元古界歪头山组、下古生界二郎坪群、上古生界小寨组。这一方案不仅统一了河南境内和豫陕两省该地层的划分对比，更重要的是理顺了产于其中的（具层控和岩控型）金、银、铁、铜、硫等赋矿层的序次。  相似文献   

Early Paleozoic continental crust accretion in the North Qinling: Evidences from geochronology,geochemistry and Sr-Nd-Hf isotopes of arc magmatic rocks in Taipingzhen areaSCIEI北大核心CSCD     

王佳营  曾威  张祺  翟文建  李承东  李光耀  刘文刚  郝爽 《岩石学报》2023,(3):803-822

二郎坪单元是位于北秦岭构造带中部的一个年轻地体,发育了大量的花岗岩类,是研究北秦岭早古生代大陆地壳增生的理想场所。本文对北秦岭构造带太平镇北英云闪长岩-奥长花岗岩体和蛮子营黑云母二长花岗岩体开展了岩石学、年代学、地球化学及Sr-Nd-Hf同位素研究。LA-ICP-MS锆石U-Pb测年表明,太平镇北奥长花岗岩和蛮子营黑云母二长花岗岩的形成时代分别为468.8±2.8Ma和462.2±1.9Ma。太平镇北岩体为高硅(71.79%-78.66%)、富钠贫钾(K_(2)O/Na_(2)O=0.27-0.77)的低钾拉斑-钙碱性系列岩石;蛮子营岩体为高硅(72.20%-74.90%)、富钾(K_(2)O/Na_(2)O=0.97-1.36)的高钾钙碱性岩石。两者轻重稀土分异均较明显,均具有富集Rb、Ba、Th、U、K等大离子亲石元素,而亏损Nb、Ta、P、Ti等高场强元素的特征。太平镇北岩体和蛮子营岩体具有类似的锆石εHf(t)值(奥长花岗岩8.2-12.7;黑云母二长花岗岩8.9-13.2)、全岩(87Sr/86Sr)i(奥长花岗岩0.704038-0.705221;二长花岗岩0.703876-0.705371)和全岩εNd(t)值(奥长花岗岩1.49-2.03;黑云母二长花岗岩1.68-1.92)。研究表明,太平镇北岩体岩浆源区为玄武质弧下地壳,岩浆结晶分异作用形成英云闪长岩和奥长花岗岩;蛮子营岩体岩浆为早期形成的英云闪长岩部分熔融形成。太平镇北岩体和蛮子营岩体均形成于洋内弧的构造环境,从弧玄武岩到富钠英云闪长岩、奥长花岗岩再到富钾的二长花岗岩,代表了地幔物质经过多阶段岩浆演化形成富硅富钾长英质地壳的过程。综上,认为洋内弧的形成和岩浆演化是北秦岭大陆地壳增生的重要方式之一。  相似文献