Chronology,Geochemistry and Tectonic Settings of the Hadamiao Granodiorite on the Northern Margin of the North China Platform

The Hadamiao granodiorite,located on the northern margin of the North China platform and acting as the country rock of gold deposits in the Hadamiao region,was formed in the same age and similar tectonic settings with the Hadamiao gold deposit and the large-scale Bilihe gold deposit in the same area.By using the LA-ICP-MS method,the U-Pb age obtained is 267±1.3 Ma,which represents the crystallized age of the granodiorite,and that of the xenolithic zircon is 442.8±5 Ma. Base on the main elements,it exhibits the features of calc-alkaline to high-potassium calc-alkaline series,low silicon,and quasi-aluminous I-type granites,and with high magnesium（Mg~#=0.45-0.57） and high sodium contents（Na_2O/K_2O=0.98-2.29）.The SREE values（81.6-110.15 ppm） are relatively low,the fractionations between LREE and HREE are obvious,showing a right-inclined dispersion in the REE distribution diagram.Compared with the primitive mantle,the rock is relatively rich in LREE（La and Ce）,LILE（K,Sr,and Th）,and intensively depleted in HFSE（Ti,P,Nb and Ta）.The ratios of Sr/Y and（La/Yb）_N and the contents of Rb,Nb and Y are relatively low,the Sr values are high （436.35-567.26 ppm）,and the Yb contents of most samples are low（1.25-1.8）,which indicate the features of typical continental margin arc and adakitic rocks.According to the values ofε_（Nd）（t）（-2.4 to ＋0.2） and I_（Sr）（0.7028-0.7083）,and variations of the La/Sm ratios,the Hadamiao granodiorite was formed from mixing of the thickened molten lower crust and the mantle wedge substances.The rock was related to the southward subduction and accretion of the Paleo-Asia Ocean in the Late Paleozoic, being Late Paleozoic magma of the continental margin arc formed on the basement of the Early Paleozoic accretion complexes,and showing a trend of turning into adakitic rocks,which indicates their great metallogenic（Au） potential.

Geochemical characteristics of upper Sinian Dengying dolomite at northern Yangtze platform: implication for Pb-Zn metallogenesis

1 Introduction and geological setting Several Pb-Zn ore deposits(i.e.,Mayuan Pb-Zn deposit)occurring inthe upper Sinian Dengying dolomitesin northern Yangtze platform have been discovered in recent years,interesting research of

A New Fauna——Qinghezhen Fauna——from the Northern Margin of the North China Platform

In the Inner Mongolia axis and Jiaoliao anteclise along the northern margin of the North China Platform.it has been found that the strata formerly considered as Archaean and Proterozoic are in fact an ophiolite suitesimilar to the Early Palaeozoic Ondor Sum Group in the Northern Geosyncline region of China. The stratahave been named in northern Liaoning as the Qinghezhen Group. The emphasis of this paper is on the discus-sion of the simall shelly fossils found in the siliceous rocks in the upper part of the Qinghezhen Group. Thisophiolite suite stretches in an E-W direction for about 1000 km along the northern margin of the North ChinaPlatform. in which 15 fossil localities with stable stratigraphic horizons have been discovered. In this paper. 4types. 7 genera (including 5 new ones) and 10 species (including 8 new ones and 1 new subspecies) aredescribed, which are collectively referred to as the Qinghezhen Fauna. The characteristics of these fossils are:shell form simple. the maximum length not exceeding 4 mm. with obvious shell wall and wall ornaments. TheQinghezhen Fauna is comparable in shell structure of some genera and species with the Meishucun Fauna inSouth China, but differs from the latter in having only monotonous fossil groups developed in a distinctly va-ried ecological environment. The two faunas may belong to the same evolutionary stage of the Early Cambrianbut have developed parallelly in different regions. The existence of the Qinghezhen Fauna represents an impor-tant biological event in the Early Cambrian in the Northern Geosyncline region of China. The discovery of theQinghezhen Fauna will bring new knowledge and profound influence to a series of problems on basic geologyand mineral deposit prospecting such as the Cambrian faunas. biogeographical povincialism in China and thegeotectonic features of the northern margin of the North China Platform.

Geological Conditions and Hydrocarbon Accumulation Processes in the Sahul Platform, Northern Bonaparte Basin, Australia

The Sahul Platform where the Sunset-Loxton Shoals and Chuditch gas fields were discovered is located between the Timor Trough to the north and the Malita Graben to the south. These areas are located respectively 440 km and 380 km northwest of Darwin in the northern Bonaparte Basin, Australia. Based on the structural evolution of the northern Bonaparte Basin, data from the wells Loxton Shoals 1, Sunset 1 and Chuditch 1 in the Sahul Platform and Heron 1 in the Malita Graben depocentre, and the Seismic Line N11606 were used to clarify the geological conditions and reconstruct the hydrocarbon accumulation processes in the study area. BasinMod 1-D, 2-D, and 3-D software was used for modeling. The Plover Formation source rock was a poor-to-good hydrocarbon generative potential and reached the middle to late mature oil window in the Sunset-Loxton Shoals field whereas in the Chuditch field, it was an overall fair-to-good hydrocarbon generative potential, and attained the Late mature oil window. The Flamingo, and the Echuca Shoals formations source rocks in the same field were a fair and good hydrocarbon generation potential respectively, and both reached mid-mature oil window. In the Malita Graben depocentre, the Petrel (Frigate) and the Echuca Shoals formations source rocks were a poor-to-very good hydrocarbon generating potential, and had attained wet gas window at the present day. The analyses of organic matter showed that the source rocks in the study area and Malita Graben were gas prone with kerogen types II2 & III and III predominantly. The Middle Jurassic Plover Formation sandstone reservoir in the Sunset-Loxton field was a poor-to-very good quality and potential for gas beds, and it was a very poor-to-very good quality and potential for gas beds in the Chuditch field. The intensities of gas generation and expulsion were more than of oil ones either in the Sahul Platform or in the Malita Graben. The Plover, Petrel (Frigate) and Echuca Shoals formations source rocks in the wells Chuditch 1 and Heron 1, except for the Flamingo Formation in the well Chuditch 1, had higher gas and oil expelling efficiencies than the Plover Formation source rock of the wells in the Sunset-Loxton Shoals field. The hydrocarbon migrated mainly from the Upper Jurassic Frigate Shale source rock in the Malita Graben depocentre (structurally lower) to the Plover Formation sandstone reservoir in the Sunset-Loxton Shoals field during the Late Cretaceous at 66 Ma. In the Chuditch field, the hydrocarbon migration to the Plover Formation sandstone reservoir was initiated during the Late Miocene at 7.5 Ma from the Middle Jurassic Plover Formation source rock in the well Chuditch 1. Nowadays, the main migration pathways are from the southeastward and southward of the Sunset-Loxton Shoals field, and from southward and eastward of the Chuditch field, precisely from the hydrocarbon source kitchens of the Malita Graben depocentre. The traps in the Sahul Platform have been effective to receive the migrated hydrocarbon.

四川盆地北部二叠系茅口组沉积特征及油气意义

基于地震资料精细解释成果,结合野外剖面及室内薄片观察,通过分析主要岩石类型及古生物、地球化学和地震相特征,对四川盆地北部二叠系茅口组沉积相展布特征进行研究,依据生物(屑)灰岩、礁灰岩和硅质岩等岩相发育规律以及地震地层结构和地层厚度变化特征,认为茅口组发育了开阔台地、台地边缘及斜坡—盆地等沉积亚相,总结出了开阔海夹点礁、开阔海夹点滩、台地边缘滩和灰质—硅质盆地等4种沉积微相组合,明确了沉积相纵向演化和平面展布规律。结果表明,台地边缘高能生物滩平面上呈条带状在剑阁—元坝—龙岗一带规模发育,生物(屑)灰岩的晶间溶孔、粒间溶孔和生物体腔孔发育,物性好,是优质储集层发育带;川西海槽和广元—旺苍海槽茅四段的硅质岩和泥岩有机碳含量高,则是优质生油岩,优越的沉积环境为该区油气成藏提供了有利的生油和储集条件。

New tectonic map of Northern-Central-Eastern Asia： Position and evolution of Mesozoic sedimentary basins

The beginning of the XXI century was marked a new rising of the international tectonic cartography as a result of analysis and synthesis of a huge volume of geological information obtained for the territory of Asia especially during the last 30 years. The previous tectonic maps for Asia were created in the 1960 s--1970 s of the last century. Since that time,the national geological surveys have compiled tectonic maps exclusively in the limits of their own state boundaries. The international cooperation of five countries since 2002( Russia,China,Mongolia,Kazakhstan and Republic of Korea) gave a unique possibility to join the data into a united cartographic form as Atlas of Geological Maps( since 2002-Atlas of Geological Maps of Central Asia and since 2007-Atlas of Geological Maps of Northern-Central-Eastern Asia). Both atlases include four maps: geological,tectonic,metallogenic,and energy resources. Tectonic Map of Northern-Central-Eastern Asia and Adjacent Areas at scale 1 ∶ 2 500 000 was the key map for further compilation of the metallogenic and energy resources( coal,oil and gas) maps. By this reason,special attention was given to showing the structure and composition of the Mesozoic sedimentary basins in Northern-Central- Eastern Asia as the most perspective structures for oil-and-gas and coal prospect.

川北地区灯四段台内丘滩储层特征及主控因素

台内丘滩是四川盆地上震旦统灯影组天然气勘探的重要后备领域,为了落实灯影组四段(以下简称灯四段)优质储层主控因素与展布特征,以川北地区灯影组台内钻井和野外露头为研究对象,通过岩心观察、薄片鉴定、储层物性等研究,对灯四段储集层基本特征及主控因素进行了综合分析。研究结果表明:(1)川北地区灯四段台内丘滩储集层岩性主要为藻粘结白云岩、藻砂屑白云岩、藻叠层白云岩和藻纹层白云岩,储集空间以晶间(溶)孔、藻格架孔、粒间溶孔以及裂缝为主;(2)台内丘滩优质储层展布主要受沉积相带控制,藻丘和浅滩沉积微相是储集层发育的有利沉积相带;(3)多期溶蚀作用能有效提升储层性能,其中早成岩期岩溶是优质储层形成的基础,埋藏期溶蚀能有效扩大储集空间,第一期埋藏溶蚀作用强度从灯四段顶部向下逐渐减弱,第二期埋藏溶蚀作用造成早期孔洞储集层进一步溶蚀扩大,形成现今储集空间。结论认为,受汉南古陆和宣汉—开江古隆起控制,在坡折带发育近南北向的台内丘滩条带,是灯四段油气勘探的有利地区。

内蒙古霍各乞宝音图群大理岩古沉积环境研究

宝音图群是华北地台北缘分布较广的地层单元之一,记录了华北地台北缘晚元古代—早新元古代期间的地质历史演化信息,研究宝音图群大理岩对于重建华北地台北缘的古地理环境具有非常重要的意义。对霍各乞宝音图群大理岩和地层组构特征研究显示,大理岩的Z值(121~130)、Sr/Ba比值(1.90~55.8)、m值(25.7~1973)、C同位素组成(δ13CV-PDB为1.25~4.79)以及地层中发育的变余层理和浪成波痕指示其古沉积环境为海相环境;大理岩弱的负Ce异常(δCe为0.78~0.97)、弱的正Eu异常(δEu为0.93~2.75)、V/Cr比值(0.46~4.09)以及地层中原生黄铁矿风化孔洞和碳质的存在指示原始沉积水体呈次氧化状态;大理岩的哈克图解、Y/Ho比值(27.2~45.0)、δLa-Yb图解及硅铝质矿物的发育指示原始沉积过程中有丰富的陆源碎屑物质输入。晚中元古代—早新元古代时期华北地台北缘为海洋环境。

陕北煤炭基地矿山生态修复成效评估体系构建与实现

煤炭资源是中国陕北地区社会经济发展的重要支柱,科学谋划矿山生态修复工作是维护陕北地区生态安全与能源安全的关键途径,而矿山生态修复成效评估是其中必不可少的环节,用以展现当地生态环境治理和自然资源保护的效益。笔者立足于矿山生态修复工作流程,通过遥感监测、物联网站点监测、人工实地调查与采样手段,基于矿山生态环境多源监测数据,从生态效益、社会效益及经济效益3大类别、12项指标出发,构建适用于陕北煤炭基地矿山生态修复成效评估体系。利用遥感、大数据、云计算等信息化技术,搭建矿山生态修复监管平台,实现修复成效智能评估功能,旨在形成高效、合理的矿山生态修复成效评估体系,全面展现陕北煤炭基地矿山生态修复工作的综合效益,以期为矿山生态修复工程监管提供理论指导和技术支撑。

塔里木盆地下寒武统肖尔布拉克组北部台缘带展布及其油气勘探意义

礁滩型白云岩是世界范围内油气勘探开发效果最好的领域之一。塔里木盆地震旦—寒武系具备规模礁滩型白云岩发育基础,但其特征与分布研究基础十分薄弱。本文采用野外剖面观察、单井资料分析、地震资料刻画等手段,落实了柯坪—塔北西部存在下寒武统台缘带,命名为北部台缘带,该台缘带呈北东走向,长约330 km,宽约7 km。野外露头资料显示,下寒武统北部台缘带发育两期微生物礁,岩性以针孔状白云岩为主,溶蚀孔洞发育;地震剖面上,可见丘状前积反射特征。北部台缘带具有得天独厚的生储盖配置优势,位于长期继承性发育的古隆起之上,具备形成大油气田的有利条件。北部台缘带的展布特征为该区下古生界白云岩的区带评价及目标优选指明了方向。

西沙海域碳酸盐台地周缘水道沉积体系

高分辨率地震资料显示,南海北部西沙海域碳酸盐台地周缘广泛发育水道沉积体系。礁缘水道底界面表现出强反射特征,内部充填弱-强、连续性好的地震相,可见底部杂乱反射特征;斜坡水道在地震剖面上表现为横向上连续发育的"V"型特征,且下切深度较浅。西沙隆起与广乐隆起之间的南北向低洼地带发育大型深水水道,并且受古地貌高点影响,水道分为南北两个分支。北分支水道可分为5期,且水道迁移现象明显;南分支水道可分为4期,水道以充填强振幅、连续性好的浊流沉积体和弱振幅、杂乱的块体搬运体系(Mass Transport Deposits,MTDs)为特征,每期水道均表现出侵蚀-充填-废弃的旋回性。分析认为西沙碳酸盐台地周缘水道沉积物源来自西沙隆起和广乐隆起的碳酸盐台地和生物礁碎屑及由火成作用产生的火成岩碎屑。西沙-广乐碳酸盐台地水道相互贯通,构成台地-斜坡-深水的水道沉积体系,为碳酸盐岩、生物礁及火山碎屑向台地周缘输送提供了良好的通道。

华北地台北部奥陶纪露头层序地层

本项研究以河北唐山、北京西山和河北曲阳剖面为重点，首次动用运用多学科的方法对华北地台北部奥陶纪露头层序地层进行综合研究。完善了研究程序，建立了层序地层划分对比标准和区内相分布格架。研究中将副层序直接用于野外分层；将副层序归纳为代表６种沉积相的２１个模型；识别了三类层序界面，即ＳＢ１面、间断型ＳＢ２面和相转换型ＳＢ２面；进行地层多级沉积旋回或分，包括２个二级旋回，６－７个三级旋回（每个旋回时限约６７Ｍａ），２２—２６个四级旋回（每个旋回时限约１５—１８Ｍａ）及１５５—１８５个五级旋回（每个旋回时限约０２１－０２６Ｍａ）；取得多项系统成果。区域相分布和相对海平面变化研究表明，区内奥陶纪台地环境的演变分为３个阶段：藻礁缓坡－台盆阶段，潮滩缓坡－台盆阶段和泻湖潮滩－缓坡阶段。

地幔岩包体中的Ni，Fe，Au，Mo含量及其意义--以山东和辽宁地区的比较分析为例

目的探讨华北南北两缘辽宁宽甸及山东临朐两地新生代地幔岩包体中成矿元素含量与矿床分布之间的关系。方法利用地幔岩包体常量元素、微量元素和稀土元素地球化学分析,结合区域矿产类型及矿产分布进行研究。结果辽宁宽甸岩石圈地幔经历了较高程度的部分熔融,后期交代作用较之山东临朐较弱;山东临胸部分熔融程度较之辽宁宽甸较低,进行的交代作用较强。辽宁宽甸的地幔岩包体成矿元素Ni,Fe,Au及Mo平均值分别为2561×10^(-6)g/g,7.07%,4.17×10^(-9)g/g,0.19×10^(-6)g/g;山东临朐的地幔岩包体的成矿元素Ni,Fe,Au及Mo平均值分别为1967×10^(-6)g/g,6.60%,10.7×10^(-9)g/g,0.37×10^(-6)g/g。中国华北地块南北两缘地幔岩包体中的成矿元素Ni,Fe含量明显表现为北缘高南缘低,而Au,Mo含量则为南缘高北缘低。结论岩石圈地幔岩Ni,Fe,Au,Mo等成矿元素含量的高低与成矿省情况基本是耦合的。地幔岩包体中Ni,Fe,Au,Mo等含量的高低对地壳矿产分布有指示意义。

扬子地台北缘寒武纪同沉积断裂控制的斜坡沉积特征

通过对扬子地台北缘寒武系剖面实测以及前人资料的综合分析,研究了同沉积断裂控制的斜坡沉积特征。斜坡区岩石类型丰富,包括砾屑石灰岩、灰泥石灰岩、硅岩和页岩等,沉积构造丰富,沉积厚度远大于台地区以及深海盆地区。断裂带在宏观上控制了扬子地台北缘寒武纪古地理分区,台地区、斜坡—深海盆地区的古地理位置在寒武纪的不同地质时期基本保持不变。寒武纪持续拉伸的构造环境造成斜坡区持续下降拗陷,从而为沉积物的堆积提供了足够大的可容空间,同时来自台地区的沉积物补给充足,导致了斜坡区相对于台地区以及深海盆地区而言具有巨厚的沉积层。

华北板块北缘西段裂谷系金矿床成矿特征及成因探讨

白云鄂博群和渣尔泰山群是华北板块北缘中新元古代裂陷谷沉积的陆缘碎屑岩、泥页岩、碳酸盐岩及少量火山岩建造,赋存的典型金矿床有白云鄂博北部金矿床、朱拉扎嘎、浩尧尔忽洞等成型金矿床。从区域成矿角度看,由西向东构成了一个巨大的Au-Cu-Pb-Zn-S(Fe)-Mn-Au-REE-Nb-Fe热水沉积成矿系统。地质特征表明金矿床均具有明显的层控型特点;元素地球化学特征显示金的来源主要与中元古代火山活动及沉积地层有关;同位素年龄暗示一期重要成矿时代与华力西晚期的岩浆-构造事件相耦合。认为金矿床成因可概括为热水喷流沉积-热液叠加改造复合型。显示具有较大的找矿潜力。

岩浆隐爆作用与金矿化的关系——以华北地台北缘金矿为例

以中元古代碎屑岩—碳酸盐岩为容矿岩石的浸染型金矿床是近年来发现的金矿新类型。本文简要介绍了该类金矿床的地质特征、矿床类型和成矿模式。提出华北地台北缘该类金矿的成矿作用与岩浆隐爆作用密切相关。

北方地区地铁车站冬季热环境影响因素分析

研究目的:基于正交试验原理,对典型地铁车站冬季热环境的影响因素进行分析,得出各影响因素主次顺序和提高车站热环境最优方案配置,从而指导北方地区冬季地铁车站站台门的选择及运营策略的制定。研究结论:(1)影响站厅温度的因素主次顺序为:土壤温度Tsoil>室外温度Tw>活塞风井开启数量δ>客流量fv>站台门开口面积s>行车周期tf;(2)影响站台温度的因素主次顺序为:土壤温度Tsoil>室外温度Tw>客流量fv>行车周期tf>站台门开口面积s>活塞风井开启数量δ;(3)采用单活塞系统时,车站平均温度达到最大值;采用闭式模式运行时,车站平均温度最低;(4)相比于安全门,北方地区冬季地铁站采用屏蔽门系统更能有效提高车站温度;(5)本研究结果可为北方地区地铁车站热环境控制提供理论基础。

华北地台北缘中段金矿控矿因素探讨

在中生代华北与华南的碰撞过程中,华北克拉通北缘再次活化造山,伴随强烈的岩浆活动和成矿作用,造就了华北地台北缘重要的金成矿带,笔者通过多年该区找金的实践和对金矿控矿因素的分析认为,金的成矿物质来源于绿岩地体,并在燕山期构造-岩浆活动中迁移、富集成矿,并提出了找矿方向。

扬子地台北缘震旦系灯影组地球化学特征及其对热水沉积暗示

震旦系灯影组在扬子地台北缘广泛分布,其岩性主要为白云岩、硅质白云岩和少量硅质岩。为探讨灯影组沉积时期的氧化还原状态并对热水沉积作用的暗示,分析了白云岩、硅质白云岩和硅质岩的微量稀土元素特征。结果表明,这3类岩石均呈现负的Ce异常,其V/Cr〉2、Ni/Co〉5、V/（V＋Ni）为0.6~0.84,表明灯影组沉积于弱氧化的浅水碳酸盐岩台地环境。另外,白云岩、硅质白云岩具有明显的正Eu异常、U/Th〉1,与海水稀土元素分布特征相比,其Ce负异常和轻稀土亏损程度明显减弱。上述特征及前人对灯影组硅质岩的Si-O同位素温度的计算结果表明,灯影组沉积时期有海底热水的混合。晚元古代晚期震旦纪扬子北缘处于裂谷构造环境,在由裂谷活跃期向平静期演化的过程中,其表现形式也由活跃的火山活动转化为热水喷流事件。灯影组即是在扬子北缘裂谷演化相对平静时期沉积的一套浅水碳酸盐岩,混合了海底喷流热液。

华北地台北缘中段银多金属矿床与火山岩

该区的银多金属矿床在空间上受前中生代基底东西向深大断裂和中生代的北东向构造岩浆带控制,由东向西构成北东—东西向带状分布的银多金属矿带集中区。其成矿与中元古代和中生代火山活动关系密切;即中元古代大红峪碱性玄武岩,中生代的酸性偏碱性火山岩。古元古代的变粒岩、中、新元古代的沉积岩中的特定层位和中生代燕山期张家口旋回火山岩具有矿源层特征。根据地质地球化学特征,提出该区存在四类银多金属矿床的认识。