双差精密定轨中地面站的选取方法

针对目前全球的地面测站数量多、测站观测数据质量参差不齐及测站地理分布不均的问题,总结了一种测站选取方法。利用该方法编制的测站选取软件对IGS站进行了选择,并根据选得的测站设计了几种定轨试验。结果显示,利用由本文的测站选取方法得到的70个基准站进行定轨时,得到的卫星位置与IGS精密星历在径向、切向、法向偏差均方根分别为1.11、2.19、1.72cm。验证了本文选站软件的可靠性,避免了选站过程中过多的人为因素,并且在保障精度的前提下提高了定轨效率。     

利用TIN和高程梯度进行高程点抽稀

为了解决系列比例尺地形图缩编过程中高程点的抽稀问题,考虑到高程点分布的密度和地形起伏等因素,基于高程点构建了TIN,再结合平均高程面、高程梯度和局部高程最值点,对高程点进行了筛选抽稀。     

准噶尔盆地玛湖凹陷大油（气）区形成条件与勘探方向研究

准噶尔盆地西北缘玛湖凹陷是全球著名的湖相富烃凹陷,最新勘探成果展示出大油(气)区特征。为及时总结,丰富发展当代中国特色叠合盆地油气地质理论与勘探实践,本文主要分析了这一大油(气)区的基本形成条件与勘探领域。结果表明,玛湖凹陷大油(气)区得以形成主要缘于三大有利基础条件:前陆碱湖优质高效烃源岩、立体输导体系、三类规模有效储层与储盖组合,由此造就油气在充足的烃源条件下,沿立体的输导体系,被三套区域性盖层有效封盖,向着三类规模有效储层,在有利圈闭中运聚成藏,因此油气富集规律可归纳为"源-输控烃、储-盖控藏"。相应,按目的层和圈闭类型形成了三大有利油气成藏领域,由浅至深依次为三叠系下统百口泉组岩性油(气)藏群、二叠系下统风城组致密油、石炭系—下二叠统大构造油气藏群。玛湖凹陷大油(气)区的勘探突破缘于勘探理念创新,具有巨大勘探潜力和基础科学研究意义。     

吉尔吉斯天山晚古生代岩浆活动及相关成矿作用

本文通过对近年来有关吉尔吉斯天山研究进展的梳理,结合在吉尔吉斯斯坦的实地考察,系统论述了吉尔吉斯天山古生代基础地质情况,着重讨论了与岩浆作用相关的成矿过程。吉尔吉斯斯坦境内的天山由"尼古拉耶夫线"和阿特巴什-伊内尔切克断裂划分为北、中、南三部分。两条缝合带限定了早古生代捷尔斯凯伊洋和晚古生代南天山洋的发展和消亡过程。吉尔吉斯天山古生代岩浆作用大致分为两个阶段:早古生代捷尔斯凯伊洋演化过程中,与弧-陆碰撞、弧-弧碰撞相关的岩浆作用和晚古生代与南天山洋闭合相关的岩浆作用。晚古生代存在两个重要的成矿阶段:晚石炭世与南天山洋向北俯冲形成的弧岩浆作用相关的斑岩型、矽卡岩型铜-金矿床;早二叠世与后碰撞花岗岩侵入作用相关,并受剪切带控制的金-多金属矿床。南天山缝合带附近出露的不同岩体在岩石地球化学及矿化特征的差异,反映了位于阿特巴什-伊内尔切克断裂以北的岩浆源区为成矿物质贫瘠的中天山前寒武纪基底,而断裂以南的岩浆作用源区为富集流体及成矿元素的增生杂岩和塔里木被动陆缘沉积物。     

新疆肯登高尔铜钼矿区侵入岩年代学、地球化学及其大地构造意义

肯登高尔铜钼矿床是新疆西天山博罗科努成矿带中一处矽卡岩型矿床,矿体赋存于纳林果勒中酸性侵入体与上石炭统东图津河组钙质粉砂岩夹碳酸盐岩的接触带上。纳林果勒岩体主要由花岗闪长岩与二长花岗岩组成。通过LA-ICP-MS锆石U-Pb同位素定年,获得花岗闪长岩和二长花岗岩的加权平均年龄分别为316.3±3.5Ma和298.9±3.3Ma,表明两者侵位时代分别为晚石炭世和早二叠世。地球化学组成上花岗闪长岩具有高硅和高钠的特征,富集Sr、Rb和Th,亏损Nb、Ta、Yb和Y,无Eu异常,岩石具有埃达克岩的特征,是造山晚期加厚下地壳部分熔融的产物。二长花岗岩具有富硅、富钾、低铝的特征,富集Rb、Th、Nb和Hf,亏损Sr、Ta和Ti,具有明显Eu负异常,岩石为高分异I型花岗岩,是岩石圈伸展减薄背景下,下地壳进一步熔融形成的基性岩浆通过分离结晶作用形成的产物。结合成岩年龄和区域构造背景,推测西天山北缘在晚石炭世进入碰撞造山阶段,在早二叠世向造山后伸展阶段过渡。     

西湖凹陷渐新世层序地层格架与沉积充填响应

东海陆架盆地是中国近海最大的沉积盆地,而西湖凹陷又是其中规模最大的富油气凹陷。多年的勘探实践证明渐新统花港组为西湖凹陷主力产气层段,但其层序地层划分长期存在较大争议。在分析了西湖凹陷盆地结构与构造格局的基础上,依据测井、岩芯以及地震反射特征,将西湖凹陷渐新统划分出5个三级层序与12个体系域,建立了其等时地层格架;并通过大量岩芯的写实性描述,结合沉积构造与遗迹化石鉴别以及地球化学资料分析对沉积环境进行了判识,分析结果认为西湖凹陷渐新统花港组沉积时期发生过两次较大的海侵事件,形成“南海北陆”的沉积格局,并发育了河流、三角洲、潮控河口湾以及无障壁海岸四种沉积体系,其沉积体系类型较多,从南到北变化巨大。西湖凹陷渐新世整体表现为“东西短轴三角洲”、“南部潮汐河口湾”、“东北缓岸滩坝”的沉积体系展布格局。系统分析了沉积相在各层序中的展布特征及其对海平面变化的响应、层序演化过程及其对海平面变化的响应,构建了东海陆架盆地西湖凹陷构造-沉积成因模式,明确了“断坳转换,海陆交替”的盆地构造背景与沉积充填的响应关系。     

广西清明山铜镍硫化物矿床上升气流微粒研究

为探讨上升气流微粒与深部隐伏矿体之间关系,在广西清明山铜镍硫化物矿床上方土壤中采集上升气流微粒,并采用透射电子显微镜(TEM)对微粒的形貌、大小、聚合状态、化学组分及结构等进行分析。结果表明,微粒主要由Cu、Co、Zn、Fe、Ca、Si、S等元素组成,其中成矿元素Cu、Co以自然Cu-Fe-Co、Zn-Fe-Co及Fe-Co合金微粒的形式存在,其余如Fe、Ca、Si、S等元素则以氢氧化物、氧化物及碳酸盐微粒形式存在。微粒可分为微粒聚合体及单个微粒,微粒的大小为50~500nm,微粒的形状多为不规则状、近椭圆形、近球状、水滴状和近长方体等。微粒中高含量的Cu、Co、Zn来源于深部隐伏矿体,含Fe、S微粒来源于矿床中金属硫化物矿物。此外,高价态的微粒组分指示微粒处于相对氧化的环境。清明山铜镍硫化物矿床的上升气流微粒组分与矿床矿物组分间存在着较好的对应性,本研究为隐伏铜镍硫化物矿床提供了新的找矿方法。     

湖北大悟大磊山金矿矿床成因与控矿构造

在翔实的野外地质工作基础上,对湖北大悟大磊山金矿床进行矿区填图,并结合前人研究成果,充分分析大磊山金矿的控矿构造及矿床成因,认为该金矿导矿、配矿构造是一种新的构造类型,二者均不是断裂构造,而是燕山期区域广泛的岩浆活动使得大磊山花岗岩穹窿上隆,导致围岩沿接触面下滑,形成剪切带,该剪切带为后期热液提供了导矿、配矿通道;新元古代片麻状二长花岗岩为金矿提供了较高的金元素背景值,燕山期岩浆活动不但使金元素活化、迁移,也为金矿成矿提供了物质来源,金矿的矿床成因是中低温岩浆期后热液矿床;根据含金石英脉充填煌斑岩脉裂隙的地质特征,利用LA-ICP MS锆石U-Pb定年法获得了煌斑岩成岩年龄为126.8±2.0 Ma,从而限定了大磊山金矿成矿年代。     

Diagenetic Evolution and Formation Mechanisms of High-Quality Reservoirs under Multiple Diagenetic Environmental Constraints: An Example from the Paleogene Beach-Bar Sandstone Reservoirs in the Dongying Depression, Bohai Bay Basin

The diagenetic environment, diagenetic responses, diagenetic transformation model and formation mechanisms of high-quality reservoirs (beach-bar sandstones of the Paleogene fourth member) in the Dongying depression were studied through the analysis of fluid inclusions, thin section and burial evolution history. The diagenetic fluids of the beach-bar sandstone reservoirs evolved from early high salinity and weak alkalinity to low salinity and strong acidity, late high salinity and strong alkalinity and late low salinity and acidity, which were accompanied by two stages of oil and gas filling. The fluids at the margins of the sandbodies were continuously highly saline and strongly alkaline. The western (eastern) reservoirs experienced early open (closed), middle open, and late closed diagenetic environments during their burial history. The flow pattern was characterized by upwelling during the majority of the diagenesis (in the east, a non-circulating pattern transitioned into an upwelling current). Due to the evolution of the diagenetic fluids, the diagenetic sequence of the beach-bar reservoirs was as follows: early weak carbonate cementation; feldspar and carbonate cement dissolution and authigenic quartz cementation; late carbonate and anhydrite cementation, authigenic feldspar cementation, and late quartz dissolution; and late carbonate cementation, feldspar dissolution, and authigenic quartz cementation. The diagenetic strength during these stages varied or was absent altogether in different parts of the reservoirs. Due to the closeness of the diagenetic environment and the flow pattern of the diagenetic fluids, the diagenetic products are variably distributed in the sandstones interbedded with mudstones and in the fault blocks. The evolution of multiple alternating alkaline and acidic diagenetic environments controlled the distribution patterns of the reservoir diagenesis and reservoir space, and the reservoir quality index, RQI, increased gradually from the margins to the centers of the sandstones. The closeness of the diagenetic environment and the flow patterns of the diagenetic fluids controlled the differences in the reservoir properties among the fault blocks. With increasing distance from the oil-source faults, the RQI values in the west gradually decreased and in the east initially increased and then decreased.     

A Discovery of ~3.1 Ga Basement in the Bohai Bay Basin

<正>Objective The North China Craton(NCC)is one of the oldest continental fragments,which underwent multistage crust growth during the early Precambrian from3.8 Ga to 1.8Ga.In previous studies,many zircon ages have been obtained from the exposed basement rocks.However,we know little about the hidden basement because of Phanerozoic to Cenozoic strata coverage.The drill holes provided a rare opportunity to obtain the basement rocks beneath the Bohai Bay Basin(BBB).In this study,we