松辽盆地泰康地区上白垩统姚家组沉积相

较系统地研究了松辽盆地泰康地区上白垩统姚家组沉积相类型和沉积特征,研究表明,泰康地区姚家组仅发育三角洲相一种沉积相类型;垂向上,从姚家组一段到姚家组三段,自下而上、自北而南由三角洲水上平原亚相或三角洲水下平原亚相沉积逐渐变为三角洲水下平原亚相或三角洲前缘亚相沉积。演化过程可大致划分为早、中、晚3个时期,不同时期沉积特征表现有差异,总体表现为一个加积到缓慢的水进转变过程,物源来自北部。砂体类型有分流河道砂体、水下分流河道砂体、河口坝砂体及决口扇、天然堤与远砂坝砂体。含油性分析表明,三角洲前缘亚相的水下分流河道微相与河口坝微相发育区应是油气富集区,是今后该区油气勘探的有利地区。     

The Formation and Circulation of the Intermediate Water in the Japan Sea

In order to clarify the formation and circulation of the Japan/East Sea Intermediate Water (JESIW) and the Upper portion of the Japan Sea Proper Water (UJSPW), numerical experiments have been carried out using a 3-D ocean circulation model. The UJSPW is formed in the region southeast off Vladivostok between 41°N and 42°N west of 136°E. Taking the coastal orography near Vladivostok into account, the formation of the UJSPW results from the deep water convection in winter which is generated by the orchestration of fresh water supplied from the Amur River and saline water from the Tsushima Warm Current under very cold conditions. The UJSPW formed is advected by the current at depth near the bottom of the convection and penetrates into the layer below the JESIW. The origin of the JESIW is the low salinity coastal water along the Russian coast originated by the fresh water from the Amur River. The coastal low salinity water is advected by the current system in the northwestern Japan Sea and penetrates into the subsurface below the Tsushima Warm Current region forming a subsurface salinity minimum layer. This revised version was published online in August 2006 with corrections to the Cover Date.     

1967—2016年黄河上游河曲地区降水变化特征研究

利用1967~2016年黄河上游河曲地区的5个气象站观测气象站的逐日地面降水和气温资料,利用气候变化趋势分析、距平、Mann-kendall 时间序列突变及趋势检验方法分析了该地区气温变化特征、不同类型各等级降水量及降水日数的气候特征。结果表明：(1)近50年黄河上游河曲地区年均气温以0.459℃/10a趋势显著上升,上升速度低于全国其它地区,且在2002年气温发生突变后升温加剧;(2)年降水量和降水日数呈减少趋势,主要是由夏季小雨量和小雨日数的减少引起;(3)在2002年气温突增后,强降水对总降水量贡献率增加,且年降水量和降水日数波动幅度也明显增大,这可能预示该地区洪涝灾害的风险在增加。降水日数的贡献率增加,增加明显的是中雨日数和小雨日数,分别增加了1.1%和1.7%。     

Building and Testing an <Emphasis Type="Italic">a priori</Emphasis> Geophysical Model for Western Eurasia and North Africa

We construct and evaluate a new three-dimensional model of crust and upper mantle structure in Western Eurasia and North Africa (WENA) extending to 700 km depth and having 1° parameterization. The model is compiled in an a priori fashion entirely from existing geophysical literature, specifically, combining two regionalized crustal models with a high-resolution global sediment model and a global upper mantle model. The resulting WENA1.0 model consists of 24 layers: water, three sediment layers, upper, middle, and lower crust, uppermost mantle, and 16 additional upper mantle layers. Each of the layers is specified by its depth, compressional and shear velocity, density, and attenuation (quality factors, Q _P and Q _S ). The model is tested by comparing the model predictions with geophysical observations including: crustal thickness, surface wave group and phase velocities, upper mantle _n velocities, receiver functions, P-wave travel times, waveform characteristics, regional 1-D velocities, and Bouguer gravity. We find generally good agreement between WENA1.0 model predictions and empirical observations for a wide variety of independent data sets. We believe this model is representative of our current knowledge of crust and upper mantle structure in the WENA region and can successfully be used to model the propagation characteristics of regional seismic waveform data. The WENA1.0 model will continue to evolve as new data are incorporated into future validations and any new deficiencies in the model are identified. Eventually this a priori model will serve as the initial starting model for a multiple data set tomographic inversion for structure of the Eurasian continent.     

鲁西沂南铜井闪长质岩体锆石U-Pb年龄、元素及同位素地球化学特征

对鲁西沂南铜井岩体的中生代闪长玢岩进行了主量元素、微量及稀土元素、Sr-Nd-Pb同位素以及锆石U-Pb年龄、Hf同位素研究,结果表明,铜井闪长玢岩SiO2含量为54.68%～63.01%,富Na,Na2O/K2O为0.93～4.46,Mg#较高,为55～66,为中钾-高钾钙碱性系列,TiO2含量较低,0.2%～0.71%。样品具有显著的LREE富集[(La/Yb)n=10～15]以及高场强元素Nb、Ta和Ti的负异常,Eu基本无异常,Sr、Ba含量高(分别为241×10-6～711×10-6和554×10-6～822×10-6)的特征。ISr和εNd(t)值分别为0.706473～0.708867和-15.13～-9.18,与鲁西方城玄武岩和前人所研究的沂南辉长岩结果有所差异,显示其源区具有多端员混合特征,除了富集岩石圈地幔外,亏损地幔和地壳物质的贡献也很重要,Pb同位素也显示其源区有扬子克拉通物质的贡献,佐证了华北克拉通中生代富集岩石圈地幔的形成与扬子克拉通的俯冲有关。闪长岩中锆石具有典型的岩浆锆石特征,U-Pb年龄为128～129Ma,锆石εHf(t)值主要在-13～-8(平均值为-10.3)范围内,暗示了岩浆来源于富集岩石圈地幔,但受到亏损地幔物质的混染。沂南铜井闪长玢岩岩浆源区的多元性以及亏损地幔物质参与程度的逐渐增强,说明该地区中生代岩石圈减薄已达到最大,岩浆源区的差异可能也是该地区与胶东地区成矿性差异的主要原因之一。     

天山上地幔结构及其对壳内构造运动的作用

以深部地球物理资料为基础,介绍了天山地震带上地幔的基本结构,讨论了天山不同地区上地幔介质的动力学性质和可能的驱动机制。认为水平挤压形变是造成西天山和天山毗邻西昆仑附近区域上地幔岩石圈缩短和增厚的主要原因;而在中天山和东天山靠近准噶尔盆地南缘一带,除了板块运动造成的水平挤压力之外,上地幔热物质有可能上浮甚至侵入到地壳之中。它们与水平运动一样,对壳内脆性介质的构造活动起到非常重要的作用,特别是地壳底部莫霍面附近的低速滑脱层成为震源区深部构造的一个明显标志。此外,自从印度 亚洲大陆碰撞以来,天山部分地区固结冷却的山根有可能在多重挤压变形和小尺度热对流的共同作用下,脱离它们的原有的层位而沉入上地幔     

中国石油地质学创新发展论评

石油地质学是国家石油战略的组成部分,是国家石油安全的组成部分,必须予以高度重视。石油地质学来源于实践。但随着石油勘探开发实践的不断深入,仅仅依靠归纳和总结来自实践的认识已经无法满足人们对石油地质学在科学层面的理解和掌握。从沉积层获得的有关构造、生油、储层方面的知识无法全面解释在结晶基底和火山岩中发育油气藏的事实,而最新揭示出金属、非金属矿床、油气藏与深部构造和深部流体存在密切关系,为我们发展石油地质学提供了崭新的思路。欧洲惠更斯号探测器发现土卫六上存在甲烷湖的事实告诉我们,石油地质学的不仅仅是地质学问题,更是天文学问题。所以,及时吸收消化各学科最新成果,创新发展中国石油地质学,已是保障国家石油安全的当务之急。     

中国大陆及邻区上地幔各向异性研究

为了深化对中国大陆及邻区上地幔介质形变强度和方向的空间变化图象、各向异性和剪切波分裂、各向异性以及应变、应变和构造过程关系的认识，我们以剪切波在分层各向异性介质中的传播理论为指导，以分裂剪切波观测为基础，借助数字化地震资料和高分辨率的信号处理技术，给出了对136次地震的分析结果，得到了20个台站下面的上地幔各向异性介质的变形强度和方向的空间变化图象；并结合已有研究结果，对中国大陆及邻区上地幔各向异性特性及其起源问题进行了讨论．      

中条裂谷的幔柱构造与成矿

中条山地区的地球物理场具有“三低一高”(低波速、低密度、低黏度及高地热异常)特点,变质核杂岩中赋存有科马堤岩并具“双层”结构,火成岩呈“双峰”状态,变质期的古地温为522～608℃,压力0.3～0.73GPa,地热梯度23℃/km,表明中条山地区为新太古代-元古宙的大陆裂谷—地幔热柱构造.其成矿作用存在着“四代同堂”的成矿模式,成矿期与岩浆侵入期的时差甚小;成矿空间上,大多数矿床沿着裂谷内两组断裂呈X型“对称式”展布,有益元素矿物组合及成矿温度自中心向周围呈有规律降低趋势.由于在新太古代以前,富铜的扬子板块俯冲至华北板块之下,促使中条裂谷的地壳加厚,形成丰富的成矿物质场,因为地幔热柱脉动式隆升,热液在运移过程中不断萃取地壳的铜质,故成为区域内独特的铜矿集中区.     

Tectonic and eustatic control on deposition and preservation of Upper Cretaceous ooidal ironstone and associated facies: Peace River Arch area, NW Alberta, Canada

The Late Coniacian, shallow-marine Bad Heart Formation of the Western Canada foreland basin is very unusual in that it contains economically significant ooidal ironstone. Deposition of shallow-water and iron-rich facies appears to have been localized over the crest and flanks of a subtle intrabasinal arch, in part interpreted as a forebulge and partly attributed to reactivation of the long-lived Peace River Arch. The formation comprises two upward-shoaling allomembers, typically 5–10 m thick, that are bounded by regionally mappable ravinement surfaces. The lower unit, allomember 1, grades up from laminated mudstone to bioturbated silty sandstone, which is abruptly overlain by bioturbated ooidal silty sandstone grading into an almost clastic-free ooidal ironstone up to 7 m thick. Ooidal ironstone was concentrated into NW- to SE-trending ridges, kilometres wide and tens of kilometres long. Ironstone formation appears to have been promoted by: (a) drowning of the arch, which progressively curtailed sediment supply; and (b) enhanced reworking over the shallowly submerged arch and over a fault-bounded block that underwent episodic vertical movement of 10–20 m during Bad Heart deposition. Allomember 2 also shoals upwards from mudstone to bioturbated and laminated silty sandstone but lacks ooids, apparently reflecting a rejuvenated supply of detrital sediment from the arch. The marine ravinement surface above allomember 2 is a Skolithos firmground, above which is developed a regional blanket of ooidal sediment. In the east, ooids are dispersed in a bioturbated silty sandstone with abundant evidence of repeated reworking and early siderite and phosphate cements. Westwards, this facies grades, over about 40 km, into almost clastic-free ooidal ironstone about 5 m thick; the lateral facies change may reflect progressive clastic starvation distal to a low-relief source area. The two allomembers are interpreted to reflect eustatic oscillations of about 10 m, superimposed on episodic tectonic warping and block-faulting events. The development of ooidal ironstone immediately above initial marine flooding surfaces indicates a close relationship to marine transgression, reflecting sediment-starved conditions. Ironstone does not appear to be related to either sequence boundaries or maximum flooding surfaces. The Bad Heart Formation is blanketed by marine mudstone deposited in response to major flexural subsidence and rejuvenation of clastic sources in the Cordillera to the SW.