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.     

1966年邢台地震静态库仑应力触发分析

通过分析1966年邢台5次地震的静态库仑应力触发情况发现,前2次地震对后面的地震有较好的触发,而MS7.2以后地震的触发不理想。从而认为,随着地震的发生和震源深度的增加,岩浆活动对地壳介质的影响越来越大,地壳介质弹性性能越来越弱,即该区域浅部可以用均匀弹性半空间来近似,而深部在岩浆等因素的影响下,用均匀弹性半空间来近似存在较大的误差,不适合用弹性位错理论计算地震的触发关系。这从侧面反映了该地区岩浆活动的剧烈性和超壳断层存在的客观性。     

桂东南那卜地区古生代变质岩系的构造演化序列

桂东南那卜地区古生代变质岩系 ,主要由花岗质岩石 (宁潭超单元 )和古生界组成。岩石构造变形强烈 ,构造形迹复杂 ,根据不同尺度上观察到的各种构造要素的几何学、运动学、构造应力场以及相互叠加关系等特征 ,可将其组成不同的构造组合 (群落 )。依据各构造组合之间的相互关系、同位素年龄 ,并结合相应的变质事件和岩浆活动事件等 ,建立起 2个旋回和 4个世代的构造变形序列。并初步探讨了古生代变质岩系的构造演化过程。     

板块构造图的制图理论与方法探讨

通过编制区域性1:300万“青藏高原板块构造图”和1:50万“柴达木北缘板块构造地质图”的体会,并结合国内学者对这两份图件的审查意见及建议,重点讨论有关区域性板块构造图编制的理论与方法,供区域地质工作者参考。     

广西若干重大基础地质特征

文章根据华南地区物探、化探、遥感编图广西综合解译成果,研究广西若干重大基础地质特征,着重讨论地壳结构、深部构造、主要隐伏深断裂带、基底性质等,以板块观点划分大地构造单元,提出广西地壳属陆壳型性质和扬子板块在广西的边界划在三江-大新一线的新认识.     

鲜水河断裂带的构造大地测量

利用短边GPS点阵、短基线标石阵和精密激光测距 ,在与鲜水河断裂带的断层破裂带垂直的剖面上和构造盆地内进行构造大地测量 ,获得了断层软弱带和断层蠕变带上的最佳形变分布。综合利用相关地学成果和理论 ,揭示了构造形变所隐含的动力学信息 ,识别了断层应变带、塑性流变带和主断面在地面的分布范围。用外围GPS远场联测成果探讨了该断裂带的驱动力机制 ,匡正了其“左旋”运动和现今活动速度的含义。最后 ,评估了该断裂的地震活动趋势     

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Reconstruction of protoliths of metamorphic rocks and tectonic setting of Wolegen Group

Parametamorphic rocks from Arong County in southeastern Inner Mongolia-Daxinganling district are regarded as Proterozoic in age,belonging to the Wolegen Group and composed of volcanoclastic and sandstone in origin,and have been disputed in tectonic setting.Because of the stability in metamorphism,the rare earth dements indicate the features of their protoliths.The authors integrated the petrologic methods with the geochemical parameters which include ∑REE,∑LREE/∑HREE,δCe,δEu,La/Yb,Sm/Nd,Th/Sc and the standard values of chondrite.The results show that the protoliths of Wolengen Group may be a group of voleanoclastic and continental margin elastic rocks,and their tectonic setting is the continent island arc.     

Zircon U-Pb geochronology and geochemistry of syenogranites in western Niubiziliang,northwestern Qaidam,Qinghai

The study presents the results of U-Pb dating of zircons and whole-rock geochemical analyses of a syenogranite located in the western Niubiziliang area,China with the aim of determining its formation time,petrogenesis and the regional tectonic setting. Zircons within the syenogranite are euhedral-subhedral and display rhythmic growth zoning,indicating a magmatic origin. Zircon U-Pb data obtained by LA-ICP-MS indicate the syenogranite formed in the Late Permian (260.7±1.5 Ma). The w(SiO_2) of syenogranites is 70.82%--73.59%,w(Al_2O_3) is 13.49%--14.82%,and w(Na_2O + K_2O) is 7.85%--8.52%,and yield K_2O/Na_2O ratios of 1.06--1.26. Therefore,the syenogranites belong to the high-K calc-alkaline and metaluminous (A/CNK 1,A/NK 1) series which display I-type granites similarly. The syenogranites also show the geochemical characteristics of volcanic arc rocks,being enriched in large-ion lithophile elements (LILEs; K,Rb) and light rare-earth elements (LREEs; La,Ce,Sm,Nd),but depleted in high field strength elements( HFSEs; Ta,Nb,P,Ti). On the whole,trace element ratios are close to the mean of the Earth's crust,indicating a lowercrust magma source. The low Sr (161--214) ×10~(-6) and Yb (1.08--1.80)×10~(-6) concentrations indicate that plagioclase and hornblende are residual mineral phases in the source. The regional geology and whole-rock geochemistry suggest that the formation of the syenogranites was related to subduction of the Zongwulong Ocean crust,and the north margin of Qaidam Block during the Late Permian was in an active continental margin tectonic setting.     

文安MS5.1地震前区域形变异常研究

对2006-07-04文安MS5.1地震前2001~2004年区域GPS站速度场和应变率场使用刚性-线弹性运动模型拟合处理的结果进行研究,获得文安MS5.1地震的1~3 a期的前兆异常。结果表明,地震发生在异常区高异常体发育的边缘梯度带的转折处。