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| 1 | Adakite-type sodium-rich rocks in Awulale Mountain of west Tianshan:Significance for the vertical growth of continental crust显示文摘The sodium-rich dacites and albite porphyries of Permian in the Awulale Mountain of west Tianshan have unique chemical and trace element signatures identical to adakite. These intermediate-acidic igneous rocks are characterized by high Na2O, Al2O3 and Sr contents and high Sr/Y and La/Y ratios (>40 and >20, respectively), and low Y and Yb contents, and strong depletion in HREE, and positive Eu anomaly. The (143Nd/144Nd)i is in the range from0.51236 to 0.51248 and the εNd(t) is positive value (+0.79-+3.11); the (87Sr/86Sr)i is in the range from 0.7052 to 0.7054. These Nd and Sr isotopic composition features indicate that the source rocks of these adakite-type rocks are from a weakly depleted mantle, or a depleted mantle, but was contaminated by the crustal materials. These adakite-type rocks were most likely derived from the partial melting of new underplated basaltic rocks under the conditions of amphibo-lite to eclogite transition in the postcollisional environment of North Xinjiang during the Permian | XIONG Xiaolin ZHAO Zhenhua BAI Zhenghua MEI Houjun WANG Yixian WANG Qiang XU Jifeng Niu Hecai BAO Zhiwei | 2001 | Chinese Science Bulletin2001，46，10： | 25 |
| 2 | Comments on the planation surface once more显示文摘The authors reviewed the research of planation surface in recent years and commented on the development of method and theory about the planation surface. Some aspects of research, such as the restrictive planation surface, the karst planation surface, the fossil planation surface, the dating of weathering crust, the research of weathering crust and environmental evolution, extremely enriched the method and theory of the planation surface. Besides, the authors pointed out that we must take further steps to study the following issues: the deformation of planation surface, the original height of planation surface, the recognition and contrast of the planation surface. The weathering crust and planation surface should be regarded as a whole, and it will still be a principal aspect in the future. | CUI Zhijiu LI Dewen FENG Jinliang LIU Gengnian | 2002 | Chinese Science Bulletin2002，47，10： | 4 |
| 3 | Poisson's ratio of eclogite: Implications for lower crustal delamination of orogens显示文摘Laboratory measurements of combined P- and S-wave-velocities of eclogite from the Dabie-Sulu ultrahigh pressure metamorphic belt and from literature data show a significant increase of Poisson抯 ratio of eclogite with its intrinsic water content H2O+ and thus the degree of hydration. Unaltered eclogites with H2O+<1.0% have an average Poisson抯 ratio between 0.24 and 0.25, which is identical to that calculated from single crystal elastic properties but lower than the averages (0.270.02) of measurements compiled by previous studies. Thus, the Poisson抯 ratio of unaltered eclogites is considerably lower than that of lower crustal mafic granulite and upper mantle peridotite. The lower crust and upper mantle of the Dabie ultrahigh pressure metamorphic belt, the northern and southern parts of the Tibetan Plateau as well as the central Andes, where eclogite may have formed during Mesozoic and Cenozoic tectonism, are characterized by the Poisson抯 ratio >0.26. This, together with their normal upper mantle P-wave velocities, implies that eclogites are no longer an important component of the present-day lower crust and upper mantle of these subduction-collision belts. Combined with age constraints on eclogite-facies metamor- phism and subsequent exhumation, this in turn suggests that the interval from formation to delamination of eclogites is confined to a very short period of <15 Ma. | 高山 Hartmut Kern 金振民 张宏飞 张本仁 | 2003 | Science China Earth Sciences2003，46，9： | 4 |
| 4 | Discovery of the Early Mesozoic granulite xenoliths in North China Craton显示文摘The discovery of the Early Mesozoic basic granulite xenoliths in the Harqin area of the Inner Mongolia Autonomous Region (for short Inner Mongolia) is reported for the first time in this paper. According to the mineral assemblage the xenoliths include two-pyroxene granulite, clinopyroxene granulite, and hypersthene granulite. Their protolytes are mainly gabbroite rocks. The zircon U-Pb age of the granulite xenoliths is 251 Ma, and K-Ar age of the hypersthene is 229 Ma. They represent the times of metamorphism and cooling of the granulite facies respectively. The host rock of the xenoliths is Early Mesozoic biotite-quartz diorites, whose whole-rock K-Ar age is 219 Ma. This discovery confirms existence of an Early Mesozoic underplating in the North China Craton, which is of much importance in research on the Early Mesozoic mantle-crust interaction in the concerned area. | 邵济安 韩庆军 李惠民 | 2000 | Science China Earth Sciences2000，43，S1： | 4 |
| 5 | A finite difference study on the basement structure beneath the Tianshan Orogen显示文摘We use the Pg seismic phase along the Korla-Jimsar profile across the Tianshan orogen and the 3D finite difference method to inverse the velocity structure of the upper crust beneath the basement of this mountain. Based on the velocity structure, the Korla-Jimsar profile can be divided into three parts, i.e. the north edge of the Tarim basin, the Tianshan orogen, and the south margin of the Junggar basin. Within the Tianshan there is a pattern of four convexities and three concavities, which correspond to the southern Tianshan, the Yanqi basin, the middle Tianshan, the Turpan basin, and the Bogda Mountains. In the north edge of the Tarim basin, the basement is about 10km deep with small lateral variations of velocity. In the Tianshan the velocity varies greatly laterally. The basement depth of the Yanqi basin is 6 km, which becomes shallow rapidly northward, and almost to the surface at the middle Tianshan. South to Kumux there is a small intermountain basin, where the maximum basement depth is 3 km, and also turns very shallow near Kumux. The Luntai fault, which bounds the Tarim basin and Tianshan, has vertical dislocation of about 5 km. The Turpan basin is covered with so thick a sediment that its basement is 7 km deep. The boundary fault between the Tianshan and Turpan is the Bolohoro fault which is characterized by quick deepening basement and 7 km vertical dislocation. In the Junggar basin the basement is 8 km deep. On the Korla-Jimsar profile, the velocity distribution of the upper crust and the structure are featured by NS symmetry on both sides of the axis of the Middle Tianshan, consistent with the deep structure revealed by this profile. It means that the Tarim ba-sin and the Junggar basin underthrust toward the Tianshan from south and north, respectively. Such a structural style is different from that of another profile, i.e. the Xayar-Burjing profile, sug-gesting that there may be an important tectonic boundary between these two profiles. | ZHAO Junmeng1,2, WANG Qingchen3, GAO Xing1, DUAN Yonghong4, JIA Shixu4 & PAN Shuzhen4 1. Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100085, China 2. Institute of Geology, China Seismological Bureau, Beijing 100029, China 3. Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China 4. Geophysical Exploration Center, China Seismological Bureau, Zhenzhou 450002, China | 2004 | Science China Earth Sciences2004，47，z2： | 2 |
| 6 | STUDY ON THE MOISTURE PASSAGE ON THE LOWER REACHES OF THE YARLUNG ZANGBO RIVER显示文摘A series of gorges on the lower reaches of the Yarlung Zangbo River is like an enormous crevice splitting the southeastern Qinghai-Xizang (Tibet)Plateau to create a passage through which warm, wet air flow from the Indian Ocean reaches the inner part of the plateau. This moisture passage was mainly strengthened after the Pleistocene epoch in the Quaternary period and has played a major role in affecting the beginning date of the rainy season and the amount of the plateau’s rainfall. It has also served as a corridor for the living things on the southern and the northern sides of the Himalayas to mingle with each other. The region along this passage is abundant in evidences of species of differentiation, variation and biological division. Also the passage has provided a favorable environment for human beings and affected natural phenomena there. | 杨逸畴 高登义 李渤生 | 1989 | Science China Chemistry1989，32，5： | 2 |
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