THE ASIAN SUMMER MONSOON AND ITS RELATIONS TO THE RAINFALL IN CHINA

In this paper, four problems are discussed: (1) the monsoon circulation over southern Asia; (2) the seasonal variation of the general circulation of the atmosphere; (3) the influence of the monsoon on the rainfall in southwestern China; and (4) the source region of water vapor for the rainfall in the Changjiang valley.     

Background Seismicity and Its Application to Seismic Hazard Assessment in the North China Region

The historical earthquake activity is intense in the North China region. However, no middle-sized earthquakes have occurred in the last decades in the region since the MS6.2 earthquake in the Zhangbei region in 1998. The quiescence of moderate and strong earthquakes is quite prominent in North China. In this paper, we use small earthquake records in 1970~2009 to study background seismic activity in the North China region. The spatial distributions of seismic parameters are presented, including b-value, the maximum magnitude and annual occurrence probability of earthquakes of M≥6.0. Our results show regions with low b-value that include the Yuncheng region in the Shanxi rift, the Suqian region located in the Tancheng-Lujiang fault zone and the Shijiazhuang region in the Taihangshan block. Our analysis on the synthetic spatial pattern of seismicity indicate that seismicity in the North China region is mainly affected by the regional dynamic factors of deep structures.     

THE NORTHWARD PROPAGATION OF THE ARC TECTONICS OF THE NORTHEAST PAMIR AND NORTHWEST TARIM BASIN

THE NORTHWARD PROPAGATION OF THE ARC TECTONICS OF THE NORTHEAST PAMIR AND NORTHWEST TARIM BASINThisworkispartoftheresearchproject“themechanismofJiashistrongearthquakeswarmandprediction ofearthquakeriskinthenortheastPamir     

HXC气田蓬莱镇组气藏河道砂体快速识别研究

仅仅100－300m宽的河道砂体的快速识别对于降低勘探开发成本，提高经济效益具有重要的作用。基于对川西坳陷HXC气田蓬莱镇组碎屑岩气藏河道砂体的气藏特征的解剖和地球物理响应模式的建立，利用先进的三维可视化技术快速地识别了气藏的河道砂体，部署的钻井获得了勘探新突破。该方法在中国广泛的陆相地层中具有较高的推广价值。     

Aluminum solubility in bridgmanite up to 3000 K at the top lower mantle

The temperature dependence of the Al2O3 solubility in bridgmanite has been determined in the system MgSiO3–Al₂O₃at temperatures of 2750–3000 K under a constant pressure of 27 GPa using a multi-anvil apparatus.Bridgmanite becomes more aluminous with increasing temperatures.A LiNbO3-type phase with a pyrope composition(Mg₃Al₂Si₃O₁₂)forms at 2850 K,which is regarded as to be transformed from bridgmanite upon decompression.This phase contains 30 mol%Al₂O₃at 3000 K.The MgSiO3 solubility in corundum also increases with temperatures,reaching 52 mol%at 3000 K.Molar volumes of the hypothetical Al₂O₃bridgmanite and MgSiO₃corundum are constrained to be 25.95
0.05 and 26.24±0.06 cm³/mol,respectively,and interaction parameters of non-ideality for these two phases are 5.6±0.5 and 2.2±0.5 KJ/mol,respectively.The increases in Al²O³and MgSiO³contents,respectively,in bridgmanite and corundum are caused by a larger entropy of Al₂O₃bridgmanite plus MgSiO₃corundum than that of MgSiO₃bridgmanite plus Al₂O₃corundum with temperature,in addition to the configuration entropy.Our study may help explain dynamics of the top lower mantle and constrain pressure and temperature conditions of shocked meteorites.     

Cenozoic Adakite-type Volcanic Rocks in Qiangtang, Tibet and Its Significance

Volcanic rocks in the study area, including dacite, trachyandesite and mugearite, belong to the intermediate-acid, high-K calc-alkaline series, and possess the characteristics of adakite. The geochemistry of the rocks shows that the rocks are characterized by SiO2>59%, enrichment in A12O3(15.09-15.64%) and Na2O (>3.6%), high Sr (649-885 μg/g) and Sc, low Y contents (<17 μg/g), depletion in HREE (Yb<1.22 μg/g), (La/Yb)N>25, Sr/Y>40, MgO<3% (Mg<0.35), weak Eu anomaly (Eu/Eu=0.84-0.94), and lack of the high field strength elements (HFSE) (Nb, Ta, Ti, etc.). The Nd and Sr isotope data (87Sr/86Sr=0.7062-0.7079, 143Nd/144Nd=0.51166-0.51253, εNd= -18.61-0.02), show that the magma resulted from partial melting (10%-40%) of newly underplated basaltic lower crust under high pressure (1-4 GPa), and the petrogenesis is obviously affected by the crust's assimilation and fractional crystallization (AFC). This research will give an insight into the uplift mechanism of the Tibetan plateau.     

地质环境及其功能的控制与开发

地质环境是天然环境的一个组成部分，是人类居住和赖以生存的浅部地质空间。地质环境具有如下特征：空间性，其上限为地表，其下限视研究目的而定；稳定性，其环境要素是相对。稳定的；可变性，地质作用及人类活动可能改变局部地质环境；系统性，地质环境是一个由生物因素和非生物因素组成的环境系统，该系统本身具有恢复调节功能。地质环境的环境功能是指它对人类居住环境质量的影响。其影响有两种，一是使环境质量恶化的影响，是一种不良的功能；一是使环境质量得以保护和改善的影响，是一种良性功能。地质环境是环境工程的一种，是控制不良地质环境功能和开发良性地质环境功能的环境工程。地质环境工程是环境地质研究的一个新思路。地质环境工程包括有：地下水环境工程、控制不良地质环境的地质环境工程、净化废物的地质环境工程、贮存废物的地质环境工程、特殊地质环境的开发和利用。     

Isotope Geochemical Characteristics and Material Sources of Tin--Bearing Porphyries in South China

Tin-bearing porphyries in South China can be divided into the F-rich and F-poorsubtypes. They are high-silica (SiO_2>71%), peraluminous (A/NKC>1.0) and rich inincompatible elements (Rb, Zr, U, W, Sn) and have weak Ce (δCe=0.68-0.82) and strong Eu(δEu=0.01-0.38) negative anomalies. Meantime, they also have low δ_(Nd)(-6.3- -8.4), high~(207)Pb/~(204)Pb (15.588-15.790), medium to high (~(87)Sr/~(86)Sr)_i (0.7084-0.7287) and relatively highδ~(18)O(9.1-10.3‰). These characteristics clearly suggest that the two subtypes of tin-bearingporphyries were derived from the crustal materials. Their differences lie only in the existence ofcertain different components in their source materials. Therefore, there is only one type oftin-bearing prophyry in South China. that is continental crust transformation type.     

Palinspastic Reconstruction for Tectonics of Northeast China and Its Vicinity

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