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61.
塔里木地块西北缘的阔什布拉克钾长花岗岩富碱(Na2O+K2O平均836%>8%),富钾(K2O/Na2O=127~147),准铝质(A/CNK=082~088),属于高钾钙碱性系列岩浆岩。岩石的稀土含量较高(ΣREE=26390×10-6~44575×10-6),富集Th、U、Ta、Nb、Hf和Y等高场强元素和大离子亲石元素Rb,具有强的负Eu异常(δEu=0003~0019),富集高不相容元素(Zr+Nb+Ce+Y=368×10-6~531×10-6>350×10-6),高Ga(Ga/Al×10〖CS%0,0,0,0〗〖CS〗000=417~472>26),显示出A型花岗岩的地球化学特征。岩石Th/U比值(平均为386)、Nb/Ta比值(平均为1275)和Rb Th富集、Ti亏损指示其壳源成因。对花岗岩进行的LA ICP MS微区原位锆石 U Pb 定年结果表明,花岗岩的结晶侵位年龄为2754±28 Ma。综合西南天山与塔里木盆地早二叠世花岗质岩浆活动的特点,认为早二叠世西南天山的后碰撞岩浆活动不仅在西南天山内部引起了强烈的花岗质岩浆活动,而且对塔里木地块西北边缘的花岗质岩浆活动也有显著的影响。阔什布拉克A型花岗岩也说明西南天山地区的碰撞造山作用在2754±28 Ma之前已经趋于结束,以南天山洋盆为代表的古亚洲洋已基本结束了其演化历史。 相似文献
62.
A sea-survey was carried out along the Chinese coast from the Bohai Sea to South China Sea, and 15 surficial samples were
taken from major coastal estuaries, i.e., from north to south, the Yellow, abandoned Yellow, Yangtze, Qiantang, Ou, Min, Han,
and Pearl River estuaries. On the basis of clay mineral analysis and published data collection, this paper discusses the characteristics
of clay minerals of each coastal river and potentials of implications of sediment sources. The results show that the change
of diagnostic clay minerals from smectite to kaolinite from the Yellow to the Pearl River estuaries is southward, as clearly
shown by the ratios of smectite to chlorite (S/Ch) and kaolinite to illite (K/I). S/Ch decreases southward, while K/I moves
reversely, implying change in climate setting from cool/dry to humid/hot with intensified weathering processes. Besides, these
two indicators in the estuaries are also linked with the derivation of parent-rock of each river-basin and coastal hydrodynamics.
The disproportional higher ratio of K/I in the Yellow and abandoned Yellow River estuaries is ascribed to their sediment sources
with abundant loess component in the north-central China. The K/I decrease offshore from the Pearl River estuary is primarily
due to hydrodynamic sorting. Therefore, the S/Ch and K/I of the present study comprehensively reflect the controls of climate,
parent-rock, and sediment transport along the coast. 相似文献
63.
Weiwei Song Wenting Yi Yidong Lou Chuang Shi Yibin Yao Yanyan Liu Yong Mao Yu Xiang 《GPS Solutions》2014,18(3):323-333
GLONASS carrier phase and pseudorange observations suffer from inter-channel biases (ICBs) because of frequency division multiple access (FDMA). Therefore, we analyze the effect of GLONASS pseudorange inter-channel biases on the GLONASS clock corrections. Different Analysis Centers (AC) eliminate the impact of GLONASS pseudorange ICBs in different ways. This leads to significant differences in the satellite and AC-specific offsets in the GLONASS clock corrections. Satellite and AC-specific offset differences are strongly correlated with frequency. Furthermore, the GLONASS pseudorange ICBs also leads to day-boundary jumps in the GLONASS clock corrections for the same analysis center between adjacent days. This in turn will influence the accuracy of the combined GPS/GLONASS precise point positioning (PPP) at the day-boundary. To solve these problems, a GNSS clock correction combination method based on the Kalman filter is proposed. During the combination, the AC-specific offsets and the satellite and AC-specific offsets can be estimated. The test results show the feasibility and effectiveness of the proposed clock combination method. The combined clock corrections can effectively weaken the influence of clock day-boundary jumps on combined GPS/GLONASS kinematic PPP. Furthermore, these combined clock corrections can improve the accuracy of the combined GPS/GLONASS static PPP single-day solutions when compared to the accuracy of each analysis center alone. 相似文献
64.
GPS Solutions - Carrier phase ambiguity resolution over long baselines is challenging in BDS data processing. This is partially due to the variations of the hardware biases in BDS code signals and... 相似文献
65.
66.
VELOCITIES OF PRECURSOR SOLITON GENERATION IN SINGLE LAYER FLOW 总被引:3,自引:0,他引:3
ImODUcrIONThegeneratingveodtyofprecmeorsolitonswasstudiedbyGrimshawetal.(l986),Wu(l987)andbeetal.(1989).TheydidnotgivetherelationbeweenthegeneratingvelocitiesandtopographyintenSityandthereexistSanunknownparameterh,inthetheoryofboetal.(l989),sotheprevioustheorycannotprediCtthegeneratingvelodtAs.ThisfurtherstudyonthetheoryofXuetal.(l996)ahetoconstIUCtatheoryonthegeneratingvefodtiesofsinglelayerflowfondbytopography.InSeCtion2,thernassandenergyoftheprecursorsolitongenerationaredetendnedint… 相似文献
67.
Xiaopeng Gong Shengfeng Gu Yidong Lou Fu Zheng Maorong Ge Jingnan Liu 《Journal of Geodesy》2018,92(7):797-809
Global navigation satellite systems (GNSS) are acting as an indispensable tool for geodetic research and global monitoring of the Earth, and they have been rapidly developed over the past few years with abundant GNSS networks, modern constellations, and significant improvement in mathematic models of data processing. However, due to the increasing number of satellites and stations, the computational efficiency becomes a key issue and it could hamper the further development of GNSS applications. In this contribution, this problem is overcome from the aspects of both dense linear algebra algorithms and GNSS processing strategy. First, in order to fully explore the power of modern microprocessors, the square root information filter solution based on the blocked QR factorization employing as many matrix–matrix operations as possible is introduced. In addition, the algorithm complexity of GNSS data processing is further decreased by centralizing the carrier-phase observations and ambiguity parameters, as well as performing the real-time ambiguity resolution and elimination. Based on the QR factorization of the simulated matrix, we can conclude that compared to unblocked QR factorization, the blocked QR factorization can greatly improve processing efficiency with a magnitude of nearly two orders on a personal computer with four 3.30 GHz cores. Then, with 82 globally distributed stations, the processing efficiency is further validated in multi-GNSS (GPS/BDS/Galileo) satellite clock estimation. The results suggest that it will take about 31.38 s per epoch for the unblocked method. While, without any loss of accuracy, it only takes 0.50 and 0.31 s for our new algorithm per epoch for float and fixed clock solutions, respectively. 相似文献
68.
西昆仑山前柯深—柯东地区断裂构造活动剧烈,在浅部地层中存在压力系数高达2.1的极高超压,对于这种超压分布特征和形成机制的研究和认识对钻井工程和油气运移研究具有十分重要的意义。综合储层实测压力、间接估算的泥岩地层压力以及超压地层岩石力学与物性的关系等资料,并结合研究区断裂发育条件和油气运移史,分析了地层压力分布特征和主控机制。结果表明,西昆仑山前柯深和柯东两地区在古近系—白垩系储层中各自形成了相对统一的异常压力系统,系统内地层压力向深部以静水压力梯度增加,储层压力大于附近泥岩压力。研究区储层压力分布特征与深部流体沿开启性断裂的向上传递密切相关。在此基础上,估算了压力传递量,并探讨了影响压力传递量的地质因素。柯深和柯东地区断裂传递增压量分别为15.0~34.0 MPa和8.1~16.5 MPa,与实测总剩余压力的比值分别为24.2%~67.2%和23.4%~53.7%。两个地区断裂传递增压量的差异主要受断裂发育及其与地层的空间配置关系的影响。 相似文献
69.
Zhang Qi Liu Qinzhi Lou Yahui Kong Dezhong 《Geotechnical and Geological Engineering》2022,40(6):3147-3168
Geotechnical and Geological Engineering - The trajectory of the actual gas drainage drilling often deviates from the design in the process of gas control drilling construction, resulting in the... 相似文献
70.
新场气田是川西的主力产气区,发育深层上三叠统(须家河组二段、须家河组四段)和中浅层中、上侏罗统(上沙溪庙组、蓬莱镇组)含气层系,均不同程度地产出地层水,气水关系复杂,不同层位间气水存在一定的联系。纵向上,深层地层水埋深为3 000~5 500 m,随埋深增加矿化度、盐化系数逐渐增大,呈现高演化地层水特征;中浅层地层水埋深为500~2 200 m,沟通较频繁,水化学特征差异不大,均呈现低矿化度、低盐化系数和高碳酸氢根离子浓度特点;两者之间为地层水混合过渡带。平面上,中浅层上沙溪庙组地层水矿化度在断裂发育带附近出现高值,高值范围与深层须家河组地层水矿化度低值区基本相对应。这主要是由局部深层与中浅层地层水沿向下断至深层、向上断至中浅层的断层垂向沟通并发生混合作用导致的。中浅层断裂附近,沿断裂带上涌的深层地层水与中浅层原始沉积地层水发生混合作用,使得砂体富含高矿化度地层水,天然气则沿渗透性砂体侧向运移并在一定距离的圈闭内聚集成藏,这对研究区中浅层天然勘探具有指导意义。 相似文献