Dissertation > Excellent graduate degree dissertation topics show

Chronology, Geochemical Characteristics of the Metabasic Volcanic Rocks from Huluhe in Eastern Section of Qilian Orogenic Belt, and Their Tectonic Significance

Author: SunRenQi
Tutor: PeiXianZhi
School: Chang'an University
Course: Mineralogy,petrology, Mineral Deposit Geology
Keywords: metabasic volcanic rocks zircon U-Pb dating geochemistry back-arc basin eastern section of Qilian orogenic belt
CLC: P588.14
Type: Master's thesis
Year: 2007
Downloads: 58
Quote: 0
Read: Download Dissertation

Abstract


This dissertation mainly studies Huluhe metabasic volcanic rocks in eastern section of Qilian orogenic belt primarily in petrography, geochemistry and isotopic geochronology combining with regional geology, structure, tectonics, etc., to define their ages, identify the cause of formation and tectonic settings, and to discuss their regional adscription. Further it illustrates the evolving history of paleo-plate in the study area; Meanwhile, it also provides important basic scientific data for discussing the composition , tectonic framework , forming and evolvement of eastern section of Qilian orogenic belt and the basic characteristics of continental orogenic belts, and exploring the continental dynamics in China.The following chief conclution and knowledge have been obtained by the studies of Huluhe metabasic volcanic rocks:(1) The Huluhe metabasic volcanic rocks are mainly composed of grayish green metabasalt and basaltic andesite, intercalated by a few offwhite-light-grey sillcalite. Geochemical characteristics of major elements, rare earth elements and trace elements , and the tectonic settings discrimination show that the metabasic volcanic rocks generally belong to back-arc basin tholeiitic basalt series- calc - alkalic basalt series with low kalium, also have the characteristics of MORB and WPB. Trace element characteristics show that the basic magma roots in enriched mantle wedge metasomatized by fluid in subduction belt, hybridized by continental crust material.(2) Using the cathodoluminescence (CL) images of zircons and LA-ICP-MS zircon U-Pb dating obtain the isotopic ages between (436.9±5.7)Ma and (443.4±1.7)Ma, which suggests that the Huluhe metabasic volcanic rocks formed in Late Ordovician.(3) Eastern section of Qilian orogenic belts extended in Late Ordovician Period , oceanic basin systems went through opening and formed Chenjiahe Group volcanic-sedimentary rock series; those oceanic basin systems went on opening and formed Huluhe metabasic volcanic rocks belt of back-arc rift-small ocean basin tectonic environment in Late Ordovician Period.(4) The comparative studies between Huluhe metabasic volcanic rocks and Hongtubao metabasic volcanic rocks show that there are conjunction and extension relation between them; they are of the same volcanic rocks belt.(5) The joining relation of Qilian and Northern Qinling tectonic belts in early Palaeozoic is that Northern Qinling extended westward to become many limited oceanic basin and small oceanic basin systems divided into by microlandmasses. These oceanic basin systems went through opening and developing various ophiolite or rift volcanic rocks etc.; Successively, many volcanic magma island arc tectonic belts formed, untill subduction, collision and orogenesis in early Palaeozoic. Early Palaeozoic Yangjiasi-Hongtubao-Fenggeling back-arc rift-small ocean basin and Humao-Xincheng intermediate-acidic volcanic island arc belts are one of the volcanic magma island arc tectonic belts.

Related Dissertations

  1. Orefield Structure and Geochemistry in the FanKou Lead and Zinc Deposit,P618.4
  2. Distribution and Causes of Heavy Metal Elements in Qingdao,X53
  3. Santanghu Basin Carboniferous volcanic reservoir rocks and geochemical characteristics,P618.13
  4. Metallogenic Geochemistry Study of the Mn Deposit in Hougou-Dapingshan in Mianxian, Shanxi Province,P618.32
  5. Research on the Environmental Geochemistry of Hazardous Element in Coal Gangue of Fushun Coalfield,X142
  6. Analysis of Sedimentary Characteristics and Provenance of Surficial Sediments on the West South Yellow Sea,P736.21
  7. Jiyang crude mechanism of gold enrichment,P618.13
  8. Sb & Au Occurrence Geochemistry Research and Utilization in Tailings of Qinglong Antimony in GuiZhou,P618.66
  9. Lancang old factory buried porphyry petrology, geochronology and genesis,P588.121
  10. Yunnan Xinping Dahongshan iron copper deposit geochemistry and prospecting analysis,P618.41
  11. Copper River District Mouding Haojiatai Geochemical Prospecting Research,P618.41
  12. Geochemical characteristics and origin of Deqin County Yangla copper deposit,P618.41
  13. Definition of Early Mesozoic Granitoids from Beishan Orogen, Origin and Their Tectonic Significance, and Spatio-temporal Distribution of Early Mesozoic Granitoids in Central and South CAOB,P588.121
  14. Study on the Ore-forming Structure and Tectonic Geochemical Prospecting of Wangershan Gold Mining in Northwest Jiaodong Peninsula,P618.51
  15. Xinjiang Cihai iron deposit geochemical characteristics,P744
  16. Characteristics of Grain Size and Element Geochemistry of Garze a Section on West Sichuan Plateau,P532
  17. Application of Several Kinds of Statistical Analysis Methods in the Geochemical Data Processing,P632
  18. Zhaotong Yiliang maoping lead-zinc Hedong structure geochemical prospecting applied research,P618.4
  19. Midu geochemical characteristics of magmatic rocks of Himalayan magmatic evolution,P588.1
  20. The central Yunnan Haojiatai River Liuju Geological and geochemical characteristics of copper deposit contrast,P618.41
  21. The Midu region of Upper Paleozoic sedimentary geochemical characteristics and paleoenvironmental analysis,P618.13

CLC: > Astronomy,Earth Sciences > Geology > Petrology > Classification of rocks > Magmatic rocks ( igneous ) > Extrusive (volcanic )
© 2012 www.DissertationTopic.Net  Mobile