Dissertation > Excellent graduate degree dissertation topics show

Genesis and an Evaluation for Granite-Pegmatite Type Columbotantalite Ore-Forming Potential in the Northern Margin of the Qaidam Basin, Qinghai, P.R. China

Author: LvXiaoQiang
Tutor: ShaoTieQuan
School: Chang'an University
Course: Mineral prospecting and exploration
Keywords: granite-pegmatite type deposit columbotantalite ore genesis metallogenicpotential north margin of the Qaidam Basin Qinghai
CLC: P618.79
Type: Master's thesis
Year: 2012
Downloads: 72
Quote: 0
Read: Download Dissertation

Abstract


The northern marginal metallogenic belt of Qaidam Basin, where is rich in ore-formingelements, such as non-ferrous metals, Cr-Ni and rare metals, possesses good material base offorming endogenetic metal ores. The pegmatites in Shengge area are the main explorationtargets for rare metal-gem deposits. In the thesis, by doing research on field geologicalfeatures, petrography, mineralogy and geochemistry of the niobium-tantalum-rich graniticpegmatites, we will study the genesis and mineralizing process of pegmatite-typecolumbotantalite. At the same time, we would discuss the formation mechanism of magmaliquid segregation, occurrence of niobium and tantalum and metallogenic evolution. We havetentatively set up a metallogenic model of the pegmatite-type columbotantalite. Throughstudying the pegmatitic metallogenesis, we have analyzed the features of metallogenic seriesand evaluated the niobium-tantalum-forming potential. The results obtained are as follows:1) The pegmatitic veins in the study area, which are small in scale and large in quantity,are distributed alternately in groups and belts. Being controlled by the regional secondaryfaults and fractures, most of the pegmatites are veined or lentoid. The pegmatites are mainlymicrocline-type, microcline-albite-type, albite-type and muscovite-type. The pegmatitic veinshave high ratio of mineralized ones to the total, uneven mineralization, high grade andconsiderable resource.2) The pegmatites develop metasomatic phenomenon widely, which is characteristic ofalbitization and muscovitization. It shows positive correlation between metasomatism andniobium-tantalum mineralization. Most of the niobium and tantalum occurs in independentmineral of columbite and columbite-tantalite, while a small quantity of them occurs in spheneand hematite by isomorphism. The tectonic superimposed stress, which occurred in and afterdiagenetic stage, resulted in obvious brittle-ductile deformation in the rocks.3) Do systemic research about the geochemical characteristics of pegmatite. Thepegmatite is alkali-rich and peraluminous. The content of REE is low and exhibit a M-typetetrad effect. The contents of Li, Rb, Nb, Ta and REE change as the alkali metasomatism(K-Na-(Li, K)) development regularly. At the same time, there is mineralization of Nb-(Nb,Ta)-Nb. 4) The pegmatitic veins are the result of magma liquid segregation. After high degree offractionation, pegmatite magma, which was rich in volatile components and rare elements,moved along structure fractures and formed abundant pegmatite veins. Rare elements, such asNb and Ta, assembled, migrated, concentrated and precipitated during this process.5) Pegmatitic veins of the same types but different geochemical characteristics have beenfound in the research area. They are all muscovite-albite pegmatite veins, but the onesoccurred in the southeast margin of the area have higher content of rare and radioactiveelements, such as the REE, Nb and Th. This feature suggests that there should be more thanone (at least two) stages of pegmatite mineralization.6) The studied object is similar to the metallogenic series of I-type granite inWuyi-Yunkai area, and can be contrast to the metallogenic setting and genetic model oftypical pegmatite-type rare metal deposits in China. With advantageous tectonic magmatichydrothermal mineralization of Nb and Ta, the area shows a great metallogenic potential.

Related Dissertations

  1. Qinghai Qilian Mountains in Sichuan Parnassiidae of foraging behavior and breeding ecology,Q968
  2. Land Desertification in Qinghai Lake Landscape Pattern Change,X171
  3. Qinghai Nationalities Area School year study into the compulsory education system,G759.2
  4. Qinghai Tibetan national consciousness of college students,G751
  5. Qinghai-Tibet railway landslide hazard assessment,P642.22
  6. Qinghai Oilfield Technology Services Knowledge Worker Incentive Strategy,F426.22
  7. Qinghai Oilfield Staff training satisfaction survey,F426.22
  8. Transfer of rural surplus labor force in Ethnic Areas Employment Research,F323.6
  9. Qinghai College Students Receive the Situation of Mass Media Sports Information,G807.4
  10. Table Tennis in Qinghai College Status and Development Strategies,G846
  11. Qinghai PE teachers job satisfaction,G807.4
  12. The Implement Program of Qinghai Oilfield Engineering Construction Human Resource Disposal,F426.22
  13. The Study on the Adaptability of Highway Traffic and Tourism Based on the Barrel Theory,F224
  14. Floristic and Geographical Characteristics and Protection Status of Rare & Endangered Plants and National Key Protected Plants in Qinghai Province,Q948
  15. A Study on Urban Systems in Qinghai Province Based on the Fractal Theory,F299.2
  16. Study on Staff Incentive Mechanism for Labor Service Company of Qinghai Oil Field,F426.22
  17. The Study on the Space-time Evolution of Road Network and the Coupling with Regional Economic Growth of Qinghai Province,F127;F224
  18. Researches on the Archaeological Culture and Ethnicity of Bronze Age in the Region of Gansu & Qinghai,K872
  19. Exploitation and Utilization of Physical Education Curriculum Resources in the Colleges and Universities in Qinghai Province,G807.4
  20. Re-employment of Retired Athletes in Qinghai Province Analysis and Research,G812.3
  21. Qinghai Province of Football Sports Development and Countermeasures,G843

CLC: > Astronomy,Earth Sciences > Geology > Of ore deposits > Deposit classification > REE and dispersed elements > Niobium
© 2012 www.DissertationTopic.Net  Mobile