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Geological Characteristics Of Jurassic Granite In Songjiang Area, Heilongjiang, China Northeast

Posted on:2015-01-15Degree:MasterType:Thesis
Country:ChinaCandidate:X Y JieFull Text:PDF
GTID:2250330422967476Subject:Unknown
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The research area is located in a’cheng city-bin county-ShangZhi city, the south ofthe Harbin city,heilongjiang province, which is situated in the eastern segment of theTianshan–Xingmeng orogenic belt. The geotectonic position belongs to East coast upliftbelt of Xiao xing an’ling–Zhangguangcai Mountains lot.The area is situated inComposite parts of Pacific Plate, Siberian Plate and North China Plate and other threecontinents blocks,which has experienced different continental blocks-put together,collision and collision of micro-continental block after stretching activities, has a uniquegeodynamic background. Since the Mesozoic, the region has entered a period of post-collision extensional stage, a large alkaline-effusive calc-alkaline granite emplacement,Songjiang area exposed granite is a typical representative ofthe Jurassic period.The research degree of Jurassic granite in Songjiang are relatively low. According tothe research of geological chronology,trace elements and rare earth elements for rockmass in songjiang are,Heilongjiang Province. In this paper we will systemically establishedgranite Geochronological framework of granite formation, discuss Rock properties, magmasources and tectonic environment, and preliminarily discuss the relationships of the Jurassicgranites and mineralization, Provide some information for Searching Jurassic rock ore(points).According to"1:50000survey of mineral resources"in the three maps includingLiaodian,Songjiang,Quanxiao, heilongjiang province ". On the basis of Field mapping,geophysical, geochemical, trenching of field geological investigation,we has confirmedthat Jurassic granites in the Songjiang area are mainly exposed alkali feldspar granite stockgranodiorite stock, monzonitic granite stock and Granite porphyry stock. According to dateof accurate U-Pb zircon in granites, in research area, those granites referred determine theages are180.05±0.46Ma、178.5±1.4Ma、176.4±1.4Ma,Respectively.And angina, otherScholar also dated them and the least age is184±2Ma. To some up, The age frame ofJurassic magma intrusion activity my be184Ma-175Ma.Those dates of age offer thelimitation of the region crustal evolution in Early Jurassic.According to geochemical and petrological of The Jurassic granite, The studies haveshowed: The Jurassic granite is the high potassium and weakly peraluminous-metaluminous calc alkaline series,which enriched U, Th, Zr, Hf, la, Ce, loss Nb, Ta, Ba,Sr.so those rock masses have The characteristics of I-type granites. The difficulty graphictrend of major elements, trace elements and rare earth elements trend to be the similar, sothose rock masses maybe the Production of different pulse from the same magma source.According to the chronology characteristics and geochemical characteristics of the granitemasses in study area, and regional structure evolution, the masses may produced in post-organic period. Due to the part of the lithosphere thickening and Production ofdelaminating effects, The asthenosphere mantle begun to upwelling in Stretch tension stateand Magma produced strong underplaying, then lower crust material is strongly melted byHeating and formed the source area, and eventually forming a large area of granite in theshallow crust. Produce delamination effects, deep mantle asthenosphere upwelling inStretch tension state and Magma produced a strong underplating,then lower crust materialis strongly melted by Heating. This area eventually forming a large area of granite of whichDynamic mechanism may be related to tectonic mechanism transformation. Jurassic graniteis a product of post-orogenic in the research area.
Keywords/Search Tags:Jurassic granite, petrography, geochemistry, diagenetic times, Songjiang area
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