本文選題：遼寧北鎮(zhèn)石墨 + 碳質(zhì)板巖�。� 參考：《中國地質(zhì)大學(xué)(北京)》2015年碩士論文

【摘要】：北鎮(zhèn)地區(qū)位于華北地臺燕山臺陷帶的遼西臺陷,醫(yī)巫閭山背斜的東翼,東部與下遼河盆地相接,受東西向要路溝—錦西殼斷裂、錦州—哈爾套殼斷裂及韌性剪切帶的控制。區(qū)內(nèi)可見構(gòu)造以斷裂構(gòu)造和背斜褶皺為主。地層由太古界建平群大營子組、瓦子峪組,中元古界長城系大紅峪組、高于莊組以及新生界第四系地層組成。巖漿巖主要為已經(jīng)變質(zhì)的太古代火山巖和中生代火山巖。該地區(qū)出露的巖石以碳質(zhì)板巖,局部大理巖和受花崗巖巖漿作用的過渡性板巖為主,屬于區(qū)域變質(zhì)巖里的低級變質(zhì)巖系列。由于研究區(qū)受到不同程度的變質(zhì)及變形作用,單靠野外巖石組合和巖石學(xué)特點來確認(rèn)北鎮(zhèn)地區(qū)變質(zhì)巖系的原巖建造是比較困難。因此,本文選擇了部分有代表性樣品進行分析。通過分析該地區(qū)全巖數(shù)據(jù)百分含量特點;計算關(guān)鍵元素對的比值、DF值、尼格里特征值,并做相關(guān)圖解判別原巖類型,通過F1—F2碎屑巖物源判別函數(shù)圖,ω(La)/ω(Th)-ω(Hf)/10-6物源屬性判別圖等構(gòu)造判別圖來分析原巖的物源及構(gòu)造背景。最后,綜合以上方法得出如下結(jié)論:1.遼寧省北鎮(zhèn)地區(qū)的巖石類型主要碳質(zhì)板巖、大理巖等,主要礦物為云母類和長石類,在鏡下礦物可見明顯的定向排列,說明在一定時期內(nèi)收到擠壓或伸展運動的影響。2.根據(jù)北鎮(zhèn)地區(qū)的巖石化學(xué)成分特征及有關(guān)數(shù)據(jù),推測該地區(qū)的原巖為沉積巖或中酸性火山巖3.鋯石SHRIMP分析顯示年齡集中在古元古代和下侏羅統(tǒng),說明他們與古元古代的古老變質(zhì)巖基底有關(guān),反映了該地區(qū)石墨沉積變質(zhì)的過程。4.根據(jù)北鎮(zhèn)地區(qū)地球化學(xué)數(shù)據(jù)及原巖恢復(fù)相關(guān)圖解,判斷研究區(qū)為副變質(zhì)巖,即原巖為沉積巖,以粘土巖、泥質(zhì)砂巖、長石質(zhì)砂巖為主;物源成分以長英質(zhì)、石英質(zhì)巖石為主,并含有火成物源及古老再循環(huán)沉積物。研究區(qū)變質(zhì)巖雖然形成于被動大陸邊緣環(huán)境,但是物源繼承了更早期活動大陸邊緣和島弧盆地的地化信息,說明該地區(qū)是從活動大陸島弧到被動陸緣逐步演化的。
[Abstract]:The Beizhen area is located in the western Liaoning platform of the Yanshan platform depression belt of the North China platform, the eastern wing of the Yiwulushan anticline, which is connected with the Lower Liaohe Basin in the east, and is controlled by the east-west Yuzhou-Jinxi crust fault, the Jinzhou-Hal crust fault and the ductile shear zone. Fault structures and anticline folds dominate the visible structures in the area. The strata are composed of the Daiying formation, the Waziyu formation, the middle Proterozoic the Great Wall system and the Dahongyu formation of the Jianping Group of the Archean, higher than that of the Zhuang formation and the Quaternary formation of the Cenozoic. Magmatic rocks are mainly metamorphic Archean volcanic rocks and Mesozoic volcanic rocks. The exposed rocks in this area are mainly carbonaceous slate, local marble and transitional slate with granitic magmatism, which belong to the low grade metamorphic series of regional metamorphic rocks. Due to the metamorphism and deformation in the study area, it is difficult to confirm the original rock formation of metamorphic rock series in Beizhen area by relying solely on the field rock assemblages and petrological characteristics. Therefore, some representative samples are selected for analysis in this paper. By analyzing the percentage content characteristics of the whole rock data in this area, calculating the ratio of key element pairs, DF value and Nigri characteristic value, and making relevant diagrams to distinguish the original rock types, The provenance and tectonic background of the original rock are analyzed by using the source discriminant function diagram of F1-F2 clastic rock and the structural discriminant map of the provenance properties of 蠅 -Lao- / 蠅 -Hf- / 10-6 provenance. Finally, combined with the above method, the following conclusion is drawn: 1. The rock types in Beizhen area of Liaoning Province are mainly carbonaceous slate, marble and so on. The main minerals are mica and feldspar. According to the characteristics of rock chemical composition and related data in Beizhen area, it is inferred that the primary rock in this area is sedimentary rock or intermediate acid volcanic rock. Zircon SHRIMP analysis shows that the ages are concentrated in Paleoproterozoic and Lower Jurassic, indicating that they are related to the basement of ancient metamorphic rocks in Gu Yuan, which reflects the process of graphite depositional metamorphism in this area .4. According to the geochemical data of Beizhen area and the related diagrams of the restoration of the original rocks, it is judged that the study area is metamorphic, that is, the primary rocks are sedimentary rocks, mainly clay rocks, argillaceous sandstones, feldspathic sandstone, and feldspathic and quartz rocks. And contains pyrogenic material sources and ancient recycled sediments. Although metamorphic rocks were formed in the passive continental margin environment, the provenance inherited the geochemistry information of the earlier active continental margin and island arc basin, indicating that the area evolved from active continental island arc to passive continental margin.
【學(xué)位授予單位】：中國地質(zhì)大學(xué)(北京)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：P619.252

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本文編號：1975913