本文選題：興蒙造山帶-華北克拉通　切入點：地球化學(xué)走廊帶　出處：《中國地質(zhì)大學(xué)(北京)》2017年博士論文　論文類型：學(xué)位論文

【摘要】：為研究興蒙造山帶-華北克拉通地球化學(xué)走廊帶區(qū)域地球化學(xué)組成及其橫向空間變化,以1～4km高密度分別采集沉積物和巖石樣品550件和1309件,選取主量元素、成礦元素和稀土元素進行數(shù)理統(tǒng)計,并以地球化學(xué)剖面圖的形式展示其空間分布;對巖石樣品進行分類,并統(tǒng)計不同巖性和地質(zhì)時代元素含量特征,重點討論了巖漿巖SiO_2、Au及花崗巖中稀土元素時代特征。結(jié)果表明:(1)SiO_2與Al_2O_3對比,表明沉積物中礦物組成是影響其含量的重要因素之一,CaO、MgO的富集主要與碳酸鹽巖密切相關(guān),降雨量對Na_2O、K_2O在沉積物中的富集影響顯著且存在差異。主量元素在沉積物中含量與空間分布除了受繼承的基巖影響外,還受到后期的風(fēng)化作用和氣候及自身地球化學(xué)性質(zhì)等復(fù)雜因素綜合影響。SiO_2的含量時代變化反映了上地殼酸性演化的趨勢,其在海西期巖漿巖中的含量最高。H20+的含量普遍較低,僅碳酸鹽巖或第四系局部較高,pH值反映北方沉積物偏堿性。(2)Au的富集與太古代-元古代結(jié)晶基底密切相關(guān),燕山造山帶Au的富集系數(shù)明顯大于魯西地塊,這也與其Au礦發(fā)現(xiàn)與分布相符。Ag與Cu富集系數(shù)曲線十分相似,而Pb、Zn則幾乎完全一致,與它們礦物密切共生有關(guān)。W富集系數(shù)曲線完美詮釋了其在花崗巖中富集的特點,在平原沉積物中較高含量,這可能受到來自燕山造山帶和魯西地塊的明顯影響。Ti與基性-超基性巖分布的空間對應(yīng)較好;江蘇北部沉積物V的異常富集,應(yīng)與魯西地塊有關(guān)。(3)沉積物和巖石ΣREE含量的空間分布,表明源區(qū)決定了稀土元素在不同構(gòu)造單元之間的整體差異,但表生條件在局部的差異也發(fā)揮著重要影響。REE含量在不同花崗巖類、構(gòu)造單元之間的差異相對地質(zhì)時代而言要大,且同一類花崗巖在不同地質(zhì)時代也如此,表明其在不同地質(zhì)時代形成過程所經(jīng)歷的不同巖漿地質(zhì)作用。(4)地理信息系統(tǒng)(GIS)強大的屬性數(shù)據(jù)和空間屬性關(guān)聯(lián)查詢的特點,可以更好地管理地球化學(xué)樣品數(shù)據(jù),提供進一步挖掘地球化學(xué)數(shù)據(jù)的潛在信息和應(yīng)用于基礎(chǔ)地質(zhì)、礦產(chǎn)預(yù)測和農(nóng)業(yè)生產(chǎn)等活動的基礎(chǔ)�？傊�,地球表層復(fù)雜系統(tǒng)中,表生環(huán)境對沉積物含量與空間分布影響復(fù)雜而重要,如:地理景觀、氣候因素,等。生物作用和人類工、農(nóng)業(yè)活動對土壤含量變化的影響值得關(guān)注,其復(fù)雜機理和空間分布值得更系統(tǒng)深入的研究,GIS可以發(fā)揮很好的作用。
[Abstract]:In order to study the regional geochemical composition and lateral spatial variation of Xingmeng orogenic belt and North China Craton geochemical corridor zone, 550 and 1309 samples of sediments and rocks were collected with high density of 1 ~ 4km, and principal elements were selected. Metallogenic elements and rare earth elements are mathematically counted, and their spatial distribution is shown in the form of geochemical profiles. Rock samples are classified and the characteristics of element contents in different lithology and geological times are counted. The age characteristics of rare earth elements in magmatic rock SiOSZ 2au and granite are discussed in detail. The results show that the mineral composition in sediments is one of the important factors affecting its content, and the enrichment of MgO in sediments is closely related to carbonate rocks, the results show that the composition of minerals in sediments is one of the most important factors affecting the content of SiO-1, and the enrichment of MgO in granites is closely related to carbonate rocks. Rainfall has a significant effect on the enrichment of Na _ 2O _ 2 K _ 2O in sediments, and there are significant differences in the concentration and spatial distribution of principal elements in sediments, except for the inherited bedrock. The complex factors such as weathering, climate and geochemical properties of the late period also influenced the time variation of the content of .SiO-2, which reflected the trend of acid evolution in the upper crust. The content of .H20 in the Hercynian magmatic rocks was generally the highest, and the content of .H20 was generally lower in the magmatic rocks of the Hercynian period. Only the higher pH values of carbonate rocks or Quaternary regions reflect that the enrichment of au in the sediments of northern China is closely related to the Archean to Proterozoic crystalline basement, and the enrichment coefficient of au in the Yanshanian orogenic belt is obviously larger than that in the western Shandong block. This is similar to the au ore discovery and distribution. Ag and Cu enrichment coefficient curves are very similar, while PBN Zn is almost identical. The .W enrichment coefficient curve, which is closely related to their mineral symbiosis, perfectly interprets its characteristics of enrichment in granite. The higher content in plain sediments may be affected by the obvious influence of Yanshanian orogenic belt and western Shandong massif on the spatial distribution of basic-ultrabasic rocks, and the anomalous enrichment of V in sediments of northern Jiangsu Province. The spatial distribution of 危 REE content in sediments and rocks is related to the Luxi massif, indicating that the source region determines the overall difference of rare earth elements among different tectonic units. However, the local differences of supergene conditions also play an important role in the different granitic types. The difference between tectonic units is larger than that of geological age, and the same type of granite is the same in different geological ages. It is shown that the strong attribute data and spatial attribute association query characteristics of different magmatic geological processes experienced in different geological ages can better manage geochemical sample data, and the GIS (Geographic Information system) (GIS) has the characteristics of strong attribute data and spatial attribute association query, which can better manage geochemical sample data. Providing potential information for further mining geochemical data and the basis for application to activities such as basic geology, mineral prediction and agricultural production. In summary, in complex systems of the Earth's surface, The influence of supergene environment on sediment content and spatial distribution is complex and important, such as geographical landscape, climatic factors, etc. The complex mechanism and spatial distribution of GIS can play a good role.
【學(xué)位授予單位】：中國地質(zhì)大學(xué)(北京)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2017
【分類號】：P632;P622.3

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相關(guān)期刊論文 前10條

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本文編號：1602124