本文關(guān)鍵詞： 章丘埠西黃土 砣磯II黃土 沉積特征 古氣候環(huán)境 物源　出處：《山東師范大學(xué)》2016年碩士論文　論文類型：學(xué)位論文

【摘要】：中國(guó)黃土堆積序列,記錄了晚新生代以來(lái)東亞地區(qū)的氣候環(huán)境演化歷史,與深海沉積物巖芯、極地冰芯并列被稱為過(guò)去全球變化研究的三大支柱。山東地區(qū)黃土位于我國(guó)黃土分布的東部邊緣,蘊(yùn)藏著豐富的中國(guó)東部季風(fēng)氣候變遷和環(huán)境演化信息,是我國(guó)黃土堆積系統(tǒng)不可或缺的重要組成部分。山東地區(qū)黃土堆積可分為兩大部分:渤海灣濱海與島嶼區(qū)和魯中山區(qū)。其中,位于渤海灣濱海與島嶼區(qū)的廟島群島又稱為長(zhǎng)島列島,橫跨膠東半島與遼東半島之間的渤海海峽,而魯中山地北黃土堆積呈近東西向沿魯中山地北麓坡地、河流階地及山間盆地分布。為了深入研究山東地區(qū)黃土沉積特征并進(jìn)行區(qū)域?qū)Ρ?在大量野外考察的基礎(chǔ)上,本文選取了位于廟島群島中部的砣磯島的砣磯II(TJII)黃土剖面和位于魯中山地的章丘埠西(BX)黃土剖面進(jìn)行研究。結(jié)合光釋光年代學(xué),應(yīng)用沉積學(xué)和地球化學(xué)手段,分析了研究區(qū)黃土的粒度組成、粒度象和粒度參數(shù)特征,運(yùn)用粒級(jí)-標(biāo)準(zhǔn)偏差法提取了環(huán)境敏感粒度組分,運(yùn)用薩胡公式對(duì)兩剖面的成因進(jìn)行判別,并分析了常量和微量元素含量特征及它們之間的比值分布模式圖。研究結(jié)果表明:(1)我們分別從山東章丘埠西剖面及砣磯島砣磯II剖面共采集15個(gè)光釋光年代樣品。測(cè)年結(jié)果表明,在章丘埠西黃土-古土壤剖面深度50cm,110cm,210cm,310cm,410cm,510cm,610cm,760cm,960cm和1310cm處避光采集的10個(gè)光釋光樣品,測(cè)年結(jié)果分別為1.0±0.1,13.2±1.0ka,14.1±3.4 ka,14.4±1.5 ka,17.1±1.6 ka,19.4±2.7 ka,24.1±3.3 ka,30.0±3.5 ka,34.8±1.2 ka和39.2±1.8 ka。在砣磯島砣磯II黃土-古土壤剖面深度60cm、180cm、280cm、380cm和480cm處避光采集的5個(gè)光釋光樣品,測(cè)年結(jié)果為14.4±0.4 ka,16.7±1.3 ka,20.8±1.0 ka,40.9±1.5 ka和47.9±3.7 ka。因此可判定兩黃土-古土壤剖面均是末次冰期以來(lái)的沉積物。但是由于海面升降和大陸架的周期性出露,使廟島群島黃土沉積不可能堆積和保存巨厚的黃土層,由此我們可以推斷砣磯II剖面全新世黃土已被侵蝕。(2)兩剖面粒度組成均是以粉砂含量為主,其中砣磯II剖面粉砂含量平均值為58.9%,埠西剖面為78.7%;砂組分是砣磯II剖面的次級(jí)組分,平均含量為32.3%,而埠西剖面次級(jí)組分為黏粒組分,平均含量為14.9%;砣磯II剖面中值粒徑(Md)為43.2μm,而章丘埠西黃土Md只有19.4μm;與山東其他黃土剖面和黃土高原典型黃土進(jìn)行對(duì)比,發(fā)現(xiàn)章丘埠西剖面粒度組成比較細(xì),TJII剖面粒度組成比黃土高原黃土粒徑還要粗。粒度頻率分布曲線為典型雙峰分布,結(jié)合薩胡判別公式對(duì)其沉積環(huán)境進(jìn)行判別,結(jié)果表明兩剖面沉積物均為風(fēng)成沉積物。沉積速率的變化以及粒度參數(shù)和粒度象特征反映了剖面沉積物在堆積過(guò)程中沉積環(huán)境并不穩(wěn)定,剖面形成過(guò)程中沉積動(dòng)力曾發(fā)生過(guò)明顯改變。(3)兩黃土剖面表現(xiàn)了相同的化學(xué)組成特征,章丘埠西剖面常量元素組成以SiO2(63.54%)、Al2O3(13.24%)、TFe2O3(4.87%)和CaO(4.54%)的百分含量最高,微量元素則是以Ba(527.25μg/g)、Zr(249.83μg/g)、Sr(173.71μg/g)、V(98.51μg/g)和Rb(98.47μg/g)為主。砣磯II剖面常量元素主要以SiO2(66.95%)、Al2O3(11.63%)、CaO(4.94%)和TFe2O3(3.76%)為主,微量元素以Ba(504.49μg/g)、Zr(443.23μg/g)、Sr(216.78μg/g)、V(83.08μg/g)和Rb(85.98μg/g)含量最高。CIA、Na/K及A-CN-K三角模型圖結(jié)果顯示,章丘埠西剖面處于初等化學(xué)風(fēng)化和中等化學(xué)風(fēng)化程度,砣磯II剖面屬于初等化學(xué)風(fēng)化,風(fēng)化程度比埠西剖面要低。常量和微量元素含量特征及常量和微量元素分子比值分布模式均具有相似的規(guī)律即砣磯II剖面與其它地區(qū)典型風(fēng)成沉積均有一定差異,埠西剖面與洛川黃土-古土壤剖面具有較高的相似性。另外,雖然同屬于山東黃土沉積,但是無(wú)論在粒度組成特征還是在常量和微量元素分子比值分布模式圖中均存在一定的差異,表明山東廟島群島和魯中山地黃土沉積環(huán)境及物質(zhì)來(lái)源的差異性,同時(shí)說(shuō)明了山東黃土沉積環(huán)境與物質(zhì)來(lái)源的復(fù)雜性。據(jù)此我們推測(cè),砣磯II黃土-古土壤剖面以近源為主,而章丘埠西黃土-古土壤剖面物質(zhì)來(lái)源比較復(fù)雜,遠(yuǎn)源為主,還有可能摻雜遠(yuǎn)源粉塵的二次搬運(yùn)物質(zhì)。(4)根據(jù)剖面末次冰期地層的組合特征,結(jié)合粒度中值粒徑、環(huán)境敏感組分、SiO2/Al2O3、TFe2O3、Rb/Sr和Ba/Sr等氣候代用指標(biāo)進(jìn)行分析,得出結(jié)論如下:章丘埠西黃土-古土壤剖面與SPECMAP時(shí)間表幾乎相同,MIS2階段氣候干冷,MIS3階段分為3a(46.36~55.48 ka)較為溫濕,3b(30.04~46.36ka)干冷,3c(24.47~30.04ka)溫濕三個(gè)階段,具明顯的D-O旋回,剖面指示的氣候波動(dòng)與全球氣候波動(dòng)具有一致性。廟島群島砣磯II黃土-古土壤剖面與SPECMAP時(shí)間表可以對(duì)應(yīng),MIS3階段也經(jīng)歷了暖濕~冷干~暖濕的氣候旋回,但是MIS2階段明顯經(jīng)歷了兩次氣候回暖,該剖面受到區(qū)域環(huán)境影響較明顯。兩剖面具有較好的對(duì)應(yīng)說(shuō)明山東地區(qū)大的氣候環(huán)境背景基本一致。造成兩剖面沉積特征差異的一方面是由于物質(zhì)來(lái)源的不同,另一方面由于砣磯II剖面受到海-陸-氣相互作用,沉積環(huán)境比較復(fù)雜。
[Abstract]:China loess accumulation sequence, recorded the evolution of East Asia Climate since the late Cenozoic, core and deep sea sediments, polar ice core side by side is called the past global change research. The three pillars of the Loess of Shandong area is located in China's eastern edge of the loess, the evolution of information contain rich China Eastern monsoon climate change and the environment is an important part of China's loess accumulation system indispensable. Can be divided into two parts: the Shandong loess deposit in Bohai Bay coastal and island area and mountain area of Shandong Province. Among them, located in the Bohai Bay coastal and island area of Miaodao islands, also known as the Long Island archipelago, between Jiaodong Peninsula and Liaodong Peninsula across the Bohai Strait. North Lu Zhongshan loess accumulation was nearly East-West along the northern slope of Zhongshan Lu, the distribution of river terraces and intermontane basin. In order to study the sedimentary characteristics of loess in Shandong And regional correlation, based on a large number of field trips, the paper selected in Miaodao islands of central Tuoji island Tuoji II (TJII) is located in the central mountain and loess section of the Zhangqiu port West (BX) loess profile is studied. Combined with the OSL chronology, sedimentology and geochemistry analysis. The grain size distribution of loess, and the characteristics of grain size parameters like particle size, extraction of environmental sensitive grain size group with grain size standard deviation method, using two section causes Sahu formula to judge, and analyzes the major and trace element distribution patterns of the ratio between the amount of map containing characteristics and. The results show: (1) we were from the Shandong Zhangqiu port west section and Tuoji island Tuoji profile II collected 15 OSL dating samples. The dating results indicate that in the Zhangqiu port west of loess soil profile depth of 50cm, 110cm, 210cm, 310cm, 410cm, 51 0cm,610cm,760cm,960cm鍜，

本文編號(hào)：1458659