【摘要】：古氣候?qū)W由于對(duì)現(xiàn)代氣候環(huán)境變化具有獨(dú)特的研究參考價(jià)值,在近年來(lái)成為當(dāng)代地質(zhì)科學(xué)中的熱點(diǎn)話(huà)題。在眾多保存氣候信息的沉積載體中,湖泊沉積物因其具有分布范圍廣、受局限條件相對(duì)較少、沉積連續(xù)穩(wěn)定、分辨率高以及易提取等特點(diǎn),在氣候和環(huán)境變化研究中具有其獨(dú)特的一面,并且在青藏高原古氣候研究中廣泛運(yùn)用。通過(guò)研究高原湖泊沉積物中的氣候代用指標(biāo),對(duì)于研究青藏高原氣候變化,特別是高原的形成對(duì)于亞洲季風(fēng)系統(tǒng)的影響,以及認(rèn)識(shí)引起氣候變化的控制因素和動(dòng)力機(jī)制具有重要研究?jī)r(jià)值。因此,本文通過(guò)提取邛多江盆地湖相沉積物中的粒度、TOC含量、TOC/TN比值和δ13Corg等代用指標(biāo),在AMS14C年代學(xué)框架基礎(chǔ)之上,分析研究區(qū)的古氣候演變史,并通過(guò)與全球其他區(qū)域諸如季風(fēng)區(qū)石筍氧同位素記錄、北大西洋海表溫度、太陽(yáng)輻射量變化等對(duì)比,對(duì)驅(qū)動(dòng)氣候變化的動(dòng)力機(jī)制進(jìn)行初步探討,并得出如下結(jié)論:1、利用AMS14C測(cè)年,獲得邛多江盆地湖相沉積物剖面頂部年齡為30.3 k a BP,底部年齡約為40.2 ka BP。2、通過(guò)對(duì)各代用指標(biāo)的分析,將邛多江盆地40~30 ka BP古氣候變化特征分為如下幾個(gè)階段:氣候暖濕期(40.2~38.5 ka BP)、氣候溫干期(38.5~35.4 k a BP)、氣候過(guò)渡期(35.4~32.4 ka BP)、氣候動(dòng)蕩期(32.4~31.7 ka BP)和氣候轉(zhuǎn)干期(31.7~30.3 ka BP)。通過(guò)代用指標(biāo)分析,我們發(fā)現(xiàn)40~30 ka期間邛多江盆地可能存在有幾次明顯的氣候事件,諸如39.3 ka短暫干旱事件、35 ka降水增強(qiáng)事件等。3、通過(guò)對(duì)邛多江盆地湖相沉積物剖面中有機(jī)碳同位素變化特征分析,除溫度和降水量?jī)蓚�(gè)影響因素外,大氣中CO2濃度可能也是導(dǎo)致該剖面有機(jī)碳同位素變化的原因之一。4、結(jié)合邛多江盆地沉積物有機(jī)碳同位素變化特征,發(fā)現(xiàn)其與全球其他區(qū)域具有明顯的響應(yīng)關(guān)系,并且在頻譜分析中識(shí)別出1552 a、1187 a、961 a和602a,這一系列周期良好地對(duì)應(yīng)了D/O旋回中1.5 ka和1 ka的周期,而602 a、538 a以及492 a對(duì)應(yīng)的可能是1000 a的半諧周期。5、在與主要受到東亞季風(fēng)控制的南京葫蘆洞石筍氧同位素變化曲線(xiàn)對(duì)比時(shí)發(fā)現(xiàn),二者存在比較不協(xié)同的氣候變化關(guān)系,初步認(rèn)為是因?yàn)閮蓚�(gè)區(qū)域是受到了不同的季風(fēng)控制導(dǎo)致了這種差異。對(duì)比各區(qū)域氣候記錄后,發(fā)現(xiàn)盆地氣候控制主要是受到西南季風(fēng)的影響,而與東亞季風(fēng)存在弱相關(guān)性,這在與桂林響水洞石筍氧同位素研究中具有良好的對(duì)比性。此外,通過(guò)與北大西洋深海沉積物氣候記錄所反映的氣候事件對(duì)比,發(fā)現(xiàn)具有良好的對(duì)應(yīng)性,說(shuō)明可能是受到溫鹽環(huán)流的因素驅(qū)動(dòng)。然而,考慮到高原的特殊地理位置和大地地貌、構(gòu)造等因素,認(rèn)為溫鹽環(huán)流和高原自身是影響邛多江盆地湖相沉積物氣候參數(shù)變化的兩個(gè)重要因素。6、結(jié)合40~30 ka BP以來(lái)的30°N和30°S的太陽(yáng)輻射量變化,初步認(rèn)為是由于受到太陽(yáng)輻射量改變從而引起的氣候與環(huán)境的改變,并且認(rèn)為在32 ka BP左右由于南北緯太陽(yáng)輻射量的差異變化,可能是導(dǎo)致邛多江盆地出現(xiàn)氣候急劇動(dòng)蕩的主要原因之一。
[Abstract]:As a reference value to the change of modern climate environment, paleoclimatology has become a hot topic in contemporary geological science in recent years. in the deposit carrier for storing the climate information, the lake sediments have the characteristics of wide distribution range, relatively few limited conditions, continuous and stable deposition, high resolution and easy extraction and the like, and have a unique side in the research of climate and environment change, And it is widely used in the study of paleoclimate in the Qinghai-Tibet Plateau. By studying the climate substitute index in plateau lake sediments, it is of great value to study the effect of climate change on the Qinghai-Tibet Plateau, especially the formation of plateau on the Asian monsoon system, as well as the control factors and dynamic mechanisms that cause climate change. Therefore, the paleoclimate evolution history of the study area is analyzed by extracting the particle size, TOC content, TOC/ TN ratio and AMS13Corg in the lake facies sediment of the Songhuangjiang Basin, and the paleoclimate history of the study area is analyzed and recorded by the oxygen isotope in other regions of the world, such as the monsoon region. Based on the comparison of the temperature of the North Atlantic Ocean and the change of solar radiation, the dynamic mechanism of driving the climate change is discussed preliminarily, and the following conclusions are obtained: 1. By using AMS14C dating, the top age of the lake facies sediment section of the Longyangjiang basin is 30. 3k a BP, and the bottom is about 40. 2ka BP. 2. According to the analysis of each substitute index, the paleoclimatic change of 40 ~ 30ka BP in the basin is divided into the following stages: climate warm-wet stage (40. 2 ~ 38. 5 ka BP), climate warm dry stage (38. 5 ~ 35. 4k a BP), climate transition period (35. 4 ~ 32. 4 ka BP). Climatic fluctuation period (32. 4 ~ 31. 7 ka BP) and dry climate (31. 7 ~ 30. 3 ka BP). Through alternative index analysis, we find that there may be several obvious climatic events, such as 39. 3ka short drought events, 35 ka precipitation enhancement events, etc. during the period of 40 ~ 30ka. in addition to that two influence factors of temperature and precipitation, the CO2 concentration in the atmosphere may also be one of the cause of the change of organic carbon isotope in the section. and 1552a, 1187a, 961a, and 602a are identified in the spectral analysis, this series of cycles well corresponds to the period of 1. 5 ka and 1 ka in the d/ o cycle, while 602a, 538a and 492a correspond to a half-harmonic period of 1000a. 5, It is found that the two regions are affected by different monsoon controls because the two regions are affected by different monsoon controls. After comparing the regional climate records, it is found that the climate control of the basin is mainly influenced by the southwest monsoon, but there is a weak correlation with the East Asian monsoon. In addition, by contrast to climate events reflected in the North Atlantic deep-sea sediment climate record, it has been found that a good correspondence may be driven by factors that are subject to warm-salt circulation. However, considering the special geographical position and geomorphology and structure of plateau, it is considered that the temperature and salt circulation and plateau itself are two important factors that affect the change of climate parameters in the lake facies sediments of the Yangtze River basin, and the solar radiation changes of 30 擄 N and 30 擄 S since 40 ~ 30 ka BP are combined. It is considered that the change of climate and environment caused by the change of the amount of solar radiation is one of the main causes of the abrupt climate change in the Erdojiang basin due to the difference in the amount of solar radiation in the north-south latitude about 32ka BP.
【學(xué)位授予單位】：成都理工大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2016
【分類(lèi)號(hào)】：P532

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 鹿化煜;張紅艷;曾琳;呂安琪;張朝暉;陳英勇;弋雙文;;溫度影響東北地區(qū)更新世植被變化的黃土記錄[J];第四紀(jì)研究;2015年04期

2 張銀環(huán);楊琰;楊勛林;殷建軍;黃帆;任小鳳;趙景耀;劉肖;聶旭東;;早全新世季風(fēng)演化的高分辨率石筍δ~(18)O記錄研究——以河南老母洞石筍為例[J];沉積學(xué)報(bào);2015年01期

3 林勇杰;鄭綿平;王海雷;;青藏高原中部色林錯(cuò)礦物組合特征對(duì)晚全新世氣候的響應(yīng)[J];科技導(dǎo)報(bào);2014年35期

4 趙華標(biāo);徐柏青;王寧練;;青藏高原冰芯穩(wěn)定氧同位素記錄的溫度代用性研究[J];第四紀(jì)研究;2014年06期

5 馬慶峰;朱立平;呂新苗;郭允;鞠建廷;王君波;汪勇;唐領(lǐng)余;;花粉揭示的青藏高原西南部塔若錯(cuò)全新世以來(lái)植被與氣候變化[J];科學(xué)通報(bào);2014年26期

6 王宗禮;何建華;陳亞?wèn)|;;湖泊碳庫(kù)效應(yīng)及校正方法[J];中國(guó)沙漠;2014年03期

7 黃文敏;伍永秋;潘美慧;張健楓;杜世松;;西藏安多剖面沉積物粒度特征及環(huán)境意義[J];中國(guó)沙漠;2014年02期

8 肖棟;趙平;王躍;田沁花;周秀驥;;末次間冰期以來(lái)北大西洋深層海溫與青藏高原氣溫的千年尺度位相關(guān)系及其演變[J];科學(xué)通報(bào);2014年01期

9 劉剛;劉普靈;張瓊;許文年;;陜北黃土區(qū)全新世氣候替代指標(biāo)意義及其關(guān)系[J];海洋地質(zhì)與第四紀(jì)地質(zhì);2013年06期

10 朱大運(yùn);王建力;;青藏高原冰芯重建古氣候研究進(jìn)展分析[J];地理科學(xué)進(jìn)展;2013年10期

，

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