早全新世渾善達(dá)克沙地古湖泊演化與環(huán)境變遷
發(fā)布時(shí)間：2018-07-23 14:11
【摘要】：目前,全球氣候變暖問題得到了世界各地關(guān)注,而區(qū)域環(huán)境演變過程對全球變化水位響應(yīng)非常敏感。渾善達(dá)克沙地位于中國內(nèi)蒙古高原中東部的干旱和半干旱氣候的過渡區(qū),處于季風(fēng)邊緣區(qū),生態(tài)環(huán)境十分脆弱。該地廣泛存在著流動沙丘、半固定沙丘和固定沙丘等,同時(shí)在沙地腹地廣泛分布著眾多的湖泊,是湖泊演化的理想之地,成為沙地與湖泊演化過程的典型地區(qū),也是兩者彼此消長耦合關(guān)系的重要場所。試圖探索季風(fēng)邊緣區(qū)過渡帶的氣候演化過程及湖泊面積變化對氣候的響應(yīng),進(jìn)而提高對季風(fēng)邊緣區(qū)環(huán)境演變的認(rèn)識。本文結(jié)合野外考察與室內(nèi)實(shí)驗(yàn)分析的方法,對該研究點(diǎn)剖面進(jìn)行粒度指標(biāo)分析和OSL年代測試,建立湖泊演化時(shí)間序列。利用湖泊數(shù)字高程模型(DEM)的方法,根據(jù)研究區(qū)存在的湖岸堤高程,反演渾善達(dá)克沙地早-中全新世的湖泊時(shí)空變化格局。本文得出的主要結(jié)論如下:1.通過系統(tǒng)的野外考察發(fā)現(xiàn),在渾善達(dá)克沙地腹地哈嘎淖爾北部保存較好的高湖岸階地,在剖面湖濱砂特征較為明顯位置,自下向上采集樣品,其中采樣點(diǎn)高程最高達(dá)到1313 m,表明該地區(qū)存在古湖的地質(zhì)地貌證據(jù);1)按照階地剖面采樣點(diǎn)海拔高程來推測,古湖水位分別高出現(xiàn)代湖泊38 m、39 m、40 m、41 m、43 m等,其OSL年代測試結(jié)果分別為9.6±1、8.9±0.8、10.3±0.8、8.1±0.6、7.5±0.6 ka,表明早中全新世初期發(fā)育高湖面,揭示了氣候濕潤;2)通過結(jié)合湖濱沉積物的OSL年代測試結(jié)果與古湖岸地高程,表明在9.6~7.5 ka間,古湖水位逐漸上升,湖泊面積不斷的擴(kuò)大,氣候環(huán)境濕潤。其中7.5 ka時(shí)期為干濕氣候的突變點(diǎn),為古湖發(fā)育達(dá)到鼎盛時(shí)期。根據(jù)1313 m的古湖面,得出244 km2的湖泊面積,多出現(xiàn)在湖泊面積243 km2,該古湖向東延伸到巴音淖爾,向北擴(kuò)張到烏日塔音淖爾,并向南部和西部擴(kuò)展,形成較大的古湖。同時(shí)其周緣的沙地被古湖水淹沒,造成沙地里的巨大濕地系統(tǒng)。表明當(dāng)時(shí)氣候相當(dāng)濕潤,生態(tài)環(huán)境極其優(yōu)越;湖泊面積演化共有兩個(gè)階段,第一階段是距今9.6~7.5 ka期間,該湖區(qū)內(nèi)氣候溫暖濕潤,湖水位連續(xù)的上漲,為湖泊水位的上升期;第二階段是在7.5 ka~至今,氣候逐漸變干旱,湖面萎縮、古湖出現(xiàn)解體,呈現(xiàn)出了哈嘎淖爾湖當(dāng)今的規(guī)模。2.剖面粒度分析結(jié)果表明,風(fēng)成沙和湖濱砂在粒徑和表面形態(tài)存在明顯的差異。風(fēng)成沙粒徑分布區(qū)間0~0.5 mm,顆粒表面形態(tài)特征有碟形坑、撞擊坑、麻面結(jié)構(gòu)等,主要特征為不光滑的麻面。而湖濱砂粒徑取值范圍0~4.2 mm,其表面形態(tài)則復(fù)雜多變,不僅存在水環(huán)境的貝殼狀斷口、平行解理面、磨光面,還有風(fēng)成環(huán)境的碟形坑、麻面等特征。
[Abstract]:At present, the problem of global warming has been paid attention to all over the world, and the regional environmental evolution process is very sensitive to the response of global water level. Hunshandake sandy land is located in the transitional region of arid and semi-arid climate in the central and eastern part of Inner Mongolia Plateau in China. It is located in the edge of the monsoon and the ecological environment is very fragile. There are moving dunes, semi-fixed dunes and fixed dunes in this area. At the same time, many lakes are widely distributed in the hinterland of sandy land, which is the ideal place for lake evolution and becomes a typical area of sand land and lake evolution process. It is also an important place for the coupling between them. This paper attempts to explore the process of climate evolution in the transitional zone of the monsoon margin and the response of the lake area changes to the climate so as to improve the understanding of the environmental evolution of the monsoon marginal zone. In this paper, based on the methods of field investigation and laboratory experiment, the granularity index and OSL age of the section of the study point are analyzed, and the time series of lake evolution are established. By using the (DEM) method of the lake digital elevation model, the spatial and temporal variation patterns of lakes in the Hunshandake sandy land during the early and middle Holocene were inversed according to the levee height of the lake bank in the study area. The main conclusions of this paper are as follows: 1. Through the systematic field investigation, it is found that in the north of Haga Nur, the hinterland of Hunshandake sandy land, the high lakeshore terrace is well preserved, and the samples are collected from the bottom up in the obvious position of the lakeside sand characteristics in the profile. The height of the sampling site is up to 1313 m, indicating that there is a geological and geomorphological evidence of the ancient lake in this area. 1) according to the elevation of the sampling site in the terrace profile, the water level of the ancient lake is respectively higher than that of the modern lake, such as 38 m ~ 39 m ~ (39 m) ~ 40 m ~ (40) m ~ (41) m ~ (43 m) and so on. The OSL dating results were 9.6 鹵18.9 鹵0.810 鹵0.810 鹵0.810 鹵0.8lb 8.1 鹵0.6n 7.5 鹵0.6 ka, respectively, indicating that high lake surface was developed in the early middle Holocene, indicating that the paleolake water level gradually increased between 9.67.5ka and 9.67.5ka by combining the OSL dating results of lakeshore sediments and the paleolake shore elevation, indicating that the high lake surface was developed in the early middle Holocene. The lake area continues to expand, the climate environment is moist. Among them, 7.5 ka period is a sudden point of dry and wet climate, which is the peak period of ancient lake development. According to the ancient lake area of 1313 m, the lake area of 244km2 is found mostly in the lake area of 244km2. The ancient lake extends eastward to Bayannur, extends northward to Uzhitanaoer, and extends to the south and west of the lake to form a larger ancient lake. At the same time, the surrounding sandy land was submerged by the ancient lake, resulting in a huge wetland system in the sandy land. The results show that the climate was very humid at that time and the ecological environment was extremely superior, and there were two stages in the lake area evolution. The first stage was the warm and humid climate and the continuous rise of the lake water level, which was the rising period of the lake water level. In the second stage, the climate gradually became dry, the lake surface shrank, and the ancient lake disintegrated, showing the present scale of Haga Nur Lake. The results of grain size analysis show that there are obvious differences in particle size and surface morphology between eolian sand and lakeside sand. The particle size distribution range of eolian sand is 0 ~ 0. 5 mm. The surface morphology of the particles is characterized by disc crater, impact crater, hemp surface structure and so on. The main features are not smooth hemp surface. On the other hand, the size of lakeside sand is in the range of 0 ~ 4.2 mm, and its surface morphology is complex and changeable. There are not only shell-like fracture surfaces in water environment, parallel cleavage surfaces, polished surfaces, but also dish pits and hemp surfaces in wind-formed environments.
【學(xué)位授予單位】：內(nèi)蒙古師范大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：P534.632
本文編號：2139663
[Abstract]:At present, the problem of global warming has been paid attention to all over the world, and the regional environmental evolution process is very sensitive to the response of global water level. Hunshandake sandy land is located in the transitional region of arid and semi-arid climate in the central and eastern part of Inner Mongolia Plateau in China. It is located in the edge of the monsoon and the ecological environment is very fragile. There are moving dunes, semi-fixed dunes and fixed dunes in this area. At the same time, many lakes are widely distributed in the hinterland of sandy land, which is the ideal place for lake evolution and becomes a typical area of sand land and lake evolution process. It is also an important place for the coupling between them. This paper attempts to explore the process of climate evolution in the transitional zone of the monsoon margin and the response of the lake area changes to the climate so as to improve the understanding of the environmental evolution of the monsoon marginal zone. In this paper, based on the methods of field investigation and laboratory experiment, the granularity index and OSL age of the section of the study point are analyzed, and the time series of lake evolution are established. By using the (DEM) method of the lake digital elevation model, the spatial and temporal variation patterns of lakes in the Hunshandake sandy land during the early and middle Holocene were inversed according to the levee height of the lake bank in the study area. The main conclusions of this paper are as follows: 1. Through the systematic field investigation, it is found that in the north of Haga Nur, the hinterland of Hunshandake sandy land, the high lakeshore terrace is well preserved, and the samples are collected from the bottom up in the obvious position of the lakeside sand characteristics in the profile. The height of the sampling site is up to 1313 m, indicating that there is a geological and geomorphological evidence of the ancient lake in this area. 1) according to the elevation of the sampling site in the terrace profile, the water level of the ancient lake is respectively higher than that of the modern lake, such as 38 m ~ 39 m ~ (39 m) ~ 40 m ~ (40) m ~ (41) m ~ (43 m) and so on. The OSL dating results were 9.6 鹵18.9 鹵0.810 鹵0.810 鹵0.810 鹵0.8lb 8.1 鹵0.6n 7.5 鹵0.6 ka, respectively, indicating that high lake surface was developed in the early middle Holocene, indicating that the paleolake water level gradually increased between 9.67.5ka and 9.67.5ka by combining the OSL dating results of lakeshore sediments and the paleolake shore elevation, indicating that the high lake surface was developed in the early middle Holocene. The lake area continues to expand, the climate environment is moist. Among them, 7.5 ka period is a sudden point of dry and wet climate, which is the peak period of ancient lake development. According to the ancient lake area of 1313 m, the lake area of 244km2 is found mostly in the lake area of 244km2. The ancient lake extends eastward to Bayannur, extends northward to Uzhitanaoer, and extends to the south and west of the lake to form a larger ancient lake. At the same time, the surrounding sandy land was submerged by the ancient lake, resulting in a huge wetland system in the sandy land. The results show that the climate was very humid at that time and the ecological environment was extremely superior, and there were two stages in the lake area evolution. The first stage was the warm and humid climate and the continuous rise of the lake water level, which was the rising period of the lake water level. In the second stage, the climate gradually became dry, the lake surface shrank, and the ancient lake disintegrated, showing the present scale of Haga Nur Lake. The results of grain size analysis show that there are obvious differences in particle size and surface morphology between eolian sand and lakeside sand. The particle size distribution range of eolian sand is 0 ~ 0. 5 mm. The surface morphology of the particles is characterized by disc crater, impact crater, hemp surface structure and so on. The main features are not smooth hemp surface. On the other hand, the size of lakeside sand is in the range of 0 ~ 4.2 mm, and its surface morphology is complex and changeable. There are not only shell-like fracture surfaces in water environment, parallel cleavage surfaces, polished surfaces, but also dish pits and hemp surfaces in wind-formed environments.
【學(xué)位授予單位】：內(nèi)蒙古師范大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：P534.632
【參考文獻(xiàn)】
相關(guān)期刊論文 前10條
1 劉嘉麒,劉強(qiáng);中國第四紀(jì)地層[J];第四紀(jì)研究;2000年02期
2 袁寶印,鄧成龍,呂金波,金昌柱,吳玉書;北京平原晚第四紀(jì)堆積期與史前大洪水[J];第四紀(jì)研究;2002年05期
3 陳發(fā)虎;黃小忠;楊美臨;楊勛林;范育新;趙暉;;亞洲中部干旱區(qū)全新世氣候變化的西風(fēng)模式——以新疆博斯騰湖記錄為例[J];第四紀(jì)研究;2006年06期
4 鹿化煜;周亞利;J.Mason;T.Stevens;弋雙文;J.Swinehart;;中國北方晚第四紀(jì)氣候變化的沙漠與黃土記錄——以光釋光年代為基礎(chǔ)的直接對比[J];第四紀(jì)研究;2006年06期
5 李華章;劉清泗;汪家興;;內(nèi)蒙古高原黃旗海、岱海全新世湖泊演變研究[J];湖泊科學(xué);1992年01期
6 安成邦;陳發(fā)虎;;中東亞干旱區(qū)全新世氣候變化的西風(fēng)模式——以湖泊研究為例[J];湖泊科學(xué);2009年03期
7 張振克,楊達(dá)源;中國西北干旱區(qū)湖泊水資源—環(huán)境問題與對策[J];干旱區(qū)資源與環(huán)境;2001年02期
8 金章東,沈吉,王蘇民,張恩樓;早全新世降溫事件的湖泊沉積證據(jù)[J];高校地質(zhì)學(xué)報(bào);2003年01期
9 張洪,靳鶴齡,蘇志珠,孫忠;全新世渾善達(dá)克沙地粒度旋回及其反映的氣候變化[J];中國沙漠;2005年01期
10 張煜星,孫司衡;《聯(lián)合國防治荒漠化公約》的荒漠化土地范疇[J];中國沙漠;1998年02期
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