引用本文: | 何梅,刘庚余,周国华,车柏林,马明明,靳建辉,刘秀铭,俞鸣同.2021.福州盆地钻孔沉积物记录的MIS3以来海侵 — 海退过程[J].地球环境学报,12(1):45-57 |
| HE Mei, LIU Gengyu, ZHOU Guohua, CHE Bolin, MA Mingming, JIN Jianhui, LIU Xiuming, YU Mingtong.2021.Transgression-regression process recorded by borehole sediments in Fuzhou Basin since MIS3[J].Journal of Earth Environment,12(1):45-57 |
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福州盆地钻孔沉积物记录的MIS3以来海侵 — 海退过程 |
何梅,刘庚余,周国华,车柏林,马明明,靳建辉,刘秀铭,俞鸣同
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1.福建师范大学 地理科学学院,福州 350007 2.福建省地质调查研究院,福州 350013
3.福建师范大学湿润亚热带山地生态国家重点实验室培育基地,福州 350007
4.福建师范大学湿润亚热带生态-地理过程教育部重点实验室,福州 350007
5. Department of Earth and Environmental Sciences, Macquarie University, Sydney NSW 2109, Australia
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摘要: |
通过对福州盆地首山路ZKCS钻孔岩芯的AMS 14C及光释光(OSL)年代测试、岩性特征、黏土浑浊水电导率值和地球化学元素测定、粒度分析以及硅藻鉴定,对钻孔沉积物的沉积环境进行分析,并与ZK004钻孔结果进行对比,结合全球古气候及区域构造记录,确认首山路ZKCS钻孔记录了两次完整的海侵—海退旋回,第一次海侵结束时间约50 ka,第二次海侵发生在全新世期间。两次海侵发生的主要原因不同,第一次海侵发生在MIS3早期,对应于前人命名的“福州海侵”,主要原因是区域构造下沉,加之此时古气候变暖引发海面上升;之后由于盆地内部的不均匀沉降,再次发生抬升,导致ZKCS钻孔记录的海侵较早结束、海侵层埋深较浅;全新世海侵即前人命名的“长乐海进”,强度比前一期强,为冰后期全球气候变暖和海面上升共同作用的结果,其次可能还伴随着盆地的下陷。 |
关键词: 福州盆地 MIS3海侵 构造活动 古气候 |
DOI:10.7515/JEE202007 |
分类号: |
基金项目:国家自然科学基金项目(41602185);福建师范大学创新团队基金(IRTL1705);福建省教育厅中青年项目
(JAT160111);福建省自然科学基金(2020J01139) |
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Transgression-regression process recorded by borehole sediments in Fuzhou Basin since MIS3 |
HE Mei, LIU Gengyu, ZHOU Guohua, CHE Bolin, MA Mingming, JIN Jianhui, LIU Xiuming, YU Mingtong
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1. School of Geographical Sciences, Fujian Normal University, Fuzhou 350007, China
2. Fujian Institute of Geological Survey, Fuzhou 350013, China 3. State Key Laboratory of Subtropical Mountain Ecology (Funded by Ministry of Science and Technology and Fujian Province), Fujian Normal University, Fuzhou 350007, China
4. Key Laboratory of Humid Subtropical Ecosystem and Geography, Ministry of Education, Fuzhou 350007, China
5. Department of Earth and Environmental Sciences, Macquarie University, Sydney NSW 2109, Australia
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Abstract: |
Background, aim, and scope With the process of global warming, seawater intrusion will happen in the low-altitude coastal areas, which brings great threat to the urban development and human life. Therefore, it is necessary to understand the formation mechanism of transgression events in geological history, that can provide references and precautions for the future transgression activities. A great deal of studies about transgression have been carried out in the Bohai Sea, the Yellow Sea and the East China Sea. The history of transgression study in Fujian Province can be traced back to the 1970s—1980s. However, there is few record for transgression study because of strong surface weathering. The sediments in Fuzhou Basin which lies in the Minjiang River estuary offers an excellent geological record. Based on the boreholes drilled from Fuzhou Basin, this study aims to reveal the transgression events and their main causes during the Late Quaternary. Materials and methods In this study, AMS 14C and Optical Stimulated Luminescence (OSL) dating, as well as lithology analysis, electric conductivity, geochemical parameters, grain size measurements and diatoms identification were carried out in borehole ZKCS (119°18′48″E, 26°01′32″N). For comparison, the measurements of electric conductivity and OSL dating were conducted for borehole ZK004 (119°18′53″E, 26°04′34″N) which lies in the basin sedimentation center. In addition, nearly 1000 boreholes data provided by Fuzhou Survey Institute were analyzed using ArcGIS software. Results Based on the lithology analysis, the measurements of electric conductivity, geochemical parameters, grain size as well as diatoms identification of borehole ZKCS, the sedimentary environment was analyzed, and it can be divided as fluvial facies, lacustrine facies and lakeshore facies, gulf facies, fluvial facies, coastal marsh facies, shallow marine facies, lacustrine facies. Therefore, it is confirmed that two complete transgression-regression cycles have been recorded in the ZKCS borehole. Based on the dating results, the first transgression ended about 50 ka, corresponding to the “Fuzhou transgression” that named in previous studies, the second one occurred during the Holocene, corresponding to the “Changle transgression”. Discussion During early MIS3, the reconstructed sea level is far lower than the modern sea level, and the ice cover area of the northern hemisphere continent is also larger than the modern ice cover area. Based on the comprehensive analysis of 913 boreholes in 25 locations, as well as compared with the active faults in Fuzhou Basin, it is found that the sedimentary center was always located in the north Fuzhou Basin, and it changed along with time, probably suggesting that there was nonuniform tectonic movement happened in the basin. Conclusions Combined the regional tectonic records and paleoclimate changes, the main reason for the MIS3 transgression is the subsidence of regional structure and then the rise of sea level caused by the paleoclimate warming. While the main reason for Holocene transgression is the melting of glaciers and global sea level rise caused by global warming during post glacial period. Recommendations and perspectives This study can provide some references for the studies of transgression history in coastal areas, as well as the studies of future sea level changes. |
Key words: Fuzhou Basin MIS3 transgression tectonic activity paleoclimate |
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