山东莱州湾南岸晚上新世以来(6.8~0.004 Ma)古植被演替与海平面波动  

Late Pliocene(6.8-0.004 Ma)vegetation evolution and sea-level fluctuations on the southern coastal plain of Laizhou Bay,Bohai Sea,China

作　　者：郝秀东 劳月英 欧阳绪红 姜兴钰[6] 王福[6] 田立柱[6] 施佩歆[6] 陈永胜[6] 王宏[6] 李建芬[6] 商志文[6] HAO Xiudong;LAO Yueying;OUYANG Xuhong;JIANG Xingyu;WANG Fu;TIAN Lizhu;SHI Peixin;CHEN Yongsheng;WANG Hong;LI Jianfen;SHANG Zhiwen(Key Laboratory of Beibu Gulf Environment Change and Resources Utilization(Nanning Normal University),Ministry of Education,Nanning 530001,Guangxi,China;Guangxi Key Laboratory of Earth Surface Processes and Intelligent Simulation,Nanning Normal University,Nanning 530001,Guangxi,China;Guangxi Academy of Sciences,Guangxi Mangrove Research Center,Guangxi Key Lab of Mangrove Conservation and Utilization,Beihai 536000,Guangxi,China;Key Laboratory of Karst Dynamics,MNR&GZAR,Institute of Karst Geology,CAGS,Guilin 541004,Guangxi,China;State Key Laboratory of Modern Paleontology and Stratigraphy,Nanjing Institute of Geology and Paleontology,Chinese Academy of Sciences,Nanjing 210008,Jiangsu,China;CGS Key Laboratory of Muddy Coast Geo-environment,Tianjin 300170,China)

机构地区：[1]南宁师范大学北部湾环境演变与资源利用教育部重点实验室,广西南宁530001 [2]南宁师范大学广西地表过程与智能模拟重点实验室,广西南宁530001 [3]广西红树林研究中心广西红树林保护与利用重点实验室,广西北海536000 [4]自然资源部/广西岩溶动力学重点实验室,中国地质科学院岩溶地质研究所,广西桂林541004 [5]中国科学院南京地质古生物研究所现代古生物学和地层学国家重点实验室,江苏南京210008 [6]中国地质调查局泥质海岸带地质环境重点实验室,天津300170

出　　处：《中国地质》2024年第2期689-700,共12页Geology in China

基　　金：国家自然科学基金项目(42001076,U20A2048,41861020);广西自然科学基金项目(2023GXNSFBA026263);中国科学院南京地质古生物研究所现代古生物学和地层学国家重点实验室开放基金(223109);广西岩溶动力学重大科技创新基地开放基金项目(KDL&Guangxi202204);广西红树林保护与利用重点实验室开放基金项目(GKLMC-201902);北部湾环境演变与资源利用教育部重点实验室开放基金项目(NNNU-KLOP-X1919,NNNU-KLOP-X2101)联合资助。

摘　　要：【研究目的】海岸带沉积物中的微体古生物化石保存着丰富的地质环境信息,本文的目的是重建莱州湾南岸晚上新世以来的古植被演替与海平面波动关系。【研究方法】拟通过对HLL01钻孔的孢粉、淡水藻类、海相沟鞭藻、有孔虫内衬等微体古生物化石的分析,恢复和重建莱州湾南岸及其附近地区晚上新世以来的古植被演替与海平面波动。【研究结果】(1)在晚上新世—早更新世阶段(约6.8~1.6 Ma),大量的陆生草本花粉(75.13%)指示研究区的植物群落主要以藜科、蒿属及禾本科为主的草原植被,气候温暖偏干。(2)在早更新世—中更新世阶段(约1.6~0.6 Ma),研究区的植物群落开始由草原向森林草原类型过渡;急剧增加的淡水藻类,则指示研究区可能有大的河流注入,或形成较大规模的湖泊;降水量增加,气候变得湿润。(3)在中更新世—晚全新世阶段(约0.6~0.004Ma),研究区的植物群落已经变成森林草原植被。淡水藻类含量略有降低,指示研究区的河流注入量开始减少,湖泊面积也开始萎缩。同时,海相沟鞭藻和有孔虫内衬等海相化石记录,指示研究区在该阶段出现了较为明显的大规模海侵事件。【结论】莱州湾晚上新世以来发生了3次古植被演替与海平面波动事件。[Objective]Microfossils,especially pollen,spores,and dinoflagellate cysts,as direct indicators or proxies,provide significant information on geological environment.Therefore,palynological analysis has an important role in restoration and reconstruction of vegetation history and sea-level fluctuations,which provides information from the sediment cores,especially in alluvial coastal plain regions.[Methods]In this study,we carry out analyses using detailed palynological records of pollen,spores,freshwater algae,marine dinoflagellate cysts,and foraminiferal organic linings from Borehole HLL01 on the southern coastal plain of Laizhou Bay,Bohai Sea,northern China.[Results]The results provide valuable information on vegetation history and sea-level fluctuations since the Late Pliocene.Large amounts of terrestrial herb pollen(75.13%;mainly composed of Chenopodiaceae,Artemisia and Poaceae)were identified at Borehole HLL01,suggesting that coastal steppes flourished in the study area and its adjacent areas,and a cold and dry climate than the present during the Late Pliocene to Early Pleistocene,ca.6.8-1.6 Ma.After that,the steppe areas began to shrink,and the transition of coastal steppes to forest grasslands occurred in the Early-Middle Pleistocene,ca.1.6-0.6 Ma,indicating a warm and humid climate.A sharp increase in freshwater algae indicates that large rivers’discharge had been injected into the study area,or large lakes were formed.Afterward,relatively cool and dry climatic conditions appeared,with little precipitation,and a relatively significant transgression event revealed by dinoflagellate cysts and foraminifera organic linings,and forest grassland vegetation was distributed in the study area and its adjacent areas,during the Middle Pleistocene to Holocene,ca.0.6-0.004 Ma.[Conclusions]Three ancient plants have occurred and the sea level fluctuations occurred since the Late Pliocene(6.8-0.004 Ma)in the Laizhou Bay.

关 键 词：孢粉组合 古植被 古环境演变 晚上新世 海岸带地质调查工程 莱州湾 山东 

分 类 号：Q948.1[生物学—植物学]