摘要
天津东部广泛分布的中新世沉积物为阐释中新世以来的古植被和古气候提供了研究载体，本文依据塘沽区1226m深G2孔的花粉分析结果，结合古地磁等定年手段，重建了天津滨海地区约7．65Ma BP 以来的古植被特征。研究显示，区域地貌环境与气候环境共同作用于周边的植被环境。沉积速率与草本花粉组合具有良好的对应关系，研究表明在约6．73-6．43与3．58-3．03 MaBP 沉积速率较大时形成相对较高的河滩高地，其他时期以盐沼和盐碱地为主。由乔木花粉显示的植被历史表明在6．90-7．65Ma BP周边植被为暖温带落叶阔叶林，代表暖湿环境，3．61-6．9 MaBP为干旱的疏林草原，2．80-3．61MaBP 为针阔叶混交林，较为凉湿，1．28-2．80 Ma BP为暖温带落叶阔叶林的景观，整体上较为暖湿。1．28 Ma BP 以来，草本与乔木花粉的波动变化，反应了更新世中后期冷暖气候的波动。
The Miocene far-ranging deposits in east plain of Tianjin provide the study carrier for palaeovegetation and palaeoclimate since the Miocene.Based on the analysis of pollens in deep borecore drilled in Tanggu,in combination with the chronostratigraphic framework recovered by the palaeomagnetic,this study regains the palaeovegtation evolution featrues for the Tianjin Coastal region since 7.65Ma BP.The results show that regional geomorphology and climate jointly acted on the circumjacent palaeovegetation environment. The corresponding relations between deposits sedimentation rate and herbaceous pollens show that the high sedimentation during period of 6.73-6.43Ma BP and 3.58-3.03Ma BP formed batture and during other periods formed mainly salt marsh and kaline soil.The history of palaeovegetation evolution shows by arborescent pollens that the palaeovegetation was temperate deciduous broad-leaved forests,and stands for warm and humid environment during 6.90-7.65Ma BP,3.61-6.90Ma BP.Palaeovegetation was dominated by arid veld.2.80-3.61Ma BP,the climate became cool and humid,and palaeovegetation turned to mixed coniferous broad leavedforest grass.During the periods of 1.28-2.80Ma BP,the climate became warm and humid and palaeovegetation became temperate deciduous broad-leaved forests.Since 1.28Ma BP,the fluctuations of herbaceous pollens and arborescent pollens revealed the fluctuations of cold-warm climate from middle-late periods of Pleistocene.
出处
《地质学报》
EI
CAS
CSCD
北大核心
2015年第6期1134-1143,共10页
Acta Geologica Sinica
基金
中国地质调查局项目(编号1212011120170
1212011120089)资助
关键词
晚中新世以来
渤海湾
植被演化
气候变化
沉积速率
Late Miocene
Bohai Bay
palaeovegetation evolution
palaeoclimate evolution
sedimentation rate
