Sporopollen Assemblage And Evolution Of Palaeoclimate In Nantong City Area Since Quaternary

The Quaternary sporopollen made a lot of work, and made gratifyingachievements in ancient vegetation, paleoclimate, the modern environmental andarchaeological environment research. This paper based on the major project of ChinaEarthquake Administration and Earthquake Administration of Jiangsu Province“Projects of cities in Jiangsu Province seismic active fault detection and seismic riskassessment （Nantong）”. Based on the sporopollen sampled analysis of controlledstandard hole（NTK01） in Nantong, we could divide sporopollen assemblage andderived the corresponding ancient climate and its evolution according to the evolutionof ancient vegetation. In addition, based on the chronological data, we madecomparative analysis of sporopollen data. So we drew some conclusion as follows:1、The sporopollen assemblage in controlled standard Nantong hole could bedivided into five sporopollen zone such asⅠ, Ⅱ, Ⅲ, Ⅳ, Ⅴ, eleven sporopollensub-zones. According to the Pollen assemblage, lithologic characteristics, combinedwith TL dating data that the pollen assemblage zone with Ⅴ reflects for the Holoceneof the deposition, Ⅳ zone reflects the Late Pleistocene of deposition, Ⅲzone reflectsthe deposition of the Middle Pleistocene, and Ⅱ zone reflects the deposition of thePleistocene, Ⅰ zone reflects the deposition of the late Pliocene.2、The sporopollen combination in nantong, mirrored the climate change andvegetation types since the quaternary start. The deposition in Holocene Rudong group（QhR）The sporopollen assemblage Ⅴ mirrored coniferous deciduous broad-leavedmixed forest-grassland, evergreen broadleaf deciduous mixed forest, coniferousdeciduous broad-leaved mixed forest, reflecting the climate underwent warm andmoist Period; The deposition in Late Pleistocene the Gehu group, the Kunshan group（Qp3G, Qp3K）, The sporopollen assemblage Ⅳ mirrored coniferous broad-leavedmixed forest-grassland, deciduous broad-leaved mixed forest and coniferous forest-grassland, reflecting the climate from the cold and dry then to warm and moist andthen to cold and dry,. The clime change is a reflection of the climate of the cold period;the deposition of the Middle Pleistocene the Qidong group （Qp2Q）, The sporopollen assemblage Ⅲ mirrored deciduous broadleaved mixed forest-grassland andconiferous forest-grassland, reflecting the warm and moist period; the deposition ofthe Pleistocene the Haimen group （Qp1H）, The sporopollen assemblage Ⅱ mirroredconiferous forest-grassland, deciduous broad-leaved coniferous mixed forest-grassland and grassland, reflecting the cold and dry period; the deposition of the latePliocene the Yancheng （N2Y）, The sporopollen assemblage zone Ⅰ mirroredevergreen broad-leaved deciduous forest–grassland, reflect a humid climate, and theclimate changing from warm and moist to cool and dry. The whole sporopollenassemblage objectively reflects the phasing of the Quaternary.3、Compared with deep-sea oxygen isotope, it is more significant that vegetationtypes and climate in Nantong affected by glacial-interglacial period. And thedeep-sea oxygen isotopes MIS3,4, and5all have well responsed to the sporopollenassemblage Ⅴb, Ⅳc, and Ⅳb.4、According to the controlling rock strata, dating drilling data, grain sizeanalysis, pollen combination, and other comprehensive analysis, this paper pointedout the integrated layers solution in quaternary at Nantong area and discussed the N/Qboundaries.