浙江白垩—第三纪孢粉组合及其古植被、古气候

CRETACEOUS—TERTIARY SPORO-POLLEN ASSEMIBLAGES OF ZHEJIANG WITH THEIR PALEOVEGETATION AND PALEOCLIMATE

浙江中新生代盆地计有40多个,大部分为断陷盆地,盆地内白垩-第三系厚达数千米。近年来,我们配合浙江的石油勘探,重点对长河盆地、金衢盆地、宁波盆地等白垩-第三纪地层进行了较系统的孢粉研究,共分析了78口钻井的2026块样品,获得了相当丰富的孢粉化石,为浙江白垩-第三纪地层、古植被、古气候研究提供了科学依据。徐金荣、杨再林、叶志华、吴妮分析样品,王秀雅、何福英清绘插图,在此表示感谢。一、孢粉组合序列浙江白垩-第三系孢粉自上而下可分为7个组合 1.Classopollis-Cicatricosispori-

Based on palynological research on sediments of Cretaceous and Tertiary from Zhejiang, seven sporo-pollen assemblages have been established, reflecting seven stages of paleovegeation and paleoclimate respectively. In the early Early Cretaceous there was a hot and slightly dry climate with a vegetation mainly composed of Cheirolepldiaceae and a few taxa of Podocarpaceae and Schizaeaceae. In the late Early Cretaceous thevegetation was represented by the coniferous forest of Cheirolepidiaceae, reflecting a hot climate of the tropicsubtropic zone, while the vegetation of Schizaeaisparites occurred in the northern, margin of the tropic zone in the early Late Cretaceous, reflecting a hot and dry climate. The hot and slightiy dry climate of the tropicsubtropic zone dominated during late Paleocene—early Eocene, with the mixed forest of conifers and broadleaf trees chiefly consisting of Ulmaceae. There was a wormer and moist climate of the southern subtropic zone with evergreen broadleaf and deciduous broadleaf forests: of angiosperms or conifers and broadleaf mixed forestin the middle and late Eocene. In early Oligocene there existed a conifer and broadleaf mixed forest of Taxodiaceae, reflecting a warm and moist climate of the middle subtropic zone. The conifer and broadleaf mixed forest, mainly composed of deciduous broadleaf trees occurred in the middle and late Oligocene, reflecting a temperate and moist climate of the northern tropic zone.