Abstract
Fossil pollen records from Tsurugashima, a city, located in northwestern part of the Kanto Plain, provides information on paleovegetation and paleoclimate changes from the Late Pleistocene through the Holocene.In this study, sediments samples from two sites were analyzed. A site IK was divided into six local pollen biozones, and a site TS was divided into two zones and subdivided into three sub zones. A zone IK-F was characterized by temperate-subarctic transition zone coniferous forests, which was indicated by Pinus(Haploxylon), Picea, Abies, and Tsuga accompanied with deciduous broad-leaved trees such as Quer- cus(Lepidobalanus) and Tilia. This zone approximately corresponds to the first transgression phase since the Last Glacial Maximum (LGM) ca. 19,000 years before present. A zone IK-E was characterized by tem- perate-subarctic transition zone coniferous forests, which was indicated by Pinus(Haploxylon), Picea, Abies, and Tsuga accompanied with cool-temperate deciduous broad-leaved trees. The Paleoclimate was colder and an upper part of this zone was estimated to correspond to the Heinrich event 1. A zone IK-D was chaacterized by a rapidly spread cool-temperate deciduous broad-leaved forests, which was indicated by Quercus(Lepidobalanus) accompanied with temperate-subarctic transition zone coniferous trees. The Paleoclimate was cool. This zone is correlated with the Bolling /Allerod oscillation and corresponds to the melt water pulse (MWP-1A), ca.14,000 years before present. A zone IK-C was characterized by warm-temperate deciduous broad-leaved forests, which was indicated by Quercus(Lepidobalanus) accompanied with warm-temperate evergreen broad-leaved trees such as Cyclobalanopsis. The Paleoclimate was warm.
Zones IK-B and TS-B ware characterized by subtropical-temperate transition zone Abies firma and Tsuga sieboldii forests that had spread to mountains. The Paleoclimate was slightly cooler and wetter than the zone IK-C. A subzone TS-B-2 is correlated with a sea-level regression called “the Yayoi regression,” ca. 3,500 to 2,000 years before present.
As described above, paleovegetation changes in the Kanto Plain, central Japan, are consistent with global paleoclimatic changes from the Late Pleistocene through the Holocene.
