[关键词]
[摘要]
根据日本中部琵琶湖深井钻探资料研究了过去3Ma的古植被、地层及古气候。由湖底取得的200m和1400m样品的孢粉组合可分别划分出19个和37个带,反映了湖区及其周围自晚上新世以来的古植被和古气候演变史。在冰期阶时琵琶湖附近山区的典型植被为亚北极带,低地为冷温带。而在间冰期阶里山区一般为温带或冷温带植被,低地则主要由落叶和常绿树组成的温带和暖温带的植被。在进行过去3Ma古植被、古气候演变对比中,当地古气候史和以下资料显示出明显的一致,例如加勒比海、西太平洋及赤道海洋的氧同位素资料,地中海西部(Mallorca)的沉积旋回,欧洲中部的风成沉积序列,日本关东和新几内亚的海平面变化记录,以及在南美波哥大高地和以色列死海裂谷根据孢粉得出的古气候变化记录。
[Key word]
[Abstract]
Investigation was carried out on the palaeovegetation, stratigraphy and palaeoclimate in the last 3 Ma based onthe long cores from the Lake Biwa, Central Japan. Samples of 200-meter and 1400-meter cores obtained from the bottom of thelake yield nineteen and thirty-seven pollen zones respectively showing the palaeovegetational and palaeoclimatic changes inand around the lake since the late Pliocene period. During the glacial stages or stadials, typical vegetation of the subpolar zoneoccurred in the mountainous area around Lake Biwa. While in the lowland area in and around the lake, characteristic plants ofthe Cool Temperate zone occurred. During the interglacial stages or interstadials the vegetation of the mountainous area wasgenerally characterized by plants of the Temperate zone and/or Cool Temperate zone, while in the lowland area the vegetationwas composed mainly of deciduous and evergreen broad-leaved trees of the Temperate and Warm Temperate zones. In theglobal correlation from the viewpoints of palaeovegetation and palaeoclimate changes during the last 3 Ma since the latePliocene period, the climate history shows remarkable parallel with the palaeotemperature records by oxygen isotope analysesof Caribbean Sea, Western Pacific and Equatorial Pacific Ocean, sedimentary cycles of Mallorca in the western MediterraneanSea, aeolian depositional sequences from Central Europe, the records of sea level changes based on the marine terraces inKanto, Japan and New Guinea, and the palaeoclimate changes based on the palynological analyses in Bogota high plain ofSouth America and Dead Sea Rift of Israel.
[中图分类号]
P532 Q914.8
[基金项目]