富县地区末次间冰期以来古气候环境的演变

研究剖面位于洛川源北部的富县县城东郊。剖面由第一层古土壤(S_1)、马兰黄土(L_1)和全新世古土壤(S_0)组成。孢粉分析结果表明,黄土地层中孢粉非常丰富,为恢复古植被与古气候提供了可靠依据。S_1的植被是以榛、菊、蒿为主的疏林草原,有亚热带树种出现,反映了末次冰期的温湿气候。L_1时主要为菊、蒿干草原,气候冷干,其间有四次乔木增多期,反映了末次间冰期中有四次间冰阶的相对温湿气候波动。近代耕土中为以松、藜、中华卷柏为主的森林草原,反映了全新世某个时期比较温凉干旱的气候。

PALAEOCLIMATE-ENVIRONMENTAL EVOLUTION SINCE LAST INTERGLACIAL STAGE IN FUXIAN AREA, SHAANXI PROVINCE

The section situated in the north of Luochuan Yuan, lies in the east suburb of Fuxian County. It consists of the First paleosoil (S1), Malan loess (L1) and Holocene paleosoil (S0). The result of spore-pollen analysis shows that loess strata are very rich in spore and pollen. Therefore, they provide a reliable evidence for reconstruction of the paleovegetation and the paleoclimate. The vegetation of S1 is of spare forest-grass land. The occurrence of some species of subtropic trees reflects the warm and humid climate of the Last Interglacial. The vegetation of L1 is mainly composed of stappe of composite and Artemisia. There are four phases of woody increasing in it. They are four relative warm and humid interstitials in the Last Glacial Stage. Forest-grass land of pinus, Chenopodiaceae and Selaginella sinensis in the modern cultivated soil reflects a moderate-cooler and arid climate in Holocene.