辽河平原东部黑土剖面孢粉组合及其时代和古气候意义

SPOROPOLLEN ASSEMBLAGE OF BLACK SOIL SECTION IN EASTERN LIAOHE PLAIN: Age and Paleoclimatic Implication

对辽河平原东部黑土剖面PM25中0~1 m开展孢粉分析,根据孢粉百分含量变化将化石自下而上划分为两个孢粉组合,其中PM25-1孢粉组合以Spiraea-Artemisia-Sanguisorba-Rosa-Echinate Asteraceae为主,气候由冷干向暖湿转变;PM25-2孢粉组合以Pinus-Cyperaceae-Chenopodium为主,指示了气候由暖湿向冷干转变.结合^(14)C测年数据,辽河平原东部黑土主要形成于1.355 ka以来的中世纪暖期.

By analysis of sporopollen in 0-1 m black soil profile PM25 in eastern Liaohe Plain,the fossils are divided into two sporopollen assemblages from bottom to top according to the sporopollen content change.The PM25-1 sporopollen assemblage is mainly Spiraea-Artemisia-Sanguisorba-Rosa-Echinate Asteraceae,with the climate changing from cold-dry to warm-wet;while the PM25-2 sporopollen assemblage is dominated by Pinus-Cyperaceae-Chenopodium,indicating the transition of climate from warm-wet to cold-dry.Combined with the ^(14)C dating data,it is concluded that the black soil in eastern Liaohe Plain was mainly formed in Medieval Warm Period since 1335 a B.P.