新疆库车库尔哈剖面两个新生代孢粉组合的时代和环境意义

Two Cenozoic palynological assemblages of the Kurha section,Kuqa,Xin jiang and their age and environmental significance

库车盆地的新生界发育比较完整,笔者在库车县城北东方向约50km的库尔哈村西的河谷中测制了剖面。于66层的44号样和90层的50号样品中获得了两个孢粉组合。66层和90层皆属于康村组,两个样品之间相差约200m(真厚度)。在此之前,尚未见到有关康村组孢粉化石的报道。44号样的孢粉组合中被子植物花粉占绝对优势,含量高达94.5%,裸子植物花粉和蕨类植物孢子均少量出现。孢粉面貌反映以草原和灌丛为主的植被类型。50号样的孢粉组合中被子植物花粉占优势(66.5%),裸子植物花粉有较高含量(32.0%),蕨类植物孢子零星出现。孢粉面貌反映盆地周缘广泛分布有以松科为主的高山针叶林带。

Cenozoic sediments are well developed in the Kuqa basin.The authors measured a section ex-posed in a river valley west of Kurha Village,about 50km northeast of the county seat of Kuqa.Two palynological assemblages were obtained from samples No.44(bed66)and No.50(bed90)respectively.The two samples are both from the Kangcun Formation,about 200m(thickness)apart.The palynological assemblage from sample No.44is dominated by pollen of angiosperms (94.5%);pollen of gymnosperms (4.4%)and spores of ferns (1.3%)are present in small amounts.The feature of this assemblage shows that grassland and bushes constituted the major part of the vegetation.The palynological assemblage from sample No.50consists mainly of pollen of angiosperms (66.5%)with subordinate pollen of gymnosperms (32.0%),and spores of ferns (1.4%)occur sporadically.The feature of this assemblage indicates that conifers represented mainly by elements of Pinaceae flourished at basin margins.