辽西北票地区义县组古气候环境标志及其意义

野外地质调查及综合研究表明，包含中华龙鸟、被子植物等珍稀化石的热河生物群的主要赋存层位为义县组二段湖相沉积岩层。对产于不同地点沉积层中的植物、孢粉化石以及木化石进行了总结研究，分析了它们所反映的古气候环境，认为义县组沉积时期存在大量的喜温湿植物，总体指示温暖湿润的生存环境。同时，一些旱生的买麻藤类植物的普遍存在、本内苏铁类的膜质叶以及松柏类的鳞状叶等的特征反映了存在季节性干旱、半干旱气候的可能性。这种气候状况的出现可能与火山活动有关。

Paleoclimatic and palaeoenvironmental proxies of the Yixian Formation in the Beipiao area,western Liaoning

Field geological surveys and integrated researches indicate that the main horizon of the Jehol biota containing rare fossils such as the reptile Sinosauropterxy and the angiosperm Archaefructus in the Yixian Formation is fossiliferous lacustrine sedimentary strata of the Second Member of the Yixian Formation be-tween the4th and5th basic-intermediate volcanic cycles.Study of the data about sporopollen,plant and wood fossils in sediments from different localities and analysis the paleoclimate and paleoenvironment reflected by them show that large numbers of hygrophilous and thermophilous plants grew during the Yixianian age,generally indicating a warm and wet habitat.The common occurrence of xerophilous Gnetales and features of Bennettiales with membranous leaves and Conifersles with scaled leaves indicate the possible occurrence of seasonal arid or semi-arid climatic conditions ,which may be associated with volcanic activity.