从山羊寨哺乳动物化石看柳江盆地洞穴堆积的时代与环境

FORMATION PERIOD AND ENVIRONMENT OF SPELEOTHEM IN THE LIUJIANG BASIN INFERRED FROM THE SHANYANGZHAI MAMMAL FOSSILS

山羊寨洞穴堆积是河北省秦皇岛"柳江盆地地质遗迹自然保护区"众多溶洞的洞穴堆积之一,其中含有大量的哺乳动物化石。经发掘整理与鉴定,采用生物地层学和哺乳动物生活习性对比分析方法,确定其时代为Qp2 3,晚于辽宁营口"金牛山下组动物群",早于河北"迁安爪村动物群"和内蒙古"萨拉乌苏动物群",其特征反映了中国华北与东北过渡地带中更新世晚期至晚更新世早期的哺乳动物面貌,并反映出当时区内森林、森林草原、草原和水域条件等生态环境的多次时空变化。如此众多哺乳动物化石的发现增加了保护区遗迹资源的多样性和保护价值;为该区洞穴堆积的时代与沉积环境研究提供了依据;改变了区内洞穴堆积仅为中更新世地层的认识。

Shanyangzhai speleal sediment which contains plenty of mammal fossils is one of the speleothem in the Liujiang Geological Remain Reservation Zone in Qinhuangdao of Hebei Province.Based on the fossil excavation and identification,the biostratigraphy and correlation analysis of the living habit of the mammals indicate that the chronology is Qp23,later than lower Jinniushan Formation fauna in Liaoning Province and earlier than Qian'an Zhaocun fauna in Hebei Province and Shalawusu fauna in the Inner Mongolia.It reflects the characteristics of mammals in the transition zone from North China to Northeast China during late Qp2 and early Qp3.The characteristics of the mammal fauna reflect the time and space variation of ecological environments such as forest,grass and water bodies in this area.This is the first time to found such plenty of mammal fossils in this area, which enriches the variety and value of geological remain resources in the reservation zone and provides a basis for studying the chronology and environment of speleothem.It also corrects the misunderstanding that the speleothem in this area only consists of Qp2 sediments.