辽西燕辽生物群分布特征及新发现

摘要

我国辽宁省西部地区一直是中生代古生物化石的重要产地,近几年发现了大量的珍稀动植物化石,产生了重要的影响,但有一些化石的层位尚不明确.近三年来,笔者在辽宁西部葫芦岛建昌以及朝阳辖区下的朝阳县、凌源市以及建平县针对一套中侏罗世火山岩所夹的沉积岩地层进行了详细的化石调查工作.首先,根据髫髻山组地层出露条件,在金岭寺—羊山盆地的建昌县玲珑塔大西山村测制了髫髻山组主干剖面,除此之外还在大平房—梅勒营子盆地和凌源—三十家子盆地测制了辅助剖面,同时在剖面上逐层进行化石采集;之后研究本次工作采集的化石以及收集该地区燕辽生物群化石资料;最后将化石落到准确的层位之上,并将各盆地化石层进行对比.通过剖面的测制以及化石的挖掘和调查,确定其为中侏罗世髫髻山组,属燕辽生物群中期,确定了一批珍稀化石的产出层位,为了方便不同盆地化石层对比,本文命名了两个新的珍稀化石层位——大西山化石层和棺材山化石层,将化石与层位一一对应,并且完成了对辽西主要盆地化石层的对比;与之同时挖掘出了一批珍贵的动植物化石,丰富了燕辽生物群古生物的内容,为今后的研究提供了翔实的资料.%Objectives:Western Liaoning Province in our country has been an important producer of Mesozoic fossils,a large number of rare animal and plant fossils was found and had a significant impact in recent years,but the layers of fossils remains unclear,this time we are going to solve this problem.Methods:In the past three years,the author carry out an investigation in detail for a sedimentary rock between two other volcanic rocks in Jianchang、Lingyuan、Chaoyang、Jianping of western Liaoning.First of all,according to the exposed of Tiaojishan formation,we set the main section in Daxishan Linglongta Jianchang,which located in Jinlingsi—Yangshan Basin,Moreover we neasured assisted sections in Dapingfang—Meileyingzi basin and Lingyuan—Sanshijiazi basin;at the same time we excavate fossils layer by layer,in order to determine the stratigraphic horizons which has fossils;after that we researched the fossils we collecting and collected the informations of fossils in western Liaoning;at last we put fossils on the correct fossil bed and comparing fossil beds in different basin.The main methods of this investigation is sectional measurement and fossil collection systematic.Result:Through out the sectional measurement and fossil collection,we determining a part of fossil beds of the Tiaojishan Formation Middle Jurassic,belonging middle of theYanliao Biota.In order to compare with fossil beds in other basins,we named two fossil beds——Daxishan fossil bed and Guancaishan fossil bed,corresponded fossil with stratigraphic horizons,and completed comparison of fossil beds in different basin;at the same time we excavated anumber of precious fossils.Conclusions:By the investigation this time,we determining a series of middle Jurassic fossil beds in western Liaoning and collecting many fossils enrich the Yanliao Biota and provid informations for studing and researching for future.