西藏南部洛扎地区中生代遗迹化石及其环境意义  

MESOZOIC TRACE FOSSILS FROM LHOZHAG AREA OF SOUTHERN TIBET AND THEIR ENVIRONMENTAL SIGNIFICANCE

作　　者：周志澄[1] H.Willems 夏军[3] 钟华明[3] 童劲松[3] 

机构地区：[1]中国科学院南京地质古生物研究所,南京210008 [2]德国不来梅大学地球科学系 [3]安徽省地质调查院,合肥230001

出　　处：《古生物学报》2004年第2期221-233,共13页Acta Palaeontologica Sinica

基　　金：国家重点基础研究发展规划项目 (G2 0 0 0 0 7770 8) ;国土资源部地质大调查项目 ( 199913 0 0 0 2 11);德国马普协会资助项目成果

摘　　要：详细描述了西藏南部洛扎地区中生代地层中所含的遗迹化石Arenicolitessp .,Beaconitesantarcticus,Chondritessp .A ,C .sp .B ,C .sp .C ,C .sp .D ,?Cruzianasemiplicata ,Palaeophycustubularis,Phycodescircina tum ,Protovirgulariadichotoma ,Skolithosverticalis,Teichichnusrectus和Unaritessuleki计 1 0遗迹属 1 3遗迹种 。According to Gansser (1964), the Tethyan Himalayas is a tectonic unit which is borded by the central Crystallines of the High Himalayas to the south and the Indus Yarlung Zangpo suture zone to the north. The Tethyan Himalayas can be subdivided into two subzones of different lithological compositions by the Kyen La Kangmar intracrustal thrust. The northern Tethyan depositional zone is dominated by slightly metamorphosed deposits of the outer shelf, continental slope and deep sea environments. The southern Tethyan zone is characterized by non metamophic shallow water deposits (Yin, 1988; Liu and Einsele, 1994; Willems et al ., 1996). On the basis of the depositional features, the northern subzone can further be divided into two areas: Lhagu Kangri area and the Yarlung Zangpo area. The Mesozoic deposits in the Yarlung Zangpo area were deposited in a more active tectonic background than that in the Lhagu Kangri area. The Lhozhag area is located to the east of Gyangze Kagmar and can be acted as the east part of Lhagu Kangri area. More than ten thousand meters of Mesozoic deep sea and shelf terrigenous detrital sediments are piled on the Kangmar Fm. aged Permian of passive margin base. Yang Shi pu et al. described Middle Upper Triassic trace fossis from Zanda area and Middle Jurassic to Early Cretaceous trace fossils from Shiquanhe Domar area of Ngari of western Tibet (1985, 1982). Zhou Zhi cheng (1997), Zhou Zhi cheng et al. (1997), and Zhou Zhi cheng et al. (2000) studied the Cretaceous Tertiary trace fossils from Gangba and Tüna areas of southern Tibet and discussed their environmental significance. The trace fossils from Lhozhag area describeded and discussed in this paper can reflect the basic aspects of Mesozoic trace fossils of Lhagu Kangri area. This is also an important evidence of the great changes in the tectonic background which resulted in the changes of sedimentary environments in these areas during Mesozoic Era.

关 键 词：遗迹化石 中生代 西藏南部 洛扎地区 沉积环境 

分 类 号：Q911[天文地球—古生物学与地层学]