Uplift and evolution of Helan Mountain  

作　　者：ZHAO HongGe LIU ChiYang WANG Feng WANG JianQiang LI Qiong YAO YaMing 

机构地区：[1]State Key Laboratory of Continental Dynamics(Northwest University),Xi'an 710069,China State Key Laboratory of Continental Dynamics(Northwest University),Xi'an 710069,China [2]College of Earth Sciences and Territory Resources,Chang'an University,Xi'an 710054,China [3]Department of Environment and technology of Zhengzhou Economic Management Institute,Zhengzhou 451191,China

出　　处：《Science China Earth Sciences》2007年第z2期217-226,共10页中国科学(地球科学英文版)

基　　金：Supported by the National Basic Research Program of China(Grant No.2003CB214607);the Development Project of Changjiang River Scholars and the Innovation Research Team in University(Grant No.IRT0559)

摘　　要：The Helan Mountain lies in the northwest margin of Ordos Basin and its uplift periods have close relations with the tectonic feature and evolution of the basin.There are many views on the uplift time of Helan Mountain,which is Late Triassic and Late Jurassic.It is concluded by the present strata,magmatic rock and hot fluid distribution that the Helan Mountain does not uplift in Late Triassic to Middle Jurassic but after Middle Jurassic.Through the research of the sedimentary strata and deposit rate in Yinchuan Graben which is near to the Helan Mountain,it is proved that the Helan Mountain uplifts in Eocene with a huge scale and in Pliocene with a rapid speed.The fission track analysis of apatite and zircon can be used to determine the precise uplift time of Helan Mountain,which shows that four stages of uplifting or cooling:Late Jurassic to the early stage of Early Cretaceous,mid-late stage of Early Cretaceous,Late Cretaceous and since Eocene.During the later two stages the uplift is most apparent and the mid-late stage of Early Cretaceous is a regional cooling course.Together with several analysis ways,it is considered that the earliest time of Helan Mountain uplift is Late Jurassic with a limited scale and that Late Cretaceous uplift is corresponding to the whole uplift of Ordos Basin,extensive uplift happened in Eocene and rapid uplift in Pliocene.

关 键 词：Helan Mountain Mesozoic strata Yinchuan Graben fission track uplift periods 

分 类 号：N[自然科学总论]