NEW RECOGNITION OF THE STRATIGRAPHIC SEQUENCE AND AGE OF THE ERLANGPING GROUP IN HENAN PROVINCE

Divergent views have long existed as to the stratigraphic division and ageof the Erlangping Group in Henan Province.On the basis of the new resultsof the 1:50000 regional surveys conducted in the Nanzhao area,the authorshave redefined the sequence of this group.From below upwards it is dividedinto the Xiaozhai and Huoshenmiao Formations which show conformable contactrelationships.The group is in fault contact with the underlying KuanpingGroup and is in turn unconformably overlain by the Triassic strata.Meanwhile,in the light of a group of cephalopod,gastrpod and brachiopod fossils collectednewly from the Damiao Formation coupled with regional structural features andisotopic ages,the authors consider that the Erlangping Group is impossible tobe of Triassic or early-middle Proterozoic age and that it was mainly formedin the Middle Ordovician.