Formation Age of BIF-Bearing Anshan Group Supracrustal Rocks in Anshan-Benxi Area: New Evidence from SHRIMP U-Pb Zircon Dating
Wan Yusheng
Dong Chunyan
Xie Hangqiang
Xie Shiwen
Liu Shoujie
Bai Wenqian
Ma Mingzhu
Liu Dunyi
Abstract：Anshan-Benxi is one of the most important BIF concentration areas in the North China Craton,the BIF occurred in the Anshan Group supracrustal rocks.Using SHRIMP U-Pb zircon dating technique,12 supracrustal samples of the Anshan Group were analyzed.Most samples present 2.50-2.55 Ga zircon ages and 2.7-3.5 Ga detrital or xenocrystal zircons are observed in some samples.Combined with previous studies,main conclusions can be drawn as follows.(1) The widespread BIF-bearing Anshan Group supracrustal rocks in the Anshan-Benxi area were deposited during the Late Neoarchean.(2) The Anshan Group supracrustal rocks were formed over a continental basement.This study confirms that Anshan-Benxi is an important conponent of the huge Late Neoarchean BIF belt along the western margin of the eastern ancient terrane,and stable tectonic environment seems to be a key factor for the formation of huge-scale BIF ore deposit.
Keywords：Anshan GroupNeoarcheanSHRIMP U-Pb zircon datingAnshan-Benxi areapetrology
Publication Date：2018-01-01
Pages：25( 57-81 )