摘要
As a typical skarn-type deposit,the Kekesala-Aimusidaiyi Fe-Cu deposit is located in the Boluokenu polymetallic belt in the northern West Tianshan,Xinjiang Province.It occurred at the contact zone between the Husite intermediate-acidic intrusive rocks of Hercynian age and Upper Ordovician carbonate rocks.The timing of host rock intrusion and mineralization is unclear yet up to this study.LA-ICP-MS U-Pb dating of this study on zircon in monzogranite from the Husite intrusive body gave a concordia age of 368.0±3.6Ma and a weighted average age of 365.6±3.2 Ma,indicating its intrusion in the latest Devonian during the southward subduction of the North Tianshan ocean under the Yili plate.Re-Os dating on molybdenite from the skarn ore gave an isochron age of 295±11 Ma and a weighted average age of 288.3±1.5 Ma,indicating the earliest Permian mineralization during the post-collisional extension.Possibilities for the wide range of the timing between host rock intrusion and mineralization include that(1)the Husite intrusive body is a complex with multiple-stage intrusions,and the Mo mineralization as well as the skarn-type Fe-Cu mineralization were associated with the contact metasomatism of magmatic rocks intruded in the early Permian,and that(2)the skarn-type Fe-Cu mineralization was associated with the intrusion and metasomatism of the intermediate-acidic rocks in the late Devonian and,later in the early Permian,was superimposed by the Mo mineralization.