Chronology and Tectonic Implications of Neoproterozoic Volcanics from Chiniot Deposit,Pakistan
Xu Jiannan
Ma Changqian
Yin Shuo
Wang Lianxun
Dun Xinhai
Abstract：This is a hotpoint that the study the breakup of Rodinia supercontinent and the formation of Chiniot iron oxide-apatite depos-it,we report zircon U-Pb ages,Hf isotopic composition and REE contents of andesite.All the zircons are magmatic origin with the similar REE patterns which are enriched in HREE with a positive Ce anomaly and a negative Eu anomaly.The zircon U-Pb isotopic an-alyses yields 206 Pb/238 U ages of 947.8±4.0 Ma and 883.0±5.1 Ma,which can be interpreted as the crystallization ages of two stages of andesites.Besides,the inherited zircons with U-Pb age of 1523.0±66 Ma may indicate a Mesoproterozoic basement.The igneous zir-cons have highly variableεHf (t )values ranging from -4.67 to +13.10,indicating that the andesites were derived from partial melting of a mixed mantle sourse.The geochemical and isotopic variation suggest that mantle-derived basic magmas have went through some degree of crustal commination during migration through Mesoproterozoic granitoids.The formation of the andesites were induced by a series of tectono-thermal events,associated with extensional rift and mantle plume during Rodinia supercontinent.There are many simi-larities between Chiniotiron deposit and Khetri Copper Belt in geological setting of ore-forming processes,indicating that the metalloge-netic potentiality of giant IOCG is very well.The northwest of Indian craton may have connection with North China-Congo-S?o Francis-co craton between 960 Ma and 880 Ma.
Keywords：Pakistanandesitemantle-derivedextensional riftRodinia supercontinentgeochronologypetrology
Publication Date：2017-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：17( 2282-2298 )