Laser ablation(in situ)Lu-Hf dating of magmatic fluorite and hydrothermal fluorite-bearing veins  

作　　者：Stijn Glorie Jacob Mulder Martin Hand Adrian Fabris Alexander Simpson Sarah Gilbert 

机构地区：[1]Department of Earth Sciences,University of Adelaide,SA 5005,Australia [2]Geological Survey of South Australia,Department for Energy and Mining,Adelaide,SA 5005,Australia [3]Adelaide Microscopy,University of Adelaide,SA 5005,Australia

出　　处：《Geoscience Frontiers》2023年第6期142-154,共13页地学前缘（英文版）

基　　金：supported by research grants DP200101881 and FT210100906 from the Australian Research Council(ARC)and additionally;the Mineral Exploration Cooperative Research Centre.

摘　　要：Fluorite(CaF_(2))is a common hydrothermal mineral,which precipitates from fluorine-rich fluids with an exceptional capacity to transport metals and Rare Earth Elements(REEs).Hence,the ability to date fluorite has important implications for understanding the timing of metal transport in hydrothermal systems.Here we present,for the first time,fluorite Lu-Hf dates from fluorite-carbonate veins from the Olympic Cu-Au Province in South Australia.The fluorite dates were obtained in situ using the recently developed LA-ICP-MS/MS Lu-Hf dating method.A fluorite-calcite age of 1588±19 Ma was obtained for the Torrens Dam prospect,consistent with the timing of the formation of the nearby Olympic Dam iron-oxide copper gold Breccia Complex.Veins in the overlying Neoproterozoic successions were dated at 502±14 Ma,indicating a temporal link between Cu-sulphide remobilisation and the Delamerian Orogeny.Additionally,we present a multi-session reproducible date for magmatic fluorite from a monzogranite in the Pilbara Craton(Lu-Hf age of 2866±19 Ma).This age is consistent with a garnet Lu-Hf age from the same sample(2850±12 Ma)and holds potential to be developed into a secondary reference material for future fluorite Lu-Hf dating.

关 键 词：Reaction-cell ICP-MS In-situ geochronology Fluorite-calcite veins Iron oxide copper-gold Critical mineral exploration Rare Earth Elements 

分 类 号：P185.83[天文地球—天文学] P597.3