Two ages of porphyry intrusion resolved for the super-giant Chuquicamata copper deposit of northern Chile by ELA-ICP-MS and SHRIMP

Abstract

Research Article| May 01, 2001 Two ages of porphyry intrusion resolved for the super-giant Chuquicamata copper deposit of northern Chile by ELA-ICP-MS and SHRIMP Julian R. Ballard; Julian R. Ballard 1Research School of Earth Sciences, Australian National University, Canberra, ACT 0200, Australia Search for other works by this author on: GSW Google Scholar J. Michael Palin; J. Michael Palin 1Research School of Earth Sciences, Australian National University, Canberra, ACT 0200, Australia Search for other works by this author on: GSW Google Scholar Ian S. Williams; Ian S. Williams 1Research School of Earth Sciences, Australian National University, Canberra, ACT 0200, Australia Search for other works by this author on: GSW Google Scholar Ian H. Campbell; Ian H. Campbell 1Research School of Earth Sciences, Australian National University, Canberra, ACT 0200, Australia Search for other works by this author on: GSW Google Scholar Alejandro Faunes Alejandro Faunes 2Superintendencia de Geología Codelco-Chile, Division Chuquicamata, Chuquicamata, Chile Search for other works by this author on: GSW Google Scholar Author and Article Information Julian R. Ballard 1Research School of Earth Sciences, Australian National University, Canberra, ACT 0200, Australia J. Michael Palin 1Research School of Earth Sciences, Australian National University, Canberra, ACT 0200, Australia Ian S. Williams 1Research School of Earth Sciences, Australian National University, Canberra, ACT 0200, Australia Ian H. Campbell 1Research School of Earth Sciences, Australian National University, Canberra, ACT 0200, Australia Alejandro Faunes 2Superintendencia de Geología Codelco-Chile, Division Chuquicamata, Chuquicamata, Chile Publisher: Geological Society of America Received: 17 Aug 2000 Revision Received: 04 Jan 2001 Accepted: 21 Jan 2001 First Online: 02 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (2001) 29 (5): 383–386. https://doi.org/10.1130/0091-7613(2001)029<0383:TAOPIR>2.0.CO;2 Article history Received: 17 Aug 2000 Revision Received: 04 Jan 2001 Accepted: 21 Jan 2001 First Online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation Julian R. Ballard, J. Michael Palin, Ian S. Williams, Ian H. Campbell, Alejandro Faunes; Two ages of porphyry intrusion resolved for the super-giant Chuquicamata copper deposit of northern Chile by ELA-ICP-MS and SHRIMP. Geology 2001;; 29 (5): 383–386. doi: https://doi.org/10.1130/0091-7613(2001)029<0383:TAOPIR>2.0.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract Zircon U-Pb ages measured in situ by excimer laser ablation–inductively coupled plasma–mass spectrometry (ELA-ICP-MS) and verified by sensitive high-resolution ion microprobe (SHRIMP) on ore-bearing felsic porphyries from the Chuquicamata porphyry copper-molybdenum deposit, northern Chile, identify two discrete igneous events. The volumetrically dominant East porphyry has an age of 34.6 ± 0.2 Ma, whereas the Bench and West porphyries yield ages of 33.3 ± 0.3 Ma and 33.5 ± 0.2 Ma, respectively. The age of the East porphyry is indistinguishable from a Re-Os age for early molybdenite mineralization (35 Ma) and the oldest reported 40Ar-39Ar ages for hydrothermal alteration, confirming a genetic link with mineralization. Previous geological studies and 40Ar-39Ar and Re-Os geochronology identify two main hydrothermal events: high-temperature potassic alteration with chalcopyrite at 33.4 ± 0.3 Ma followed by lower temperature quartz- sericite alteration with pyrite at 31.1 ± 0.3 Ma. The ages of the West and Bench porphyries match the ages for potassic alteration. Younger quartz-sericite alteration may reflect an additional fourth intrusion concealed at depth. The anomalously large size of Chuquicamata appears to be due to a protracted igneous history resulting in the superposition of at least two temporally distinct magmatic-hydrothermal systems. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.