Growth History of Sphalerite in a Modern Sea Floor Hydrothermal Chimney Revealed by Electron Backscattered Diffraction

Abstract

Research Article| February 01, 2019 Growth History of Sphalerite in a Modern Sea Floor Hydrothermal Chimney Revealed by Electron Backscattered Diffraction Si-Yu Hu; Si-Yu Hu 1Commonwealth Scientific and Industrial Research Organisation (CSIRO) Mineral Resources, Australian Resources Research Centre, 26 Dick Perry Avenue, Kensington, Western Australia 6151, Australia †Corresponding author: e-mail, siyu.hu@csiro.au Search for other works by this author on: GSW Google Scholar Stephen J. Barnes; Stephen J. Barnes 1Commonwealth Scientific and Industrial Research Organisation (CSIRO) Mineral Resources, Australian Resources Research Centre, 26 Dick Perry Avenue, Kensington, Western Australia 6151, Australia Search for other works by this author on: GSW Google Scholar A. Matthew Glenn; A. Matthew Glenn 2Commonwealth Scientific and Industrial Research Organisation (CSIRO) Mineral Resources, Research Way, Clayton, Victoria 3169, Australia Search for other works by this author on: GSW Google Scholar Anais Pagès; Anais Pagès 1Commonwealth Scientific and Industrial Research Organisation (CSIRO) Mineral Resources, Australian Resources Research Centre, 26 Dick Perry Avenue, Kensington, Western Australia 6151, Australia Search for other works by this author on: GSW Google Scholar Joanna Parr; Joanna Parr 3Commonwealth Scientific and Industrial Research Organisation (CSIRO) Mineral Resources, 11 Julius Avenue, North Ryde, New South Wales 2113, Australia Search for other works by this author on: GSW Google Scholar Colin MacRae; Colin MacRae 2Commonwealth Scientific and Industrial Research Organisation (CSIRO) Mineral Resources, Research Way, Clayton, Victoria 3169, Australia Search for other works by this author on: GSW Google Scholar Ray Binns Ray Binns 3Commonwealth Scientific and Industrial Research Organisation (CSIRO) Mineral Resources, 11 Julius Avenue, North Ryde, New South Wales 2113, Australia Search for other works by this author on: GSW Google Scholar Author and Article Information Si-Yu Hu 1Commonwealth Scientific and Industrial Research Organisation (CSIRO) Mineral Resources, Australian Resources Research Centre, 26 Dick Perry Avenue, Kensington, Western Australia 6151, Australia Stephen J. Barnes 1Commonwealth Scientific and Industrial Research Organisation (CSIRO) Mineral Resources, Australian Resources Research Centre, 26 Dick Perry Avenue, Kensington, Western Australia 6151, Australia A. Matthew Glenn 2Commonwealth Scientific and Industrial Research Organisation (CSIRO) Mineral Resources, Research Way, Clayton, Victoria 3169, Australia Anais Pagès 1Commonwealth Scientific and Industrial Research Organisation (CSIRO) Mineral Resources, Australian Resources Research Centre, 26 Dick Perry Avenue, Kensington, Western Australia 6151, Australia Joanna Parr 3Commonwealth Scientific and Industrial Research Organisation (CSIRO) Mineral Resources, 11 Julius Avenue, North Ryde, New South Wales 2113, Australia Colin MacRae 2Commonwealth Scientific and Industrial Research Organisation (CSIRO) Mineral Resources, Research Way, Clayton, Victoria 3169, Australia Ray Binns 3Commonwealth Scientific and Industrial Research Organisation (CSIRO) Mineral Resources, 11 Julius Avenue, North Ryde, New South Wales 2113, Australia †Corresponding author: e-mail, siyu.hu@csiro.au Publisher: Society of Economic Geologists Accepted: 21 Dec 2018 First Online: 28 Feb 2019 Online Issn: 1554-0774 Print Issn: 0361-0128 © 2019 Economic GeologyEconomic Geology Economic Geology (2019) 114 (1): 165–176. https://doi.org/10.5382/econgeo.2019.4626 Article history Accepted: 21 Dec 2018 First Online: 28 Feb 2019 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Si-Yu Hu, Stephen J. Barnes, A. Matthew Glenn, Anais Pagès, Joanna Parr, Colin MacRae, Ray Binns; Growth History of Sphalerite in a Modern Sea Floor Hydrothermal Chimney Revealed by Electron Backscattered Diffraction. Economic Geology 2019;; 114 (1): 165–176. doi: https://doi.org/10.5382/econgeo.2019.4626 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 SocietyEconomic Geology Search Advanced Search Abstract Active sea floor hydrothermal systems are modern analogues of ancient volcanogenic massive sulfide deposits. Hydrothermal sulfide chimneys are one of the important components in these systems and are formed by rapid mixing between seawater and metal-rich hydrothermal fluids venting onto the sea floor. Previous models of chimney growth have been built up mainly based on studies including optical petrographic observations and scanning electron microscopy (SEM). The present study, conducted on a sample from the PACMANUS hydrothermal field (Manus basin, Papua New Guinea), reports for the first time the electron backscattered diffraction (EBSD) observations on a modern sea floor chimney, coupled with synchrotron X-ray fluorescence (SXRF) and scanning electron microscopy-backscattered electron (SEM-BSE) imagery to reveal fine-scale and primary microstructures of sphalerite, allowing the reconstruction of crystal growth history. The results show that sphalerite clusters are formed via the coalescence of multiple smaller sphalerite globules. Electron backscattered diffraction images also highlight that each globule includes an inner zone with fine-grained particles (<1 μm) and an outer zone with elongate blade-shaped crystals (length up to 40 μm), in some cases showing branching dendritic habit. Both zones are dominated by sphalerite with minor other sulfides, such as chalcopyrite, pyrite, and wurtzite. The individual globules are interpreted as forming under conditions of supersaturation within high-temperature gradients, for example, during the mixing between high-temperature (e.g., 300°C) hydrothermal fluids and ambient cold seawater. The occurrence of these contrasting inner and outer zones reflects fluctuation between two regimes: bursts of rapid nucleation from supersaturated fluids that occurred almost instantaneously during the initial mixing and the skeletal crystal growth of particular crystal faces from limited nucleation sites where diffusion-limited boundary layers developed around the growing crystals. Those growing globules then coalesced into columnar aggregates. These observations could potentially have important implications for identifying fossil chimneys in ancient ore deposits. Moreover, this study emphasizes the benefits of advanced techniques, such as EBSD and SXRF, in order to characterize sulfides in various hydrothermal chimneys to reveal crystal growth and fluid mixing history and gain further insight into chimney growth processes. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.