Contrasting Structural Styles of Orogenic Gold Deposits, Reefton Goldfield, New Zealand

Research Article| November 01, 2018 Contrasting Structural Styles of Orogenic Gold Deposits, Reefton Goldfield, New Zealand Andrew Allibone; Andrew Allibone 1 Rodinian (NZ) Ltd., P.O. Box 758, Wanaka 9343, New Zealand †Corresponding author: e-mail, Rodinian@msn.com Search for other works by this author on: GSW Google Scholar Hamish Blakemore; Hamish Blakemore 2 Oceana Gold, 22 McLaggan Street, Dunedin 9016, New Zealand Search for other works by this author on: GSW Google Scholar Jon Gane; Jon Gane 2 Oceana Gold, 22 McLaggan Street, Dunedin 9016, New Zealand Search for other works by this author on: GSW Google Scholar Jonathan Moore; Jonathan Moore 2 Oceana Gold, 22 McLaggan Street, Dunedin 9016, New Zealand Search for other works by this author on: GSW Google Scholar Doug MacKenzie; Doug MacKenzie 3 Department of Geology, University of Otago, P.O. Box 56, Dunedin 9054, New Zealand Search for other works by this author on: GSW Google Scholar Dave Craw Dave Craw 3 Department of Geology, University of Otago, P.O. Box 56, Dunedin 9054, New Zealand Search for other works by this author on: GSW Google Scholar Author and Article Information Andrew Allibone 1 Rodinian (NZ) Ltd., P.O. Box 758, Wanaka 9343, New Zealand Hamish Blakemore 2 Oceana Gold, 22 McLaggan Street, Dunedin 9016, New Zealand Jon Gane 2 Oceana Gold, 22 McLaggan Street, Dunedin 9016, New Zealand Jonathan Moore 2 Oceana Gold, 22 McLaggan Street, Dunedin 9016, New Zealand Doug MacKenzie 3 Department of Geology, University of Otago, P.O. Box 56, Dunedin 9054, New Zealand Dave Craw 3 Department of Geology, University of Otago, P.O. Box 56, Dunedin 9054, New Zealand †Corresponding author: e-mail, Rodinian@msn.com Publisher: Society of Economic Geologists Accepted: 26 Aug 2018 First Online: 19 Nov 2018 Online Issn: 1554-0774 Print Issn: 0361-0128 © 2018 Economic GeologyEconomic Geology Economic Geology (2018) 113 (7): 1479–1497. https://doi.org/10.5382/econgeo.2018.4599 Article history Accepted: 26 Aug 2018 First Online: 19 Nov 2018 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Andrew Allibone, Hamish Blakemore, Jon Gane, Jonathan Moore, Doug MacKenzie, Dave Craw; Contrasting Structural Styles of Orogenic Gold Deposits, Reefton Goldfield, New Zealand. Economic Geology 2018;; 113 (7): 1479–1497. doi: https://doi.org/10.5382/econgeo.2018.4599 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 This paper describes the structural setting of the Globe-Progress and Blackwater orogenic gold deposits, the only two +1-million ounce (Moz) deposits discovered to date within the Reefton goldfield of central New Zealand. Most of the Globe-Progress deposit is located along the Globe-Progress shear zone, a curviplanar, brittle-ductile, structure that juxtaposes tightly folded rocks in its footwall against largely unfolded rocks in its hanging wall. At its eastern end the Globe-Progress shear zone merges with the fold-parallel Oriental shear zone, with the Globe-Progress shear zone acting as a tear fault that transferred contractional deformation on the Oriental shear zone across the structural grain of the adjacent folded rocks, during or soon after the end of greenschist facies metamorphism. An early phase of mineralization at ca. 438 Ma (K-Ar, sericite) accompanied this contractional deformation, whereas a second phase of mineralization occurred during later brittle, oblique-normal, reactivation of the two shear zones at ca. 386 Ma (K-Ar, sericite). The resulting ore shoots plunge moderately towards the southwest, along intersections between (1) the two shear zones, (2) the Globe-Progress shear zone and minor normal faults in its hanging wall, and (3) the Globe-Progress shear zone and W-dipping bedding in its hanging wall.The kilometer-long Birthday reef in the Blackwater mine is located on a narrow, mineralized, brittle-ductile fault that can be traced for 3+ km through the adjacent Greenland Group sandstones and argillites. The reef occupies that part of the fault that is close to parallel with bedding on a relatively gently (~60°) W-dipping segment of the western limb of the Waiuta anticline. The reef pinches out where the dip of the host fault steepens and its strike swings from north-northeast toward north. This change in orientation occurs where the fault refracts onto the near vertical axial plane of the Waiuta anticline above/north of the reef, and follows an open flexure in the orientation of bedding on the western limb of the Waiuta anticline below/south of the reef. Both ends of the reef, and its more intensely mineralized internal ore shoots, plunge 35° toward the north-northeast, parallel to the intersection of the host fault and the axial planar cleavage associated with the adjacent Waiuta anticline. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.