Island Arc and Backarc (BI-ARC)

Objective: Convergent margins, where oceanic lithosphere is subducted into the mantle, form the key interface for large–scale chemical and thermal recycling amongst the ocean, crust, mantle, and atmosphere. Intra-oceanic convergent margins typically produce a forearc-island arc-backarc sequence within an extensional stress regime and contain a disproportionate number of hydrothermal vents per unit area.  The working group hopes to foster a holistic approach to address fundamental questions about intra-oceanic arc and backarc basin processes by examining the long-term and short-term evolutionary cycles using geochemical, hydrothermal, biological, tectonic and subduction dynamics approaches.  In addition, we aim to bridge the gap between geologists who study onshore, accreted island-arc and back-arc systems and marine geoscientists who study in-situ backarc systems.  The working group seeks to bring together experts from both the observational and modeling communities to facilitate the linkage between surface processes and the deep earth.   

Chair: Maria Seton (USYD, Australia); Co-chair: Cornel de Ronde (GNS Science, New Zealand)

Group Members: Richard Wysoczanski (NIWA/U. Victoria), Richard Arculus (ANU, Australia), Michael Gurnis (Caltech, USA), Jo Whittaker (USYD, Australia), Dietmar Müller (USYD, Australia), Colin Macpherson (Durham, UK), Erin Todd (Munster, Germany), Jim Gill (UCSC, USA), Sven Petersen (GEOMAR, Germany), Jonny Wu (NUT, Taiwan), Yoshihiko Tamura (JAMSTEC, Japan), Hiromi Watanabe (JAMSTEC, Japan), Jonathan Aitchison (USYD, Australia)

2012 Update

• An initial working group planning meeting is scheduled during the International Geological Congress (IGC) Meeting in Brisbane (6-10 August, 2012)
 Members are involved in convening themes/symposia at the IGC 2012:
o Theme: Mineral Deposits and Ore Forming Processes (Large, de Ronde)
o Symposium: Volcanic and basin-hosted ores (Fe, Zn-Pb, Cu, U) (Gemmell, de Ronde, Bull, Leach) 
o Symposium: Marine minerals in Oceania (Cronan, de Ronde, Exon)

WG proposal

Drivers of the Episodic life-cycle of Intra-oceanic Arc-Backarc Hydrothermal Systems 

Convergent margins, where oceanic lithosphere is subducted into the mantle, form the key interface for large–scale chemical and thermal recycling amongst the ocean, crust, mantle, and atmosphere. Intra-oceanic convergent margins typically produce a forearc-island arc-backarc sequence within an extensional stress regime and contain a disproportionate number of hydrothermal vents per unit area.