Meso-Scales Studies Working Group Meeting Summary

Back-Arc Basin Studies Workshop

11-13 October 1993 - Seattle, USA

Co-Convenors: Julian Pearce and Kensaku Tamaki

The objectives of this workshop were to define the critical scientific problems currently posed by the study of spreading in back-arc basins, to exchange information concerning recent and planned surveys, to formulate funding proposals for multi-national co-operative study of crustal accretion in back-arc basins, and to produce a white paper specifying the research targets of this InterRidge project. The convenors and invited speakers summarised the current state of knowledge of back-arc basins and 22 workshop participants presented reports on recent and planned research.

Two aspects of crustal accretion in back-arc basins were identified by InterRidge as being of particular importance. The first is the effect of subduction on the processes of crustal accretion. The second is the fact that ophiolites and their associated ore bodies of economic importance are more closely related to ridges in back-arc basins than to mid-ocean ridges.

Choosing to focus on the first aspect, the workshop participants defined three sub-topics:

* melt generation
* spreading processes
* energy, biological and mass fluxes.

The proposed multi-disciplinary approach to the study of these three topics includes seismic tomography, high-resolution bathymetry and swath mapping, geochemistry and petrology, long-term monitoring of mass and energy fluxes, and comparison with mid-ocean ridge spreading systems.

The participants also recommended that InterRidge:

* establish links with the Ocean Drilling Program
* coordinate a geographic index of existing geophysical and geochemical data sets as well as proposed/funded projects.

Steps were taken towards the compilation of a geochemical and geophysical data base archive for back-arc basins which would be compiled by individual investigators and administrated by InterRidge.