Geochemical Constraints on Physical Processes in Subduction Zones
Abstract
Physical processes in subduction zones (SZs) control metamorphism of downgoing slabs, transfer of fluids and melts to the overlying mantle wedge, and ultimately the geochemistry of arc magmas. Much of the variability seen in arc magmas both locally and globally can be explained by differences in the thermal state of the respective SZs. This, in turn, is linked to plate tectonic variables (e.g., plate age, velocity, etc.). The geochemistry of arc magmas also reflects the time-integrated history of the magma sources as well as dynamics of the mantle wedge. An integrated view of SZ processes, and how they might contribute to crustal growth and evolution, can be inferred from spatial and temporal variations in the compositions of arc basaltic magmas. Fluid-mobile elements (B, Li) are particularly useful in this regard as they provide key constraints on fluid contributions and on volatile budgets in SZs.
- Publication:
-
AGU Spring Meeting Abstracts
- Pub Date:
- May 2008
- Bibcode:
- 2008AGUSM.V43A..06L
- Keywords:
-
- 1031 Subduction zone processes (3060;
- 3613;
- 8170;
- 8413);
- 3613 Subduction zone processes (1031;
- 3060;
- 8170;
- 8413);
- 3619 Magma genesis and partial melting (1037);
- 8170 Subduction zone processes (1031;
- 3060;
- 3613;
- 8413);
- 8185 Volcanic arcs