Collaborative Research: Magma Generation and Tectonics in the Early
Mariana Arc System Revisited
|
|||||||||||||||||||||||||||||||||||||||
| MARGINS Focus Area | Subduction Factory |
| NSF Org | OCE |
| Latest Amendment Date | August 31, 2000 |
| Award Number | 0001902 |
| Award Instrument | Standard Grant |
| Program Manager | Bilal U. Haq OCE DIVISION OF OCEAN SCIENCES GEO DIRECTORATE FOR GEOSCIENCES |
| Start Date | January 1, 2001 |
| Expires | December 31, 2003 (Estimated) |
| Expected Total Amount | $186,827 (Estimated) |
| Investigator | Mark K. Reagan (Principal Investigator current) |
| Sponsor | University of Iowa Iowa City, IA 52242 |
| NSF Program | 1620 MARINE GEOLOGY AND GEOPHYSICS |
| Field Application | 0204000 Oceanography |
| Abstract | Recommended project is for a comprehensive geochemical and geochronological examination of Eocene to Miocene volcanism in the southern arc and backarc of the Izu-Bonin-Marianas (IBM) arc system, tracing its older development with time. In doing so, the recommended research will also re-examine well-characterized samples that have been previously investigated using older, obsolescent anayltical techniques. This study will examine the changing nature of volcanism in the IBM system, as it transformed from "boninitic" volcanism associated with subduction initiation to the more "normal" tholeitic and cal-clkaline arc volcanism also seen today in the modern volcanic arc and backarc. This study also will examine the changing nature of the mantle sources during this transformation, as well as the implications they carry for tectonic processes during the arc system evolution. Previously sampled lavas and other volcanic rocks will be supplemented by collection of new samples during field work on Guam; all of these samples will be analyzed for major and trace elemental composition, isotopic composition, and geochronological (40 Ar - 39 Ar) dating using the latest analytical techniques. |