UTIG RESEARCH PROJECTS ARCHIVE

Principal Investigators: Paul Mann, Thomas H. Shipley, and Millard F. Coffin

Funded by: National Science Foundation - OCE 9301608

Some results
- data from EW9511 cruise
- Publications
- Seismic Imaging of Oceanic Plateau Accretion Within the Malaita Accretionary Prism, Solomon Islands (by Eric Phinney)

This is a U.S.-Japan cooperative program to map crustal and perhaps upper mantle structures in the Solomon Islands convergent zone. The primary objective of the MCS study and an independently proposed OBS study by Drs. K. Suyehiro and colleagues at the Ocean Research Institute in Tokyo, Japan, is to test two models for the formation of the Malaita anticlinorium - the deformed wedge of Cretaceous-Cenozoic pelagic limestone, basalt, and clastic rocks that most previous workers agree to be an emergent part of the Ontong Java Plateau. One model predicts tectonic wedging of the Solomon island arc beneath the Ontong Java plateau. A second, alternative model predicts a more familiar oceanic accretionary wedge geometry with northeastward (plateauward) offscraping and thrust imbrication of plateau rocks. Our proposed MCS-OBS study focusing on the Malaita anticlinorium and North Solomon trench will use state-of-the-art data acquisition and processing techniques to address fundamental questions concerning the subduction/accretion/fragmentation of oceanic plateaus at subduction zones and their deformational effects on the overriding island arc-including collision-related arc polarity reversal. Answers to these questions are important for understanding how oceanic plateaus may contribute to growth of continents through time and how subduction zones initiate by polarity reversal.

Publications
Mann, P., 1997, Model for the formation of large, transtensional basins in zones of tectonic escape: Geology, v. 25, p. 211-214.

Phinney, E., Mann, P., Coffin, M., and Shipley, T., 1999, Sequence stratigraphy, structure, and tectonics of the southwestern Ontong Java Plateau adjacent to the North Solomon trench and Solomon island arc: Journal of Geophysical Research, v. 104, p. 20449-20466.

Special issue of Tectonophysics: "Tectonics, Seismicity, and Crustal Structure of the Ontong Java Plateau-Solomon Island Arc Convergent Zone, Southwest Pacific Ocean" (P. Mann and A. Taira, guest editors)

Mann, P. and Taira, A., 2004, Global tectonic significance of the Solomon Islands and Ontong Java Plateau convergent zone, Tectonophysics, vol. 389, 137-190.

Miura, S., Suyehiro, K., Shinohara, M., Takahashi, N., Araki, E., and Taira, A.. 2005, Seismological structure and implications of collision between the Ontong Java Plateau and Solomon island arc from ocean bottom seismometer-airgun data; Tectonophysics, v. 389(3-4), 191-220.

Phinney, E.J., Mann, P., Coffin, M.F., and Shipley, 2004, Sequence stratigraphy, structural style, and age of deformation of the Malaita accretionary prism (Solomon arc-Ontong Java Plateau convergent zone), Tectonophysics, vol. 389(3-4), 221-246.

Taira, A., P. Mann and R. Rahardiawan, 2004, Incipient subduction of the Ontong Java Plateau along the North Solomon trench, Tectonophysics, vol. 389, issue 3-4, 247-266.

Cowley, S., Mann, P., Coffin, M.F., and Shipley, 2004, Oligocene to Recent tectonic history of the Central Solomon intra-arc basin as determined from marine seismic reflection data and compilation of onland geology, Tectonophysics, vol. 389(3-4), 267-307.