Geophysical investigation of the tectonic and volcanic history of the Nauru Basin, Western Pacific

UNCW Author/Contributor (non-UNCW co-authors, if there are any, appear on document)
Michael J. Murphy (Creator)
Institution
The University of North Carolina Wilmington (UNCW )
Web Site: http://library.uncw.edu/
Advisor
Lewis Abrams

Abstract: In the western Pacific, oceanic crust is Jurassic in age based on magnetic anomaly lineations. However, drilling expeditions have instead recovered mid-Cretaceous age basalts in deep, supposedly Jurassic age basins such as the Nauru, East Mariana, and Pigafetta. In the southern Nauru Basin, mulitchannel seismic reflection and sonobuoy refraction data support an off-ridge tectonic setting for the emplacement of mid-Cretaceous flood basalts over original Late Jurassic-Early Cretaceous oceanic crust. Forward modeling of refraction data provide velocity structure for coincident seismic reflection data to determine the types and thickness of materials overlying oceanic crust in the southern Nauru Basin. From these models the detection of thin, high velocity sills/flows within a thick, lower velocity layer are evident over a rough reflection surface interpreted as oceanic crust, with an age given by Mesozoic magnetic anomaly lineations. Oceanic crust clearly exists in the southernmost Nauru Basin without the overburden of high velocity sills/flows. Observations of thin sills/flows and oceanic crust beneath reflections from the mid-Cretaceous material cored at Deep Sea Drilling Project Site 462 indicate the presence of previously unsampled lithologic units in the Nauru Basin, notably oceanic crust.

Additional Information

Publication
Thesis
A Thesis Submitted to the University of North Carolina Wilmington in Partial Fulfillment Of the Requirements for the Degree of Master of Science
Language: English
Date: 2009
Keywords
Geology Structural--Western Pacific--Nauru Basin, Plate tectonics--Western Pacific--Nauru Basin, Volcanism--Western Pacific--Nauru Basin
Subjects
Geology, Structural -- Western Pacific -- Nauru Basin
Plate tectonics -- Western Pacific -- Nauru Basin
Volcanism -- Western Pacific -- Nauru Basin