Reassembling the Ontong Java-Manihiki-Hikurangi large igneous province; insights and challenges

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http://abstractsearch.agu.org/meetings/2012/FM/T31B-2597.html
Author(s): Chandler, M. T.; Wessel, P.; Taylor, B.; Sager, W. W.
Author Affiliation(s): Primary:
University of Hawaii at Manoa, School of Ocean and Earth Science and Technology, Honolulu, HI, United States
Other:
Texas A&M University, United States
Volume Title: AGU 2012 fall meeting
Source: American Geophysical Union Fall Meeting, Vol.2012; American Geophysical Union 2012 fall meeting, San Francisco, CA, Dec. 3-7, 2012. Publisher: American Geophysical Union, Washington, DC, United States
Note: In English
Summary: The tectonic history of ∼30% of the Pacific plate south of Equator which formed during the Cretaceous Normal Supercron is difficult to establish due to its lack of a lineated magnetic anomaly pattern. This region, including the Ontong Java, Manihiki, and Hikurangi large igneous provinces, as well as the interlying Ellice Basin and Osbourn Trough, lacks active seafloor spreading centers and has thus been largely neglected by seagoing research scientists. Nonetheless, the CNS South Pacific may prove to be important for understanding Pacific history. Ontong Java's mean basement paleolatitude measurement differs from absolute plate model (APM) reconstructions for the plateau by ∼8--19 degrees (Chandler et al. (2012)), indicating that either current APM models are erroneous, substantial plume drift or true polar wander occurred, or that Ontong Java experienced unrecognized motion early in its history. In support of the latter are recent findings that little to no Louisville plume drift occurred after ∼70 Ma (Gee et al. (2011)), that true polar wander estimates for the ∼125 Ma Ontong Java vicinity are negligible (Steinberger and Torsvik (2008)), and our recent observation of a 2:1 bias between Ontong Java's paleolatitude and latitude differences (Chandler and Wessel (2011), Chandler et al. (In prep)). These differences, computed among ODP Sites 807 and 1183 - 1187, suggest significant clockwise rotation of ∼40 degrees since Ontong Java's formation at ∼125 Ma. Although this rotation does not resolve the paleolatitude discrepancy it does suggest that Ontong Java's paleolatitudes may not be suitable for constraining Pacific APM. Seafloor formed at the Osbourn Trough and in the Ellice Basin make up much of the CNS South Pacific. These regions exhibit fossil spreading centers believed responsible for the breakup of Earth's largest known igneous province, the Ontong Java-Manihiki-Hikurangi super-plateau (e.g., Taylor (2006), Chandler et al. (2012)). Understanding this little studied portion of the South Pacific is therefore imperative for adequate understanding and modeling of Pacific plate history.
Year of Publication: 2012
Research Program: IODP Integrated Ocean Drilling Program
ODP Ocean Drilling Program
Key Words: 07 Marine Geology and Oceanography; Equatorial Pacific; Integrated Ocean Drilling Program; Leg 130; Leg 192; Marine sediments; North Pacific; Northwest Pacific; ODP Site 1183; ODP Site 1184; ODP Site 1185; ODP Site 1186; ODP Site 1187; ODP Site 807; Ocean Drilling Program; Ontong Java Plateau; Pacific Ocean; Sediments; South Pacific; Southwest Pacific; West Pacific
Coordinates: S011100 S011100 E1570100 E1570100
N033622 N033626 E1563730 E1563728
Record ID: 2014080660
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