Pacific mantle plume motion and bends in hotspot tracks

Author(s): Tarduno, John
Author Affiliation(s): Primary:
University of Rochester, Rochester, NY, United States
Volume Title: 33rd international geological congress; abstracts
Source: International Geological Congress [International Geological Congress, Abstracts = Congrès Géologique International, Résumés, Vol.33; 33rd international geological congress, Oslo, Norway, Aug. 6-14, 2008. Publisher:], [location varies], International CODEN: IGABBY
Note: In English. 5 refs.
Summary: The Hawaiian-Emperor hotspot chain, and its distinctive bend at 47 Ma, have figured prominently in the development of ideas concerning the nature of mantle plumes, plate motion, and frames of reference. However, paleomagnetic data from Ocean Drilling Program (ODP) Leg 197 (Tarduno et al., 2003), together with results from plate circuit (e.g. Cande et al., 1995) and geodynamic modeling studies (e.g. Steinberger and O'Connell, 1998), indicate southward motion of the Hawaiian hotspot during formation of the Emperor Seamounts. These analyses confirm the idea that mantle plumes should be influenced by mantle flow and that such motion must be considered when constructing frames of reference for plate motion. (It is important to note that Kevin Burke considered hotspot motion early in his career; see Burke et al., 1973.) An important corollary of this finding on hotspot motion is that long-term polar wander of Earth, which has been inaccurately assessed by viewing paleomagnetic data in a fixed hotspot reference frame, has been far less than previously thought. Here the ODP Leg 197 analysis is extended in the following three ways: i. paleomagnetic data and their uncertainties relative to volcanic propagation rates are considered (Tarduno, 2007); ii. consistency tests of plate circuit models and global paleomagnetic data are performed; and iii. intra-basin motion of plumes, and the role of Pacific apparent polar wander is examined through new analyses of Late Cretaceous lavas from New Zealand. The first analysis suggests that while Late Cretaceous--Paleogene hotspot motion was the dominant factor in forming the Emperor track (and thus the famous bend morphology), smaller- scale plate motion changes might still be preserved in the track. The second set of analyses help point to deficiencies in the global paleomagnetic data set, whereas the third highlights that motion between groups of hotspots is a dominant feature during mid-Cretaceous to Paleogene times. These studies are used to evaluate the potential processes that could cause the Hawaiian-Emperor bend, and bends in other hotspot tracks. Further attempts to distinguish between candidate processes, and their influence on reference frames, will be discussed. dd
Year of Publication: 2008
Research Program: ODP Ocean Drilling Program
Key Words: 18 Geophysics, Solid-Earth; Cenozoic; Cretaceous; Emperor Seamounts; Hawaiian Plume; Hot spots; Leg 197; Mantle; Mantle plumes; Mesozoic; North Pacific; Northwest Pacific; Ocean Drilling Program; Pacific Ocean; Paleogene; Plate tectonics; Tertiary; Upper Cretaceous; West Pacific
Coordinates: N340000 N520000 E1730000 E1670000
Record ID: 2009022427
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