Other Scholarly Content

 

New 40Ar/39Ar age progression for the Louisville hot spot trail and implications for inter–hot spot motion Public Deposited

Downloadable Content

Download PDF
https://ir.library.oregonstate.edu/concern/defaults/3t945w969

Descriptions

Attribute NameValues
Creator
Abstract
  • In this study we present 42 new ⁴⁰Ar/³⁹Ar incremental heating age determinations that contribute to an updated age progression for the Louisville seamount trail. Louisville is the South Pacific counterpart to the Hawaiian‐Emperor seamount trail, both trails representing intraplate volcanism over the same time interval (~80 Ma to present) and being examples of primary hot spot lineaments. Our data provide evidence for an age‐progressive trend from 71 to 21 Ma. Assuming fixed hot spots, this makes possible a direct comparison to the Hawaiian‐Emperor age progression and the most recent absolute plate motion (APM) model (WK08G) of Wessel and Kroenke (2008). We observe that for the Louisville seamount trail the measured ages are systematically older relative to both the WK08G model predictions and Hawaiian seamount ages, with offsets ranging up to 6 Myr. Taking into account the uncertainty about the duration of eruption and magmatic succession at individual Louisville volcanoes, these age offsets should be considered minimum estimates, as our sampling probably tended to recover the youngest lava flows. These large deviations point to either a contribution of inter–hot spot motion between the Louisville and Hawaiian hot spots or to a more easterly location of the Louisville hot spot than the one inferred in the WK08G model. Both scenarios are investigated in this paper, whereby the more eastern hot spot location (52.0°S, 134.5°W versus 52.4°S, 137.2°W) reduces the average age offset, but still results in a relatively large maximum offset of 3.7 Myr. When comparing the new ages to the APM models (S04P, S04G) by Steinberger et al. (2004) that attempt to compensate for the motion of hot spots in the Pacific (Hawaii) or globally (Hawaii, Louisville, Reunion and Walvis), the measured and predicted ages are more in agreement, showing only a maximum offset of 2.3 Myr with respect to the S04G model. At face value these more advanced APM models, which consider both plate and hot spot motions, therefore provide a better fit to the new Louisville age data. The fit is particularly good for seamounts younger than 50 Ma, a period for which there is little predicted motion for the Louisville hot spot and little inter–hot spot motion with Hawaii. However, discrepancies in the Louisville age‐distance record prior to 50 Ma indicate there is an extra source of inter–hot spot motion between Louisville and the other Pacific hot spots that was not corrected for in the global S04G model. Finally, based on six new ⁴⁰Ar/³⁹Ar age dates, the 169°W bend in the Louisville seamount trail seems to have formed at least 3 Myr before the formation of the Hawaiian‐Emperor bend. The timing of the most acute parts of both bends thus appears to be asynchronous, which would require other processes (e.g., plume motions) than a global plate motion change between 50 and 47 Ma to explain these two observations.
Resource Type
DOI
Date Available
Date Issued
Keyword
Rights Statement
Funding Statement (additional comments about funding)
  • Financial support is provided by NSF‐OCE 0351512. Lauren Colwell was supported by REU support from NSF‐IODP and Molly Gowen by the OSU REU program in 2008.
Replaces
Additional Information
  • Geochemistry, Geophysics, Geosystems
  • Vol. 12 no. 12
  • description.provenance : Submitted by Deborah Campbell (deborah.campbell@oregonstate.edu) on 2012-05-31T16:30:09Z No. of bitstreams: 1 KoppersAnthonyAPCEOASNewProgressionLouisville.pdf: 11725087 bytes, checksum: b71e14f8068d2476de1639d26b22f400 (MD5)
  • description.provenance : Made available in DSpace on 2012-05-31T16:30:09Z (GMT). No. of bitstreams: 1 KoppersAnthonyAPCEOASNewProgressionLouisville.pdf: 11725087 bytes, checksum: b71e14f8068d2476de1639d26b22f400 (MD5) Previous issue date: 2011-12-30

Relationships

Parents:

This work has no parents.

Items