Subduction zone dynamics in the SW Pacific plate boundary region constrained from high-precision Pb isotope data

Details Subduction zone dynamics in the SW Pacific plate boundary region constrained from high-precision Pb isotope data Subduction zone dynamics in the SW Pacific plate boundary region constrained from high-precision Pb isotope data

Nov 2011

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2011e%26psl.311..328s&link_type=abstract

Earth and Planetary Science Letters, Volume 311, Issue 3, p. 328-338.

Other

Subduction, Solomon Islands, Pacific Plate, Pb Isotopes, Mc-Icp-Ms

Scientific paper

This study presents high-precision Pb isotope data obtained by MC-ICP-MS for lavas from the Solomon island arc that covers ca. 1000 km of the SW Pacific plate boundary. Following a reversal of subduction polarity, the presence of the old subducted Pacific oceanic crust, and the presently subducting Indian-Australian plate beneath the entire island arc is confirmed by geophysical and geochemical evidence. New high-precision Pb isotope data now permit to distinguish more clearly between Indian and Pacific-type subduction components in this complex plate tectonic constellation. The values range from 206Pb/204Pb = 18.345 to 18.845, 207Pb/204Pb = 15.498 to 15.545, and 208Pb/204Pb = 38.120 to 38.372, indicating the absence of pelagic sediments in the sub-arc mantle. These data reveal a predominance of subduction components derived from ancient subduction of the Pacific plate. In contrast, lavas with Indian-type Pb isotope signatures are confined to the central New Georgia Group of the Solomon Islands, where the young Woodlark Ridge spreading centre is currently subducting. All other Solomon arc segments with a lower geothermal gradient have apparently not yet been overprinted by younger subduction components over the past 6 Myrs. Moreover, trace element and Pb isotope data for Woodlark Ridge basalts show that subduction components from the fossil Pacific slab have locally modified the source of Woodlark Basin lavas. Altogether, our study highlights the potential of high-resolution Pb isotope measurements to distinguish between Indian and Pacific-type subduction components along the SW Pacific plate boundary.

Affiliated with

Also associated with

No associations

Rating

Subduction zone dynamics in the SW Pacific plate boundary region constrained from high-precision Pb isotope data does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Subduction zone dynamics in the SW Pacific plate boundary region constrained from high-precision Pb isotope data, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Subduction zone dynamics in the SW Pacific plate boundary region constrained from high-precision Pb isotope data will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1056295