have contributed heat to the asthenosphere under the rift, so produc-ing the thick sequences of lavas imaged as the seaward-dipping re-flector series (SDRS). The recognition of a strong thermal input in the form of the thick lava sequences and absence of any chemically en-riched components in the la...
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| Format: | Text |
| Language: | English |
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| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.560.2348 http://www-odp.tamu.edu/publications/152_SR/VOLUME/CHAP_06.PDF |
| Summary: | have contributed heat to the asthenosphere under the rift, so produc-ing the thick sequences of lavas imaged as the seaward-dipping re-flector series (SDRS). The recognition of a strong thermal input in the form of the thick lava sequences and absence of any chemically en-riched components in the lavas (Shipboard Scientific Party, 1994a; 1994b) suggest that there may have been a marked detachment be-tween the thermal and chemical effects of the plume at the time of continental breakup. A similar effect can be seen today, as the effects of the modern plume extend as far south as 62°N on the Reykjanes Ridge in terms of trace and rare earth elements and radiogenic isotope ratios (Hart et al., 1973; Schilling, 1973). However, elevated topog-raphy on the spreading ridge extends as far south as 50°N (Klein and Langmuir, 1987), as well as north along the Kolbeinsey Ridge (Mertz et al., 1991), indicating that the thermal effect of the plume is still more widespread than the chemical. The goal of this paper is to in- |
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