Constraints on past plate and mantle motion from new ages for the Hawaiian‐Emperor Seamount Chain

Abstract

[1] Estimates of the relative motion between the Hawaiian and Louisville hot spots have consequences for understanding the role and character of deep Pacific-mantle return flow. The relative motion between these primary hot spots can be inferred by comparing the age records for their seamount trails. We report the seamount chain, including the HEB. This model predicts an age for the oldest Emperor Seamounts that matches published ages, implying that a linear age-distance relationship might extend back to at least 82 Ma. In contrast, Hawaiian age progression was much faster since at least $15 Ma and possibly as early as $27 Ma. Linear age-distance relations for the Hawaii-Emperor and Louisville seamount chains predict $300 km overall hot spot relative motion between 80 and 47.5 Ma, in broad agreement with numerical models of plumes in a convecting mantle, and paleomagnetic data. We show that a change in hot spot relative motion may also have occurred between $55 Ma and $50 Ma. We interpret this change in hot spot motion as evidence that the HEB reflects a combination of hot spot and plate motion changes driven by the same plate/mantle reorganization.

Astronomical calibration of the Ypresian timescale: implications for seafloor spreading rates and the chaotic behavior of the solar system?

“…The exact age of the increase cannot be precisely located using the reversal pattern only, but it probably occurred somewhere in C23r or C23n.2n between 51.0 and 52.5 Ma. Interestingly, this timing is synchronous with a major reorganization of the plate-mantle system (Whittaker et al, 2007), the subduction initiation of the Izu-Bonin-Mariana arc (Ishizuka et al, 2011), and the bend in the Hawaii-Emperor seamount chain (O'Connor et al, 2013). Changes in spreading rates in the interval from 51.0 to 52.5 Ma thus seem to be a global phenomenon pointing to a major common driving mechanism.…”

Philippine Sea Plate inception, evolution, and consumption with special emphasis on the early stages of Izu-Bonin-Mariana subduction

“…Thirdly, transpression along a former transform boundary between two oceanic plates may allow the younger plate to subduct beneath the older as presently observed along the Hjort Trench (Meckel et al 2005). (4) The most reasonable trigger is the subduction of the Izanagi-Pacific (IP) Ridge beneath Asia at ∼ 60-55 Ma (Whittaker et al 2007;O'Connor et al 2013;Seton et al 2015). Rapid subduction of the still-spreading IP ridge, over a vast distance, likely triggered a chain reaction of tectonic plate reorganization (Fig.…”

New Constraints on Temporal Variations in Hawaiian Plume Buoyancy Flux

“…Reproducing the swell progression of Asaadi et al [2011], without a shift in plate velocity, emphasizes the decreased efficiency of swell widening associated with NonNewtonian rheology (blue solid line). Including an increase in plate velocity relative to the plume location, as suggested by O'Connor et al [2013] for the Pacific plate moving over the Hawaiian Plume, (Fig. 3B), shows that the increase in plate velocity tends to narrow the swell.…”

“…Changes in this velocity, as measured by O'Connor et al [2013] using volcanic ages along the Hawaiian Ridge, can be caused by changes in the motion of the plate or by lateral motion of the plume conduit beneath the lithosphere. An increase in relative plate velocity reduces the volume of plume material that can accumulate beneath any one section of the plate and thus decreases the overall width of the swell.…”

“…Previous estimates of the plume flux have assumed constant Pacific plate motion over a stationary plume, despite studies that suggest changes in the motion of the Pacific plate [O'Connor et al, 2013] and of the plume itself [Steinberger & O'Connell, 1998;Steinberger & Antretter, 2006;Tarduno et al, 2003;. Both movements result in a change of the observed motion of the plate relative to the underlying plume, which is a key parameter that determines the rate at which plume material accumulates beneath the plate [Christensen & Ribe, 1994], forming the swell.…”