What's missing in these hotspot volcanic models? Answer: geokinematics

Three recent "hotspot" papers (Ballmer et al., 2009, 2010, and Presnall & Gudfinnsson, 2011) share a common feature. They are missing something -- a piece of evidence which none of the three confront: geokinematics. In fairness, however, first, these papers are not unique; and, second, the authors [of the second paper] could with equal some validity claim that geokinematics papers neglect geochemical and geodynamic models, too.
Ballmer et al. (2009 and 2010) emphasize small-scale convection so as to explain what they describe as "complex age-distance patterns" in hotspot traces, especially the familiar chains of the South Pacific: Austral, Cook, and Samoan. Presnall and Gudfinnsson (2011) attempt explanation of hotspot traces in general in terms of propagating fractures, perhaps the longest-lived hypothesis for the origin of such chains (see, e.g., Dana et al., 1849, or beginning "within" plate tectonics, Jackson et al., 1972).
Ballmer et al. acknowledge that the South Pacific "complex" chains may be related, genetically, to Cretaceous seamounts. However, they do not explicitly reference the kinematic models of, e.g., Wessel and Kroenke (2006, 2008) and Jackson et al. (2010; of course, this paper is quite recent), as applied to the Cretaceous-to-Present seamount chains: the Magellan, Gilbert, Tokelau, Samoa, Cook, Austral, Macdonald, and Foundation. The convective mechanism of Ballmer et al. may be relevant, however, the geokinematic evidence would also imply an additional constraint -- the source regions for each composite trace (see, e.g., this post) which are stable within the same, larger "hotspot" reference frame.
Presnall and Gudfinnsson, 2011, emphasize the geochemical evidence for relatively shallow and cool origin for hotspot volcanism and argue that their models imply fracturing of oceanic plate accesses the source region. However, Presnall & Gudfinnsson do not touch on the two additional components of hotspot traces that any mechanism for their origin must incorporate: evidence for the melting anomalies existent within reference frames, of which there appear to be three (e.g., Norton, 2000; Pilger, 2003). It is difficult to expect progressive fracturing to be consistent in propagation rate, not only over a single plate (e.g., the Pacific), but also the Nazca and eastern Australian plates (e.g., Pilger, 1982, 2007). More critically, how does a simple propagating fracture mechanism explain hotspot traces which extend over multiple plates (e.g., Easter-Nazca-Tuamotu; Reunion-Chagos-Laccadive-Deccan, Duncan, 1981; Kerguelen-Ninetyeast; Great Meteor-New England: Pilger, 2003, 2007, and references therein)?
Yes, kinematic/reconstruction models for plate-hotspots need to incorporate geochemical and geodynamic models. But, given their simplicity, why are kinematic models seemingly ignored? Or are kinematic models simple indeed? Code for plate reconstructions is available from multiple sources, while their underlying algorithms were provided early in the development of plate tectonics. For example Pilger (2003) provides C-code which is digitally reproduced here. A collection of published plate reconstruction parameters can be found here.      
Finally, there is an ongoing problem with both plume and non-plume models for the origin of hotspot traces: Morgan's original hypothesis linked plumes and their fixity. However, it became apparent quite early that Atlantic-Indian Ocean hotspot traces are inconsistent with Pacific Ocean traces and both with respect to the Earth's spin axis (see references in Pilger, 2003). Geodynamic models of plumes now are largely independent of plume fixity, either relative to one another or to any "absolute" reference frame (e.g., O'Neill et al., 2005). Whether hotspots (hypothetical plumes) are fixed relative to one another is largely irrelevant to confirmation of plume models. However, there is strong evidence for three distinct hotspot reference frames which may represent plumes or, alternatively, some sort of fertile region which persists across plate boundaries (Pilger, 2003, 2007).
In sum, fracture and small-scale convection models may be relevant to the origin of hotspots, but some sort of melting anomaly (plume, fertile region, ancient subduction zone...?) is still required. For more discussion, see here, here,  here, and here.
References
Ballmer, M. D., van Hunen, J., Ito, G. & Bianco, T. A., 2009, Intraplate volcanism with complex age-distance patterns: A case for small-scale sublithospheric convection, 10, No.6, 24, Q06015, doi:10.1029/2009GC002386, ISSN: 1525-202.
Ballmer, M. D., Ito, G., van Hunen, J., & Tackley, P. J., 2010, Small-scale sublithospheric convection reconciles geochemistry and geochronology of ‘Superplume’ volcanism in the western and south Pacific, Earth and Planetary Science Letters, 290, 224–23.
Dana, J. D., 1849, Geology, in Wilkes, C., ed., United States Exploring Expedition 10, Philadelphia, NewYork, Putnam, 756 p.
Jackson, E. D., Silver, E. A. & Dalrymple, G. B., 1972, Hawaiian-Emperor chain and its relation to Cenozoic circumpacific tectonics, Geological Society of America Bulletin, 83, 601-618.
Duncan, R. A., 1981, Hotspots in the Southern Oceans — an absolute frame of reference for motion of the Gondwana continents, Tectonophysics, 74, 29-42.

Jackson, M. G., Hart, S. R., Konter, J. G., Koppers, A. A. P., Staudigel, H., Kurz, M. D., Blusztajn, J., & Sinton, J. M., 2010, Samoan hot spot track on a “hot spot highway”: Implications for mantle plumes and a deep Samoan mantle source, Geochemistry, Geophysics, Geosystems (G3), 11, Q12009, 24 p. doi:10.1029/2010GC003232.http://www.agu.org/pubs/crossref/2010/2010GC003232.shtm 
Norton, I. O., 2000, Global hotspot reference frames and plate motion, American Geophysical Union Geophysical Monograph 121, 339-357.
O’Neill, C., Müller, D., and Steinberger, B., 2005, On the uncertainties in hot spot reconstructions and the significance of moving hotspot reference frames: Geochemistry, Geophysics, Geosystems (G3), Q04003, 35 p., doi: 10.1029/2004GC000784. 
Pilger, R.H. 1982. The origin of hotspot traces: evidence from Eastern Australia, Journal of Geophysical Research, 87, 1825-1834.
Pilger, R. H., 2003, Geokinematics: Prelude to Geodynamics, Springer-Verlag, Berlin, 338 p.
Pilger, R. H., 2007, The Bend, Geological Society of America Bulletin, 119; 302–313, doi: 10.1130/B25713.1, Data Repository item 2007006, https://docs.google.com/leaf?id=0B4YxGFE9X3wSNjBiNWRiMGMtMTc0Ny00ZDJlLWE0NDYtYmZjNWJiMWViNWQ4&hl=en,.
Presnall, D. C., & Gudfinnsson, G., 2011, Oceanic volcanism from the Low-Velocity Zone without mantle plumes, Journal of Petrology, advance access published February 8, 2011.
Wessel, P., Harada, Y., & Kroenke, L. W., 2006, Toward a self-consistent, high-resolution absolute plate motion model for the Pacific, Geochemistry, Geophysics, Geosystems (G3), 7, Q03L12, doi:10.1029/2005GC001000.
Wessel, P., and L. W. Kroenke, 2008, Pacific absolute plate motions since 145 Ma, Journal of Geophysical Research, 113 (B06101), doi:10.1029/2007JB005499.

[Originally published February 15, 2011; updated July 5, 2020 -- added missing reference, corrected typos]

Refocus: The Hotspot-Plume Debate

[Incomplete draft, 2003]
In recent years the ongoing hotspot-plume debate has seemingly increased in intensity, extending beyond refereed publications to sometimes passionate exchanges in opinion and letters sections of organization newsletters and even the popular scientific press. Some of the debate is reminiscent of a political exchange. Assertions are sometimes imprecise or misleading, while counter assertions ignore the initial assertion, providing a response that raises entirely new and different issues. Like ships passing in the night, the debate seems to involve much more miss than hit. Rather than continue this sequence of mixed metaphors, it is preferable to try to refocus the debate. What are the fixed hotspot [1,2] and plume [2,3] hypotheses (while coupled, they can be viewed as separate proposals – either complementary or even competing)? What evidence have we to consider in elaborating and testing the hypotheses? Can we perhaps come to a minimal consensus on these basics, as a basis for progress in future research? This note is an attempt to bring some clarity to the debate while introducing some pertinent observations from both recently published research and earlier, yellowing publications.

Plate and Subplate Interactions, U.S. Cordillera (2005)

Plate and Subplate Interactions: Understanding U.S. Cordilleran Tectonics in the Late Mesozoic and Cenozoic

Plate Kinematic Reconstruction and Restoration via Fractal Error Minimization

GSA-Annual Meeting, 2010-Denver

Jack Oliver, RIP

Jack Oliver

Another of the giants is gone. As inspiring as his ground-breaking (pun intended) contributions were, Jack Oliver was also a very generous man. I, as a young professor, enjoyed and valued my brief interactions with him during visits to Cornell, in seminars, and in various research-planning workshops. RIP

Further confirmation of hotspot trace overprinting: the end of the "super swell"?

Jackson et al. (2010, p. 17) write 

When backtracked through time using the plate motion model of Wessel and Kroenke [2008], the Rurutu hot spot passed through the WESAM province in the region of Bayonnaise seamount, then its trajectory bent to the northwest with the production of the Gilbert chain (Figure 7). The Macdonald hot spot [Hémond et al., 1994] back-tracks through the ESAM, and the hot spot reconstruction model has the chain turning northeast through the Tokelau chain [see also Koppers and Staudigel, 2005]. The reconstructed path of the Rarotonga hot spot passes along the southern fringes of the Samoan hot spot and trends through the Enriched Mantle 1 (EM1) seamounts in the Western Pacific Seamount Province (WSPC [Koppers et al., 2003]). Lending credence to the plate reconstructions, each lineament exhibits isotopic affinities with its respective active hot spot [Konter et al., 2008]. In summary, evidence from plate motion models supports the hypothesis of a “hot spot highway”: Older volcanism left over from three earlier hot spots could be present in the Samoan region.

Their interpretation is in accord, almost fully, with my previous observations:

Hotspot Frames and Shear-wave Tomography

Wagner, Forsyth, Fouch, and James (2010) have produced an intriguing model of the shear wave velocity structure beneath the northwestern US from Rayleigh wave tomography. I've calculated the predicted locus of the the Yellowstone hotspot relative to stable North America and plotted it (Fig.1) on top of their Fig. 8, (-3 percent velocity variation).

Figure 1. Wagner et al.'s (2010) Fig. 8, showing the -3 percent shear velocity anomaly, overlain by calculated locus of Yellowstone hotspot, present to 50 Ma, relative to stable North America (red line and solid circles every five m.y., calculated using Africa-hotspot parameters of Müller et al., 1993, time scale of Gradstein et al., 2005, North American-Africa parameters of Müller et al., and spline interpolation method of Pilger, 2003). The -3 percent anomaly ranges in apparent depth from ~60 to ~140 km, with the greatest apparent lateral extent at ~60 to ~80 km, from Wagner et al.'s Fig. 7. (Click graphic to enlarge, then back button to return to post.)