Lithospheric controls on magma composition along Earth’s longest continental hotspot track


Hotspots are anomalous regions of volcanism at Earth’s surface that show no obvious association with tectonic plate boundaries. Classic examples include the Hawaiian–Emperor chain and the Yellowstone–Snake River Plain province. The majority are believed to form as Earth’s tectonic plates move over long-lived mantle plumes: buoyant upwellings that bring hot material from Earth’s deep mantle to its surface1. It has long been recognized that lithospheric thickness limits the rise height of plumes2,3,4 and, thereby, their minimum melting pressure. It should, therefore, have a controlling influence on the geochemistry of plume-related magmas, although unambiguous evidence of this has, so far, been lacking. Here we integrate observational constraints from surface geology, geochronology, plate-motion reconstructions, geochemistry and seismology to ascertain plume melting depths beneath Earth’s longest continental hotspot track, a 2,000-kilometre-long track in eastern Australia that displays a record of volcanic activity between 33 and 9 million years ago5,6, which we call the Cosgrove track. Our analyses highlight a strong correlation between lithospheric thickness and magma composition along this track, with: (1) standard basaltic compositions in regions where lithospheric thickness is less than 110 kilometres; (2) volcanic gaps in regions where lithospheric thickness exceeds 150 kilometres; and (3) low-volume, leucitite-bearing volcanism in regions of intermediate lithospheric thickness. Trace-element concentrations from samples along this track support the notion that these compositional variations result from different degrees of partial melting, which is controlled by the thickness of overlying lithosphere. Our results place the first observational constraints on the sub-continental melting depth of mantle plumes and provide direct evidence that lithospheric thickness has a dominant influence on the volume and chemical composition of plume-derived magmas.

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Figure 1: The distribution and classification of eastern Australian Cenozoic volcanic centres and their relationship to regional lithospheric thickness variations.
Figure 2: Trace-element abundances of volcanic samples along the Cosgrove hotspot track.


  1. 1

    Morgan, W. J. Convection plumes in the lower mantle. Nature 230, 42–43 (1971)10.1038/230042a0

    Article  ADS  Google Scholar 

  2. 2

    Davies, G. F. Thermomechanical erosion of the lithosphere by mantle plumes. J. Geophys. Res. 99, 15709–15722 (1994)

    Article  ADS  Google Scholar 

  3. 3

    Farnetani, C. G. & Richards, M. A. Thermal entrainment and melting in mantle plumes. Earth Planet. Sci. Lett. 136, 251–267 (1995)

    CAS  Article  ADS  Google Scholar 

  4. 4

    White, R. S. & McKenzie, D. Mantle plumes and flood basalts. J. Geophys. Res. 100, 17543–17585 (1995)

    CAS  Article  ADS  Google Scholar 

  5. 5

    Cohen, B. E., Knesel, K. M., Vasconcelos, P. M., Thiede, D. S. & Hergt, J. M. 40Ar/39Ar constraints on the timing and origin of Miocene leucitite volcanism in southeastern Australia. Aust. J. Earth Sci. 55, 407–418 (2008)

    CAS  Article  ADS  Google Scholar 

  6. 6

    Cohen, B. E., Knesel, K. M., Vasconcelos, P. M. & Schellart, W. P. Tracking the Australian plate motion through the Cenozoic: constraints from 40Ar/39Ar geochronology. Tectonics 32, 1371–1383 (2013)

    Article  ADS  Google Scholar 

  7. 7

    Duncan, R. A. & Richards, M. A. Hotspots, mantle plumes, flood basalts and true polar wander. Rev. Geophys. 29, 31–50 (1991)

    Article  ADS  Google Scholar 

  8. 8

    Steinberger, B. Plumes in a convecting mantle: models and observations for individual hotspots. J. Geophys. Res. 105, 11127–11152 (2000)

    Article  ADS  Google Scholar 

  9. 9

    Courtillot, V., Davaille, A., Besse, J. & Stock, J. Three distinct types of hotspots in the Earth’s mantle. Earth Planet. Sci. Lett. 205, 295–308 (2003)

    CAS  Article  ADS  Google Scholar 

  10. 10

    Campbell, I. H. & Griffiths, R. W. The changing nature of mantle hotspots through time: implications for the geochemical evolution of the mantle. J. Geol. 100, 497–523 (1992)

    CAS  Article  ADS  Google Scholar 

  11. 11

    Wellman, P. & McDougall, I. Cainozoic igneous activity in eastern Australia. Tectonophys. 23, 49–65 (1974)

    CAS  Article  Google Scholar 

  12. 12

    Johnson, R. W. (ed.) Intraplate Volcanism in Eastern Australia and New Zealand Ch. 1.1 (Cambridge Univ. Press, 1989)

    Google Scholar 

  13. 13

    Knesel, K. M., Cohen, B. E., Vasconcelos, P. M. & Thiede, D. S. Rapid change in drift of the Australian plate records collision with Ontong Java plateau. Nature 454, 754–757 (2008)

    CAS  Article  ADS  Google Scholar 

  14. 14

    Sutherland, F. L., Graham, I. T., Meffre, S., Zwingmann, H. & Pogson, R. E. Passive-margin prolonged volcanism, east Australian plate: outbursts, progressions, plate controls and suggested causes. Aust. J. Earth Sci. 59, 983–1005 (2012)

    CAS  Article  ADS  Google Scholar 

  15. 15

    Davies, D. R. & Rawlinson, N. On the origin of recent intra-plate volcanism in Australia. Geology 42, 1031–1034 (2014)

    Article  ADS  Google Scholar 

  16. 16

    King, S. D. & Anderson, D. L. Edge-driven convection. Earth Planet. Sci. Lett. 160, 289–296 (1998)

    CAS  Article  ADS  Google Scholar 

  17. 17

    Ewart, A., Chappell, B. W. & Menzies, M. A. An overview of the geochemical and isotopic characteristics of the eastern Australian Cainozoic volcanic provinces. J. Petrol. 1, 225–273 (1988)

    Article  Google Scholar 

  18. 18

    Torsvik, T. H., Steinberger, B., Gurnis, M. & Gaina, C. Plate tectonics and net lithosphere rotation over the past 150 Myr. Earth Planet. Sci. Lett. 291, 106–112 (2010)

    CAS  Article  ADS  Google Scholar 

  19. 19

    Leitch, A. M. & Davies, G. F. Mantle plumes and flood basalts: enhanced melting from plume ascent and an eclogite component. J. Geophys. Res. 106, 2047–2059 (2001)

    CAS  Article  ADS  Google Scholar 

  20. 20

    Tarduno, J. A. et al. The Emperor Seamounts: southward motion of the Hawaiian hotspot plume in Earth’s mantle. Science 301, 1064–1069 (2003)

    CAS  Article  ADS  Google Scholar 

  21. 21

    Davies, D. R. & Davies, J. H. Thermally-driven mantle plumes reconcile multiple hotspot observations. Earth Planet. Sci. Lett. 278, 50–54 (2009)

    CAS  Article  ADS  Google Scholar 

  22. 22

    Sleep, N. H. Lateral flow of hot plume material ponded at sublithospheric depths. J. Geophys. Res. 101, 28065–28083 (1996)

    Article  ADS  Google Scholar 

  23. 23

    Rawlinson, N., Kennett, B. L. N., Salmon, M. & Glen, R. A. in The Earth’s Heterogeneous Mantle: A Geophysical, Geodynamical, and Geochemical Perspective Ch. 2 (eds Khan, A., & Deschamps, F. ) 47–78 (Springer, 2015)

    Google Scholar 

  24. 24

    Kennett, B. L. N., Fichtner, A., Fishwick, S. & Yoshizawa, K. Australian Seismological Reference Model (AuSREM): mantle component. Geophys. J. Int. 192, 871–887 (2013)

    Article  ADS  Google Scholar 

  25. 25

    Farrington, R. J., Stegman, D. R., Moresi, L. N., Sandiford, M. & May, D. A. Interactions of 3D mantle flow and continental lithosphere near passive margins. Tectonophys. 483, 20–28 (2010)

    Article  Google Scholar 

  26. 26

    Paul, B., Hergt, J. M. & Woodhead, J. D. Mantle heterogeneity beneath the Cenozoic volcanic provinces of central Victoria inferred from trace-element and Sr, Nd, Pb and Hf isotope data. Aust. J. Earth Sci. 52, 243–260 (2005)

    CAS  Article  Google Scholar 

  27. 27

    Hofmann, A. W. in Treatise on Geochemistry Vol. 2 (ed. Carlson, R. W. ) 61–101 (Elsevier, 2003)

    Google Scholar 

  28. 28

    Ringwood, A. E. Composition and Petrology of the Earth’s Mantle (McGraw-Hill, 1975)

    Google Scholar 

  29. 29

    Rawlinson, N. et al. Complex continental growth along the proto-Pacific margin of East Gondwana. Geology 42, 783–786 (2014)

    Article  ADS  Google Scholar 

  30. 30

    Montelli, R., Nolet, G., Dahlen, F. A. & Masters, G. A catalogue of deep mantle plumes: new results from finite-frequency tomography. Geochem. Geophys. Geosys. 7, Q11007 (2006)

    Article  ADS  Google Scholar 

  31. 31

    McDonough, W. F. & Sun, S.-S. The composition of the Earth. Chem. Geol. 120, 223–253 (1995)

    CAS  Article  ADS  Google Scholar 

  32. 32

    Antretter, M., Steinberger, B., Heider, F. & Soffel, H. Paleolatitudes of the Kerguelen hotspot: new paleomagnetic results and dynamic modelling. Earth Planet. Sci. Lett. 203, 635–650 (2002)

    CAS  Article  ADS  Google Scholar 

  33. 33

    Tarduno, J. A., Bunge, H.-P., Sleep, N. & Hansen, U. The bent Hawaiian-Emperor hotspot track: inheriting the mantle wind. Science 324, 50–53 (2009)

    CAS  Article  ADS  Google Scholar 

  34. 34

    Rawlinson, N. & Urvoy, M. Simultaneous inversion of active and passive source datasets for 3-D seismic structure with application to Tasmania. Geophys. Res. Lett. 33, L24313 (2006)

    Article  ADS  Google Scholar 

  35. 35

    Rawlinson, N., Tkalcic, H. & Reading, A. M. Structure of the Tasmanian lithosphere from 3D seismic tomography. Aust. J. Earth Sci. 57, 381–394 (2010)

    Article  ADS  Google Scholar 

  36. 36

    Rawlinson, N., Salmon, M. & Kennett, B. L. N. Transportable seismic array tomography in southeast Australia: illuminating the transition from Proterozoic to Phanerozoic lithosphere. Lithos 189, 65–76 (2014)

    CAS  Article  ADS  Google Scholar 

  37. 37

    Simons, F. J. & van der Hilst, R. D. Age-dependent seismic thickness and mechanical strength of the Australian lithosphere. Geophys. Res. Lett. 29, 1529 (2002)

    Article  ADS  Google Scholar 

  38. 38

    Fishwick, S. & Rawlinson, N. 3-D structure of the Australian lithosphere from evolving seismic datasets. Aust. J. Earth Sci. 59, 809–826 (2012)

    CAS  Article  ADS  Google Scholar 

  39. 39

    Yoshizawa, K. Radially anisotropic 3-D shear wave structure of the Australian lithosphere and asthenosphere from multi-mode surface waves. Phys. Earth Planet. Inter. 235, 33–48 (2014)

    Article  ADS  Google Scholar 

  40. 40

    Fishwick, S., Heintz, M., Kennett, B. L. N., Reading, A. M. & Yoshizawa, K. Steps in lithospheric thickness within eastern Australia: evidence from surface wave tomography. Tectonics 27, TC4009 (2008)

    Article  ADS  Google Scholar 

  41. 41

    Kennett, B. L. N. & Salmon, M. AuSREM: Australian seismological reference model. Aust. J. Earth Sci. 59, 1091–1103 (2012)

    Article  ADS  Google Scholar 

  42. 42

    Nelson, D. R., McCulloch, M. T. & Sun, S.-S. The origins of ultrapotassic rocks as inferred from Sr, Nd, and Pb isotopes. Geochim. Cosmochim. Acta 50, 231–245 (1986)

    CAS  Article  ADS  Google Scholar 

Download references


D.R.D. is funded by an Australian Research Council Future Fellowship (FT140101262). G.I. acknowledges support from the Ringwood Fellowship at the Australian National University. Digital geological data were provided by Geosciences Australia.

Author information




D.R.D. conceived this study and integrated all interdisciplinary observational constraints. N.R. created the lithospheric thickness map by combining constraints from the AuSREM reference model and body-wave data from the WOMBAT array. He also devised and implemented the method for estimating uncertainty in lithospheric thickness. G.I. performed the hotspot-track reconstruction and estimated the associated uncertainties. D.R.D. and I.H.C. undertook the geochemical synthesis. D.R.D. wrote the paper, following discussion with, and contributions from, all authors.

Corresponding author

Correspondence to D. R. Davies.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Extended data figures and tables

Extended Data Figure 1 Locations of the 15 volcanic centres used in our reconstruction of the Cosgrove hotspot track.

The hotspot track is indicated with a dashed line.

Extended Data Figure 2 The Cosgrove hotspot track.

As in Fig. 1a but incorporating all 15 dated volcanic complexes and extended southwards to show the predicted present-day location of the underlying mantle plume (green square to the northwest of Tasmania). The approximate location of the East Australia Plume System, imaged previously using finite frequency tomography30, is marked by the dotted green line.

Extended Data Figure 3 Reconstruction score map.

The number of predicted volcanic centre locations, from a total of 15 (listed in Extended Data Table 1), that fall within the uncertainty circles surrounding the dated volcanic centres, for a range of plume drift velocities and melt region diameters. Note that the reconstructions illustrated in Fig. 1a and Extended Data Fig. 2 assume a plume drift velocity of 1 cm yr−1 and a melt region diameter of 100 km (black square).

Extended Data Figure 4 Location of WOMBAT array stations used to create the three-dimensional P-wave velocity model from which our lithospheric thickness estimate was derived.

Station spacing is 50 km, which roughly equates to the maximum horizontal resolution of the three-dimensional velocity model.

Extended Data Figure 5 Depth slice at 120 km, through the three-dimensional P-wave velocity model.

North of 28° S, the model reverts to the AuSREM mantle model, owing to a lack of additional data coverage in this region (see Extended Data Fig. 4).

Extended Data Figure 6 Lithospheric thickness estimate and associated uncertainty.

a, b, Lithosphere thickness model illustrated in Fig. 1b (a), alongside an estimate of its uncertainty (b), given by the standard deviation (σ) of an ensemble of 540 plausible models examined. Note that south of 28 °S, the lithospheric thickness estimate is constrained by high-resolution body-wave tomography (50 km horizontal resolution), whereas north of this latitude it is constrained entirely by the AuSREM mantle model (200–250 km horizontal resolution)24.

Extended Data Table 1 Age estimates, derived via 40Ar–39Ar geochronology, for the volcanic centres considered in this study
Extended Data Table 2 Rock type, sample locations, sample numbers and data source, from previously analysed samples along the Cosgrove track
Extended Data Table 3 Trace-element concentrations for a number of samples along the Cosgrove track

PowerPoint slides

Source data

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Davies, D., Rawlinson, N., Iaffaldano, G. et al. Lithospheric controls on magma composition along Earth’s longest continental hotspot track. Nature 525, 511–514 (2015).

Download citation

Further reading


By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.


Quick links

Sign up for the Nature Briefing newsletter for a daily update on COVID-19 science.
Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing