Abstract
The oldest blueschists—metamorphic rocks formed during subduction—are of Neoproterozoic age1, and 0.7–0.8 billion years old. Yet, subduction of oceanic crust to mantle depths is thought to have occurred since the Hadean, over 4 billion years ago2. Blueschists typically form under cold geothermal gradients of less than 400 °C GPa−1, so their absence in the ancient rock record is typically attributed to hotter pre-Neoproterozoic mantle prohibiting such low-temperature metamorphism; however, modern analogues of Archaean subduction suggest that blueschist-facies metamorphic conditions are attainable at the slab surface3. Here we show that the absence of blueschists in the ancient geological record can be attributed to the changing composition of oceanic crust throughout Earth history, which is a consequence of secular cooling of the mantle since the Archaean4. Oceanic crust formed on the hot, early Earth would have been rich in magnesium oxide (MgO). We use phase equilibria calculations to show that blueschists do not form in high-MgO rocks under subduction-related geothermal gradients. Instead, the subduction of MgO-rich oceanic crust would have created greenschist-like rocks—metamorphic rocks formed today at low temperatures and pressures. These ancient metamorphic products can hold about 20% more water than younger metamorphosed oceanic crust, implying that the global hydrologic cycle was more efficient in the deep geological past than today.
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References
Maruyama, S., Liou, J. G. & Terabayashi, M. Blueschists and eclogites of the world and their exhumation. Int. Geol. Rev. 38, 485–594 (1996).
Turner, S., Rushmer, T., Reagan, M. & Moyen, J. F. Heading down early on? Start of subduction on Earth. Geology 42, 139–142 (2014).
Syracuse, E. M., van Keken, P. E. & Abers, G. A. The global range of subduction zone thermal models. Phys. Earth Planet. Inter. 183, 73–90 (2010).
Herzberg, C., Condie, K. & Korenaga, J. Thermal history of the Earth and its petrological expression. Earth Planet. Sci. Lett. 292, 79–88 (2010).
Bailey, E. H. Metamorphic facies of the Franciscan formation of California and their geologic significance. Geol. Soc. Am. Spec. 68, 4–5 (1961).
Ernst, W. G. Petrogenesis of glaucophane schists. J. Petrol. 4, 1–30 (1963).
Stern, R. J. Evidence from ophiolites, blueschists, and ultrahigh-pressure metamorphic terranes that the modern episode of subduction tectonics began in Neoproterozoic time. Geology 33, 557–560 (2005).
Hamilton, W. B. Plate tectonics began in Neoproterozoic time, and plumes from the deep mantle have never operated. Lithos 123, 1–20 (2011).
Shirey, S. B. & Richardson, S. H. Start of the Wilson Cycle at 3 Ga shown by diamonds from subcontinental mantle. Science 333, 434–436 (2011).
Furnes, H., de Wit, M., Staudigel, H., Rosing, M. & Muehlenbachs, K. A vestige of Earth’s oldest ophiolite. Science 315, 1704–1707 (2007).
Martin, H. & Moyen, J. F. Secular changes in tonalite–trondhjemite–granodiorite composition as markers of the progressive cooling of Earth. Geology 30, 319–322 (2002).
Kirby, S. H., Durham, W. B. & Stern, L. A. Mantle phase changes and deep-earthquake faulting in subducting lithosphere. Science 252, 216–225 (1991).
Peacock, S. M. in Subduction: Top to Bottom Vol. 96 (eds Bebout, G. E. et al.) 119–133 (Geophysical Monograph of the American Geophysical Union, 1996).
Foley, S. F., Buhre, S. & Jacob, D. E. Evolution of the Archean crust by delamination and shallow subduction. Nature 421, 249–252 (2003).
Furnes, H., Dilek, Y. & de Wit, M. Precambrian greenstone sequences represent different ophiolite types. Gondwana Res. 27, 649–685 (2014).
Ziaja, K., Foley, S. F., White, R. W. & Buhre, S. Metamorphism and melting of picritic crust in the early Earth. Lithos 189, 173–184 (2014).
Clarke, G. L., Powell, R. & Fitzherbert, J. A. The lawsonite paradox: A comparison of field evidence and mineral equilibria modelling. J. Meteorol. Geol. 24, 715–725 (2006).
Brown, M. Duality of thermal regimes is the distinctive characteristic of plate tectonics since the Neoarchean. Geology 34, 961–964 (2006).
Griffin, W. L. et al. The origin and evolution of Archean lithospheric mantle. Precambr. Res. 127, 19–41 (2003).
Warren, C. J., Beaumont, C. & Jamieson, R. A. Modelling tectonic styles and ultra-high pressure (UHP) rock exhumation during the transition from oceanic subduction to continental collision. Earth Planet. Sci. Lett. 267, 129–145 (2008).
Korenaga, J. Initiation and evolution of plate tectonics on Earth: Theories and observations. Annu. Rev. Earth Sci. 41, 117–151 (2013).
Husson, L., Brun, J. P., Yamato, P. & Faccenna, C. Episodic slab rollback fosters exhumation of HP–UHP rocks. Geophys. J. Int. 179, 1292–1300 (2009).
St-Onge, M. R., Rayner, N., Palin, R. M., Searle, M. P. & Waters, D. J. Integrated pressure–temperature–time constraints for the Tso Morari dome (northwest India): Implications for the burial and exhumation path of UHP units in the western Himalaya. J. Metamorph. Geol. 31, 469–504 (2013).
Whitney, D. L. & Davis, P. B. Why is lawsonite eclogite so rare? Metamorphism and preservation of lawsonite eclogite, Sivrihisar, Turkey. Geology 34, 473–476 (2006).
van Keken, P. E., Hacker, B. R., Syracuse, E. M. & Abers, G. A. Subduction factory: 4. Depth-dependent flux of H2O from subducting slabs worldwide. J. Geophys. Res. 116, B01401 (2011).
Grove, T. L., Till, C. B., Lev, E., Chatterjee, N. & Médard, E. Kinematic variables and water transport control the formation and location of arc volcanoes. Nature 459, 694–697 (2009).
Hargraves, R. B. Faster spreading or greater ridge length in the Archean? Geology 14, 750–752 (1986).
Schmidt, M. W. & Poli, S. Experimentally based water budgets for dehydrating slabs and consequences for arc magma generation. Earth Planet. Sci. Lett. 163, 361–379 (1998).
Powell, R. & Holland, T. J. B. An internally consistent thermodynamic dataset with uncertainties and correlations: 3. Application to geobarometry, worked examples, and a computer program. J. Metamorph. Geol. 6, 173–204 (1988).
Holland, T. J. B. & Powell, R. An internally consistent thermodynamic dataset for phases of petrological interest. J. Metamorph. Geol. 16, 309–343 (1998).
Acknowledgements
Comments from B. Kaus and J. Castro (JGU Mainz) are gratefully appreciated. R. Powell (Univ. Melbourne) is thanked for providing code to calculate densities with THERMOCALC.
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R.M.P. conceived the idea and performed the calculations. Both authors analysed the data and wrote the paper.
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Palin, R., White, R. Emergence of blueschists on Earth linked to secular changes in oceanic crust composition. Nature Geosci 9, 60–64 (2016). https://doi.org/10.1038/ngeo2605
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DOI: https://doi.org/10.1038/ngeo2605
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