initiation of plate tectonics in the hadean eclogitization triggered by the abel bombardment

Accepted Manuscript Initiation of plate tectonics in the Hadean: Eclogitization triggered by the ABEL Bombardment S Maruyama, M Santosh, S Azuma PII: S1674-9871(16)30207-9 DOI: 10.1016/j.gsf.2016.11.009 Reference: GSF 514 To appear in: Geoscience Frontiers Received Date: May 2016 Revised Date: 13 November 2016 Accepted Date: 25 November 2016 Please cite this article as: Maruyama, S., Santosh, M., Azuma, S., Initiation of plate tectonics in the Hadean: Eclogitization triggered by the ABEL Bombardment, Geoscience Frontiers (2017), doi: 10.1016/ j.gsf.2016.11.009 This is a PDF file of an unedited manuscript that has been accepted for publication As a service to our customers we are providing this early version of the manuscript The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain AC C EP TE D M AN U SC RI PT ACCEPTED MANUSCRIPT ACCEPTED MANUSCRIPT P a g e ‐|‐1 1‐ ‐ 1‐ Initiation of plate tectonics in the Hadean: 2‐ Eclogitization 3‐ Bombardment by 4‐ S Maruyamaa,b,*, M Santoshc,d,e, S Azumaa a 6‐ 7‐ ABEL SC 5‐ the RI PT triggered Earth-Life Science Institute, Tokyo Institute of Technology, 2-12-1, Ookayama-Meguro-ku, Tokyo 152-8550, Japan b Institute for Study of the Earth’s Interior, Okayama University, 827 Yamada, Misasa, Tottori 682-0193, Japan c Centre for Tectonics, Resources and Exploration, Department of Earth Sciences, University of Adelaide, SA 5005, Australia d School of Earth Sciences and Resources, China University of Geosciences 13‐ 14‐ Beijing, 29 Xueyuan Road, Beijing 100083, China e Faculty of Science, Kochi University, Kochi 780-8520, Japan 15‐ *Corresponding author E-mail address: smaruyam@geo.titech.ac.jp 16‐ 17‐ Abstract EP TE D M AN U 8‐ 9‐ 10‐ 11‐ 12‐ When plate tectonics began on the Earth has been long debated and AC C 18‐ 19‐ here we argue this topic based on the records of Earth-Moon geology and 20‐ asteroid belt to conclude that the onset of plate tectonics was during the middle 21‐ Hadean (between 4.37–4.20 Ga) The trigger of the initiation of plate tectonics is 22‐ the ABEL Bombardment, which delivered oceanic and atmospheric components 23‐ on a completely dry reductive Earth, originally comprised of enstatite 1‐ ‐ ACCEPTED MANUSCRIPT P a g e ‐|‐2 2‐ ‐ chondrite-like materials Through the accretion of volatiles, shock metamorphism 25‐ processed with vaporization of both CI chondrite and supracrustal rocks at the 26‐ bombarded location, and significant recrystallization went through under wet 27‐ conditions, caused considerable eclogitization in the primordial continents 28‐ composed of felsic upper crust of 21 km thick anorthosite, and 50 km or even 29‐ thicker KREEP lower crust Eclogitization must have yielded a powerful slab-pull 30‐ force to initiate plate tectonics in the middle Hadean Another important factor is 31‐ the size of the bombardment By creating Pacific Ocean class crater by 1000 km 32‐ across impactor, rigid plate operating stagnant lid tectonics since the early 33‐ Hadean was severely destroyed, and oceanic lithosphere was generated to 34‐ have bi-modal lithosphere on the Earth to enable the operation of plate tectonics 35‐ Considering the importance of the ABEL Bombardment event which initiated 36‐ plate tectonics including the appearance of ocean and atmosphere, we propose 37‐ that the Hadean Eon can be subdivided into three periods: (1) early Hadean 38‐ (4.57–4.37 Ga), (2) middle Hadean (4.37–4.20 Ga), and (3) late Hadean 39‐ (4.20–4.00 Ga) AC C EP TE D M AN U SC RI PT 24‐ 40‐ 2‐ ‐ ACCEPTED MANUSCRIPT P a g e ‐|‐3 3‐ ‐ 41‐ Keywords: Initiation of plate tectonics; ABEL Bombardment; Eclogitization; 42‐ Stagnant lid tectonics; Primordial continents RI PT 43‐ Introduction 44‐ The Earth is the only example among all planets in our solar system with 46‐ active plate tectonics (Fig 1), and also life-bearing since Hadean (e.g Turner et 47‐ al., 2014; Ebisuzaki and Maruyama, 2016) This rocky planet is characterized by 48‐ both H2O ocean and wide-spread granitic continents covering its surface The 49‐ appearance of ocean triggered the operation of plate tectonics, which promoted 50‐ subduction of oceanic plate at the trench and generation of TTG 51‐ (tonalite-trondhjemite-granodiorite) magmas at the continental region As a 52‐ result, important nutrients are being continuously supplied for the survival for life, 53‐ together with CO2, N2, and H2O as components of the building blocks of life 54‐ Thus, the Habitable Trinity environment is sustained which is one of the basic 55‐ conditions for life Plate tectonics, life, H2O ocean, and granitic continents must 56‐ genetically relate with each other (e.g Dohm and Maruyama, 2015) AC C EP TE D M AN U SC 45‐ 57‐ “When plate tectonics began on this planet” is one of the most heated 58‐ debates in Earth Sciences ever since the new paradigm of plate tectonics was 3‐ ‐ ACCEPTED MANUSCRIPT P a g e ‐|‐4 4‐ ‐ established in 1968 (e.g., Le Pichon, 1968; Morgan, 1968; McKenzie, 1969) 60‐ The major argument to demonstrate the operation of plate tectonics was based 61‐ on the presence or absence of ophiolites remaining as a thin and narrow belt 62‐ within orogenic belts as an index of the tectonic movement of the oceanic plates 63‐ which have already disappeared by collision of continents (e.g Komiya et al., 64‐ 1999) However, definition of ophiolite depends on the rock assemblages 65‐ (Maruyama et al., 1989), and therefore when, where, and how plate tectonics 66‐ began to operate remains unsolved To tackle these questions, we start from 67‐ clarifying what plate tectonics is from its most essential characters such as 68‐ rigidity, plate boundary processes, role of water as a driving force, mantle 69‐ potential temperature, and evaluate the multi-disciplinary aspects of the theory 70‐ Finally, we propose a trigger to initiate plate tectonics on Hadean Earth EP TE D M AN U SC RI PT 59‐ AC C 71‐ What is plate tectonics? 72‐ 73‐ 74‐ 2.1 Definition of plate tectonics and three-dimensional structure of 75‐ lithosphere 4‐ ‐ ACCEPTED MANUSCRIPT P a g e ‐|‐5 5‐ ‐ Plate tectonics is basically defined as follows; The Earth’s surface is 77‐ covered by more than a dozen rigid lithospheres called plate The movement of 78‐ these plates is rotational motion on the spherical body of the Earth Hence both 79‐ the rotational pole and angular velocity of the rotation are given to all plates on 80‐ the globe Thus, the motion at any point on the globe is determined, if both 81‐ direction of plate motion and speed are given on the globe This is the core of the 82‐ theory of plate tectonics M AN U SC RI PT 76‐ Another important factor of plate tectonics is the rigidity of the plate The 84‐ Earth is characterized by rigid lithospheric plates, and the rigidity accompanies 85‐ brittle deformation However, the deformation mechanism of rocks changes with 86‐ increase in temperature from brittle to ductile, as seen in rock types from basalts, 87‐ gabbros and mantle peridotites which can be highly ductile above 800 °C (Arzi, 88‐ 1978; Kohlstedt et al.,1995) If volatiles such as H2O and CO2 are present, rocks 89‐ start melting at around this temperature The presence of volatiles and melts are 90‐ imaged through velocity drop in geophysical studies (e.g Nehlig, 1993) 91‐ Furthermore, the ductility acts as a catalyzer to promote slippage at the bottom 92‐ of the lithosphere AC C EP TE D 83‐ 5‐ ‐ ACCEPTED MANUSCRIPT P a g e ‐|‐6 6‐ ‐ One of the major features of plate tectonics is the three-dimensional 94‐ subduction of lithosphere in the shape of plate In the upper mantle, the platy 95‐ structure of lithosphere is preserved during the subduction process However, 96‐ the lithosphere cannot keep the platy form in the lower mantle Platy or 97‐ curtain-like structure of lithosphere seen above 410 km changes to blob-shaped 98‐ structure in the lower mantle through the mantle transition zone at 410–660 km 99‐ depth with the phase changes from olivine to wadsleyite at 410 km, wadsleyite to 100‐ ringwoodite at 520 km, and finally into perovskite and wüstite at 660 km depth 101‐ The recent observations, particularly derived from seismic tomographic data, 102‐ have revealed the architecture of subducting plates at depth (Fukao, 1992; 103‐ Maruyama, 1994; Maruyama et al., 2007) including the total amount of 104‐ accumulated slabs EP TE D M AN U SC RI PT 93‐ Recent multidisciplinary research of the deep Earth including deep 106‐ mantle and even core have brought new insights into the dynamics of the Earth 107‐ combined with geologic history of the Earth, particularly back to 200 Ma, with 108‐ information on the location of slab graveyards that have been well documented 109‐ in seismic tomographic images A ca 300 m topographic bulge over 3000 km 110‐ above the Pacific superplume has been identified where independent hot AC C 105‐ 6‐ ‐ ACCEPTED MANUSCRIPT P a g e ‐|‐7 7‐ ‐ spots are concentrated beneath the southern Pacific region (e.g Zhao, 2007) 112‐ These observations have led to the concept of a coupled tectonic system where 113‐ upper mantle is dominated by horizontal plate movement with curtain-like 114‐ upwelling beneath the mid-oceanic ridge down to the 400 km depth (Zhao, 2004, 115‐ 2009; Zhao et al., 2007) Curtain-like upwelling makes the platy lithosphere at 116‐ mid-oceanic ridge which then moves to the trench and subducts to a depth of 117‐ 660 km At the mantle transition zone from 410 to 660 km, the platy structure 118‐ becomes unclear with stagnation From this depth to the bottom of the 119‐ core-mantle boundary (CMB), the plates not show a simple curtain-like 120‐ structure Instead, blob shaped structure can be seen presumably in the 121‐ transition zone where olivine recrystallizes to wadsleyite (beta phase), 122‐ ringwoodite (gamma phase) and finally to perovskite plus wüstite In the 123‐ presence of water, such recrystallization results in fine-grained crystal 124‐ aggregates and reduction in viscosity by to order of magnitude, causing the 125‐ shape change of lithosphere (Fig 2) Tomographic images clearly indicate blob 126‐ shaped independent down-going slabs that finally accumulate in the D” layer at 127‐ the bottom of the mantle This is what we define as vertical tectonics, or drip 128‐ tectonics On the other hand, rising mega-plume such as those documented AC C EP TE D M AN U SC RI PT 111‐ 7‐ ‐ ACCEPTED MANUSCRIPT P a g e ‐|‐8 8‐ ‐ underneath Africa and southern Pacific originated from older slab graveyards 130‐ formed during the amalgamation of Gondwana and Rodinia supercontinents, 131‐ respectively Thus, the Permian superplume of Africa originated from the slab 132‐ graveyard of Gondwana, and the Pacific superplume from that of Neoproterozoic 133‐ Rodinia (Maruyama et al., 2007) Mantle upwelling is the characteristic feature in 134‐ the lower mantle, and therefore, the lower mantle is controlled by vertical 135‐ tectonics, mainly superplume and plume which is different from the horizontal 136‐ tectonics of the upper mantle In general, the behavior of the upper mantle is 137‐ independent from the lower mantle But over the long geological duration, the 138‐ scenario turns to be different, like the case of the Cretaceous pulse (Larson, 139‐ 1991) Large volume of stagnant slabs at 660 km must have collapsed to make 140‐ slab avalanche to the bottom of CMB, and generated extensive magmatism only 141‐ in the Pacific domain It did not affect the Indian and Atlantic domains, as have 142‐ been well documented from the width of magnetic stripe About double to four 143‐ times more production of MORB in the Pacific domain as well as OIB volcanism 144‐ was caused by faster subduction along the Pacific subduction zones to create 145‐ voluminous TTG, basalt and felsic volcanics (Maruyama, 1994) Episodic AC C EP TE D M AN U SC RI PT 129‐ 8‐ ‐ ACCEPTED MANUSCRIPT P a g e ‐|‐62 62‐ 62‐ ‐ craters at four different times (Marchi et al., 2014) At each time step, Earth’s 1092‐ surface has the region that are not influenced by impact-induced melt, excepting 1093‐ for >4.475 Gyr However, almost all Earth’s surface is affected by impactors by 1094‐ 4.4 Gyr RI PT 1091‐ SC 1095‐ Figure 12 Hadean history of the Earth At 4.55 Ga, dry Earth was formed By 1097‐ 4.53 Ga, mantle was solidified to form layered structure and stagnant lid 1098‐ tectonics operated Between 4.37 and 4.20 Ga, ABEL Bombardment progressed 1099‐ deliver atmospheric and oceanic components on dry Earth Due to great 1100‐ destruction of stagnant lid by huge impactors, stagnant lid tectonics shifted to 1101‐ plate tectonics By 4.30 Ga, bi-modal lithosphere (continental curst and oceanic 1102‐ crust) appeared following to bombardment to operate plate tectonics Due to 1103‐ tectonic erosion, primordial continent (anorthosite, komatiite, and KREEP I) was 1104‐ removed into deep mantle The densest KREEP I dripped down to the bottom of 1105‐ the mantle to accumulate (almost all KREEP I should have accumulated at CMB 1106‐ by 4.0 Ga) KREEP I heated up the bottom of the lower mantle to generate 1107‐ plumes at CMB due to radioactive decay heat, where anti-crust formed at the 1108‐ same time Restite enriched in Ca-perovskite split off from KREEP I as high AC C EP TE D M AN U 1096‐ 62‐ ‐ ACCEPTED MANUSCRIPT P a g e ‐|‐63 63‐ 63‐ ‐ temperature solid plume to accumulate at the top of the lower mantle On the 1110‐ other hand, solid core also melts down due to radioactive decay heat By 4.20 1111‐ Ga, TTG magma was generated to increase granitic continental crust at the 1112‐ consuming plate boundary Removed anorthositic crust moved down to 1113‐ 660–1000 km depth to accumulate Within the lower mantle, coming up plumes 1114‐ from CMB accumulated at 660 km depth At 4.0 Ga, subducting oceanic 1115‐ lithosphere has accumulated at 660 km depth as stagnant slab TTG crust also 1116‐ removed from the surface to accumulate at the mantle transition zone (410–660 1117‐ km), forming second continent At the bottom of the lower mantle, D” layer 1118‐ mostly formed to be third continent TE D M AN U SC RI PT 1109‐ AC C EP 1119‐ 63‐ ‐ AC C EP TE D M AN U SC RI PT ACCEPTED MANUSCRIPT AC C EP TE D M AN U SC RI PT ACCEPTED MANUSCRIPT AC C EP TE D M AN U SC RI PT ACCEPTED MANUSCRIPT AC C EP TE D M AN U SC RI PT ACCEPTED MANUSCRIPT AC C EP TE D M AN U SC RI PT ACCEPTED MANUSCRIPT AC C EP TE D M AN U SC RI PT ACCEPTED MANUSCRIPT AC C EP TE D M AN U SC RI PT ACCEPTED MANUSCRIPT AC C EP TE D M AN U SC RI PT ACCEPTED MANUSCRIPT AC C EP TE D M AN U SC RI PT ACCEPTED MANUSCRIPT AC C EP TE D M AN U SC RI PT ACCEPTED MANUSCRIPT AC C EP TE D M AN U SC RI PT ACCEPTED MANUSCRIPT AC C EP TE D M AN U SC RI PT ACCEPTED MANUSCRIPT ACCEPTED MANUSCRIPT Initiation of plate tectonics in the Hadean: RI PT Eclogitization triggered by the ABEL Bombardment S Maruyamaa,b,*, M Santoshc,d,e, S Azumaa a SC Earth-Life Science Institute, Tokyo Institute of Technology, 2-12-1, Ookayama-Meguro-ku, Tokyo 152-8550, Japan b M AN U Institute for Study of the Earth’s Interior, Okayama University, 827 Yamada, Misasa, Tottori 682-0193, Japan c Centre for Tectonics, Resources and Exploration, Department of Earth Sciences, University of Adelaide, SA 5005, Australia d School of Earth Sciences and Resources, China University of Geosciences Beijing, 29 Xueyuan Road, Beijing 100083, China e Faculty of Science, Kochi University, Kochi 780-8520, Japan EP Research Highlights TE D *Corresponding author E-mail address: smaruyam@geo.titech.ac.jp Presence of water is the most critical factor for plate tectonics AC C Bombardment of carbonaceous chondrites delivered water on completely dry Earth Eclogitization provided slab-pull force to initiate plate tectonics Stagnant lid tectonics shifted to plate tectonics by the ABEL Bombardment ... the independent motion of plate, indicating that the Earth would 329‐ have potential for the initiation of plate tectonics in the Hadean This also means 330‐ that water is necessary for the initiation. .. on the globe This is the core of the 82‐ theory of plate tectonics M AN U SC RI PT 76‐ Another important factor of plate tectonics is the rigidity of the plate The 84‐ Earth is characterized by. .. to conclude that the onset of plate tectonics was during the middle 21‐ Hadean (between 4.37–4.20 Ga) The trigger of the initiation of plate tectonics is 22‐ the ABEL Bombardment, which delivered