Scholarly article on topic 'Triggers and sources of volatile-bearing plumes in the mantle transition zone'

Triggers and sources of volatile-bearing plumes in the mantle transition zone Academic research paper on "Earth and related environmental sciences"

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{Asia / "Pacific-type convergent margin" / "Continental crust material" / "Hydrated/carbonated oceanic crust" / Subduction / Melting}

Abstract of research paper on Earth and related environmental sciences, author of scientific article — Inna Safonova, Konstantin Litasov, Shigenori Maruyama

Abstract The paper discusses generation of volatile-bearing plumes in the mantle transition zone (MTZ) in terms of mineral-fluid petrology and their related formation of numerous localities of intra-plate bimodal volcanic series in Central and East Asia. The plume generation in the MTZ can be triggered by the tectonic erosion of continental crust at Pacific-type convergent margins and by the presence of water and carbon dioxide in the mantle. Most probable sources of volatiles are the hydrated/carbonated sediments and basalts and serpentinite of oceanic slabs, which can be subducted down to the deep mantle. Tectonic erosion of continental crust supplies crustal material enriched in uranium and thorium into the mantle, which can serve source of heat in the MTZ. The heating in the MTZ induces melting of subducted slabs and continental crust and mantle upwelling, to produce OIB-type mafic and felsic melts, respectively.

Academic research paper on topic "Triggers and sources of volatile-bearing plumes in the mantle transition zone"

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Triggers and sources of volatile-bearing plumes in the mantle transition zone Dr. Inna Safonova , Konstantin Litasov , Shigenori Maruyama

PII: S1674-9871(14)00157-1

DOI: 10.1016/j.gsf.2014.11.004

Reference: GSF 336

To appear in: Geoscience Frontiers

Received Date: 27 October 2014 Revised Date: 17 November 2014 Accepted Date: 27 November 2014

Please cite this article as: Safonova, I., Litasov, K., Maruyama, S., Triggers and sources of volatile-bearing plumes in the mantle transition zone, Geoscience Frontiers (2015), doi: 10.1016/ j.gsf.2014.11.004.

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coeval

Intracontinental

Island arc

Pressure-solution creep of infiltrated layer

Carbonate

Partially molten carbonate

3 Inna Safonova a,b,*3 Konstantin Litasov a,b, Shigenori Maruyama c

5 a V.S. Sobolev Institute of Geology and Mineralogy SB RAS, Novosibirsk, Russia

6 b Novosibirsk State University, Novosibirsk, Russia

7 c Earth-Life Science Institute, Tokyo Institute of Technology, Tokyo, Japan

9 * Corresponding author.

10 Dr. Inna Safonova: Institute of Geology and Mineralogy SB RAS, Novosibirsk, Russia; Tokyo Institute of Technology,

11 Tokyo, Japan

12 E-mail address: inna@igm.nsc.ru

14 Abstract: The paper discusses generation of volatile-bearing plumes in the mantle transition zone (MTZ) in

15 terms of mineral-fluid petrology and their related formation of numerous localities of intra-plate bimodal

16 volcanic series in Central and East Asia. The plume generation in the MTZ can be triggered by the tectonic

17 erosion of continental crust at Pacific-type convergent margins and by the presence of water and carbon

18 dioxide in the mantle. Most probable sources of volatiles are the hydrated/carbonated sediments and basalts

19 and serpentinite of oceanic slabs, which can be subducted down to the deep mantle. Tectonic erosion of

20 continental crust supplies crustal material enriched in uranium and thorium into the mantle, which can serve

21 source of heat in the MTZ. The heating in the MTZ induces melting of subducted slabs and continental crust

22 and mantle upwelling, to produce OIB-type mafic and felsic melts, respectively.

24 Key words: Asia; Pacific-type convergent margin; Continental crust material; Hydrated/carbonated oceanic

25 crust; Subduction; Melting

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The deep mantle processes at the mantle transition zone (MTZ), i.e. between a depth of 410 and 660 km, and at the core-mantle boundary (CMB), i.e. at a depth of 2700 km, which could be linked to the supply/presence of water in the mantle and the processes at Pacific-type (P-type) convergent margins (Fig. 1) resulting in subduction and accumulation of crustal material in the MTZ, have been discussed in many publications (Maruyama, 1994; Clift and Vanucchi, 2004; Ohtani et al., 2004; Maruyama et al., 2007, 2014; Yamamoto et al., 2009; Kawai et al., 2009; Litasov, 2011; Safonova and Maruyama, 2014). The widely discussed model of superplumes or "dry" plumes generated at the CMB in relation to the accumulation of subducted slabs therein and perovskite-postperovskite phase transition (Maruyama et al., 2007, 2011) did not explain well the causes and sources of intra-continental rifting and its related mafic and bi-modal volcanism, i.e. coeval and co-existing geochemically contrast volcanic series consisting of basalts and dacite-rhyolites, which localities are abundant in central and eastern Asia (Safonova and Maruyama, 2014). Recently, processes of partial melting and plume generation in the MTZ have been discussed in terms of tectonic erosion at P-type consuming boundaries as a mechanism providing the supply of oceanic slabs and continental crust material into the mantle and in terms of the presence of water and carbon dioxide in the mantle, which could significantly affect the temperature of melting (e.g., Kawai et al., 2009, 2013; Senshu et al., 2009; Litasov, 2011; Harte and Richardson, 2012; Ivanov and Litasov, 2014; Safonova and Maruyama, 2014). In this paper we discuss volatile-bearing mantle plumes in the MTZ with a focus to the formation of dense hydrous magnesium silicates (DHMS) by the dehydration of subducted slabs, which may serve sources of water, and to the subduction of small amounts of carbonates, which may serve sources of carbon dioxide in the MTZ. More evidence for the occurrence of carbonates in the deep mantle comes from inclusions in super-deep diamonds (e.g. Harte and Richardson, 2012; Zedgenizov et al., 2014a,b). The dehydration of DHMS and the melting of carbonates can trigger generation of volatile-bearing plumes. An

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earth elements (LREE) and radiogenic LILE (e.g., uranium, thorium and potassium), which all are necessary to produce typical OIB lavas (Safonova, 2009; Safonova et al., 2014; Safonova and Santosh, 2014).

59 2. Delivery of continental crust material to the MTZ

61 During the recent ca. 15 years it has been shown that convergent margins are sites of

62 intensive destruction of continental crust (e.g., Clift and Vanucchi, 2004; Scholl and von Huene,

63 2007; Stern and Scholl, 2010; Stern, 2011 and references therein). The geological record of the

64 Chichibu and Shimanto accretionary complexes of south-eastern Japan in the modern western

65 Pacific, which is a world standard of consuming convergent margin of Pacific type, indicates a

66 continuous subduction back to ca. 200 Ma and its related tectonic erosion (Fig. 2; Yamamoto et al.,

67 2009; Maruyama et al., 2011; Safonova and Maruyama, 2014). A best example of probable tectonic

68 erosion is the late Cretaceous Shimanto accretionary complex, which is adjacent to the coeval

69 Ryoke granitoid batholith (Isozaki et al., 2010). Such an adjacent or neighboring position of coeval

70 accretionary units and suprasubduction granitoids suggests erosion of older units, which once

71 separated the complex and the batholite (Fig. 3; Nakajima, 1994). More evidence for the tectonic

72 erosion of continental crust material comes from the presence of at least six "submerged" intra-

73 oceanic arcs, including the Izu-Bonin arc, in the Philippine Sea, four of which are now under the sea

74 level. Those arcs are currently subducting under the Nankai trough in south-western Japan, but not

75 accreting, suggesting ongoing subduction of arc tonalite-andesitic material (Yamamoto et al., 2009).

76 Based on P-wave tomographic data, the Izu-Bonin arc is now subducting directly under the Central

77 Honshu arc with negligible amount of accretion to the present plate boundary landward (Yamamoto

78 et al., 2009). Moreover, it is obvious that no accretion occurred back to 17 Ma under the Honshu

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accreted, the present crust must have a thickness up to 100 km.

Many scientists believe that the continental crust cannot be subducted to depths greater than the Moho boundary, i.e. about 30-35 km, because it consists mostly of granitic rocks, which possess relatively low density (ca. 2.5-2.8) compared to upper mantle rocks (3.3-3.5). Kawai with co-authors (Kawai et al., 2009, 2013) used the First Principle Calculation mode to calculate the densities of major rock-forming minerals of TTG, pyrolite, harzburgite, MORB and anorthosite and concluded that beneath the depth of 270 km the rocks of granitic composition acquire negative buoyancy compared to the ambient mantle due to the coesite-stishovite, olivine-wadsleyite and wadsleyite-ringwoodite transformations at 270, 410 and 520 km, respectively, resulting in higher densities allowing those rock to be subducted to the depths from 270 to 660 km, but not deeper into the lower mantle (Kawai et al., 2013). Using Preliminary Reference Earth Model calculations (PREM) for the MTZ Kawai with co-authors (2009) compared the PREM-based P- and S-wave velocities of TTG with those of peridotite (pyrolite, harzburgite) and MORB to show that only the TTG boundaries fit the PREM ones. All these facts make the initial statement that granitic rock cannot be subducted doubtful.

3. Source of volatiles in the MTZ

Water can be transported to the mantle by subducting oceanic slabs consisting of basalts, serpentinites, and oceanic sediments. Basalts can be strongly carbonatized in submarine conditions, at mid-oceanic ridge hydrothermal systems (e.g. Staudigel, 2014). The basalts are covered by a layer of hydrous oceanic sediments deposited after their formation at spreading centers until arrival to the trench. Typically, the hydrous minerals and carbonates can be transported down to the deep mantle by old, dense and thick cold oceanic slabs, which have lower geothermal gradient and can be dehydrated and decarbonatized within the "big mantle wedge" (Maruyama et al., 1996, 2014; Zhao

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wadsleyite and ringwoodite (Inoue, 1994; Kawamoto et al., 1996; Ohtani et al., 2004; Litasov, 2011), i.e. the source of water in the MTZ is dense hydrous magnesium silicates, such as phase A, E, and superhydrous B (Komabayashi et al., 2009).

The water released from the subducting slab may acquire reduced mobility in the transition zone due to its significant solubility in the MTZ minerals, such as wadsleyite and ringwoodite. Along the mantle adiabat these minerals can accommodate up to 0.5 wt.% H2O (Litasov, 2011; Litasov et al., 2011). Water will be resided in wadsleyite and ringwoodite until the saturation limit, however, the transition zone would hardly contain more than 0.3-0.4 wt.% H2O in average at ca. 60% of olivine in the mantle. Therefore it would be hard to exceed that "wadsleyite/ringwoodite" saturation limit, in particular, taking into account that the average peridotite mantle may contain up to 40 vol.% of garnet and other minerals possessing relatively low abilities to accommodate H2O.

In this respect carbon dioxide may play a more significant role as a volatile component in the transition zone (Litasov et al., 2013) more mobile than water. The carbonated subducting slabs can be partly decarbonatized within the "big mantle wedge" to release carbon dioxide into the ambient mantle and then transport the carbonates deeper into the mantle (Omori and Santosh, 2008; Zhao and Ohtain, 2009; Santosh et al., 2010; Litasov, 2011). It has been recently shown that the melting of subducted carbonates can occur at depths of the transition zone. Evidence for this comes from the summary of phase diagrams for carbonated systems (Fig. 5). Actually, such a suggestion is valid for both the stagnant and downgoing slabs, because the solidi of carbonated lithologies for the average slab geotherms intersect exactly at the depths corresponding to the transition zone. An important issue is the source of the volumes of carbonates sufficient to provide those melting processes. The volume of marine carbonates, for example, carbonate capped oceanic islands and plateaus, is typically rather low, however, the basaltic oceanic crust can be altered/carbonatized in the conditions of oceanic floor hydrothermal metamorphism, although to a small degree, and therefore helps to increase a little the amount of CO2 supplied deep to the transition zone (see a

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magma generation, because, according to thermodynamic modelling data (Kerrick and Connolly, 2001), it is hard to melt 100% of carbonates at those levels. In addition, recent geochemical data suggest that 20-80% carbonates would survive through the subduction-related melting and can be delivered to greater depths (Johnston et al., 2011).

137 4. Generation of volatile-bearing plumes

139 The fate of subducted water and carbon dioxide in the deep mantle can be variable. On one

140 hand, the water released from cold subduction slab by dehydration of dense hydrous magnesium

141 silicates at the depths of the transition zone may not cause significant melting and melt movement

142 due to the capture of water by wadsleyite and ringwoodite. On the other hand, the subduction of

143 carbonates and their melting in the transition zone can trigger the dehydration of hydrous wadsleyite

144 and ringwoodite and then the generation of volatile-bearing plumes. The next key question is the

145 mobility and/or solubility and the mechanism of transportation of hydrous, carbonated, and

146 hydrous-carbonated melts, i.e. plumes, in the conditions of deep mantle.

147 Recently, a dissolution-precipitation mechanism for the penetration of carbonatite melt

148 diapirs through the mantle was proposed (Litasov et al., 2013a,b; Shatskiy et al., 2013). That

149 mechanism can be applied not only for the MTZ and the melting of subducted carbonates, but also

150 to the lower mantle and core-mantle boundary conditions. By using a simple numerical modeling

151 procedure (Litasov et al., 2013b) we argued for the formation of carbonated diapirs by the melting

152 of subducted carbonates in the transition zone. Fig. 6 shows the three main stages of the formation

153 of a carbonatite diapir: (1) the extraction of carbonatite melt from the slab modeled for a ca. 500 m

154 thick carbonated basalt slab containing 2 wt.% CO2; (2) upward infiltration of the melt and its

155 accumulation at the slab-mantle interface to form a diapir; (3) ascent of the diapir towards the

156 surface via the dissolution-precipitation mechanism driven by the pressure-solution creep at the

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reduced surrounding mantle, which may containing minor Fe0, towards the f(O2) conditions of the CCO buffer (Fig. 6) (Litasov et al., 2013 a,b).

In this model the mobility of the melt is linked with the solubility of the silicate melt in the carbonate melt and vice versa. The extracted melt can acquire an acceptable mobility if the solubility of silicates is rather low (Fig. 5). Those conditions are possible if a carbonated melt is in equilibrium with peridotite/eclogite. About 5-10 wt.% of SiO2 only can be dissolved in the carbonated melt along the mantle adiabat. The hydrous melt will probably have a limited mobility as the solubility of silicates in such a melt would be very high: more than 70 wt.% along the mantle adiabat (Fig. 5).

Addition of water to the carbonate melt may reduce its mobility, but not drastically, allowing the hydrous-carbonated melts to be efficiently transported through the mantle. The hydration of carbonated melts is possible by the dehydration of hydrous wadsleyite and ringwoodite in the area surrounding the subducting slab and atop the 410 km discontinuity, where the dehydration of the slab and the enrichment of the plumes by water is unavoidable due to the difference between the solubility of H2O in wadsleyite and overlying olivine (Litasov, 2011; Maruyama et al., 2011). The details of those processes of plume generation and melt ascent are still far from clear and/or full understanding, but we think that such a model explains well the formation of volatile-bearing plumes in different mantle environments and depths and may account different lithologies subducted to the deep mantle.

In a recently suggested scenario, the eroded and subducted continental crust material may be accumulated at the MTZ, i.e. between 410 and 660 km (Maruyama et al., 2011; Kawai et al., 2013; Safonova and Maruyama, 2014). That material should contain several hundreds to 1000 times higher concentrations of radioactive elements (K, U, Th) than the ambient upper mantle (see Table 1 in Maruyama et al., 2013) and thus play a key role in its heating, upwelling, and generation of mantle plumes (Safonova and Maruyama, 2014). The heat generated by the subducted continental

200 201 202

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Archean and ca. 100 K during the Phanerozoic (Senshu et al., 2009). Therefore, the accumulation of continental crust material and the heating in the MTZ can induce mantle upwelling and generate volatile-bearing plumes, which may reach the lithosphere (Fig. 7). Moreover, the dehydration of hydrous wadsleyite and ringwoodite, which is necessary for the melting, is possible above such a heater at the MTZ only.

The melts generated in the MTZ can separate and ascend to form a cluster of smaller plumes, which then can merge to form a larger plume. These volatile-bearing plumes may appear responsible for the formation of rifting-related mafic and bi-modal volcanic intra-continental series consisting of Ti-Nb-LREE enriched OIB-type basalts and dacite-rhyolite varieties. A source of Ti and Nb, could be recycled oceanic crust (MORB) (Brenan et al., 1994; Prytulak and Elliott, 2007). Nb can reside in the subducting oceanic slab (Saunders et al., 1988) and fractionate from other incompatible elements through subduction-induced dehydration to accumulate through the mixing of subducted oceanic slabs back into the deep mantle, possibly reaching even the CMB (McCulloch and Gamble, 1991; Brenan et al., 1994). Ti and Nb elements behave similarly during them melting and both are incompatible in Ti-Fe oxides only, and therefore both can be derived from such a recycled MORB crust, which is present at both the CMB and MTZ as so-called "slab graveyards" (e.g., Maruyama et al., 2007; Santosh et al., 2010). The crustal material subducted and accumulated at the MTZ could be a source of light rare-earth elements and radiogenic LILE (e.g., uranium, thorium and potassium). Basaltic melts may form by the melting of recycled MORB subducted and accumulated in the MTZ (Kawai et al., 2013; Safonova and Maruyama, 2014). In turn, felsic melts may form by the melting of continental crust by the volatile-bearing plumes. Finally, those plumes may provide melt ascent and crust rifting and volcanism (Fig. 7) (Safonova and Maruyama, 2014).

207 5. Evidence from East Asia

Bi-moaai volcanic series probably iormea by volatile-bearing plumes are very common in the intra-continental areas of Central and East Asia (Yarmolyuk et al., 2011; Zhang et al., 2013; Ivanov and Litasov, 2014; Simonov et al., 2014). Several plumes were identified under East Asia, which tomographic models trace those plumes down to a depth of 410 km, but not much deeper (Huang and Zhao, 2006). The initiation of plumes in Central and East Asia can be related to the collision of the Siberian, Kazakhstan, Tarim and North China continental blocks and the assembly of the Laurasia quasi-supercontinent in late Silurian-early Carboniferous time (Maruyama and Sakai, 1986). The Laurasian blocks were surrounded by numerous subduction zones and arcs (e.g., Gao et al., 2008; Gordienko et al., 2010; Biske et al., 2013; Donskaya et al., 2013), which crust could contribute to the initiation of plume magmatism of the Tarim large igneous province (early Permian, ca. 280 Ma), Junggar Basin (early Jurassic, ca. 180 Ma) and Central Tienshan (late Cretaceous-Paleocene; ca. 80 Ma) (e.g., Zhang et al., 2013; Simonov et al., 2014). The Devonian-early Permian subduction zones around the Mongolo-Okhotsk Ocean, which separated the Siberian and North China cratons (Donskaya et al., 2013) could also have supplied volatile-saturated and crustal material into the mantle and induced plumes and their related Cretaceous and early Cenozoic intra-plate volcanism and rifting in south-eastern Transbaikalia and eastern Mongolia (Yarmolyuk et al., 2011; Ivanov and Litasov, 2014). The Cenozoic intra-plate magmatism in south-western and north-eastern Transbaikalia, Mongolia and East China (e.g., Kuzmin et al., 2010; Fig. 1A) probably resulted from the ca. 200 Ma subduction of the Pacific plate beneath East Asia, which is still continuing. The hydrous plume could be also responsible for the formation of rift-type sedimentary basins in Russian Transbaikalia-northern Mongolia, e.g., at Barguzin, Muya, Chara, Tunka, Darhad, etc. (Logachev, 2003; Krivonogov et al., 2012). Such a model is an alternative to the formation of those basins in connection with the India-Eurasia collision (Molnar and Tapponier, 1975).

235 6. Conclusions

237 The crustal material, provided by eroding Pacific-type convergent margins as well as direct

238 arc subduction, can be subducted deep to the mantle and accumulate at the MTZ. The subducted

239 material and the volatile-bearing minerals approaching the MTZ can induce the heating and melting

240 and finally generate volatile-bearing mantle plumes. The hydrous minerals and carbonates can be

241 transported to the MTZ by old and cold subducting oceanic slabs. Sources of water are hydrous

242 oceanic sediments and hydrated MORB with minor serpentinite. Carbon dioxide can be supplied by

243 limitedly preserved marine carbonates and minor carbonatized basaltic oceanic crust generated and

244 altered at mid-oceanic ridges and their related hydrothermal systems. The erosion of Pacific-type

245 convergent margins and subduction of arcs may result in its accumulation of huge amounts of

246 crustal material, water, and carbon dioxide at the MTZ beneath Asia and extensive intra-continental

247 rifting and magmatism.

249 Acknowledgments

251 This work was supported by the Ministry of Education and Science of the Russian

252 Federation (project No. 14.B25.31.0032), Scientific Project of the Institute of Geology and

253 Mineralogy SB RAS, Grant-in-Aid for Scientific Research No. 23224012, Global COE program

254 "From the Earth to "Earths" (SM), and JSPS Grant-in-Aid No. 14526 (IS). It is contribution to

255 IGCP#592 Project "Continental construction in Central Asia" under the patronage of UNESCO-

256 IUGS.

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Figure captions

Figure 1. Tectonic outline of Asia (A; modified from Li, 2006; Safonova, 2009) and a scheme of Pacific-type convergent margins (B; modified from Maruyama et al., 2011). The red dashed line and the stars show the main field of the Late Cenozoic intra-plate volcanism in Transbaikalia and Mongolia and its smaller manifestations, respectively (after Kuzmin et al., 2010). Abbreviations for oceans and their related orogenic belts: PPO/PO - Paleo-Pacific/ Pacific; PTO/TO - Paleo-Tethyan/Tethyan; MOO - Mongol-Okhotsk.

Figure 2. Main terranes of south-eastern Japan (modified from Kojima et al., 2000) including the Cretaceous Shimanto accretionary complex, the Jurassic Chichibu accretionary complex and the pre-Jurassic accretionary units of the Sanbagama metamorphic terrane. The frames show areas of probable tectonic erosion. The dashed line shows an approximate position of the section in Fig. 3.

Figure 3. A scheme of tectonic erosion from south-eastern Japan (modified from Nakajima, 1994) showing that coeval accretionary complex and supra-subduction granitoids are typically separated by older accretionary units.

Fig. 4. The model of "big mantle wedge" (Zhao and Ohtani, 2009) related to decarbonatization of subducting slabs in the transition zone (applicable also for stagnant slabs; modified from Litasov et al., 2013a).

Fig. 5. The averaged solidi of the peridotite-H2O (A) and peridotite-CO2 (B) systems. "Wet" solidus is solidus of peridotite with excess water (Iwamori, 2004). "H2O" minerals in is the upper stability limit of dense hydrous magnesium silicates (Litasov, 2011). CP2 is the second critical point in the system MgO-SiO2-H2O (Stalder et al., 2001). Dashed lines show equilibrium water content in melt/supercritical fluid (A), from experimental data (Inoue, 1994; Litasov and Ohtani, 2002) and CO2 and SiO2 contents in carbonatite melt (B) (Litasov et al., 2011; Ghosh et al., 2014). CMASN-CO2 is solidus of the system CaO-MgO-Al2O3-SiO2-Na2O peridotite-CO2 (Litasov and Ohtani, 2009). Solidus of carbonated peridotite was chosen to be the same as for K-bearing carbonatite from (Litasov et al., 2013a). Average mantle adiabat. Shield geotherm and average subduction slab PT-profile are shown after (Litasov, 2011; Litasov et al., 2013b).

Fig. 6. The formation of carbonated diapir (Litasov et al., 2013a,b), see Fig. 4 and text for details. CCO (diamond-CO2) and IW (iron-wustite) are oxygen buffers.

Fig. 7. Accumulated continental crust material in the mantle transition zone under the supercontinent. That material can heat the overlying hydrated and carbonated mantle transition zone to induce the melting and generate volatile-bearing plumes (modified from Senshu et al., 2009).

: Pacific-type convergent margins (subduction ) ^ Precambrian continents Paleo-Asian sutures L* "I Paleo-Tethys sutures

\//A Phanerozoic orogens "1 Paleo-Pacific sutures Tethys sutures

1200 km

CPAB - Circum Pacific accretionary belt

g fore-arc

olistostrorpe mid-oceanic ridge

high-P/T regional metamorphic belt ophiolite

100 km

back-arc basin

T., Terrane M., metamorphic terrane G., Granitoid terrane AC, accretionary complex is., Island

130°E

coeval

Intracontinental

Island arc

«* -9 -9 co2 4

A. Peridotite-HoO

Depth (km) 400 600

to 1400

10 15 20 25 Pressure (GPa)

B. Peridotite-C02

Depth (km) 0 200 400 2200 n

600 J_

10 15 20 Pressure (GPa)

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Triggers and sources of volatile-bearing plumes in the mantle transition zone

Inna Safonova a,b1,1, Konstantin Litasov a,b, Shigenori Maruyama c

a V.S. Sobolev Institute of Geology and Mineralogy SB RAS, Novosibirsk, Russia b Novosibirsk State University, Novosibirsk, Russia c Earth-Life Science Institute, Tokyo Institute of Technology, Tokyo, Japan

- Mantle plumes can be generated in the mantle transition zone (MTZ).

- Those plumes can be triggered by erosion of continental crust and by presence of volatiles in the MTZ.

- Volatile-bearing plumes produced abundant Cenozoic intra-continental volcanic series in Asia.