各位老師和同學(xué)：
應李元研究員邀請，英國牛津大學(xué)田猛博士訪(fǎng)問(wèn)我所，并將于本周四上午做“同位素室學(xué)術(shù)報告”2018年第26次報告。歡迎大家參加并積極參與討論！

報告題目：俯沖板片脫揮發(fā)分過(guò)程的數值模擬（Modelling Devolatilization of Subducting Slabs）
報 告 人：Dr. Meng Tian (University of Oxford, UK)
報告時(shí)間：7月26日（周四）上午10:00
報告地點(diǎn)：綜合樓701會(huì )議室

報告人簡(jiǎn)介：
田猛博士，2005？2009年于北京大學(xué)獲得地球化學(xué)學(xué)士學(xué)位，2009？2016于耶魯大學(xué)獲得博士學(xué)位，2016至今受英國皇家學(xué)會(huì )牛頓獎學(xué)金資助在牛津大學(xué)地球科學(xué)系做博士后。主要研究興趣為地球動(dòng)力學(xué)，巖石學(xué)中的熱力學(xué)（相圖、擴散）以及相關(guān)的科學(xué)計算。

Abstract：
Compared with other plate-tectonic boundaries, subduction zones (SZ) host the most drastic mechanical, thermal, and chemical changes. The transport of carbon through this complex environment is crucial to mantle carbon budget but remains the subject of active debate. Synthesis of field studies suggests that carbon subducted with the incoming slab is almost completely returned to the surface environment [Kelemen and Manning, 2015], whereas thermodynamic modelling indicates that a significant portion of carbon is retained in the slab and descends into the deep mantle [Gorman et al., 2006]. To address this controversy and quantify the carbon fluxes within SZs, it is necessary to treat the chemistry of fluid/volatile–rock interaction and the mechanics of porous fluid/volatile migration in a consistent modelling framework. This requirement is met by coupling a thermodynamic parameterization of de/revolatilization with a two-phase flow model of subduction zones.
The two-phase system is assumed to comprise three chemical components: rock containing only nonvolatile oxides, H2O and CO2; the fluid phase includes only the latter two. Perple_X is used to map out the binary subsystems rock+H2O and rock+CO2; the results are parameterised in terms of volatile partition coefficients as a function of pressure and temperature. In synthesising the binary subsystems to describe phase equilibria that incorporate all three components, a Margules coefficient is introduced to account for non-ideal mixing of CO2/H2O in the fluid, such that the partition coefficients depend further on bulk composition. This procedure is applied to representative compositions of sediment, MORB, and gabbro for the slab, and peridotite for the mantle. The derived parameterization of each rock type serves as a lightweight thermodynamic module interfaceable with two-phase flow models of SZs. We demonstrate the application of this thermodynamic module through a simple model of carbon flux with a prescribed flow direction through (and out of) the slab. This model allows us to evaluate the effects of flow path and lithology on carbon storage within the slab.