Dynamic Two‐Phase Flow Modeling of Melt Segregation in Continental Crust: Batholith Emplacement Versus Crustal Convection, With Implications for Magmatism in Thickened Plateaus
نویسندگان
چکیده
Magmatic processes in the continental crust such as crustal convection, melt ascent, magma emplacement, and batholith formation are not well understood. We solve conservation equations for mass, momentum, energy two-phase flow of solid 2D, a thick heated from below by one or several heat pulses. A simplified binary melting model is incorporated. systematically vary (a) retention number, characterizing mobility, (b) intensity pulses applied at bottom, (c) density solidified evolved rock. Two characteristic modes identified: “batholith emplacement mode,” segregation sufficiently strong allowing melts to separate convective flow. This freezes form buoyant SiO2-rich layers. In “convective recycling formed lower crust, rise together with hot rock little segregation, freeze shallow depth but partly recycled back where they remelt. Phase-change-driven convection dominates. Mode favored high input, multiple pulses, low less intense heating, denser rocks. scaling law derived based on thermal, melt, compositional Rayleigh numbers number. The Altiplano-Puna low-velocity zone (LVZ) could represent mode voluminous magmas causing volcanism. Tibetan LVZ associated volcanism might mode.
منابع مشابه
Simulations of crustal anatexis: Implications for the growth and differentiation of continental crust
There is overwhelming and incontrovertible petrological and geophysical evidence for the significant role played by mantle-derived mafic magma in the generation and growth of continental crust. Likewise, intrusion of mafic magmas beneath or into continental crust is very likely the major source of enthalpy that drives intracrustal differentiation. A simple dynamical model has been constructed t...
متن کاملFormation of new continental crust in Western British Columbia during transpression and transtension
Crustal growth in the Coast Mountains, along the leading edge of the Canadian Cordillera, was the result of processes associated with horizontal flow of material during transpression and subsequent transtension, and the vertical accretion of mantle derived melts. From 85 to 58 Ma, as exotic terranes were translated northward during transpression, the crust was thickened to about 55 km, and melt...
متن کاملMelt segregation mechanism controls on the geochemistry of crustal melts
Crustally-derived granites may be generated in a variety of tectonic settings, but whatever the ultimate causse of heating crustal thickening, crustal extension, enhanced heat flux from the mantle, or magmatic advection by mantle-derived melts crustal melting likely occurs in a dynamic environment. Under these conditions deviatoric stress acting on an anisotropic crustal source region will lead...
متن کاملLarge Igneous Provinces: Crustal Structure, Dimensions, and External Consequences
Large igneous provinces (LIPs) are a continuum of voluminous iron and magnesium rich rock emplacements which include continental flood basalts and associated intrusive rocks, volcanic passive margins, oceanic plateaus, submarine ridges, seamount groups, and ocean basin flood basalts. Such provinces do not originate at "normal" seafloor spreading centers. We compile all known in situ LIPs younge...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Geochemistry Geophysics Geosystems
سال: 2023
ISSN: ['1525-2027']
DOI: https://doi.org/10.1029/2023gc010860