Collaborative Research: Energy-Constrained Geochemical Models for Open System Magma Bodies with Anatexis, Replenishment, Magma Mixing and Fractional Crystallization

SperaEAR-0073932现有的模拟开放系统岩浆体的地球化学演化的工具受到几个限制，其中最关键的是缺乏对能量守恒的考虑，也没有包括围岩部分熔融的后果。将开发一种新的工具，称为能量受限的补给同化分数结晶(EC-RAFC)，用于模拟岩浆体-围岩系统的地球化学演化。将开发一个用户友好的EC-RAFC计算机代码，用Visual Basic编写，其中能量、质量和物种在岩浆经历分离结晶、岩浆补充和部分熔融围岩的同化过程中守恒。输入参数包括岩浆体、围岩和补给岩浆的热和化学特征。EC-RAFC模型将结合熔体生产力函数Fa(Ta)和Fm(Tm)的信息，将相平衡和热化学约束结合起来，用于用户定义的初始岩浆、围岩和补给岩浆的成分。EC-RAFC计算机编码还将允许在EC-RAFC岩浆体内开发和维护成分不同的熔体储集层，从而使EC-RAFC能够应用于分区的火成岩。该项目的一个关键组成部分是开发代码功能，该功能可以对小于1的熔体提取效率进行建模，从而可以将质量和能量添加分离。将EC-RAFC模拟器应用于跨越各种地质环境的一些有充分记录的岩浆系统，将允许探索特定构造-岩浆环境(例如，MOR、大陆弧)的岩浆体中存在的分离结晶、补给和同化的相对作用中存在的潜在系统学。这项研究有可能影响大量地球科学家的工作，他们从现存和古老的岩浆系统中产生和解释地球化学、地质年代学、岩石学和岩石学数据，并将与描述岩浆系统的地球化学数据的数量和质量的显著改善相平行。

SperaEAR-0073932Existing tools that model the geochemical evolution of open-system magma bodies suffer from several limitations, the most critical of which are lack of accounting of energy-conservation and lack of inclusion of the consequences of wallrock partial melting. A new tool will be developed, called Energy-Constrained Recharge Assimilation Fractional Crystallization (EC-RAFC), that models the geochemical evolution of a magma body-wallrock system. A user-friendly EC-RAFC computer code, written in Visual Basic, will be developed in which energy, mass and species are conserved as magma undergoes, fractional crystallization, magma recharge, and assimilation of partially melted wallrock. Input parameters include thermal and chemical characteristics of the magma body, wallrock, and replenishment magma. The EC-RAFC model will couple phase equilibria and thermochemical constraints by incorporating information from melt productivity functions fa (Ta) and fm(Tm) for user-defined compositions of initial magma, wallrock and replenishment magma. The EC-RAFC computer code will also allow for the development and maintenance of compositionally distinct melt reservoirs within an EC-RAFC magma body, thus enabling application of EC-RAFC to zoned ignimbrites. A critical component of this project is development of code capability that can model melt extraction efficiency that is less than unity so that mass and energy addition can be decoupled. Application of the EC-RAFC simulator to a number of well-documented magmatic systems spanning a range of geologic environments will allow exploration of the potential systematics that exist in the relative roles of fractional crystallization, recharge and assimilation in magma bodies from particular tectonic-magmatic settings (e.g., MOR, continental arcs). This research has the potential to impact the work of the large number of geoscientists who generate and interpret geochemical, geochronological, petrographic and petrologic data from extant and ancient magmatic systems and will parallel the dramatic improvement in the amount and quality of geochemical data describing magmatic systems.