不同岩浆作用过程的定量模型及鉴别

不同的岩浆作用过程,对岩浆的成岩成矿作用具有决定性的影响。本文给出了不同岩浆作用过程的几种定量模型(批武熔融模型、分馏熔融模型、平衡结晶模型、分馏结晶模型及岩浆混合模型)和鉴别方法。相对于前人给出的模型而言,这些模型具有两个明显的优点:(1)不管上述不同岩浆作用的物理机制区别多大,在作者选定的坐标系中都表现为直线关系。(2)对不同岩浆过程的鉴别,不必事先知道岩浆中固、液两相的比例、固相中各矿物相的含量以及元素的初始浓度和总分配系数等一些难以确定的参数。此外,本文还提出了一种计算元素初始比值的新方法,并给出了不同岩浆作用过程鉴别的实例。

QUANTITATIVE MODELS OF DIFFERENT MAGMATIC PROCESSES AND THEIR QUANTITATIVE IDENTIFICATION APPROACH

Different magmatic processes have different influence on the magmapetrogenesis and related minera1ization. A new approach has been made toquantitatively identifyin\g different magmatic processes. The authors havegiven the new quantitative models of different magmatic processes, includingbatch melting, fractiona1 melting, equilibrium crystallization, fractionalcrystallization and magma mixing, and identification methods of theseProcesses. The present new models given by the authors have evidentadvantages over the previous ones as follows: (1) All the models arelinear in our specially selected coordinate systems despite of how differentthe physical mechanisms of these magmatic processes are. (2) Differentmagmatic processes could be easily identified without knowing the unknownparameters, which are difficult or even impossible to determine, such asthe initial concentrations of trace elements, the total distribution coeffi-cients, the proportion of the solid phase to the liguid phase in magma, the relative contents of minerals in the solid phase. In addition, a new methodto calcu1ate the initial ratios between the concentrations of any two traceelements has been proposed and some typica1 examp1es about the applicationof these new models to solving some debating geological problems concernedhave been discussed.