Non-linear dynamics, chaos, complexity and enclaves in granitoid magmas
Non-linear dynamics, chaos, complexity and enclaves in granitoid magmas
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花岗岩岩浆中的非线性动力学、混沌、复杂性和飞地
DOI：
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发表时间：
1996
影响因子：
1.2
通讯作者：
J. Clemens
中科院分区：
文献类型：
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作者：
J. Flinders;J. Clemens
摘要：大多数自然系统表现为非线性动态行为。岩浆混合和混合过程可能是混乱的，这应该是正确的。最能代表混沌自然系统行为的方程是不可解的，因此建模涉及线性化。假设线性化方程和“真实”方程的解之间的差异很小，因为假设丢弃的项不重要。这可能是非常误导的，因为这些术语的重要性是未知和不可知的。线性化方程通常不能很好地描述自然，也不能预测或回溯大多数自然系统的演化。从二维角度看，两种或两种以上视觉上对比鲜明的流体的混合通过折叠和拉伸产生图案。这增加了界面面积，减少了条纹厚度。这提供了动态岩浆系统中确定性混沌的直观类比，其中包裹体岩浆与宿主岩浆混合和混合。在这里，两个最初相邻的飞地团块可能会被任意地、指数地驱赶到很远的地方，同时在它们的组成上经历独立的（可能是不同的）变化。本文列举了个别长英质岩浆中微花岗岩包体的形态、化学特征和Nd同位素系统的巨大差异，认为这些差异代表了非线性动力学驱动下复杂岩浆系统时间演化的不同阶段。如果这是真的，那么对于解释飞地在花岗质岩浆的形成和演化中所起的作用将产生重大影响。
ABSTRACT: Most natural systems display non-linear dynamic behaviour. This should be true for magma mingling and mixing processes, which may be chaotic. The equations that most nearly represent how a chaotic natural system behaves are insoluble, so modelling involves linearisation. The difference between the solution of the linearised and ‘true’ equation is assumed to be small because the discarded terms are assumed to be unimportant. This may be very misleading because the importance of such terms is both unknown and unknowable. Linearised equations are generally poor descriptors of nature and are incapable of either predicting or retrodicting the evolution of most natural systems. Viewed in two dimensions, the mixing of two or more visually contrasting fluids produces patterns by folding and stretching. This increases the interfacial area and reduces striation thickness. This provides visual analogues of the deterministic chaos within a dynamic magma system, in which an enclave magma is mingling and mixing with a host magma. Here, two initially adjacent enclave blobs may be driven arbitrarily and exponentially far apart, while undergoing independent (and possibly dissimilar) changes in their composition. Examples are given of the wildly different morphologies, chemical characteristics and Nd isotope systematics of microgranitoid enclaves within individual felsic magmas, and it is concluded that these contrasts represent different stages in the temporal evolution of a complex magma system driven by nonlinear dynamics. If this is true, there are major implications for the interpretation of the parts played by enclaves in the genesis and evolution of granitoid magmas.