Lucky box model for mantle evolution

I have developed a model to simulate variable degrees of mantle melting since 4.4 Ga. The present model explicitly tracks variable degrees of melt depletion and refertilization in more than 26,000 parcels representing the chemically diverse peridotitic mantle. We assume uniform primitive mantle 4.55 billion years ago and simplify the effect of mantle convection by setting a remelting interval and allowing a proportion of newly produced oceanic residual parcels to subduct into lower mantle. In exchange for down-going mass, the same amount of parcels from the lower mantle enters the upper mantle. The code is compatible with Python 3.12.0 (1) Run batch_parallel.py to simulates mantle evolution. The two important model parameters are: 'phase_1_rate_relative_values': [1], # the rate of global melting in the first stage relative to present day 'oceanic_deep_subduction_p_values': [0.2], # the likelihood of subducting oceanic mantle to lower mantle The default model considers slow diffusion of HFSE. If you want to choose equilibrium melting, change HFSE_DK to 0 in mantle_geochem_constants.py (2) Run batch_plot.py to plot results of trace elements and Nd-Hf isotope ratios.本研究构建了一款可模拟自44亿年（Ga）以来地幔熔融不同程度的模型。当前模型可显式追踪超过26000个代表化学组成多样的橄榄岩质地幔（peridotitic mantle）块体的熔体亏损与再富集过程的变化程度。本模型假设45.5亿年前的原始地幔（primitive mantle）组分均一，通过设定重熔间隔并允许部分新生成的洋壳残余地幔块体俯冲进下地幔（lower mantle），以简化地幔对流（mantle convection）的影响；作为俯冲物质的补偿，等量的下地幔块体将进入上地幔（upper mantle）。 本代码兼容Python 3.12.0版本。 (1) 运行batch_parallel.py以模拟地幔演化过程。 模型的两个核心参数如下： 'phase_1_rate_relative_values': [1], # 第一阶段全球熔融速率相对于现今的比值 'oceanic_deep_subduction_p_values': [0.2], # 洋壳残余地幔俯冲进下地幔的概率 默认模型采用高场强元素（High Field Strength Elements，HFSE）的缓慢扩散模式；若需选择平衡熔融模式，请在mantle_geochem_constants.py文件中将HFSE_DK设置为0。 (2) 运行batch_plot.py以绘制微量元素与Nd-Hf同位素比值的结果图。