The elemental composition of a sediment is set by the composition of its protolith and modified by weathering, sorting, and diagenesis. An important problem is deconvolving these contributions to a sediment's composition to arrive at information about processes that operate on the Earth's surface. We approach this problem by developing a predictive and invertible model of sedimentary major‐element composition. We compile a dataset of sedimentary rock, river sediment, soil, and igneous rock compositions. Principal component analysis of the dataset shows that most variation can be simplified to a small number of variables. We thus show that any sediment's composition can be described with just two vectors of igneous evolution and weathering. We hence define a model for sedimentary composition as a combination of these processes. A 1:1 correspondence is observed between predictions and independent data. The log‐ratios ln(K₂O/M_gO) and ln(Al₂O3/Na₂O) are found to be simple proxies for, respectively, the model's protolith and weathering indices. Significant deviations from the model can be explained by sodium‐calcium exchange. Using this approach, we show that the major‐element composition of the upper continental crust has been modified by weathering and we calculate the amount of each element that it must have lost to modify it to its present composition. By extrapolating modern weathering rates over the age of the crust we conclude that it has not retained a significant amount of the necessarily produced weathering restite. This restite has likely been subducted into the mantle, indicating a crust‐to‐mantle recycling rate of 1.33 ± 0.89×10¹³ kg yr^‐1.

中文翻译：

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就风化和物源而言，沉积物中的主要元素组成：对地壳再循环的影响

沉积物的元素组成由其原石的组成决定，并通过风化，分选和成岩作用进行修改。一个重要的问题是将这些对沉积物组成的贡献进行反卷积，以获得有关在地球表面运行的过程的信息。我们通过建立沉积性主要元素组成的预测和可逆模型来解决这个问题。我们汇编了沉积岩，河流沉积物，土壤和火成岩成分的数据集。数据集的主成分分析表明，大多数变化都可以简化为少量变量。因此，我们表明，仅用火成演化和风化的两个向量就可以描述任何沉积物的成分。因此，我们将这些过程的组合定义为沉积物组成模型。A 1：在预测和独立数据之间观察到1对应关系。对数比ln（K_发现2 O / M _g O）和ln（Al ₂ O3 / Na ₂ O）分别是该模型的原石和风化指数的简单代理。钠钙交换可以解释模型的显着偏差。使用这种方法，我们证明了上陆壳的主要元素组成已被风化改变，并且我们计算了将其修改为当前组成所必须损失的每个元素的数量。通过推断地壳年龄的现代风化率，我们得出结论，它没有保留大量必不可少的风化辉石。该残余物可能已被俯冲到地幔中，表明地壳对地幔的回收率为1.33±0.89×10 ¹³千克yr ^-1。