Abstract Cataclasis is a first-order mechanism shaping fault-rock development in the brittle crust. The most accepted model for cataclasis is “constrained comminution” which predicts a power-law distribution of particle size described by the fractal dimension, D. In this paper, we statistically test for the presence of power-law scaling in 61 naturally and experimentally deformed fault rocks, thereby assessing the validity of the constrained comminution model. We find that no data set exhibits compelling evidence for power-law scaling, even when a lower threshold is applied to promote the appearance of power-law scaling. Log-normal distributions provide better fits to statistically conclusive test cases, both when using a lower threshold (91% of cases) and when examining the full data sets. Thus, our results are not consistent with constrained comminution. We propose that log-normal distributions provide a more useful description of fault-rock particle-size distributions and discuss the implications for the mechanisms of cataclasis.

中文翻译：

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去D还是不去D？重新评估天然和实验断层岩中的粒度分布

摘要 碎裂作用是脆性地壳断层岩发育的一级机制。最广为接受的 cataclasis 模型是“约束粉碎”，它预测由分形维数 D 描述的粒度的幂律分布。在本文中，我们统计测试了 61 个自然和实验变形的幂律缩放的存在断层岩，从而评估约束粉碎模型的有效性。我们发现没有数据集显示出幂律缩放的令人信服的证据，即使应用较低的阈值来促进幂律缩放的出现也是如此。在使用较低阈值（91% 的案例）和检查完整数据集时，对数正态分布可以更好地拟合统计上确凿的测试案例。因此，我们的结果与约束粉碎不一致。我们建议对数正态分布提供了对断层岩粒度分布的更有用的描述，并讨论了对碎裂机制的影响。