As rock-derived primary minerals weather to form soil, they create reactive, poorly crystalline minerals that bind and store organic carbon. By implication, the abundance of primary minerals in soil might influence the abundance of poorly crystalline minerals, and hence soil organic carbon storage. However, the link between primary mineral weathering, poorly crystalline minerals, and soil carbon has not been fully tested, particularly at large spatial scales. To close this knowledge gap, we designed a model that links primary mineral weathering rates to the geographic distribution of poorly crystalline minerals across the USA, and then used this model to evaluate the effect of rock weathering on soil organic carbon. We found that poorly crystalline minerals are most abundant and most strongly correlated with organic carbon in geographically limited zones that sustain enhanced weathering rates, where humid climate and abundant primary minerals co-occur. This finding confirms that rock weathering alters soil mineralogy to enhance soil organic carbon storage at continental scales, but also indicates that the influence of active weathering on soil carbon storage is limited by low weathering rates across vast areas.

随着岩石衍生的主要矿物质风化形成土壤，它们会产生反应性、结晶性差的矿物质，这些矿物质可以结合和储存有机碳。这意味着，土壤中原生矿物质的丰度可能会影响结晶性较差的矿物质的丰度，从而影响土壤有机碳的储存。然而，主要矿物风化、结晶性差的矿物和土壤碳之间的联系尚未得到充分测试，特别是在大空间尺度上。为弥补这一知识差距，我们设计了一个模型，将主要矿物风化率与美国各地低结晶矿物的地理分布联系起来，然后使用该模型评估岩石风化对土壤有机碳的影响。我们发现，在维持较高风化率的地理有限区域中，结晶较差的矿物最丰富，并且与有机碳的相关性最强，这些区域的潮湿气候和丰富的原生矿物共存。这一发现证实了岩石风化改变了土壤矿物学以增强大陆尺度的土壤有机碳储存，但也表明活跃风化对土壤碳储存的影响受到广大地区低风化率的限制。