Subalkali and alkali rocks occur in distinct tectonic environments

The claim posits that subalkali and alkali rocks occur in distinct tectonic environments. Papers [0], [1], and [2] provide evidence supporting the traditional view that alkaline and calc-alkaline or subalkaline rocks correspond to distinct settings like intraplate vs. subduction or compressional vs. extensional. However, papers [6] and [9] complicate or contradict this strict mapping by demonstrating that calc-alkaline signatures can arise outside of subduction regimes via fractional crystallization, and that similar alkaline magmas can form across various tectonic settings. Consequently, the balance of evidence points to a contested relationship rather than a strict one-to-one environmental exclusivity.