The paper by Amato et al. (2015) contains some new and interesting data on the geology of the South Anyui suture (SAS), a key element for understanding the tectonic evolution of northeast Asia, the eastern Arctic, and the Amerasian Basin. The SAS remains understudied and new U-Pb dating of detrital and magmatic zircons and geochemical and petrographic studies will be welcome by all geologists interested in Arctic geology. Unfortunately, there are significant inaccuracies in the Amato et al. (2015) presentation of the local geology; this results in erroneous geological interpretations and has major consequences for their tectonic model. In addition, Amato et al. (2015) neglected to consider alternative hypotheses related to the closure of the SAS and subduction zone polarity. These points are discussed in more detail herein.

The most recent geological maps covering the study area include the central part of the SAS, adjoining parts of Chukotka and the Alazeya-Oloy zone (sheets Q-58-XI, Q-58-XII, Q-58-XVII, and Q-58-XVIII, scale 1:200,000; ­Shekhovtsov and Glotov, 2000, 2001). These maps are significantly different from the older maps on which Amato et al. (2015, their figs. 3–5) based their geological sampling and tectonic interpretations. This has resulted in the following misinterpretations.