资源环境科技发展态势分析平台

The origin and history of the Amerasia basin are long-running debates, which hinder our knowledge of the Mesozoic tectonic configurations and geodynamic processes in the Arctic. This lack of knowledge is due in part to the paucity of accurate magnetic data in the ice-covered basin. Here, we identify the crustal age of the Canada Basin, a major part of the Amerasia Basin, through high-resolution deep-tow and sea-surface magnetic data. The best fit of the four pairs of magnetic lineations revealed by the high-resolution magnetic data is 139.5-128.6 Ma (or 142.4-132.8 Ma, depending on the geomagnetic polarity timescale). The crustal age provides crucial constraints on the evolution of the circum-Arctic tectonic features and generally supports the hypothesis that the opening of the Amerasia Basin is related to the subductions during the closure of the South Anyui Ocean.