Abstract A high-resolution 3-D P-wave velocity model of the upper mantle beneath the Western Junggar is determined by inverting a large number of relative travel-time residuals of teleseismic events. Our results reveal a prominent high-velocity (high-V) anomaly beneath the western Junggar basin and a low-velocity (low-V) anomaly beneath the Darbut belt. The NE-SW striking high-V anomaly at depths of 50–200 km beneath the western Junggar basin dips toward the northwest, which represents a fossil oceanic slab. The low-V anomaly may reflect an intraoceanic arc-related terrain that has experienced strong metasomatism by hot upwelling asthenosphere in the late Paleozoic, resulting in adakitic intrusions and concentration of porphyry Cu Au deposits in the Darbut belt. These results shed new light on the geodynamic evolution of the Western Junggar and formation mechanisms of the adakites and porphyry Cu Au deposits.

中文翻译：

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西准噶尔上地幔层析成像：对其地球动力学演化的启示

摘要 通过反演大量远震事件的相对走时残差，确定了西准噶尔下地幔上地幔的高分辨率3-D P波速度模型。我们的结果揭示了在准噶尔盆地西部下方的一个突出的高速 (high-V) 异常和 Darbut 带下方的一个低速 (low-V) 异常。准噶尔盆地西部 50-200 公里深处的 NE-SW 显着的高 V 异常向西北倾斜，代表一个化石大洋板块。低V异常可能反映了晚古生代热上升流软流圈经历强烈交代作用的洋内弧形相关地形，导致埃达克岩侵入和斑岩铜金沉积在达布特带。