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根据在阿德朗达克—西魁北克地震带及其邻近地区的59台短周期数字地震仪记录的直达P波走时观测值,用地震层析成像方法反演了该地区地壳三维速度结构.结果表明,地壳上层(0—5km)在阿德朗达克穹隆山的中南部地区出现正速度异常;第二层(5—10km)及第三层(10—15km)的速度横向变化较小,介质相对比较均匀;第四层(15—25km)出现显著的速度异常,一个是位于地震带中部的正速度异常(+4％),它与布格重力正异常一致;另一个是位于阿德朗达克穹隆山下的负速度异常(—4％).结合已有的地质及地球物理资料进行对比,可以认为阿德朗达克是一个正在发展的穹隆上升山,但其热源前锋尚未到达地面的大陆热点.
Based on the observations of direct P-wave travel recorded by 59 short-period digital seismographs in the Adirondack-Québec North seismic zone and its vicinity, the three-dimensional velocity structure of the crust was retrieved using seismic tomography. Results The results show that the upper crust (0-5 km) shows positive anomalies in the south-central Adelaide Dome. The velocity variation of the second layer (5-10 km) and the third layer (10-15 km) The medium is relatively uniform; a significant velocity anomaly occurs in the fourth layer (15-25 km), one is an anomalous positive velocity (+ 4%) located in the middle of the seismic zone, which is consistent with Bouguer gravity anomaly; Negative velocity anomaly under the Rondeck Dome (-4%). In comparison with the available geological and geophysical data, Adirondack can be considered as a growing dome-uphill mountain but its heat source front has not yet reached the ground Mainland hot spots.