Lithospheric discontinuities in Central Australia
Lithospheric discontinuities in Central Australia
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DOI：
10.1016/j.tecto.2018.06.008
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发表时间：
2018-10
期刊：
影响因子：
2.9
通讯作者：
B. Kennett;C. Sippl
中科院分区：
文献类型：
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作者：
B. Kennett;C. Sippl
岩石圈不连续性难以捉摸，其特性与频率密切相关。沿澳大利亚中部南北横断面临时部署宽带站以及永久阵列 ASAR 和 WRA 的结果用于评估岩石圈特征的空间相干性，特别是岩石圈中部不连续性。我们利用叠加的台站自相关图来估计台站下方的 P 波反射率，并采用利用远震波到达的成像方法。我们使用 Ps 接收器函数的公共转换点 (CCP) 叠加和使用 P 波列自相关的反射点成像。结果与莫霍面吻合良好，并且与更深层次具有良好的一般对应关系。尽管反射率频率变化导致岩石圈中部不连续性的迹象出现在相似的深度，但高频（约 2Hz）特定特征的空间连续性约为 10-15km。可以在整个剖面上追踪更广泛的趋势，但无法绘制出强烈的岩石圈界面，除了剖面南部穿过岩石圈的南倾特征（可能是前地幔脱离区）。
Lithospheric discontinuities are elusive, with properties that are strongly frequency dependent. Results from a temporary deployment of broadband stations along a north-south transect through Central Australia, and the permanent arrays ASAR and WRA, are used to evaluate the spatial coherence of lithospheric features, particularly mid-lithospheric discontinuities. We exploit stacked station autocorrelograms that provide an estimate ofP-wave reflectivity beneath stations, with imaging methods exploiting teleseismic arrivals. We use both common conversion point (CCP) stacking fromPsreceiver functions and reflection point imaging using the autocorrelation of thePwavetrain. The results tie well for the Moho and have a good general correspondence for deeper levels. Although indications of mid-lithospheric discontinuities from changes in the frequency of reflectivity occur at similar depths, the spatial continuity of specific features at high frequency (around 2 Hz) is of the order of 10–15 km. Broader trends can be tracked across the profile, but no strong lithospheric interfaces can be mapped, except for a south dipping feature traversing the lithosphere on the southern part of the profile that is likely to be a former mantle detachment zone.