The Sichuan Basin magnetic anomaly is the most striking regional aeromagnetic anomaly in South China. It is characterized by a continuous large-scale linear magnetic anomaly and contains long-wavelength constituents which could still be detected on satellites. However, Sichuan Basin is covered by 4 to 10 km thick non-magnetic sedimentary layers from Neoproterozoic to Cenozoic, which conceals the magnetic sources in the Precambrian basement and makes it difficult to explore the geological origin of the Sichuan Basin magnetic anomaly. In this study, we applied 3D inversion to the magnetic data, and then compared our inverted susceptibility model with geological maps. We found that the spatial distribution of the Sichuan Basin magnetic anomaly controls the range of the rigid basement beneath Sichuan Basin and it is surrounded by the widespread Neoproterozoic magmatic complexes. Based on our analysis, we proposed that the geological origin of the Sichuan Basin magnetic anomaly might be related to the craton-scale Neoproterozoic magmatic event, which has played an important role in the stabilization of the basement and the evolution of the deep crust in Sichuan Basin.

中文翻译：

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华南四川盆地磁异常三维反演及其地质意义

四川盆地磁异常是华南地区最显着的区域航磁异常。它的特点是连续的大尺度线性磁异常，并含有仍可在卫星上检测到的长波长成分。然而，四川盆地被新元古代至新生代4～10km厚的非磁性沉积层所覆盖，掩盖了前寒武纪基底的磁源，使得四川盆地磁异常的地质成因难以探索。在这项研究中，我们将 3D 反演应用于磁数据，然后将我们的反演磁化率模型与地质图进行了比较。我们发现四川盆地磁异常的空间分布控制着四川盆地下方刚性基底的范围，并被广泛分布的新元古代岩浆杂岩所包围。根据分析，我们提出四川盆地磁异常的地质成因可能与克拉通尺度的新元古代岩浆事件有关，该岩浆事件对四川盆地基底的稳定和四川深部地壳的演化起到了重要作用。盆地。