The Mongolia-Baikal region, located between the Siberia, North China, and Tarim cratons, exhibits the most pronounced lithospheric accretion and extension since the Phanerozoic. Despite its distance from plate boundaries, the region's notable tectonic activity underscores its importance for studying intraplate lithospheric deformation. However, its lithospheric thermal structure, particularly at high resolution, remains inadequately characterized. By integrating magnetic anomaly constraints with heat flow measurements, we have obtained a high-resolution lithospheric thermal structure for the Mongolia-Baikal region, revealing lithospheric thicknesses ranging from 60 to 180 km. The Curie depth and mantle heat flow also show diverse variations across different regions. Our results suggest that elevated mantle heat flow in the Baikal Rift Zone, coupled with a uniform Curie depth and minimal lithospheric thinning, likely reflects lithospheric weakening from mantle upwelling, facilitating rifting in the early stages of the rift's formation. Additionally, some localized lithospheric thermal variations identified in our results may be closely linked to the formation of the Hangai Plateau and the low magnetic anomalies observed in the Mongolia-Okhotsk suture.

中文翻译：

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蒙古-贝加尔湖地区的居里表面和岩石圈热结构


蒙古-贝加尔湖地区位于西伯利亚、华北和塔里木克拉通之间，是自显生代以来最明显的岩石圈吸积和延伸。尽管远离板块边界，但该地区显着的构造活动强调了它对研究板块内岩石圈变形的重要性。然而，它的岩石圈热结构，特别是在高分辨率下，仍然没有得到充分的表征。通过将磁异常约束与热流测量相结合，我们获得了蒙古-贝加尔湖地区的高分辨率岩石圈热结构，揭示了 60 至 180 公里的岩石圈厚度。居里深和地幔热流在不同地区也表现出不同的变化。我们的结果表明，贝加尔湖裂谷带中地幔热流的增加，加上均匀的居里深度和最小的岩石圈变薄，可能反映了地幔上升流引起的岩石圈减弱，促进了裂谷形成早期阶段的裂谷。此外，在我们的结果中发现的一些局部岩石圈热变化可能与杭爱高原的形成和在蒙古-鄂霍次克缝合线中观察到的低磁异常密切相关。