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Abstract

Combine with the ground, aeromagnetic and low altitude CHAMP satellite measurments (~300km), the lithospheric field of Xinjiang and Tibet of China is investigated through the three-dimensional Surface Spline (3DSS) model, regional Spherical Harmonic Analysis (RSHA) model and CHAOS-7.11, then compared our result with original data, NGDC720, LCS-1 models and the newest SHA model with degree 1000 (SHA1000). Moreover, the error estimation and the geological analysis have been carried out, and we analyze the possible correspondence between the lithospheric field and the surface heat flow. Results show that the 3DSS model can better describe the detailed distribution of lithospheric field after comparing it with other models. Some new features are reflected, particularly in the Southern Xinjiang and Tibet areas, such as a positive anomaly stripe in the southwest bordering the Tashkurgan-Hotan-Cele-Minfeng-Qiemo-Ruoqiang belt and the middle edge of the Kunlun Mountains. The strip, in terms of rock composition, has a shallow magnetic field source and is related to magnetic intrusions; the lithospheric field in Tibet is weak. Additionally, when the distribution of heat flow was compared to the results, two heat flow anomalies were found that were caused by magnetic fields with opposite signs. Large heat flow values may be related to the shallow Curie surface, which shows that demagnetization is happening close to the surface, but more Ferromagnetic mineral, Titanium magnetite, is found there.