Preliminary geological interpretation of long-wavelength magnetic anomalies over China and surrounding regions

Long-wavelength (>500 km) magnetic anomaly originated from lithosphere were found by satellite magnetic surveys. Compared to the striking magnetic anomalies around the world, the long-wavelength magnetic anomalies in China and surrounding regions are relatively weaker, and specialized research on a certain anomaly is quite inadequate, resulting in unclear geological origins of these anomalies and hindering their further tectonic applications. In this region, there are six magnetic high anomalies over the (1) Tarim Basin, (2) Sichuan Basin (3) Great Xing’an Range, (4) Barmer Basin, (5) Central Myanmar Basin and (6) Sunda and Banda Arcs, and a striking magnetic low anomaly along the southern part of the Himalayan-Tibetan Plateau. We analyzed their geological origins based on review of related research and detailed comparison with geological results. The tectonic backgrounds for these anomalies are belong to two cases: ancient basin basement or subduction-collision zone. For large-scale regional magnetic anomalies, their geological origins are always dispute mainly because of limited exposure of sources, later tectonic destruction and multi-phase events superposition.