Correlation Analysis Method and its Application to Interpretation of Local Gravity and Magnetic Anomalies in Eastern Tianshan, China

Abstract

Based on detailed analysis of Bouguer gravity anomaly and magnetic anomaly by reduced to the pole, this paper uses correlation analysis method to analyze local gravity and magnetic anomalies of different filter scales, including filter scales of 50km, 90km, and 130km, and then discusses the contributing factors of local gravity and magnetic anomalies in eastern Tianshan. The results show that local gravity and magnetic anomalies are cogenetic anomalies in some areas, such as northeastern Santanghu, Shaqiuhe, southern Huangtuya, northern Dikan, and western Qijiaojing, and gravity and magnetic anomalies are allogenic anomalies in other areas. The study reveals that local gravity and magnetic anomalies are chiefly caused by Cenozoic – Mesozoic strata with lower density and weaker magnetism in northern Santanghu, and igneous rock with higher density and stronger magnetism in Shaqiuhe, and uplifting of older strata in northern Dikan, and Carboniferous strata with higher density and lower magnetism than its south and north areas in Qijiaojing. The study also reveals that local negative gravity and magnetic anomalies are chiefly caused by Cenozoic – Mesozoic strata with lower density and weaker magnetism, while local positive gravity and magnetic anomalies are mainly caused by Pre-Jurassic strata higher density and stronger magnetism in southern Huangtuya.