Interpretation of high resolution aeromagnetic data for structures study and exploration of polymetallic deposits in Kalatage area, eastern Tianshan (NW China)

Abstract

A high resolution aeromagnetic survey of Kalatage area was carried out, aimed at providing detailed geological structures information and guiding for further mineral prospecting. The recently acquired data was processed and interpreted to better understand the mode of occurrence of the Cu-Au polymetallic deposits and associated structural features. Several analysis techniques, such as reduction to the pole, spectral analysis, low-pass filtering, were applied to process the aeromagnetic data to understand the distribution of magnetic sources. The depth of magnetic sources was estimated by spectral analysis, and the shallower and deeper sources anomalies were analyzed. The Euler deconvolution, total horizontal derivative, tilt angle derivative and theta map were used to study lineament structures. The new structural scheme was established by comparison of above derivative results and geological data of the Kalatage area. The results show that the study area is affected by sets of NWW-SEE/NW-SE, NNE-SSW/NE-SW and nearly E-W directions faults structures; various probable magmatic rocks may be the results of the ascent and intrusion of magma along these regional fractures in the process of large-scale and deep tectonic-magmatic activities. The polymetallic ore deposits are mainly distributed within the eastern portion of the study area and are confined probably along structure lineament suggesting that it is structurally controlled. Furthermore, the favorable area for mineralization was proposed. These analyses help the recognition of structure features of differing magnetizations, interpretation of tectonic evolution, which could have important reference for further mineral prospecting.