High-resolution aeromagnetic data, a new tool for mapping intrabasinal faults: Example from the Albuquerque basin, New Mexico

High-resolution aeromagnetic surveys flown over the Albuquerque basin, New Mexico, demonstrate that aeromagnetic methods can successfully map concealed and poorly exposed faults in sediment-filled basins. This is the first known use of aeromagnetic data as an aid to surficial mapping and hydrogeologic studies in a basin. Aeromagnetic maps show detailed fault patterns within the basin fill that revise the structural view of the basin. Concealed faults are more numerous and more closely spaced than expected. The Hubbell Springs fault is the central splay of three generally north-striking fault splays that can be traced for nearly 50 km. The splays converge on the north and may represent the southern extension of the Tijeras fault, contradicting the proposed southwest extension of the Tijeras fault across the basin. In profile view, the linear aeromagnetic anomalies associated with faults show a variety of signatures. One signature has potential for mapping fault-controlled sedimentation in the subsurface because it identifies increases in magnetic, likely coarse-grained, material in the hanging walls of faults.