Evolution of the Structural Style of the North Atlantic Basement from the Breakup of the Continent to Modern Rifting according to the Anomalous Gravity Field

The basement structure of the Newfoundland–Iberian segment of the Atlantic–Arctic rift system bounded by the 1st order demarcation faults, within which the demarcation boundary of the 2nd order is distinguished, fundamentally differs to the north and south of it according to the relief and gravity anomalies. The “aspect” attribute calculated from the free air gravity is a morphometric attribute that reflects as plausibly as possible the basement structures beneath the sedimentary cover near the continental margins of the segment and in the Mid-Atlantic Ridge area free of sedimentary cover. Evaluation of methods for calculating the quantitative characteristics of this attribute in test areas with the predominance of typical mutually orthogonal seafloor structural elements showed that the 2D spectra of the analyzed field in the local areas, in addition to the orientation of structures, also demonstrate their amplitude in the initial field and their spatial periodicity, and adequately describe the structural style of the basement in the present-day coordinates, varying from the basin periphery to the mid-ocean ridge. Evolution leads to the formation of basement with a variable geometry, which involves seafoor rotation by ∼10°–15° and deviations due to superimposed atypical structures.