Abstract <p>The structure of the northwestern part King’s Trough and the Gnitsevich Plateau is explored, based on the data obtained during the 57th expedition of the R/V <i>Akademik Nikolai Strakhov</i>. These structures form a mesostructural cluster located on the eastern flank of the Mid-Atlantic Ridge in the North Atlantic. Bathymetric and hydromagnetic surveys, seismoacoustic profiling, and bottom sampling by dredging were carried out. It has been established that this part of the trough consists of six deep parts of different depths. These subparallel deeps continue each other along a strike and are separated by median ridges and ledges. The flanks of the trough are formed by volcanic plateaus, which are built up by multi-dimensional cone-shaped volcanic edifices. At the same time, the southern and northern flanks are complementary to each other both in depth and in morphology, and merge into a single plateau in the area of the northwestern closure of the trough. An area of volcanic edifices of various sizes and morphology was formed around the King’s Trough: cone-shaped structures, calderas, and the Gnitsevich Plateau, which involves several seamounts on the common basement. It is shown that the anomalous magnetic field of the study area is a superposition of linear and isometric anomalies; the latter is associated with large volcanic seamounts. Linear anomalies C6n and younger are located to the northwest of the King’s Trough and are not interrupted, and linear anomalies between the C6n and C13n chrons are found only on the trough flanks, whereas they are absent in the area of deeps. The recovered rock material can be divided into two main associations: spreading (nonporous basalt, dolerite, gabbro, mylonite) and intraplate (porous volcanics close to basalts). The rocks of the first of them form the sides of deeps and median ridges, those of the second form plateaus and volcanic edifices. Limestones, breccias, and Fe–Mn crusts are found in both associations. Seismoacoustic studies, along with seismic facies, previously established in the upper part of the King’s Trough sedimentary cover, have revealed channel drifts formed by the deposition of clastic material transported by near-bottom (contourite) currents. Preliminary conclusions about the origin of the mesostructural cluster of King’s Trough and the Gnitsevich Plateau are as follows: the formation of the King’s Trough was preceded by the formation of a northwest-striking arched rise, which became the scene of intense intraplate volcanism. The arch rise was formed as a result of uplift of the oceanic crust formed in the axial zone of the Mid-Atlantic Ridge The near-axial part of the volcanic plateau subsided between 33.2 and 18.75 Ma as a result of northeast–southwestward tension of the ocean floor along two subparallel fractures that expanded up to intra-trough deeps. This volcanism also intensified magmatism in the nearest parts of the axial part of the Mid-Atlantic Ridge up to the appearance of the large volcanic edifices that formed the Gnitsevich Plateau.</p>