Seismic volcano-stratigraphic characteristics and igneous province assessment of the Jan Mayen microcontinent, central NE-Atlantic

We present the kinematic evolution of the Jan Mayen microcontinent (JMMC) and the its subdivision of igneous provinces affected by the Cenozoic rift systems in association with the formation of the JMMC, based on detailed seismic stratigraphic mapping, interpretation of available geophysical data, supplemented by new geochemical analyses and radiometric dating of basalt sections from DSDP Leg 38 sites 350 and 348 cores. The Cenozoic evolution of the JMMC and surrounding areas is characterized by six main phases, corresponding to several major igneous units, unconformities and related structures observed across the microcontinent, the central East Greenland margin, and the Iceland-Faroe Ridge area. Important events include the emplacement of Early Eocene plateau basalts across the N-Atlantic region during pre-break-up time (56 - 55 Ma), the forming of seaward dipping reflectors and a distinct volcanic margin with landward lava flows along the east and southeast flanks of the JMMC, and the initiation of seafloor spreading in the Norway Basin along the Ægir Ridge (C24n2r, 53.36 Ma). The initiation of the Iceland Plateau during Early Eocene (C22n, 49.3 Ma), represented by sill and dyke intrusives along the eastern and southeastern flanks of JMMC. A change from quasi-symmetric to asymmetric seafloor spreading along the Ægir Ridge occurred during mid-Eocene (C21n-r, 47-44 Ma), accompanied by variable crustal accretion along the Ægir rift system and initiation of rfting west of the JMMC. The oblique rift system caused uplift with intrusive activity along the southern flank of the JMMC. Simultaneous igneous activity is recorded along the northeastern margin of the Blosseville Kyst in Greenland. Extensive lava flows and flank intrusions accompanied a ridge relocation west of the Ægir Ridge during Late Eocene to Early Oligocene (C13n, 33.1 Ma). Increased volcanism occurred along the southwestern flank of JMMC during its final separation from Greenland in early Miocene (C6b, 22.2-21.7 Ma) and the northward propagation of the fully established Kolbeinsey Ridge after seafloor spreading cessation in the Norway Basin around 22 Ma.