Seismic Volcanostratigraphy: The Key to Resolving the Jan Mayen Microcontinent and Iceland Plateau Rift Evolution

Abstract

Volcanostratigraphic and igneous province mapping of the Jan Mayen microcontinent (JMMC) and Iceland Plateau Rift (IPR) region have provided new insight into the development of rift systems during breakup processes. The microcontinent's formation involved two breakup events associated with seven distinct tectono-magmatic phases (∼63-21 Ma), resulting in a fan-shaped JMMC-IPR igneous domain. Primary structural trends and anomalous magmatic activity guided initial opening (∼63-56 Ma) along a SE-NW trend from the European margin and along a WNW-ESE trend from East Greenland. The eastern margin of the microcontinent formed during the first breakup (∼55-53 Ma), with voluminous subaerial volcanism and emplacement of multiple sets of SSW-NNE-aligned seaward-dipping reflector sequences. The more gradual, second breakup (∼52-23 Ma) consisted of four northwestward migrating IPR (I-IV) rift zones along the microcontinent's southern and western margins. IPR I and II (∼52-36 Ma) migrated obliquely into East Greenland, interlinked via segments of the Iceland-Faroe Fracture Zone, in overlapping sub-aerial and sub-surface igneous formations. IPR III and IV (∼35-23 Ma) formed a wide igneous domain south and west of the microcontinent, accompanied by uplift, regional tilting, and erosion as the area moved closer to the Iceland hotspot. The proto-Kolbeinsey Ridge formed at ∼22-21 Ma and connected to the Reykjanes Ridge via the Northwest Iceland Rift Zone, near the center of the hotspot. Eastward rift transfers, toward the proto-Iceland hotspot, commenced at ∼15 Ma, marking the initiation of segmented rift zones comparable to present-day Iceland.

Petrography of Pyrobitumens in Middle – Late Jurassic Sandstones From Thermally Degraded Hydrocarbon Accumulations, East Greenland

“…1) which led to gradual northward separation at ca. 33-21 Ma (Blischke et al, 2022). This magmatic phase is therefore limited to central East Greenland and the JMM, and was not experienced on the northwest European margin or northeastern Greenland.…”

Crustal and Thermal Heterogeneities Across the Fram Strait and the Svalbard Margin

“…After the extinction of the Mid‐Labrador Ridge (Labrador Basin Bay) in the Early Oligocene (33.7 Ma, C13) (Oakey & Chalmers, 2012; Roest & Srivastava, 1989; Srivastava & Roest, 1999; Suckro et al., 2013), the relative motion between Norway and Greenland changed from NNW‐SSE to WNW‐ESE (31–28 Ma, C12‐10) (Gaina et al., 2017). From this reorganization, the ultraslow spreading Ægir Ridge became extinct after C10, causing the development of the Kolbeinsey Ridge and the detachment of Jan Mayen Microplate Complex from Greenland at ∼24 Ma (C7‐6) (Blischke et al., 2017, 2022; Gernigon et al., 2015, 2019; Schiffer et al., 2019). To the north, the Knipovich Ridge initiated at c. 20 Ma (C6) (Dumais, Gernigon, et al., 2020).…”