Thulean Plateau
The North Atlantic Igneous Province (NAIP) is a large igneous province in the North Atlantic, centered on Iceland. In the Paleogene, the province formed the Thulean Plateau, a large basaltic lava plain, which extended over at least 1.3×106 km2 in area and 6.6×106 km3 in volume. The plateau was broken up during the opening of the North Atlantic Ocean leaving remnants existing in Northern Ireland, bits of northwestern Scotland, the Faroe Islands, bits of northwestern Iceland, eastern Greenland and western Norway and many of the islands located in the north eastern portion of the North Atlantic Ocean. The igneous province is the origin of the Giant's Causeway and Fingal's Cave. The province is also known as Brito-Arctic province (also known as the North Atlantic Tertiary Volcanic Province) and the portions of the province in the British Isles is also called the British Tertiary Volcanic Province or British Tertiary Igneous Province.
Isotopic dating indicates the most active magmatic phase of the NAIP was between ca. 60.5 and ca. 54.5 Ma (million years ago) (mid-Paleocene to early Eocene) - further divided into Phase 1 (pre-break-up phase) dated to ca. 62-58 Ma and Phase 2 (syn-break-up phase) dated to ca. 56-54 Ma.
Continuing research also indicates that continental plate movement (Eurasian, Greenland, and North American), that regional rifting events, and that seafloor spreading between Labrador and Greenland may have begun as early as ca. 95-80 Ma, ca. 81 Ma, and ca. 63-61 Ma respectively (late Cretaceous to early Paleocene).
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