High Arctic Large Igneous Province
The High Arctic Large Igneous Province (HALIP) is a Cretaceous large igneous province in the Arctic. The region is divided into several smaller magmatic provinces. Svalbard, Franz Josef Land, Sverdrup Basin, Amerasian Basin, and northern Greenland (Peary Land) are some of the larger divisions. Today, HALIP covers an area greater than 1,000,000 km2, making it one of the largest and most intense magmatic complexes on the planet. However, eroded volcanic sediments in sedimentary strata in Svalbard and Franz Josef Land suggest that an extremely large portion of HALIP volcanics have already been eroded away.
The HALIP event lasted from 130 million years ago to approximately 60 million years ago. During its active period, there were two distinct phases of volcanism. The first phase lasted from 130 million years ago to 80 million years ago and was characterized by tholeiitic igneous activity. During this time, numerous dykes and sills formed, and there were eruptions of basaltic flow. The basalts formed at this time are relatively rich in TiO2 and have a similar composition to continental flood basalts. The second phase lasted from approximately 85 million years ago to 60 million years ago and was characterized by mildly alkaline igneous activity and the eruption of flood basalts. The igneous rocks formed during the second phase have a similar geochemical makeup as the intra-plate composition.
The Arctic Ocean is a few hundred million years old, making it the youngest ocean on Earth. In the Precambrian, when the Arctic was located south of the Equator, the continent Arctica (or Arctida) filled the gap between the cratons that today surround the Arctic region. Arctica rifted apart in the Late Precambrian (950 Ma) and was reassembled in a new configuration in the Late Paleozoic (255 Ma).
During the Jurassic-Cretaceous this second continent, known as Pangea, broke apart, opening the Amerasian Basin and the Arctic Ocean. HALIP dispersed the components of this second continent around the margins of the Arctic Ocean where they are now terranes and microplates embedded into fold belts or overlain by sediments. As the Atlantic and Arctic oceans opened during the Mesozoic and into the Cenozoic, the Arctic Region underwent several stages of rifting, sedimentation, and magmatism.
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