Building and breaking a large igneous province: An example from the High Arctic

Abstract

The genesis of the Amerasia Basin in the Arctic Ocean has been difficult to discern due to overprint of the Cretaceous High‐Arctic Large Igneous Province (HALIP). Based on detailed analysis of bathymetry data, new Arctic magnetic and gravity compilations, and recently published radiometric and seismic data, we present a revised plate kinematic model of the northernmost Amerasia Basin. We show that the smaller Makarov Basin is formed by rifting and seafloor spreading during the latest Cretaceous (to middle Paleocene). The opening progressively migrated into the Alpha Ridge structure, which was the focus of Early‐to‐Middle Cretaceous HALIP formation, causing breakup of the proto‐Alpha Ridge into the present‐day Alpha Ridge and Alpha Ridge West Plateau. We propose that breakup of the Makarov Basin was triggered by extension between the North America and Eurasian plates and possibly North Pacific plate rollback.

A Global Plate Model Including Lithospheric Deformation Along Major Rifts and Orogens Since the Triassic

“…A recent crustal velocity structure analysis of the Aleutian Basin failed to find differences in crustal structure to support an alternative back‐arc basin model (Christeson & Barth, ). The opening of the Makarov Basin between the Alpha and Lomonosov Ridges from 57 to 69 Ma is modeled after Alvey et al () and Døssing et al () (Figure ). The counterclockwise rotation of Greenland relative to North America in the course of the opening of the Labrador Sea and Baffin Bay resulted in the Eurekan Orogeny from 68 to 19 Ma, implemented following Gion et al ().…”

Basalts From the Chukchi Borderland: 40Ar/39Ar Ages and Geochemistry of Submarine Intraplate Lavas Dredged From the Western Arctic Ocean

“…The HALIP, invoked for the continental breakup that opened the Arctic Ocean, is an extensive magmatic province emplaced in the Early Cretaceous over landmasses now widely separated in the circum‐Arctic Ocean region, including Arctic Canada, Greenland, Svalbard, Franz Josef Land, and the DeLong Islands (Figure 1). Subaerial occurrences of HALIP volcanism are in the form of dike swarms, sills, and multiple layers of flood basalts (Døssing et al, 2017; Evenchick et al, 2015; Golonka & Bocharova, 2000; Lawver et al, 2002; Nejbert et al, 2011). Despite the impressive areal extent and voluminous stacks of lava, the HALIP is one of the least studied LIPs in the world—its remoteness and inaccessibility certainly contributing to that fact.…”

The effective elastic thickness of the lithosphere in the Amerasia Basin, Arctic Ocean

“…Therefore, spatial variations in Te provide information on the age and tectonic evolutions of the lithosphere. (Døssing et al, 2013(Døssing et al, , 2017. Therefore, we speculate that EMB may have been affected…”