Chapter 50 Geology and tectonic development of the Amerasia and Canada Basins, Arctic Ocean

Abstract

Amerasia Basin is the product of two phases of counterclockwise rotational opening about a pole in the lower Mackenzie Valley of NW Canada. Phase 1 opening brought ocean-continent transition crust (serpentinized peridotite?) to near the seafloor of the proto-Amerasia Basin, created detachment on the Eskimo Lakes Fault Zone of the Canadian Arctic margin and thinned the continental crust between the fault zone and the proto-Amerasia Basin to the west, beginning about 195 Ma and ending prior to perhaps about 160 Ma. The symmetry of the proto-Amerasia Basin was disrupted by clockwise rotation of the Chukchi Microcontinent into the basin from an original position along the Eurasia margin about a pole near 728N, 165 W about 145.5-140 Ma. Phase 2 opening enlarged the proto-Amerasia Basin by intrusion of mid-ocean ridge basalt along its axis between about 131 and 127.5 Ma. Following intrusion of the Phase 2 crust an oceanic volcanic plateau, the Alpha-Mendeleev Ridge LIP (large igneous province), was extruded over the northern Amerasia Basin from about 127 to 89-75 Ma. Emplacement of the LIP halved the area of the Amerasia Basin, and the area lying south of the LIP became the Canada Basin.

Geological features of the northeastern Canadian Arctic margin revealed from analysis of potential field data

“…Chian et al, this volume) as Arctic Alaska and Chukchi/Northwind Ridge moved away from the Canadian Arctic Islands (e.g. Tailleur, 1973;Embry, 1990; Embry and Dixon, 1990;Moore et al, 1994;Grantz et al, 2011;Døssing et al 2013a). This rotational model is supported by the presence of a curvilinear negative Free-Air gravity anomaly (i.e.…”

“…gravity low designated as CBR on Figure 2) within Canada Basin inferred to be an extinct seafloor spreading ridge (e.g. Grantz et al, 2011). Some authors have also cited various similarities in geology and geophysical character of the Canadian Arctic Islands, Arctic Alaska, Northwind Ridge and Chukchi Plateau (e.g.…”

“…Some authors have also cited various similarities in geology and geophysical character of the Canadian Arctic Islands, Arctic Alaska, Northwind Ridge and Chukchi Plateau (e.g. Embry, 1990; Embry and Dixon, 1990;Grantz et al, 2011;Gottlieb et al, 2014) although this remains a matter of considerable debate (e.g. Lane et al, 2016.…”

Hemipelagic deposits on the Mendeleev and northwestern Alpha submarine Ridges in the Arctic Ocean: acoustic stratigraphy, depositional environment and an inter-ridge correlation calibrated by the ACEX results

“…Possible trajectories of transmitted far-field effects from tectonic events are difficult to document as there is no reported significant sediment deformation in the Eurasia Basin (Jokat et al 1995b;Jokat and Micksch 2004), in the Makarov Basin (Sorokin et al 1999), or in the central Canada Basin (Grantz et al 2009). The central part of Lomonosov Ridge started subsiding in the early Miocene, 35 million years after separation from the Barentsand Kara Sea margin ), but how this delay relates to regional plate stresses remains highly speculative (O'Reagan et al 2008).…”

Plume origin of the Central Arctic uplifts evolution in the Amerasian Basin of the Arctic Ocean

“…Continental margins of these regions are characterized by continental rifting in the Permian-Triassic and Cretaceous [Barents shelf plate, 1988;Grantz, 2011]. Therefore, their common geological nature can be assumed.…”