U–Pb age determinations on Proterozoic to Devonian rocks from northern Ellesmere Island, Arctic Canada

Abstract

This paper presents age determinations on six units of the Franklinian deep-water basin and the Pearya Terrane of northern Ellmere Island and discusses their tectonic implications.Four different fractions of detrital zircon from the Lower Cambrian Grant Land Formation of the deep-water basin all have average 207Pb/206Pb ages of 2.2–2.4 Ga, suggesting that the sediments were derived mainly from Aphebian–Archean parts of the Canadian Shield rather than from the Neohelikian crystalline basement of Pearya, as assumed earlier. The first evidence for Ordovician arc-type volcanism in the northern part of the deep-water basin is provided by a Llandeilo(?) zircon age of [Formula: see text] but the fault-bounded volcanic unit could be exotic.Four major stratigraphic successions are recognized in Pearya. Present zircon studies confirm that succession I has been affected by a 1.0–1.1 Ga orogeny, as inferred earlier by Sinha and Frisch from a Rb–Sr isochron. A zircon age of [Formula: see text] on a rhyolite demonstrates that succession II extended into the Late Cambrian or Early Ordovician.Granitic intrusions in the Pearya Terrane, at Cape Richards and Cape Woods, are, respectively, Middle Ordovician (463 ± 5 Ma) and Devonian (382 ± 18 Ma or, more likely, 390 ± 10 Ma) in age on the basis of combined zircon and sphene determinations. They are post-tectonic with regard to major deformations in the Middle Ordovician and Late Silurian. Both have a significant component of xenocrystic zircon, which appears to have been derived from succession I of Pearya on the basis of upper intercept ages.

Provenance of North American Triassic strata from west-central and southeastern Yukon: correlations with coeval strata in the Western Canada Sedimentary Basin and Canadian Arctic Islands

“…9Q; Miller et al 2006). The Middle Ordovician age also correlates with 463 Ma intrusive rocks known to the Pearya terrane (Trettin et al 1987 ).…”

“…950-1150 Ma correspond with Pennsylvanian to Triassic strata of the Northwest Laurentian and Arctic reference frames (Figs. 9L, 9M, 9O-9Q; Gehrels and Ross 1998;Miller et al 2006 (Trettin et al 1987) and the Ellesmerian foreland in northern Yukon (Lane 2007).…”

Chapter 6 Phanerozoic palaeoenvironment and palaeolithofacies maps of the Arctic region

“…In the north and northeastern parts of the craton, in the basins of the Peri-Innuitian zone, sandy deposition changed to carbonate and terrigeneous -carbonate. The thicknesses are not large and exceed 800 m only in the southeastern part of Ellesmere Island (Trettin & Balkwill 1979;Trettin 1987Trettin , 1989Trettin , 1994Trettin , 1998Trettin et al 1987;Long 1989;Estrada et al 2003). Carbonate deposition prevailed in the eastern regions of Greenland shelf, with mixed shallow-sea carbonates and clastic on the adjacent Barentsia (Harland 1979;Rønnevik et al 1982;Johansen et al 1993;Bogatski et al 1996;Henriksen & Higgins 2000;Smith et al 2004).…”

“…The largest one was in the present-day north, in the so-called Peri-Innuitian zone, where sandy deposits were formed at shallow marine conditions. Northwards they changed to carbonate deposits of thickness exceeding 2000 m (Trettin & Balkwill 1979;Trettin 1987Trettin , 1989Trettin , 1994Trettin , 1998Trettin et al 1987;Long 1989;Estrada et al 2003). In the eastern regions of Greenland, shelf carbonate deposits were accumulated (Harland 1979;Henriksen & Higgins 2000;Smith et al 2004).…”

Proterozoic Evolution of the North Atlantic–Arctic Caledonides: Insights from Detrital Zircon Analysis of Metasedimentary Rocks from the Pearya Terrane, Canadian High Arctic

“…Succession I orthogneiss units of the presumed depositional basement yield ages ranging from 962 to 973 Ma, with older ages of 1000-1100 Ma (Sinha and Frisch 1975;Trettin et al 1987Trettin et al , 1992 interpreted to reflect inherited components (Malone and McClelland 2010). Intrusions of this age are absent in Succession II, leading Trettin (1998) to propose a basement-cover relationship between the Succession I orthogneiss units and Succession II.…”