The quest for chron E23r at Partridge Island, Bay of Fundy, Canada: CAMP emplacement postdates the end-Triassic extinction event at the North American craton

Abstract

The Partridge Island stratigraphic section at the Bay of Fundy, Maritime Canada, reveals a continental sedimentary succession with the end-Triassic mass extinction level closely followed by basalts of the Central Atlantic Magmatic Province (CAMP). New Paleomagnetic data show that a short reverse magnetic polarity chron, correlative to E23r of the Newark Geomagnetic Polarity Time Scale (GPTS), is present below the extinction event. Organic carbon isotope data and basalt geochemistry further indicate that the onset of CAMP emplacement in the Bay of Fundy was roughly synchronous with emplacement in the Newark basin, but slightly postdates the oldest CAMP volcanism in Morocco by ∼20 ka. These results confirm the potential for long-distance CAMP correlations based on geochemical trace elements, indicate substantiate provincialism of latest Triassic palynoflora, and suggest a very concise period (<<100 ka) of CAMP emplacement in the northern Atlantic region.

Stratigraphic and temporal context and faunal diversity of Permian-Jurassic continental tetrapod assemblages from the Fundy rift basin, eastern Canada

“…But the correlation between the strata themselves or the extinction event has not appreciably changed, except that the extinction level and hence the Partridge Island Member are now late Rhaetian in age by definition. Deenen et al (2011) found the reverse polarity chron E23r, first identified in the Newark basin (Kent et al 1995), at the type section at Partridge Island below the palynological extinction level (Fig. A5).…”

“…Based on zircon U-Pb dates, the age of the Partridge Island Member is latest Rhaetian at 201.564±0.015 Ma (Blackburn et al 2013). Although Olsen (1997) and Olsen et al (2005a, b) interpreted the Partridge Island Member as comprising the base of TS IV, it rests conformably on the underlying Blomidon Formation (contra Kozur and Weems 2010) as shown by the position of E23r (Deenen et al 2011) (see . .…”

“…At its type section, the Partridge Island Member consists of about 1 m of interbedded red, purple, grey, and black (variegated) mudstone and minor carbonates that have proven critical to the interpretation of the end-Triassic extinction (e.g., Blackburn et al 2013). The unit contains pollen and spores at several levels, documenting the initial phase of the end-Triassic extinction (Fowell and Traverse 1995;Whiteside et al 2007;Cirilli et al 2009), has three modest iridium anomalies (Tanner and Kyte 2005; Tanner et al 2008;Kyte et al 2008), and contains the upper part of palaeomagnetic polarity chron E23r (Deenen et al 2011), which extends downward into the uppermost portion of the White Water Member (see Appendix). Based on zircon U-Pb dates, the age of the Partridge Island Member is latest Rhaetian at 201.564±0.015 Ma (Blackburn et al 2013).…”

Paleomagnetism of the Central Atlantic Magmatic Province in the Algarve basin, Portugal: First insights

“…USA (Kent and Olsen, 1999;Knight et al, 2004;Deenen et al, 2010;Deenen et al, 2011;Font et al, 2011).…”

“…Paleomagnetic data of the CAMP relics are well documented in North America Olsen, 1999,2008;Donohoo-Hurley et al, 2010;Deenen et al, 2011) , Morocco Ortas et al, 2006;Font et al, 2011;Ruiz-Martinez et al, 2012) and South America (de Min et al, 2003;Ernesto et al, 2003), but are still poorly constrained in Iberia. Actually, the sole reliable paleomagnetic pole comes from the Messejana dyke (Ortas et al, 2006), a giant dolerite intrusion that obliquely cuts across the South Portuguese, Ossa-Morena and Central Iberian zones of the Variscan Iberian Massif for more than 530 km .…”