Pliensbachian magnetostratigraphy: new data from Paris Basin (France)

The Global Boundary Stratotype Section and Point (GSSP) for the base of the Pliensbachian Stage (Lower Jurassic), Wine Haven, Yorkshire, UK

“…This preliminary magnetostratigraphy compares well with the published studies from the Breggia Gorge in Switzerland (Horner and Heller, 1983), and the Montcornet borehole from the Paris Basin (Yang et al, 1996;Moreau et al, 2002). The reverse magnetozone at sample level 16 best equates with the reverse magnetozone from Montcornet, which there ranges from the mid uppermost part of the Obtusum Zone to the Raricostatum Subzone (Figure 13).…”

“…Consequently, most of the samples were treated to thermal demagnetisation up to 250 ºC (some to 325 ºC), followed by alternating field demagnetisation. This is similar to the best procedure identified by Yang et al (1996) and Moreau et al (2002) in paleomagnetic studies of the Lower Jurassic of the Paris Basin (see also Hounslow et al 2004). In the present study, one to three specimens were measured from most horizons, usually two per horizon.…”

“…The magnetostratigraphy suggests that the reverse magnetozone within the Aplanatum Subzone at Winehaven probably correlates to the reverse magnetozone between 918-915 m in the Montcornet core (Figure 13). However, Moreau et al (2002) placed the position of the Jamesoni Zone in the Montcornet core at 920.65 m on the basis of the occurrence of the ammonite Polymorphites sp. at 920.7 m (indicative of Jamesoni Zone), above Paltechioceras gr.…”

Paleontology of the Bears Ears National Monument: history of exploration and designation of the monument

“…This is consistent with magnetostratigraphic data from the Kayenta Formation and interfingering Tenny Canyon Tongue of the Navajo Sandstone in southwestern Utah, which Steiner and Tanner (2014) correlated with the lower-middle Pliensbachian, but would be equally consistent with an upper Pliensbachian-lower Toarcian age (cf. Moreau et al, 2002;Ogg and Hinnov, 2012).…”

A complementary section for the proposed Toarcian (Lower Jurassic) global stratotype: The Almonacid de la Cuba section (Spain)

“…The column from the Paris Basin (Moncomet) studied by Moreau et al (2002) shows important sedi mentary discontinuities at the Pliensbachian-Toar cian boundary. The Moncomet section provides a good description of the reversals of the Earth's mag netic field for the Early Pliensbachian, other than for the Upper.…”