Jurassic and Early Cretaceous Apparent Polar Wander paths for North America and implications for Jura-Cretaceous tectonic reconstructions
Bernard Housen, Western Washington University
Abstract
Despite much study, there remain significant differences between different compilations and models for paleomagnetic poles for North America and construction of APWP models for Jurassic and Early Cretaceous time. This presentation will highlight recent models of North America APWP by Kent and Irving, 2010, Kent et al, 2015, Muttoni and Kent (2019), Mirzaei et al., 2021, Kulakov et al., 2021, and Vaes et al., 2023. For Jurassic through Early Cretaceous (~130 Ma) time, APWP that use combined global models place NA at very high paleolatitudes during, whilst inclination-corrected data from sedimentary strata from place NA at more moderate paleolatitudes. These have implications for terrane reconstruction and also for documentation of the sense and magnitude of rotation of terranes for this span of time.
The APWP results from NA sedimentary rocks include the Middle Jurassic Summerville Formation Steiner, 2003, and Mirzaei et al., 2021, and inclination-corrected results from the Upper Jurassic Morrison Fm (Tauxe et al., 2018). Kent and Irving (2010), Kent et al., 2015, and Muttoni and Kent (2019) reject all of the sedimentary-rock derived data from Jurassic rocks of NA, and instead use a collection of data from kimberlites in New York, Ontario, and Quebec, along with coeval results from Adria (rotated into NA coordinates). Kulakov et al (2021) present new paleomagnetic and geochronology data from a series of mafic dikes in Greenland, obtaining a new 148 Ma paleopole, which is compared to the Kent et al., 2015 and Kent and Muttoni 2019 studies. The Vaes et al., 2023 results are based on a site-level reanalysis of existing paleomagnetic data from global compilations, and using a moving-window model produces a global APWP that can be rotated into a specific plate's coordinate system. An expected set of paleolatitudes and declinations will be determined for the location of the Blue Mtns from these different models, and compared with the data from Housen (2018) for the Bald Mountain Batholith (140-150 Ma), the Wallowa Batholith (130-125 Ma), and from small intrusive bodies near Ritter, OR, and data from Wilson and Cox (1980) for the 115 Ma Cornucopia Stock.
Session
Cordilleran tectonics