Mid-Jurassic age for the Botany Bay Group: implications for Weddell Sea Basin creation and southern hemisphere biostratigraphy

• Main Authors: Hunter, Morag A., Cantrill, David J., Flowerdew, Michael J., Millar, Ian L.
• Format: Dataset
• Language: unknown
• Published: Geological Society of London 2016
• Subjects: Geology; FOS Earth and related environmental sciences; Antarctic; Antarctic Peninsula; Botany Bay; Latady; The Antarctic; Weddell; Weddell Sea; Antarc*
• Online Access: https://dx.doi.org/10.6084/m9.figshare.3454298; https://geolsoc.figshare.com/articles/dataset/Mid-Jurassic_age_for_the_Botany_Bay_Group_implications_for_Weddell_Sea_Basin_creation_and_southern_hemisphere_biostratigraphy/3454298

New U–Pb zircon ion-microprobe ages from the alluvial conglomerates and flood plain sediments of the Botany Bay Group demonstrate that sedimentation occurred at c. 167 Ma, coeval with rift-related silicic volcanism in the northern Antarctic Peninsula. In contrast, rift-related volcanism and sedimentation in the southern Antarctic Peninsula (Latady Basin) occurred at c. 183 Ma. The new data indicate that syn-rift sedimentation and volcanism was diachronous from south to north, consistent with early opening of the Weddell Sea embayment by anti-clockwise rotation of the Antarctic Peninsula in the Mid-Jurassic. A definitive date for the Botany Bay Group floras has important implications for Southern Hemisphere biostratigraphic correlations.