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

• Main Authors: Morag A. Hunter, David J. Cantrill, Michael J. Flowerdew, Ian L. Millar
• Format: Dataset
• Language: unknown
• Published: 2016
• Subjects: Geology; Weddell Sea embayment; Weddell Sea Basin creation; Southern Hemisphere biostratigraphic correlations; Ma; sedimentation; Antarctic Peninsula; Botany Bay Group floras; Botany Bay Group; volcanism; implication; Antarctic; Botany Bay; Latady; The Antarctic; Weddell; Weddell Sea; Antarc*
• Online Access: https://doi.org/10.6084/m9.figshare.3454298.v1; https://figshare.com/articles/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.