1. Initial results of coring at Prees, Cheshire Basin, UK (ICDP JET project): Towards an integrated stratigraphy, timescale, and Earth system understanding for the Early Jurassic
- Author
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Hesselbo, Stephen P., Al-Suwaidi, Aisha, Baker, Sarah J., Ballabio, Giorgia, Belcher, Claire M., Bond, Andrew, Boomer, Ian, Bos, Remco, Bjerrum, Christian J., Bogus, Kara, Boyle, Richard, Browning, James V., Butcher, Alan R., Condon, Daniel J., Copestake, Philip, Daines, Stuart, Dalby, Christopher, Damaschke, Magret, Damborenea, Susana E., Deconinck, Jean Francois, Dickson, Alexander J., Fendley, Isabel M., Fox, Calum P., Fraguas, Angela, Frieling, Joost, Gibson, Thomas A., He, Tianchen, Hickey, Kat, Hinnov, Linda A., Hollaar, Teuntje P., Huang, Chunju, Hudson, Alexander J.L., Jenkyns, Hugh C., Idiz, Erdem, Jiang, Mengjie, Krijgsman, Wout, Korte, Christoph, Leng, Melanie J., Lenton, Timothy M., Leu, Katharina, Little, Crispin T.S., Macniocaill, Conall, Manceñido, Miguel O., Mather, Tamsin A., Mattioli, Emanuela, Miller, Kenneth G., Newton, Robert J., Page, Kevin N., Pálfy, József, Pieńkowski, Gregory, Porter, Richard J., Poulton, Simon W., Riccardi, Alberto C., Riding, James B., Roper, Ailsa, Ruhl, Micha, Silva, Ricardo L., Storm, Marisa S., Suan, Guillaume, Szűcs, Dominika, Thibault, Nicolas, Uchman, Alfred, Stanley, James N., Ullmann, Clemens V., Van De Schootbrugge, Bas, Vickers, Madeleine L., Wadas, Sonja, Whiteside, Jessica H., Wignall, Paul B., Wonik, Thomas, Xu, Weimu, Zeeden, Christian, Zhao, Ke, Hesselbo, Stephen P., Al-Suwaidi, Aisha, Baker, Sarah J., Ballabio, Giorgia, Belcher, Claire M., Bond, Andrew, Boomer, Ian, Bos, Remco, Bjerrum, Christian J., Bogus, Kara, Boyle, Richard, Browning, James V., Butcher, Alan R., Condon, Daniel J., Copestake, Philip, Daines, Stuart, Dalby, Christopher, Damaschke, Magret, Damborenea, Susana E., Deconinck, Jean Francois, Dickson, Alexander J., Fendley, Isabel M., Fox, Calum P., Fraguas, Angela, Frieling, Joost, Gibson, Thomas A., He, Tianchen, Hickey, Kat, Hinnov, Linda A., Hollaar, Teuntje P., Huang, Chunju, Hudson, Alexander J.L., Jenkyns, Hugh C., Idiz, Erdem, Jiang, Mengjie, Krijgsman, Wout, Korte, Christoph, Leng, Melanie J., Lenton, Timothy M., Leu, Katharina, Little, Crispin T.S., Macniocaill, Conall, Manceñido, Miguel O., Mather, Tamsin A., Mattioli, Emanuela, Miller, Kenneth G., Newton, Robert J., Page, Kevin N., Pálfy, József, Pieńkowski, Gregory, Porter, Richard J., Poulton, Simon W., Riccardi, Alberto C., Riding, James B., Roper, Ailsa, Ruhl, Micha, Silva, Ricardo L., Storm, Marisa S., Suan, Guillaume, Szűcs, Dominika, Thibault, Nicolas, Uchman, Alfred, Stanley, James N., Ullmann, Clemens V., Van De Schootbrugge, Bas, Vickers, Madeleine L., Wadas, Sonja, Whiteside, Jessica H., Wignall, Paul B., Wonik, Thomas, Xu, Weimu, Zeeden, Christian, and Zhao, Ke
- Abstract
Drilling for the International Continental Scientific Drilling Program (ICDP) Early Jurassic Earth System and Timescale project (JET) was undertaken between October 2020 and January 2021. The drill site is situated in a small-scale synformal basin of the latest Triassic to Early Jurassic age that formed above the major Permian-Triassic half-graben system of the Cheshire Basin. The borehole is located to recover an expanded and complete succession to complement the legacy core from the Llanbedr (Mochras Farm) borehole drilled through 1967-1969 on the edge of the Cardigan Bay Basin, North Wales. The overall aim of the project is to construct an astronomically calibrated integrated timescale for the Early Jurassic and to provide insights into the operation of the Early Jurassic Earth system. Core of Quaternary age cover and Early Jurassic mudstone was obtained from two shallow partially cored geotechnical holes (Prees 2A to 32.2g¯m below surface (mg¯b.s.) and Prees 2B to 37.0g¯mg¯b.s.) together with Early Jurassic and Late Triassic mudstone from the principal hole, Prees 2C, which was cored from 32.92 to 651.32g¯m (corrected core depth scale). Core recovery was 99.7g¯% for Prees 2C. The ages of the recovered stratigraphy range from the Late Triassic (probably Rhaetian) to the Early Jurassic, Early Pliensbachian (Ibex Ammonoid Chronozone). All ammonoid chronozones have been identified for the drilled Early Jurassic strata. The full lithological succession comprises the Branscombe Mudstone and Blue Anchor formations of the Mercia Mudstone Group, the Westbury and Lilstock formations of the Penarth Group, and the Redcar Mudstone Formation of the Lias Group. A distinct interval of siltstone is recognized within the Late Sinemurian of the Redcar Mudstone Formation, and the name "Prees Siltstone Member"is proposed. Depositional environments range from playa lake in the Late Triassic to distal offshore marine in the Early Jurassic. Initial datasets compiled from the core in
- Published
- 2023