Expedition 397 methods

作者：Fatima F Abrantes, David A Hodell, Carlos A. Alvarez Zarikian, Hannah L. Brooks, William Clark, L.F.B. Dauchy-Tric, V. dos Santos Rocha, José‐Abel Flores, Timothy D. Herbert, S.K.V. Hines, Huai‐Hsuan May Huang, H. Ikeda, Stefanie Kaboth‐Bahr, Junichiro Kuroda, Jasmin M. Link, Jerry F McManus, Bryce Mitsunaga, Lucien Nana Yobo, C.T. Pallone, Xiaolei Pang, Marion Peral, Emı́lia Salgueiro, S. Sanchez, K. Verma, Jiawang Wu, Chuang Xuan, Jimin Yu · 发表于：Proceedings of the International Ocean Discovery Program. Expedition reports · 年份：2024 · DOI：10.14379/iodp.proc.397.102.2024 · 被引用次数：8 · 研究领域：Geology and Paleoclimatology Research、Geological formations and processes、Methane Hydrates and Related Phenomena

Common coring-induced deformation includes the concave-downward appearance of originally horizontal bedding.Piston action may result in fluidization (flow-in) at the bottom of, or sometimes in, APC cores.Retrieval of unconsolidated (APC) cores from depth to the surface typically results to some degree in elastic rebound, and gas that is in solution at depth may become free and drive core segments in the liner apart.When gas content is high, pressure must be relieved for safety reasons before the cores are cut into segments.Holes are drilled into the liner, which forces some sediment and gas out of the liner.As noted above, XCB coring typically results in biscuits mixed with drilling slurry.During Expedition 397, the main drilling disturbance observed was APC-induced flow-in and XCB coring-induced biscuiting.Severe gas expansion at Site U1588 prompted us to adopt a strategy of half advances of the XCB system and allowing the sediment to expand in the empty liner.We refer to this method as half XCB.Drilling disturbances are described in the Lithostratigraphy section of each site chapter and are indicated on graphic core summary reports, also referred to as visual core descriptions (VCDs). Downhole measurements 1.4.1. Formation temperatureFormation temperature measurements were taken at specified intervals with the advanced piston corer temperature (APCT-3) tool (see Downhole measurements) embedded in the APC coring shoe.These measurements were used to obtain temperature gradien...