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Table T2. Lithostratigraphic layers identified offshore during Expedition 346 and the corresponding Techlog zone in the TXT supplementary file.

Techlog zone Lithostratigraphic layer Key lithologies Primary structures
A 1a Clayey silt Silty clay Silty sand Nannofossil-rich clayey silt Biosiliceous-rich clayey silt Nannofossil ooze Meter- to several tens of meters–scale alternations of biogenic component–rich clayey silt and biogenic component–poor clayey silt.
B 1b Clayey silt Silty clay Silt Nannofossil-rich clayey silt Biosiliceous-rich clayey silt Nannofossil ooze Zone B is distinguished from Zone A by the lack of dark color intervals and the occurrence of laminated sediment. Lithology is similar to that of Zone A and is characterized by the same meter-scale alternations in biogenic component abundance.
C 2a Diatom-bearing and diatom-rich clay Clay This subunit is considered transitional from Zone B to the underlying Zone D, which is defined by the consistent appearance of diatom ooze. In general, sediments in this unit are heavily bioturbated, leading to poor preservation of original sedimentary structures.
D 2b Dominated by diatom ooze (typically >70% (and as much as 95%) of the sediment) Limited clay intervals Moderate to heavy bioturbation and distinctive mottling are also displayed in some sections. Tephra layers (vitric and scoriaceous) and occasional individual pumice stones are a minor but common component.
E 3a Diatomaceous ooze Diatom-rich silty clay Diatom-bearing silty clay Alternating layers that show decimeter- to meter-scale cycles of diatom ooze (relatively clay poor) and diatom-rich silty clay (relatively fewer diatoms and more clay).
F 3b Well lithified gray siliceous claystone Occasional parallel laminations, burrows, and carbonate concretions appear as layers and nodules.

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