A 65-Myr-Long Astronomical Time Scale for the Mesozoic Deep-Sea Sequence (Inuyama, Japan): Implications for the Triassic–Jurassic Time Scale

摘要: The astronomical time scale (ATS) for geological records is nearly complete Cenozoic strata, and attempts have been made to extend the Mesozoic older ages. However, construction of ATS hampered by chaotic behaviour solar planets lack a continuous pelagic sequence early due subduction ocean floor. Here, we present constructed from deep-sea Inuyama area, central Japan. sedimentary rhythms bedded chert display full range climatic precession-related cycles: ~20-kyr cycle as chert–shale couplet ~100-kyr, 405-kyr, ~2000–4000-kyr, ~10,000-kyr (~10-Myr) cycles bed thickness variations, which principally reflect changes in burial rate biogenic silica, most likely silicate weathering rates. newly established tuned 405-kyr anchored at end-Triassic radiolarian extinction level gives ages consistent with radiometric projected onto using biostratigraphy. Thus, cyclostratigraphy provides numerical Triassic Lower Jurassic stage boundaries, constraints on planets, information biogeochemical silica-cycle dynamics.