Precambrian

Long-term cyclicities in Phanerozoic sea-level sedimentary record and their potential drivers

“…For the evaluation in the z dirction, we limit ourselves to 100 pc, which is larger than the excursion of the Sun. We can thus use a simple model of the form (5) that fits very well the numerical data obtained by solving the propagation law ( 4) (see Fig. 5).…”

Triassic Eustatic Variations Reexamined

“…Since the last update of the Triassic third-order sea-level variations (Haq and Al-Qahtani, 2005) that was calibrated to an earlier version of the time scale, there have been several refinements to the Triassic chronostratigraphy. The latest version of the time scale (Ogg et al, 2016) modifies the boundaries of Triassic standard stages (ages) by anywhere between <1 m.y. to almost 6 m.y.…”

“…Since much of the Pangaean landscape was dominated by terrestrial sediments, regional correlations often rely on palynology, ostracods and tetrapods that do not lend themselves to wider correlations with marine records. Ogg et al (2016) ascribe a Bilal U. Haq, Smithsonian Institution, Washington, D.C., USA, and Sorbonne University, Paris, France composite error of between 0.2 and 0.59 m.y.…”

“…Even a cursory look at the most recent update of the Triassic time scale (Ogg et al, 2016) reveals its extreme lopsidedness: while the Early Triassic spans only 5.1 m.y. and the Middle Triassic increases to 9.1 m.y., the Late Triassic jumps to a substantial span of 35.6 m.y.…”

“…The Triassic Period encompasses 50.5 m.y., spanning an interval from 251.9 to 201.4 Ma (Ogg et al, 2016). By this time, the megacontinent of Pangaea had already assembled, surrounded by the Panthalassa Ocean that covered >70% of Earth's surface, and by the mid-Triassic the Pangaean landmass was almost evenly distributed in the two hemispheres around the paleo-equator (see Fig.…”