Notes:

This is a 2002 working version of the Triassic-Early Jurassic time scale based on the results of the Newark Basin Coring Project.

The time scale is based on the following (in sequence):

1) Composite stratigraphic column based on Olsen et al. (1996a and 1996c).
2) Astronomical calibration under the assumption that the McLaughlin lithological cycle corresponds in time to the 404 ky eccentricity cycle (g2-g5) by Kent et al. (1995).
3) Astronomical calibration based on a filtered and smoothed depth rank and color times series numerically tuned to the 404 ky cycle by Olsen and Kent (1996b,1999) and extended into the Stockton Formation. The result differs in only very minor ways from Kent et al. (1995). This allowed recognition of the 1.75 m.y. long modulating cycle corresponding to the g3-g4 astronomical cycle.
4) Revision of nomenclature of the Geomagnetic Polarity Time Scale (GPTS) by Kent and Olsen (1999) (E23 and E24 only).
5) Correlation of the Newark basin magnetic polarity sequence with a polarity sequence based on cores from the Taylorsville basin (Virginia) by LeTourneau (1999). This correlation strongly suggests a small hiatus at the base of E7r at the probable position of the Tectonostratigraphic Sequence (TS) II - III boundary (of Olsen, 1977).
6) Correlation of the pre-Raven Rock portions of the Stockton Formation to TS II of the Taylorsville basin based on the long modulating and Laskar cycles, the latter corresponding to the Libration period of the Solar system (Laskar, 1990, 1999).
7) Astronomical calibration of the pre-Raven Rock portions of the Stockton using the 1.75 m.y. g3-g4 and the newly recognized 3.5 m.y. Libration period).
8) Age (Ma) is based on the U-Pb and 40Ar/39Ar ages of the basalt flows interbedded with the earliest Hettangian age sedimentary strata and intrusive feeders in the Newark basin. The average age of these igneous rocks is 201.5±1 Ma, which places a tie point for this time scale at Triassic-Jurassic boundary (Sutter, 1988; Dunning and Hodych, 1990), which we round to 202 Ma.

Dunning, G. R., and Hodych, J. P., 1990, U/Pb zircon and baddeleyite ages for the Palisades and Gettysburg sills of the northeastern United States: Implications for the age of the Triassic/Jurassic boundary, Geology, v. 18, p. 795-798, 1990). LeTourneau, P. M., 1999, Depositional History and Tectonic Evolution of Late Triassic Age Rifts of the U. S. Central Atlantic Margin: Results of an Integrated Stratigraphic, Structural, and Paleomagnetic Analysis of the Taylorsville and Richmond Basins. [Ph.D. thesis]: New York, New York, Columbia University, 294 p. Kent, D. V. and Olsen, P.E., 1999, Astronomically tuned geomagnetic polarity time scale for the Late Triassic, Journal of Geophysical Research, v. 104, p. 12,831-12,841. Kent, D. V., Olsen, P. E., and Witte, W. K., 1995, Late Triassic-Earliest Jurassic geomagnetic polarity reference sequence from cyclic continental sediments of the Newark rift basin (eastern North America). Albertiana v. 16, p. 17-26. Muttoni, G., Kent, D.V. , Di Stefano, P., Gullo. M., Nicora, A., Tait. J., and Lowrie, W., 2001, Magnetostratigraphy and biostratigraphy of the Carnian/Norian boundary interval from the Pizzo Mondello section (Sicani Mountains, Sicily), Palaeogeography, Palaeoclimatology, Palaeoecology, 166, 383-399. Olsen, P. E., 1997, Stratigraphic record of the early Mesozoic breakup of Pangea in the Laurasia-Gondwana rift system. Annual Reviews of Earth and Planetary Science v. 25, p. 337-401. Olsen, P. E., Kent, D V., Cornet, B., Witte, W. K., and Schlische, R. W., 1996a, High-resolution stratigraphy of the Newark rift basin (Early Mesozoic, Eastern North America): Geological Society of America, v. 108, 40-77. Olsen, P. E. and Kent, D. V., 1996b, Milankovitch climate forcing in the tropics of Pangea during the Late Triassic. Palaeogeography, Palaeoclimatology, and Palaeoecology, v. 122, p. 1-26. Olsen, P.E. and Kent, D. V., 1999, Long-period Milankovitch cycles from the Late Triassic and Early Jurassic of eastern North America and their implications for the calibration of the early Mesozoic time scale and the long-term behavior of the planets. Philosophical Transactions of the Royal Society of London (series A), v. 357, p. 1761-1787. Olsen P. E, Schlische R. W, Fedosh M. S., 1996c, 580 ky duration of the Early Jurassic flood basalt event in eastern North America estimated using Milankovitch cyclostratigraphy. in Morales, M. (ed.) The Continental Jurassic, Museum of Northern Arizona Bulletin 60, p. 11-22. Olsen, P.E. and Kent, D. V., 1999, Long-period Milankovitch cycles from the Late Triassic and Early Jurassic of eastern North America and their implications for the calibration of the early Mesozoic time scale and the long-term behavior of the planets. Philosophical Transactions of the Royal Society of London (series A), v. 357, p. 1761-1787. Sutter, J. F., 1988, Innovative approaches to the dating of igneous events in the early Mesozoic basins of the Eastern United States, US Geological Survey Bulletin 1776, p. 194-200.