Orbital Scale

The orbital scale is constructed by stratons: chronostratigraphic units that are tuned by the long-eccentricity 405,000-year E-cycle (Laskar et al., 2004), the tuning fork or astronomical metronome of stratigraphy (Hinnov and Ogg, 2007).

E-cycle 1 (base Straton 1) started 371,000 years before present. Stratons are numbered as integers and the start of any Straton M is 0.371 + (M-1) × 0.405 million years before present (Ma).

The orbital scale predicts that 36 stratons form an orbiton, which lasts 14.58 million years (Myr). Orbitons are sequence-stratigraphic architectures bounded by major sequence boundaries (SB). Orbiton-level SBs are manifested as maximum regression surfaces (MRS), unconformities or disconformities, time gaps (hiatus), and lowstand deposits.

The base of any Orbiton N has a predicted age of:

SB N = 1.586 + (N × 14.58) Ma

Al-Husseini (2015) divided the Phanerozoic Era/Erathem into 37 orbitons, with Orbiton 1 deposited between SB 1 at 16.166 Ma and SB 0 (zero) at 1.586 Ma. SB 37 is predicted at 541.046 Ma and is correlated to the Precambrian/Cambrian boundary (PCB) radiometrically dated at 541.0 + 1.0 Ma in the Geological Time Scale GTS 2016.

Orbitons are subdivided into three dozons, each consisting of 12 stratons, that last 4.86 Myr. Dozons are named in ascending order as A, B and C, and are generally also bounded by major sequence boundaries. The 12 stratons in a dozon are named in ascending order as A-1 to A-12, B-1 to B-12, and C-1 to C-12. Stratons A-12, B-12 and C-12 typically consist of major lowstands and are capped by SBs.

Dozons typically break into ‘third-order’ sequences that last 2.025 Myr (5 stratons, short sequence), 2.43 Myr (6 stratons, nominal sequence), and 2.835 Myr (7 stratons, long sequence) Matthews and Frohlich (2002). The break-up of dozons typically occurs above or below the sixth straton (A-6, B-6 and C-6).

For further information please contact:

Dr. Moujahed Al-Husseini (moujaheda@gmail.com)