Length of day and obliquity of the ecliptic 850 MA ago: Preliminary results of a stromatolite growth model

Abstract

A sinusoidal growth pattern in a columnar stromatolite from the approximately 850 million year‐old Bitter Springs Formation suggests a method for deducing length of day and other geophysical parameters. Phototropic microorganisms following the seasonal inclination of the Sun are proposed as responsible for the estimated 410 or more laminae (daily) per sine wave (annual). A preliminary paleomagnetic analysis yields results consistent with the proposed model.