Stromatolites and Earth--sun--moon Dynamics

Vanyo, J.P. and Awramik, S.M., 1985. Stromatolites and Earth--Sun--Moon dynamics. Precambrian Res., 29 : 121--142. Inclination of stromatolite columns, caused by nonvertical direction of averaged incident solar radiation, provides a signal for deducing astronomical and geophysical data at time of stromatolite formation. A sample of Anabaria juvensis (Bitter Springs Formation, central Australia) shows a sinusoidal growth pattern which, interpreted as an annual signal (obliquity of the ecliptic) with daily production of laminae, indicates 435 days per year, a result consistent with other available estimates. A sample of Inzeria from the same formation also shows a sinusoidal pattern and a similar estimate for days per year. Both samples indicate growth rates of centimeters per year. Several laboratory measurement techniques offer systematic procedures for extracting data.