Application of Wavelets to the Cyclostratigraphy of the Upper Homerian (Silurian) Gėluva Regional Stage in the Viduklė-61 Deep Well (Western Lithuania)

Abstract

The Gėluva age (late Homerian: Silurian) is an important interval of time during which one of the major episodes of mass extinction occurred, affecting many clades of marine organisms. In this study, we investigated a stratigraphic series of gamma logs in the Viduklė-61 well. To test the possible presence of sedimentary cycles, we applied wavelet and other time-series analysis techniques. As a result, we found two cycles with different periods: a 16.7-m-long cycle and a 6.7-m-long cycle. Based on our calculations, the cycles are best explained as being caused by two Milankovitch eccentricity cycles (400 and 100 kyr, respectively). If this interpretation is correct, then it gives us a good tool for understanding the tempo of the lundgreni extinction event and subsequent biotic recovery.