The radiocarbon time scale was obtained using accelerator mass spectrometry (AMS) dating of terrestrial macrofossils selected from the Soppensee sediment.
Because of an unlaminated sediment section during the Younger Dryas (10000–11000 C y BP), the absolute time scale, based on counting annual layers (varves), had to be corrected for missing varves.
These alternating layers of sediments and sometimes organic material are called varves and by counting each varve sequentially a varve chronology can be constructed.
Varve chronologies are a window to the past and have been used to study past climate conditions, the periodicity of volcanic eruptions and as an independent test of radiocarbon (C14) dating methods.
These formed as the result of large volcanic explosions.
This image is a web site that documents the research on the varves from this location: Why is Lake Suigetsu a good place to examine varves?
Our goal was to assess possible deviations of Pb-derived ages from true sediment ages provided by varve chronology and to check how different numerical procedures can improve the consistency of the chronologies.Do places on Earth exist where annual records have been stored for tens of thousands of years and can be accessed today?Ice-cores and tree rings can preserve long records of yearly events but some of the best records come from layers of sediment underlying some lakes which, if formed under the right conditions, can be read like the annual rings of an oak tree.For example, the Hasu River enters Lake Mikata where the sediments suspended in the river, even during a large flood, will fall out of the water column.The sediment-depleted water then flows through a narrow but shallow channel into Lake Suigetsu which is surrounded by high cliffs on all sides and has almost no input of water from the surrounding area.