Interesting question! From the Dendrochronology article on Wikipedia it seems we can at most go 14k years into the past with tree rings: > Bard et al write in

Interesting question! From the Dendrochronology article on Wikipedia it seems we can at most go 14k years into the past with tree rings: > Bard et al write in 2023: "The oldest tree-ring series are known as floating since, while their constituent rings can be counted to create a relative internal chronology, they cannot be dendro-matched with the main Holocene absolute chronology. However, 14C analyses performed at high resolution on overlapped absolute and floating tree-rings series enable one to link them almost absolutely and hence to extend the calibration on annual tree rings until ≈13 900 cal yr BP." https://en.wikipedia.org/wiki/Dendrochronology?wprov=sfti1#Continuous_sequence https://en.wikipedia.org/wiki/Dendrochronology?wprov=sfti1#C... Interestingly it seems that tree ring chronologies can be mapped to increases in cosmic radiation named "Miyake events". https://en.wikipedia.org/wiki/Miyake_event https://en.wikipedia.org/wiki/Miyake_event