Dating the Methuselah Walk Bristlecone Pine Floating Chronologies

Abstract

Two floating, ring-width chronologies predate the long bristlecone pine (Pinus longaeva) absolutely-dated, ring-width chronology from the Methuselah Walk (MWK) site in the White Mountains of California. The two non-overlapping floating chronologies were derived from samples that crossdate internally but are temporally unconnected to each other and to the nearly 9000-year, ring-width sequence that is crossdated to the calendar year. We used radiocarbon wiggle-matching and crossdating to place the two floating sequences more accurately in time and to better understand the temporal relationships between the three time series. The trees from the oldest floating sequence were alive near the beginning of the Pleistocene/Holocene boundary and they do not overlap with the other chronologies because of a gap of two-to-three centuries between the two floating series. However, the trees from the younger floating sequence likely do overlap with the long, calendar-dated MWK chronology. We find a possible 57-year overlap that connects these two. If confirmed with additional work, the resulting tree-ring dated annual record from this single location will span 10,359 years, a unique accomplishment in dendrochronology.