title: Testing the annual nature of speleothem banding.
abstract: Speleothem laminae have been postulated to form annually, and this lamina-chronology is widely applied to high-resolution modern and past climate reconstructions. However, this argument has not been directly supported by high resolution dating methods. Here we present contemporary single-lamina (230)Th dating techniques with 2σ precision as good as ±0.5 yr on a laminated stalagmite with density couplets from Xianren Cave, China, that covers the last 300 years. We find that the layers do not always deposit annually. Annual bands can be under- or over-counted by several years during different multi-decadal intervals. The irregular formation of missing and false bands in this example indicates that the assumption of annual speleothem laminae in a climate reconstruction should be approached carefully without a robust absolute-dated chronology.
authors.affiliation: High-Precision Mass Spectrometry and Environment Change Laboratory (HISPEC), Department of Geosciences, National Taiwan University, Taipei 10617, Taiwan ROC.
authors.forename: Chuan-Chou
authors.initials: CC
authors.lastname: Shen
authors.forename: Ke
authors.initials: K
authors.lastname: Lin
authors.forename: Wuhui
authors.initials: W
authors.lastname: Duan
authors.forename: Xiuyang
authors.initials: X
authors.lastname: Jiang
authors.forename: Judson W
authors.initials: JW
authors.lastname: Partin
authors.forename: R Lawrence
authors.initials: RL
authors.lastname: Edwards
authors.forename: Hai
authors.initials: H
authors.lastname: Cheng
authors.forename: Ming
authors.initials: M
authors.lastname: Tan
references.citation: Science. 2001 Oct 5;294(5540):148-51
references.pmid: 11588259
references.citation: Science. 2001 Dec 14;294(5550):2345-8
references.pmid: 11743199
references.citation: Anal Chem. 2003 Mar 1;75(5):1075-9
references.pmid: 12641225