DECODING CLIMATE RHYTHMS WITH "ASTROCHON: AN R PACKAGE FOR ASTROCHRONOLOGY"

Studies in paleoclimatology and cyclostratigraphy routinely utilize geologically preserved temporal rhythms – such as the Milankovitch cycles – to decipher mechanisms of climate change and to develop high-resolution/high-precision time scales. Statistical time series analysis provides the quantitative toolbox for the assessment of such rhythms. However major challenges in cyclostratigraphic analysis include (1) the problem of searching for temporal rhythms in stratigraphic data for which the underlying time scale is poorly constrained, and (2) the development of null hypothesis tests that appropriately consider stochastic variability and distortion of the stratigraphic signal (e.g., hiatus and sedimentation rate change). In this talk, I will discuss recent advances in cyclostratigraphic analysis that address these two challenges, and their implementation in 'Astrochron: An R Package for Astrochronology'.

Astrochron is a new software package that is under development in association with NSF project "CAREER: Deciphering the Beat of a Timeless Rhythm- The Future of Astrochronology". Software design follows four guiding principles: (1) to provide a robust statistical platform for the evaluation of astronomical-climate linkages, the development of astronomical time scales, and the integration of astrochronologies with other geochronologic/chronostratigraphic data (e.g., radioisotopic geochronology), (2) to facilitate efficient and transparent (open source) communication of the analytical approaches used, enabling rapid verification of results, and continual innovation through community involvement, (3) the incorporation of integrated manuals, examples, and modeling tools to provide instruction on mathematical/statistical concepts relevant to astrochronology, with an eye towards fostering community involvement in the development of new analytical methods, and (4) the creation of free software that is fun to use and works on all common operating systems. To date, Astrochron contains over 70 functions, and has been a central component of three international workshops/summer schools.