T160 EARTHTIME: From Developing Tools to Teaching about Time

Tuesday, 20 October 2009
8:00 AM - 12:00 PM
C123

THE EARTHTIME INITIATIVE: PROGRESS AND PROMISE

Paper number: T160-1
Program: Technical Sessions
Time: 8:00 AM – 8:15 AM

Authors

Abstract

The EARTHTIME initiative is a community-based effort to focus attention on the calibration of at least the last 800 million years of Earth history. This requires using a unified, multi-chronometer (radioisotopic and cyclostratigraphic) approach integrated with paleobiological and climate proxy datasets, enabling earth scientists to pose questions that rely on knowledge of precise rates of biological, geological, and climatic change. The goals of the first phase were to: 1) forge links between geochronologists, paleontologists, and stratigraphers, and identify key intervals of Earth history for which higher resolution temporal constraints are essential, 2) develop the tools necessary to calibrate earth history using both U-Pb and 40Ar/39Ar geochronology and, 3) to develop a program of education and public outreach. We now have more than 300 members and a parallel effort in Europe.

A major effort has been to minimize and/or eliminate inter-laboratory and inter-technique bias. The U-Pb community has manufactured, distributed, and calibrated a 205Pb-233U-235U tracer solution and synthetic zircon solutions to monitor long-term analytical reproducibility. In addition, a new open-source data reduction and age calculation software ,U-Pb_Redux, is available for transparent reduction, analysis, and archiving of all U-Pb geochronological data with links to global databases and will function as a teaching tool.

The 40Ar/39Ar community has undertaken two major inter-laboratory comparison experiments involving more than twenty labs. Under controlled experimental conditions, variability between laboratories for relative ages of commonly used standards is significantly outside individually quoted precision. Ongoing determination of inter-laboratory bias is a priority.

EARTHTIME outreach activities include development of curriculum for middle- and high-school students and hands-on exercises. Our goal is to seamlessly integrate U-Pb, 40Ar/39Ar, and cyclostratigraphic techniques to construct high-fidelity records of earth history. Ultimately, the level of community involvement in general, and forging alliances between geochronologists and paleontologists in particular, will determine the degree to which the goals of EARTHTIME are realized.