Construction of a Magnetostratigraphic Framework for Global Correlation of the Ediacaran Period
Extended Abstract – Prato 2004

T. D. Raub
Dept Geology & Geophysics Yale University, New Haven CT 06520 USA
(email: timothy.raub@yale.edu)

Number of Words: 212
Number of References: 0
Number of Figures: 0 
Number of Tables:  0

Running header text: Magnetostratigraphic Framework

Some of the challenges that have previously tended to limit palaeomagnetic investigations of Precambrian rocks to pole-position determinations from redbeds may soon be overcome. Construction of rapid automatic sample handling systems in several laboratories will speed throughput of samples by ~5 times, allowing for efficient determination of high-resolution magnetostratigraphies. Controlled- atmosphere demagnetization appears to stabilize behaviour of a wide range of lithologies previously considered unsuitable for palaeomagnetism studies, including carbonates, grey and green siltstones, and even chalks. New instruments like the ultra-high resolution scanning SQuID microscope offer hope for field tests of magnetization (i.e. conglomerate tests, fold tests) in even undeformed, platformal strata. 
A series of magnetostratigraphic sample suites has been collected from the type-Ediacaran interval in South Australia, from the Avalon Zone of Newfoundland, and from the Baltic Platform. Preliminary results from Australia indicate a relatively high palaeomagnetic reversal frequency that should aid in establishing a global polarity time scale for the Ediacaran Period. Magnetostratigraphic tests of the True Polar Wander hypothesis may resolve some of the spatio-temporal ambiguities that have, for example, set standard terminal Neoproterozoic palaeogeographic reconstructions at odds with Ediacara biota vicariance biogeographies.
Preliminary results from Australia will be presented, and the scope of extending similar studies to other critical sections through the Ediacaran interval will be discussed.