Ediacaran Paleomagnetism and Geochronology of Eastern Baltica: A Key to Paleogeography and Climatic History of the Continent

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All intervals of geologic time are filled with mysteries and enigmas but some offer more intrigue than others. The span of geologic time that stretches from the late Neoproterozoic through the Middle Cambrian (~800-501 million years ago) heralded the evolution of complex animals; some of the most severe glacial episodes in Earth history; rapid changes in continental configurations; increased oxygen levels in the atmosphere and oceans and a host of other enigmatic geological, geophysical and astronomical events. In particular, this interval of time includes the Cambrian 'explosion' from 535-513 million years ago. Precise causes for this unique biological period in Earth history are unknown, but speculation about the rise of animals has run the gamut from purely intrinsic biological causes to extrinsic triggers or some combination of both. Tectonic events during this same time interval created the framework that 'guided' the Phanerozoic development of the present-day globe. It is intriguing that numerous and superficially disconnected phenomena seem to be interrelated at a profound level. There have been many attempts to provide paleogeographic maps for this interval of time and one important tool for accomplishing this goal is paleomagnetism. Paleomagnetic studies provide the only quantitative method from which the ancient spatial distribution of major landmasses can be established. Yet, it is precisely this time period where paleomagnetic data are the most controversial. The problems are particularly acute for North America and Baltica where the paleomagnetic data are argued to support high or low latitude positions, rapid continental drift, rapid true polar wander, inertial interchange true polar wander and unusual magnetic field configurations. This work is examining the paleomagnetic signature recorded in sedimentary sequences along the margins of Baltica (in the Ural Mountains) in an effort to unravel the complexities of paleogeography during and preceding the Cambrian explosion. The research is part of an international collaboration between scientists of the University of Florida and Russian researchers. In addition to the scientific goals of the project, the proposal is helping to train the next generation of geologists (including groups typically under-represented in the field) by providing support for graduate and undergraduate students. The project is also communicating research results to the general public via outreach efforts through the Geological Science Ambassador group at the University of Florida and Florida Citizen's for Science.