T127 From Nuna to Rodinia: Proterozoic Growth and Evolution of Laurentia I

Monday, 10 October 2011
1:30 PM - 5:30 PM
Room 200DE

LATE ARCHAEAN TO MESOPROTEROZOIC GEOLOGY OF FENNOSCANDIA ILLUSTRATED AS A TIME-SPACE CORRELATION CHART AND TIME-SLICE PALAEOGEOGRAPHIC RECONSTRUCTIONS

Paper number: T127-16
Program: Technical Sessions
Time: 5:15 PM – 5:30 PM

Authors

Abstract

The Late Archaean to Mesoproterozoic geology of Fennoscandia has been compiled in a preliminary time-space correlation chart comprising utilizing the system developed for the IGCP 509 project. Attribute information for lithostratigraphic units, together with inferred geodynamic setting and environment of sedimentation plus geochronological information (age of plutonism, volcanism, metamorphism and cooling) and model neodymium ages have been compiled in two online databases (StratDB and DateView, both available from http://sil.usask.ca). Attribute information exported from the databases are used to construct the chart utilising GIS technology to facilitate creation and querying of the finished chart. The databases also store information for large igneous provinces and global ore deposits which may be added to the charts.

A series of time-slice palaeogeographic reconstructions are based on available published palaeomagnetic information, supplemented by locally constrained structural vergence directions to further refine possible plate movement vectors. The reconstructions were constructed using the Paleogis plugin for ArcGIS. Plate modeling also utilised the Gplates software. Timing of igneous, metamorphic and cooling activity are shown, together with the intrusion of major dykes swarms and of mineralisation. Regionally distinct patterns of activity are clearly apparent and may be compared with information for other regions of Nuna, using standardized symbology across all domains.

Comparison of the Fennoscandian and North American charts emphasizes similarities in the age of activity but also highlights differences in timimg. The palaeogeographic reconstructions demonstrate the importance of information from Greenland, an area in which information is generally scarce. The contribution presented here is intended as a step in expanding coverage of Palaeoproterozoic domains beyond the charts already available for southern Africa and North America.