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 NUNA ILLUSTRATED AS A TIME-SPACE CORRELATION CHART AND TIME-SLICE PALAEOGEOGRAPHIC RECONSTRUCTIONS

Paper number: T127-15
Program: Technical Sessions
Time: 5:00 PM – 5:15 PM

Authors

Abstract

The Late Archaean to Mesoproterozoic geology of Nuna has been compiled in a large time-space correlation chart comprising 67 geodynamic domains 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.

The database systems are also designed to facilitate links to existing GIS maps so as to easily draw together information from multiple GIS featureclasses. 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 provide a visual aid to better understand the geological evolution of the region.

The correlation chart clearly illustrates the regional correlation of Palaeoproterozoic activity whilst also allowing one to identify areas in which information is scarce. It provides a valuable resource to geologists who may not have specialist knowledge of the specific domains of interest and provides a mechanism whereby earth scientists may share expert knowledge. The contribution presented here is intended as one step in the process of compiling information for most global Palaeoproterozoic domains by providing a quantitative, updatable resource for future work.