Geology, stratigraphy, mineralogy, geochemistry, petrogenesis, and platinum group element-copper-nickel mineralization in the River Valley intrusion, Sudbury area, Ontario, Canada.

摘要

The River Valley Intrusion (RVI) is an early Proterozoic, ca . 100 km2 area of gabbronoritic and related rocks, located approximately 50 km northeast of Sudbury, Ontario. The RVI has been precisely dated at 2475 +2/-1 Ma, which is within the same age range as the East Bull Lake Intrusion (EBLI) and related EBLI-type intrusions. The RVI intrudes Archean granitic plutonic rocks (alkali feldspar granite and syenite), and regionally folded migmatitic gneiss, but lies in fault contact with Huronian metavolcanic and metasedimentary rocks. This intrusion has been variably affected by the Grenville Orogeny, and lies within the Grenville Province, mainly within the Grenville Front Tectonic Zone.; Whole rock geochemistry indicates that all rocks of the River Valley intrusion formed from a parent magma of high-Mg, high-Al, low-Ti tholeiitic character similar to, but distinguishable from, that documented for the other East Bull Lake suite intrusions. A primitive boninite-like, equigranular orthopyroxene phyric norite found near the eastern margin of the River Valley intrusion is proposed as the likely parent magma for this intrusion.* (Abstract shortened by UMI.); *This dissertation is a compound document (contains both a paper copy and a CD as part of the dissertation). The CD requires the following system requirements: Adobe Acrobat; Microsoft Office.