Publication Type:Journal Article
Source:Terra Nova, Wiley-Blackwell, Oxford, United Kingdom, Volume 27, Number 1, p.9-20 (2015)
Keywords:Canada, chondrites, comets, crust, eastern canada, geochemistry, Geomorphology, heterogeneity, Huronian, impact features, melts, meteorites, Onaping Formation, Ontario, Precambrian, proterozoic, sampling, siderophile elements, stony meteorites, Sudbury structure, upper Precambrian
Siderophile and lithophile trace element data for 69 samples from the Sudbury impact crater fill (Onaping Formation) and quartz diorite offset dikes help constrain the sources of the established moderately elevated platinum group element signature associated with the impact structure. The siderophile element distribution of the crater fill requires contributions from bulk continental crust, mafic rocks and a chondritic component. A mantle component is absent, but the involvement of mid to lower crust is implied. After considering post-impact hydrothermal alteration, melt heterogeneity and mafic target admixture, the projectile elemental ratios were determined on a more robust data subset. Chondrite discrimination diagrams of these ratios identify an ordinary or enstatite chondrite as the most probable source of meteoritic material in the Sudbury crater fill. However, the relative and absolute siderophile element distributions within the impact structure as well as bolide size models are congruent with the bolide being a comet that had a chondritic refractory component. Abstract Copyright (2010), John Wiley & Sons, Ltd.
GeoRef, Copyright 2018, American Geological Institute.<br/>2015-092385